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Ieva Jacerytė
 Metalo proteinazių sekrecijos ypatumai lyginant dvimates ir trimates žmogaus mezenchiminių kamieninių ląstelių kultūras
 Kamieninės ląstelės ir jų panaudojimo galimybės yra šių dienų regeneracinės medicinos, audinių inžinerijos ir kitų mokslo sričių tyrimų objektas. Mezenchiminės kamieninės ląstelės (MKL) pasižymi terapinėmis savybėmis, kurios kaip manoma priklauso nuo ląstelių sekretuojamų medžiagų. Šiame darbe buvo tiriami ir lyginami ląstelių sekretuojami faktoriai, kuriuos skirtingomis sąlygomis augintos ląstelės išskiria į kultūrinę terpę. Tai matrikso metalo proteinazės 2 ir 9 (MMP-2, MMP-9), taip pat - uždegiminiai mediatoriai: interleukinas-6 (IL-6) ir monocitų chemoatraktantinis baltymas-1 (MCP-1). Riebalinio audinio kilmės MKL (RAKL) buvo auginamos in vitro įprastoje 2D kultūroje ir 3D kultūroje naudojant kabančio lašo metodą. MMP sekrecijos skirtumai įvertinti pasitelkus pusiau kiekybinį metodą – zimografiją ir imunologinį tyrimą – ELISA. Juo taip pat buvo vertinama ir uždegiminių mediatorių sekrecija. Pagal atliktus stebėjimus, ląstelės auginamos skirtingu būdu išskiria į terpę skirtingus kiekius minėtų molekulių ir tas skirtumas yra statistiškai patikimas. 3D auginimo sąlygos sukuria artimesnę in vivo situacijai aplinką ir, tikėtina, labiau tinka terapiniam naudojimui.
 Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, rezultatai ir jų aptarimas, išvados, literatūros sąrašas.
 Darbo apimtis – 37 p. teksto be priedų, 12 pav., 1 lent., 52 bibliografiniai šaltiniai.
 Raktiniai žodžiai: mezenchiminės kamieninės ląstelės, matrikso metalo proteinazės, interleukinas-6, monocitų chemoatraktantinis baltymas-1, kabantis lašas, zimografija, ELISA.
 Nowadays stem cells and their possible clinical applications are among main study objects in regenerative medicine, tissue engineering and others science fields. Mesenchymal stem cells (MSC) are multipotent stem cells recognized for their certain therapeutic and pro-regenerative effects. It is known, that MSC mediate regenerative processes by releasing factors into cell culture medium. In the present study we have analyzed and compared several secreted factors based on the different conditions of MSC culture, i.e. 2D vs. 3D conditions. Matrix metal proteinases 2 and 9 (MMP-2, MMP-9), as well as inflammatory mediators: interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) were analyzed. Adipose tissue derived MSC (ADSC) were cultivated in hanging drop 3D cultures and usual 2D environment. MMP secretion was assessed via semi-quantitative method – zymography, and immunological test – ELISA. The latter was also applied to assay inflammatory mediators secretion. We report that 2D and 3D cells exhibit significant quantitative differences when compared for secretion of substances mentioned above. We suggest, that 3D environment better mimics in vivo conditions and should be employed when expanding cells for therapeutic applications.
 Structure: introduction, literature review, materials and methods, results and discussion,conclusions, references.
 Thesis consists of: 37 p. text without appendixes, 12 pictures, 1 table, 52 bibliographical entries.
 Raktiniai žodžiai: mesenchymal stem cells, matrix metal proteinases, interleukin-6, monocyte chemoattractant protein-1, hanging drop, zymography, ELISA.
 Ektoino ir hidroksiektoino poveikis temperatūros sukeltai baltymų agregacijai
 doc. dr. Jolanta Sereikaitė
 Šiame darbe tirtas ektoino ir hidroksiektoino poveikis temperatūros sukeltai baltymų agregacijai. Šių priedų efektyvumas palygintas su amino rūgšties arginino efektyvumu. Ektoinas efektyviai slopina 60 laipsnių Celsijaus temperatūros sukeltą rekombinantinio audinės augimo hormono agregaciją- mažėja agregacijos pirmo laipsnio reakcijos greičio konstantos bei didėja raAH agregacijos pradžios temperatūra. Hidroksiektoinas yra mažiau efektyvus raAH temperatūros sukeltos agregacijos slopiklis nei ektoinas. L- argininas yra efektyvesnis raAH temperatūros sukeltos agregacijos slopiklis nei ektoinai. Apskritiminio dichroizmo spektrai rodo, jog mėginiuose esant ektoinų, kinta rekombinantinio audinės augimo hormono tretinė struktūra. Tirpale, kurio pH žemesnis nei raAH izoelektrinis taškas (6,0<6,83), esant 1 M hidroksiektoino koncentracijai, baltymo molekulė denatūruojama.
 Darbą sudaro šešios dalys: įvadas, literatūros apžvalga, metodinė dalis, rezultatai ir jų aptarimas, išvados, literatūros sąrašas. Darbo apimtis – 68 p. teksto be priedų, 28 iliustr., 7 lent., 49 bibliografiniai šaltiniai.
 Raktiniai žodžiai: ektoinas, hidroksiektoinas, argininas, temperatūros sukelta agregacija, žiedinis dichroizmas
 In this work the influence of ectoine and hydroxyectoine on temperature-induced aggregation of proteins was investigated. The effect of these additives was compared to that of arginine. In the presence of ectoine the first order constants of the recombinant mink growth hormone aggregation reaction induced by 60 degrees Celsius temperature decreased while the onset of aggregation temperature increased. Hydroxyectoine was less effective suppressor of the protein aggregation as compared to ectoine. Arginine was the most effective suppressor of rmGH aggregation of all used additives. Circular dichroism spectra showed that ectoines significantly affect the tertiary structure of the protein. When the pH of the solution was lower than the pI of rmGH, the protein was denatured by 1 M concentration of hydroxyectoine.
 Structure: introduction, 3 chapters, conclusions, references. Thesis consist of: 68 p., 28 pictures, 7 tables, 49 bibliographical entries.
 Raktiniai žodžiai: ectoine, hydroxyectoine, arginine, temperature-induced aggregation, circular dichroism
 Lakazės ir gliukozės dehidrogenazės elektrocheminių savybių tyrimas anglies ir aukso nanostruktūrose
 Baigiamajame bakalauro darbe buvo tirtos fermentų lakazės iš Didymocrea sp. (LAC) ir gliukozės dehidrogenazės iš Ewingiella americana (GDH) pagrindu pagamintų bioelektrokatalizinių sistemų elektrocheminės savybės. Buvo ištirta, kaip šios sistemos veikia fermentus imobilizavus ant anglies nanovamzdeliais (CNT) arba chemiškai modifikuotomis aukso nanodalelėmis (AuNP) padengtų elektrodų. LAC sistemos katalizuoja molekulinio deguonies redukciją, o GDH sistemos katalizuoja gliukozės oksidaciją, taip generuojant srovę. Ištyrus CNT/LAC sistemas, buvo nustatyta, kad pH 4,0 terpėje veikė dauguma tirtų sistemų, o pH 7,0 terpėje aktyvumu pasižymėjo tik viena tirta sistema. Ištyrus CNT/GDH sistemas, buvo nustatyta, kad pH 4,0 terpėje, nors ir silpnai, veikė dauguma tirtų sistemų, o pH 7,0 terpėje sistemos buvo neaktyvios. Ištyrus cheminių modifikatorių įtaką AuNP/GDH sistemoms buvo identifikuoti trys cheminiai modifikatoriai, kurie smarkiai pagerino sistemos efektyvumą ir yra tinkami efektyviai veikiančių bioelektrokatalizinių sistemų gamyboje.
 Darbą sudaro: įvadas, 3 skyriai, išvados, literatūros sąrašas.
 Darbo apimtis – 47 p. teksto, 15 paveikslų, 1 lentelė, 46 bibliografiniai šaltiniai.
 Raktiniai žodžiai: anglies nanovamzdeliai, aukso nanodalelės, bioelektrokatalizinė sistema, biokatalizė, gliukozės dehidrogenazė, lakazė.
 In this bachelor thesis, a study of electrochemical properties of bioelectrocatalytic systems based on enzymes laccase from Didymocrea sp. (LAC) and glucose dehydrogenase from Ewingiella americana (GDH) was performed. It was examined how those systems operated when the enzymes were immobilized onto electrodes modified with either carbon nanotubes (CNT) or chemically modified gold nanoparticles (AuNP). LAC based systems catalyze reduction of molecular oxygen, whereas GDH based systems catalyze oxidation of glucose, generating a current as a result. It was determined that in pH 4.0 medium most of the CNT/LAC systems were working, but in pH 7.0 medium only one studied system was active. It was also determined that in pH 4.0 medium, although faintly, most of the CNT/GDH systems were working, but in pH 7.0 medium none of the systems were active. The influence of chemical modifiers on AuNP/GDH systems was also examined, and three chemical modifiers, which greatly improved the efficiency of the systems, were identified. and are suitable for production of effective bioelectrocatalytic systems, were identified.
 Thesis consist of: 47 p. text, 15 pictures, 1 table, 46 bibliographical entries.
 Raktiniai žodžiai: biocatalysis, bioelectrocatalytic system, carbon nanotubes, glucose dehydrogenase, gold nanoparticles, laccase.
 Enrika Celitan
 Daržovių atranka biciklo[3.3.1]nonan-2,6-diolio diacetato biotransformacijai
 Biciklo[3.3.1]nonano dariniai naudojami kaip pirmtakai chemijos bei farmacijos pramonėje, ir yra laikomi naudingais modeliais konformacinėje analizėje. Šiame darbe atlikta įvairių daržovių kaip biokatalizatorių atranka raceminio biciklo[3.3.1]nonan-2,6-diolio diacetato stereoselektyviai biotransformacijos reakcijai. Geriausi rezultatai gauti panaudojus morką (Daucus carota), imbierą (Zingiber Officinale) ir pastarnoką (Pastinaca sativa). Biotransformacijos metu vyko raceminio biciklo[3.3.1]nonan-2,6-diolio diacetato hidrolizės reakcija ir buvo gauti optiškai aktyvūs (+)-biciklo[3.3.1]nonan-2,6-diolio monoacetato, (-)-biciklo[3.3.1]nonan-2,6-diolio monoacetato ir (+)-biciklo[3.3.1]nonan-2,6-diolio enantiomerai. Hidrolizės produktai išgryninti atlikus kolonėlinę chromotografiją ir identifikuoti užrašius branduolio magnetinio rezonanso (BMR) 1H ir 13C spektrus.
 Darbą sudaro šešios dalys: įvadas, literatūros apžvalga, metodinė dalis, tyrimo rezultatai ir jų aptarimas, išvados ir literatūros sąrašas. Darbo apimtis – 44 p. teksto, 28 paveikslai, 4 lentelės, 40 bibliografinių šaltinių.
 Raktiniai žodžiai: Raceminis biciklo[3.3.1]nonan-2,6-diolio diacetatas, stereoselektyvi biotransformacija, daržovės, biokatalizatoriai, optiškai aktyvūs enantiomerai, branduolio magnetinis rezonansas.
 Bicyclo[3.3.1]nonane derivatives are used as precursors in chemistry and pharmacy industries and are considered as useful models in conformational analysis. In this thesis various vegetables as biocatalysts were screened for racemic bicyclo[3.3.1]nonane-2,6-diol diacetate stereoselective biotransformation. The best results were obtained using carrot (Daucus carota), ginger (Zingiber Officinale) and parsnip (Pastinaca sativa). During biotransformation hydrolysis of racemic bicyclo[3.3.1]nonane-2,6-diol diacetate took place and as products optically active (+)-bicyclo[3.3.1]nonane-2,6-diol monoacetate, (-)-bicyclo[3.3.1]nonane-2,6-diol monoacetate and (+)-bicyclo[3.3.1]nonane-2,6-diol enantiomers were obtained. Products of hydrolysis reaction were purified by using column chromatography and identified by nuclear magnetic resonance (NMR) 1H and 13C spectra.
 Structure: introduction, literature review, methodology, results and discussion, conclusions and references. Thesis consists of: 44 p. text, 28 pictures, 4 tables, 40 bibliographical entries.
 Raktiniai žodžiai: Racemic bicyclo[3.3.1]nonan-2,6-diol diacetate, stereoselective biotransformation, vegetables, biocatalysts, optically active enantiomers, nuclear magnetic resonance.
 Rugilė Nedzveckaitė
 Citotoksinių ir imunosupresinių ląstelių tyrimas sergančiųjų autoimuninėmis ligomis periferiniame kraujyje
 dr. Irena Dumalakienė
 Autoimuninės ligos yra vienos iš pagrindinių sergamumo bei mirtingumo priežasčių visame pasaulyje. Dauguma šių ligų yra arba neišgydomos, arba labai sunkiai gydomos dėl akivaizdžios priežasties – savų antigenų pašalinti negalima.
 Manoma, kad pagrindiniai veiksniai, galintys iššaukti šias ligas, yra infekcija (virusinis susirgimas), paveldimumas (genetinis faktorius) bei hormonai (dauguma sergančių – moterys).
 Baigiamojo darbo metu buvo lyginamos pirminiu bei antriniu Sjögreno sindromu bei reumatoidiniu artritu sergančių pacientų citotoksinės bei imunosupresinės ląstelės, kontrolę sudarė pacientai, kuriems nustatytas neautoimuninis sausumo sindromas. Įvertinta Sjogreno sindromo autoantikūnų A ir B ekspresija kraujo serume, pirminio Sjogreno sindromo grupėje nustatyti 19 pacientų, teigiamų bent pagal vieną iš šių autoantikūnų, toliau tyrimai atlikti analizuojant gautus rezultatus ir išsiaiškinant skirtumus tarp bendros pirminio Sjogreno sindromo bei grupės, teigiamos pagal autoantikūnus, ir lyginant abi grupes su kitomis tiriamųjų grupėmis. Kiekybiškai įvertinti citotoksiniai T limfocitai, natūralios naikintojos bei natūralios naikintojos T ląstelės pacientų, sergančių autoimuninėmis ligomis periferiniame kraujyje. Darbui atlikti taikyti tėkmės citometrijos bei imunofermentinės analizės metodai. Rezultatams vertinti buvo taikytos statistinės savybės: vidurkis, mediana, standartinė vidurkio paklaida. Nustatytas reikšmingas limfocitų populiacijos sumažėjimas reumatoidinio artrito ir antrinio Sjogreno sindromo grupėse. Autoantikūnų ekspresija pirminio Sjogreno sindromo pacientuose reikšmingai įtakojo bendros limfocitų populiacijos, natūralių naikintojų bei natūralių naikintojų T ląstelių populiacijų absoliutaus kiekio sumažėjimą, bet neturėjo įtakos citotoksiniams T limfocitams.
 Darbo apimtis – 51 p. teksto be priedų, 20 paveikslų, 3 lentelės, 82 bibliografiniai šaltiniai.
 Raktiniai žodžiai: Sjögreno sindromas, neautoimuninis sausumo sindromas, reumatoidinis artritas, autoimuninės ligos, citotoksinės ląstelės, imunosupresinės ląstelės, tėkmės citometrija, imunofermentinė analizė, natūralios naikintojos, natūralios naikintojos T ląstelės, citotoksiniai T limfocitai.
 Autoimmune diseases are one of the leading causes of morbidity and death worldwide. Most of them are either incurable or tend to be difficult to cure because of one obvious reason- self-antigens cannot be eliminated.
 It is thought that the main reasons that can trigger these diseases are infection (viral), inheritance (genetic factor) as well as hormones (most of the diseased are women). In this final thesis cytotoxic and immunosuppressive cells of patients with primary and secondary Sjögren‘s syndrome and rheumatoid arthritis were analyzed and compared, patients with non-autoimmune sicca syndrome were taken as a control group. Expression of Sjogren’s syndrome autoantibodies A and B were determined, 19 positive patients with primary Sjogren’s syndrome were found. Then analysis of the results were made, differences between total Sjogren’s syndrome group and positive Sjogren’s syndrome group were found, after that these groups were compared with other patient groups. Cytotoxic T cells, natural killer and natural killer T cells were quantitatively assessed in peripheral blood of patients with these diseases. Flow cytometry and enzyme-linked immunosorbent assay were used. For assessment of the results statistical properties: mean, median and standard error of the mean were used. Significant decrease in total number of lymphocytes in rheumatoid arthritis and secondary Sjogren’s syndrome were found. Expression of autoantibodies in patients with primary Sjogren’s syndrome blood serum significantly affected the total number of lymphocytes, natural killer and natural killer T cells populations but did not influence the total number of cytotoxic T lymphocytes.
 Structure: introduction, literature, materials and methods, results and discussion, conclusions, references.
 Thesis consists of: 51 p. text without apendixes, 20 pictures, 3 tables, 82 bibliographical entries.
 Raktiniai žodžiai: Sjögren‘s syndrome, non-autoimmune sicca syndrome, rheumatoid arthritis, autoimmune diseases, cytotoxic cells, immunosuppressive cells, flow cytometry, enzyme-linked immunosorbent assay, natural killers, natural killer T cells, cytotoxic T lymphocytes
 Mantas Michalauskas
 Obuolių ekosistemose palitusių mielių įvairovė ir tarpusavio suderinamumas
 Baigiamojo bakalaurinio darbo metu buvo atlikti Lietuvoje augančių obuolių ekosistemoje paplitusių mielių tyrimai. Atliktas morfologinis kolonijų ir ląstelių apibūdinimas, mikroskopinė analizė, mielių augimo greičio priklausomybės nuo temperatūros įvertinimas bei mielių sugyvenamumo tyrimai. Nustatyta, kad ant Lietuvoje augančių obuolių vyrauja 11 skirtingų mielių rušių, kurių augimo parametrai skiriasi priklausomai nuo kultivavimo temperatūros. Tarp 4 mielių rūšių – Saccharomyces paradoxus, Pichia kluyveri, Pichia membranifaciens ir Pichia terricola - nustatyti skirtingi simbiotiniai ryšiai. Darbą sudaro septynios dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, tyrimo rezultatai, rezultatų aptarimas, išvados ir literatūros sąrašas. Darbo apimtis: 42 puslapių teksto, 9 paveikslai, 4 lentelės ir 37 bibliografiniai šaltiniai.
 Raktiniai žodžiai: obuoliai, mielės, augimo greitis, tarpusavio suderinamumas.
 The aim of this thesis was to identify diversity of yeast in apple ecosystems and to determine interactions between isolated species. The morphological-microscopic analysis of yeast colonies and cells was performed, the dependence of yeast growth rate on the temperature was evaluated. It was demonstrated that eleven yeast species are prevalent on the apple surface and their growth parameters vary depending on cultivation temperature. Four yeast species, as Saccharomyces paradoxus, Pichia membranifaciens, Pichia kluyveri and Pichia terricola are linked by different types of symbiotic relationships. Structure: introduction, literature overview, materials and methods, results, discussion, conclusions and references. Thesis consists of 42 pages of text, 9 pictures, 4 tables and 37 biobliographical entries.
 Raktiniai žodžiai: apple, yeast, growth rate, interactions.
 Paula Kundreckaitė
 In vivo koherentinės anti-Stokso ramano sklaidos mikroskopijos tyrimas nustatant karotinoidų kiekį mikrodumbliuose Chlorococcum hypnosporum
 Mikrodumbliai yra natūralių pigmentų, tokių kaip karotinoidai, šaltinis. Šių cheminių junginių biosintezei pagreitinti naudojamas efektyviausias būdas – streso sąlygų taikymas, t.y. druskingumas, intensyvi šviesa ir kt. Lygiai taip pat svarbus yra susikaupusių karotinoidų analizės metodas. Šiame darbe pateikiamas koherentinės anti-Stokso Ramano sklaidos mikroskopijos metodas, kuris puikiai pritaikomas karotinoidų tyrimui Chlorococcum hypnosporum mikrodumbliuose. KARS metodas suteikia galimybę atlikti eksperimentus in vivo ir gauti operatyvius karotinoidų vaizdininmo rezultatus. KARS gaunamas signalas priklauso nuo skirtingų individualių molekulinių vibracijų. Šiuo atveju karotinoidams stebėti naudojamas 1520 cm-1 dažnis, o gautus rezultatus fiksuoja KARS skenuojantis mikroskopas. Tikslesniems rezultatamas gauti, metodas buvo optimizuotas. Po optimizacijos buvo gautas žymiai tikslesnis rezultatas (beveik 91% visos amplitudės).
 Mikrodumblių kaupiamų karotinoidų biosintezei aktyvinti buvo naudojama padidinta NaCl koncentracija ir intensyvi 405 nm ilgio šviesa. Buvo nustatyta, kad 48 val. trukmės intensyvus apšvietimas nesuaktyvina karotinoidų kaupimo ląstelėse, o po 96 val. Sukelia ląstelių apoptozę. Keičiant druskos koncentraciją nuo 0 iki 2 M karotinoidų kiekis didėja, tačiau artėjant prie 4 M koncentracijos karotinoidų santykinė koncentracija mažėja. Trumpai tariant, šis darbas įrodo, kad KARS mikroskopija yra galinga priemonė nustatinėjant karotinoidų koncentraciją bei lokalizaciją mikrodumbliuose Chlorococcum hypnosporum. Optimizavus KARS metodą streso sąlygų įtaka karotinoidams buvo stebima in vivo.
 Raktiniai žodžiai: Mikrodumbliai, Chlorococcum hypnosporum, karotinoidai, KARS, streso sąlygos.
 Microalgae is a source of naturally grown pigments such as carotenoids. There are many ways to accelerate the accumulation of carotenoids, for example, stressful growth conditions. It is equally important to have experimental method to control the accumulation of carotenoids. In this work we demonstrate the utility of coherent anti-Stokes Raman scattering (CARS) microscopy for the study of carotenoids in Chlorococcum hypnosporum microalgae. Such advanced optical method, enable to investigate microalgae in vivo, and provides express technique for observing the accumulation of carotenoids.
 CARS exploits molecular vibrations to extract the optical response from a certain chemical, in our case from carotenoids. The frequency of double C=C bound at 1520 cm-1 was chosen as a marker of carotenoids and their distribution within algae cell was recorded by CARS scanning microscope. For better result the experimental setup was optimized revealing almost pure (92% of total amplitude) response from carotenoids.
 The growth of algae under stress conditions was carried out by changing the salinity of the growth environment or by the enhanced illumination at 405 nm wavelength. It was found that intense light exposed during up to 48 hours does not lead to increase of carotenoids quantity, moreover, after 96 hours of exposure it may cause apoptosis of algae cells. Changing the salinity of medium in range from 0 to 2M of NaCl an increase in the concentration of carotenoids was observed. Further increase of sodium chloride concentration to 4M leads to decrease of carotenoids.
 To sum up, this work describes the CARS microscopy as a powerful tool to investigate the dynamics of carotenoids concentration in Chlorococcum hypnosporum. Stress-induced changes were monitored in vivo emphasizing the expediance of the proposed CARS method.
 Raktiniai žodžiai: Chlorococcum hypnosporum, microalgae, CARS, carotenoids, stress, light, salinity. Julija Arūnaitė
 Maltozinių sirupų gamybos sąlygų optimizavimas
 doc. dr. Ingrida Bružaitė
 Darbe nagrinėjama ir optimizuojama maltozinių sirupų gamyba. Tyrimų su skirtingomis beta-amilazėmis metu, naudojant HPLC būdą, nustatytos optimalios šių parametrų vertės: pululanazės kiekis, beta-amilazės-S kiekis ir cukrinimo trukmė. Gauta, kad cukrinimo metu naudojant beta-amilazę-S, gaunamos didesnės maltozės išeigos nei naudojant beta-amilazę-W. Tyrimo su alfa-amilaze-M metu, naudojant pirmaisiais tyrimais nustatytas optimalias cukrinimo sąlygas, gauta, kad padidinus temperatūrą 4 oC, maltozės išeiga sumažėjo. Cukrinimo etape naudojant mažesnį pradinį dekstrozės ekvivalentą turintį substratą, gaunami didesni maltozės kiekiai sirupe. Tyrimų su skirtingų gamintojų alfa-amilazėmis (alfa-amilaze-M ir alfa-amilaze-L) metu, nustatyta, kad skystinimo etape naudojant neinaktyvuotą alfa-amilazę-L, maksimalus maltozės kiekis sirupe pasiekiamas sparčiau nei naudojant inaktyvuotą alfa-amilazę-L arba neinaktyvuotą alfa-amilazę-M. Nustačius optimalias maltozinių sirupų gamybos sąlygas, pateikiamos baigiamojo bakalauro darbo išvados.
 Darbą sudaro 8 dalys: paveikslų ir lentelių sąrašas, santrumpų sąrašas, įvadas, literatūros apžvalga, medžiagos ir metodai, tyrimo rezultatai ir jų aptarimas, išvados ir literatūros sąrašas.
 Darbo apimtis – 39 p. teksto be priedų, 9 pav., 8 lentelės, 21 bibliografinis šaltinis.
 Raktiniai žodžiai: krakmolo hidrolizė, maltoziniai sirupai, maltozė, skystinimas, cukrinimas, alfa-amilazė, beta-amilazė, pululanazė, dekstrozės ekvivalentas, Furje transformacijos infraraudonųjų spindulių spektroskopija, aukšto efektyvumo skysčių chromatografija
 In this work production of syrups containing maltose was investigated and optimized. The optimal values of pullulanase amount, beta-amylase-S amount and saccharification time were determined using HPLC method. The yield of maltose in saccharification process remains higher using beta-amylase-S than beta-amylase-W. The yield of maltose, which is obtained during saccharification with alpha-amylase-M, decreases when the temperature is increased by 4 oC. The lower initial dextrose equivalent containing substrate is used in saccharification step, the higher amount of maltose syrup is produced. It was determined that in liquefaction step the highest amount of maltose in syrup using inactivated alpha-amylase-L is achieved faster than using activated alpha-amylase-L or inactivated alpha-amylase-M. Once the optimum conditions of syrups containing maltose were determined, the conclusions of final thesis were introduced.
 Structure: list of abbreviations, list of figures and tables, introduction, literature review, materials and methods, results and discussion, conclusions, references. Thesis consist of: 39 p. text without appendixes, 9 pictures, 8 tables, 21 bibliographical entries.
 Raktiniai žodžiai: starch hydrolysis, syrups containing maltose, maltose, liquefaction, saccharification, alpha-amylase, beta-amylase, pullulanase, dextrose equivalent, Fourier transform infrared spectroscopy, high pressure liquid chromatography
 Augusta Jankutė
 Genų, dalyvaujančių N4-acetilcitozino katabolizme, paieška ir funkcijų tyrimas mikroorganizmuose
 Baigiamajame bakalauro darbe buvo tiriamas S. cerevisiae uracilo auksotrofinių kamienų, turinčių pavienes genų YEL029C, YHR183W, YPR062W, YOR221C delecijas, gebėjimas panaudoti N4-acetilcitoziną kaip uracilo šaltinį. Manoma, kad N4-acetilcitozinas nežinomo fermento yra verčiamas citozinu, o citozino deaminazė citoziną verčia į uracilą. Parodyta, kad visi mutantiniai kamienai augo šiek tiek geriau minimalioje MD terpėje esant uracilo nei citozino arba N4-acetilcitozino. Norint gauti ryškesnius augimo skirtumus buvo atliekamos homologinių genų, galimai dalyvaujančių N4-acetilcitozino skaidyme, delecijos E.coli. Patvirtinta, kad sėkmingai buvo atlikta gnd ir pdxY genų delecija. Patikrinus mutantinių kamienų augimą minimalioje M9 terpėje kaip uracilo šaltinį naudojant uracilą, N4-acetilcitoziną, arba citoziną parodyta, kad gnd genas, koduojantis 6-fosfogliukonato dehidrogenazę, neturi įtakos N4-acetilcitozino virtimui citozinu, bet yra reikšmingas citozino virtimui uracilu.
 Darbą sudaro šešios dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, rezultatai ir jų aptarimas, išvados ir literatūros sąrašas. Darbo apimtis – 45 p. teksto be priedų, 16 paveikslų, 7 lentelės, 26 bibliografiniai šaltiniai.
 Raktiniai žodžiai: N4-acetilcitozinas; skaidymas; tRNR modifikacijos; atviro skaitymo rėmelis; S. cerevisiae; E. coli
 In this thesis, the ability of S. cerevisiae uracil auxotrophs with single YEL029C, YHR183W, YPR062W, YOR221C gene deletions to use N4-acetylcytosine as a source of uracil was analyzed. It is believed that N4-acetylcytosine is converted into cytosine by the unknown enzime, whereas the cytosine deaminase converts latter into uracil. It was showed that all the mutants grow better in MD medium containing uracil than the one containing cytosine or N4-acetylcytosine. In order to obtain more pronounced growth differences, single homologue gene knockout mutants in E.coli uracil auxotroph strain was created. These genes are potentially involved in the cababolism of N4-acetylcytosine. It was confirmed that the deletion of either gnd and or pdxY genes was carried out successfully. The obtained mutants were grown in minimal M9 medium containing either N4-acetylcytosine, cytosine, or uracil as the source of uracil. It was showen that gnd gene, encoding the 6-phosphogluconate dehydrogenase is not involved in the conversion of N4-acetylcytosine into cytosine, but involved in conversation of cytosine into uracil.
 Structure of this manuscript: introduction, literature overview, the materials and methods, the results and discussion, conclusions, references. Thesis consist of 45 pages without the appendixes, 16 pictures, 7 tables, 26 bibliographical entries.
 Raktiniai žodžiai: N4-acetylcytosine; catabolism; tRNR modification; open reading frame; S. serevisiae; E.coli
 Pasterizacijos impulsiniu elektriniu lauku įtaka fizinėms ir mikrobinėms pieno išrūgų savybėms
 doc. dr. Albinas Žilinskas
 Pieno išrūgos yra svarbus sūrio gamybos produktas, kuriose gausu žmogui naudingų
 baltymų. Baltymai yra labai jautrūs terminės pasterizacijos poveikiui, todėl šiuo metu yra
 nagrinėjami alternatyvūs pasterizacijos būdai, leidžiantys išsaugoti produktų maistines
 savybes. Baigiamajame bakalauro darbe buvo ištirtas pasterizacijos impulsiniu elektriniu
 lauku poveikis pieno išrūgų fizinėms ir mikrobinėms savybėms. Tyrimams buvo naudojami
 iš AB „Pieno žvaigždės“ gauti pieno išrūgų mėginiai. Pasterizacijos efektyvumui tirti buvo
 naudojama 39 kV/cm-1 stiprumo, 1 ?s trukmės impulsus generuojanti įranga ir pratekamoji
 kiuvetė. Tiriant pieno išrūgose esančių mikroorganizmų gyvybingumo priklausomybę nuo
 elektrinių impulsų dažnio nustatyta, kad reikšmingas pasterizacijos poveikis pasiekiamas
 išrūgas veikiant 4 Hz dažniu. Tyrimų metu taip pat nustatytas impulsinio elektrinio lauko
 pasterizacijos poveikis veikiant tik išrūgų terpę. Tiriant mėginio pradinės temperatūros įtaką
 pasterizacijos efektyvumui nepastebėta reikšmingo skirtumo. Pieno išrūgų fizinėms
 savybėms poveikis impulsiniu elektriniu lauku nedarė jokios įtakos.
 Darbą sudaro: 5 skyriai, 10 paveikslėlių, 3 lentelės, 5 priedai, 35 bibliografiniai
 Raktiniai žodžiai: impulsinis elektrinis laukas, pieno išrūgos, pasterizacija, PEF poveikis
 Milk whey is an important cheese making product, which has a lot of proteins
 important to human organism. Due to protein suscebtability to thermal pasteurization,
 alternative methods of pasteurization, which can preserve the nutritional value of various
 products, are being researched. A study of pulsed electric field pasteurization effects on
 physical and microbial properties of milk whey was performed in this bachelor thesis. Milk
 whey samples were aquired from AB „Pieno žvaigždės“. To study the effects of
 pasteurization, equipment, capable of producing 39 kV/cm-1, 1 ?s pulses was used. Significant
 cell inactivation was achieved, when the frequency of electric pulses was 4 Hz. Pulsed electric
 field pasteurization effect was also tested by affecting only the milk whey medium. Study
 also concluded that inital sample temperature has minimal effect on the effectiveness of cell
 inactivation and the physical properties of milk whey.
 Thesis consists of: 5 sections, 10 pictures, 3 tables, 5 appendixes, 35 bibliographical
 Raktiniai žodžiai: Pulsed electric field, PEF, milk whey, pasteurization
 Auksė Rapnikaitė
 Paviršiuje imobilizuotų membranų sudėties ir funkcijos tyrimas taikant skirtingus membranų paruošimo metodus
 Baigiamajame bakalauro darbe tirta skirtingos sudėties hibridinės lipidinės membranos (hBLM) struktūriniai ir funkciniai skirtumai. Viena hBLM sudaryta tik iš 1,2 – dioleoil – sn – glicerolio – 3 – fosfocholino (DOPC), o kita iš DOPC ir cholesterolio sumaišytų lygiomis dalimis. Jų formavimui naudojama 30 nm, 100 nm, 200 nm dvisluoksnės liposomos ir daugiasluoksnės liposomos. Tyrimui atlikti naudojami paviršiaus plazmonų rezonanso ir elektrocheminio impedanso spektroskopijos metodai.
 Apskaičiuota dvikomponentę hBLM sudarančių DOPC ir cholesterolio santykis, kuris kinta priklausomai nuo membranos formavimo būdo.
 Nustatyta hBLM, sudarytos iš 50% DOPC ir 50% cholesterolio, sąveika su baltymu vaginolizinu (VLY) kai membrana yra formuojama skirtingais būdais (VLY koncentracija – 50 nM) ir kai formavimui naudojama daugiasluoksnės liposomos, o VLY koncentracija skirtinga: 10 nM, 20 nM, 35 nM, 50 nM, 70 nM.
 Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, metodinė dalis, tyrimo rezultatai ir jų aptarimas, išvados, literatūros sąrašas. Darbo apimtis – 34 p. teksto, 14 iliustr., 3 lent., 26 bibliografiniai šaltiniai.
 Raktiniai žodžiai: hibridinė lipidinė membrana, DOPC, cholesterolis, daugiasluoksnės liposomos, dvisluoksnės liposomos, vaginolizinas.
 The structural and functional differences between hybrid bilayer lipid membranes (hBLM), which have different composition, were investigated in this Bachelor’s thesis. One of hBLM consisted only 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and the other consisted a mixture of equal portions of DOPC and cholesterol. 30 nm, 100 nm, 200 nm unilamellar and multilamellar vesicles were used for the hBLM formation. An experiment was performed using the surface plasmon resonance and the electrochemical impedance spectroscopy.
 A ratio between DOPC and cholesterol was calculated for two-component hBLM. The ratio depended on the membrane formation method. Vaginolysin (VLY) interaction with hBLM, which consisted 50% of cholesterol and 50% of DOPC, depended on the membrane formation method, when a concentration of VLY was constant – 50 nM). The impact of VLY also relied on its concentration (10 nM, 20 nM, 35 nM, 50 nM, 70 nM) when interacting with the hBLM formed from multilamellar vesicles
 Structure: introduction, literature review, methodical part, results of investigation and discussion, conclusions, references. Thesis consist of: 34 p., 14 pictures, 3 tables, 26 bibliographical entries.
 Raktiniai žodžiai: hybrid bilayer lipid membrane, DOPC, cholesterol, multilamellar vesicles, unilamellar vesicles, vaginolysin.
 Gabrielė Aleknaitė
 Antocianinų poveikis mitochondrijų funkcijoms ir ląstelių žūčiai smegenų išemijos metu
 Smegenų išemija vienas iš dažniausiai pasitaikančių neurologinių pažeidimų, kurių metu yra sutrikdoma kraujotaka, vyksta hipoksija ir maistinių medžiagų trūkumas, pažeidžiama mitochondrijų struktūra ir jų funkcijos, kurios lemia ląstelių žūtį nekrozės arba apoptozės būdu. Remiantis literatūros duomenimis yra žinoma, kad antocianinai pasižymi stipriomis citochromą c redukuojančiomis savybėmis. Šio darbo tikslas – ištirti antocianinų, kurie tarpusavyje skiriasi angliavandenio dalimi, poveikį žiurkės smegenų mitochondrijų oksidacinio fosforilinimo sistemai ir įvertinti jų apsauginį poveikį nuo išemijos sukeliamų pažeidimų. Tyrimuose buvo atliekama skirtingų koncentracijų antocianinų pefuzija in vivo ir taikomas išemijos modelis in vitro. Tiriamų medžiagų poveikis oksidacinio fosforilinimo sistemai įvertintas naudojant oksimetrinę sistemą. Spektrofotometriškai matuojamas LDH aktyvumas ląstelių nekrozei įvertinti, o apoptoziniams procesams nustatyti fluorimetriškai matuojamas kaspazės-3 skilimo greitis. Išemijos pažeistų smegenų pusrutulių bei smegenėlių plotams įvertinti naudojami TTC dažai. Spektrofotometriškai įvertinamas tiriamų antocianinų gebėjimas redukuoti citochromą c. Tyrimais nustatyta, kad Cy3Gal ir Cy3R pasižymi citochromą c redukuojančiomis savybėmis. Perfuzija Cy3Gal apsaugo žiurkės smegenų mitochondrijų oksidacinio fosforilinimo sistemą ir sumažina ląstelių žūti apoptozės ir nekrozės būdu. Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, metodika, tyrimų rezultatai ir jų aptarimas, išvados, literatūros sąrašas. Darbo apimtis – 45 p. teksto be priedų, 15 iliustr., 75 bibliografiniai šaltiniai.
 Raktiniai žodžiai: Smegenų išemija, antocianinai, mitochondrijos, apoptozė, nekrozė, cianidino-3-rutinozidas, cianidino-3-galaktozidas.
 Cerebral ischemia is one of the most common neurological disorder, when blood flow to the brain is restricted. This leads to limited oxygen supply or cerebral hypoxia. Due to mitochondrial structure and functions become damaged, which leads to cell death by necrosis or apoptosis. According to the literature anthocyanins could highly reduce cytochrome c. The aim of this study was to investigate the anthocyanins, with different carbohydrate part, effect of rat brain mitochondrial oxidative phosphorylation system and to evaluate their protective effect against ischemia induced damage. In this study in vivo perfusion and in vitro brain ischemia models were applied. The effects of anthocyanins to the oxidative phosphorylation system were evaluated using oxygraph system. To evaluate cells necrosis, LDH activity was measured Spectrophotometric. Apoptotic processes were evaluated using fluorametric measurements by caspase-3 rate of biodegradation. To estimate areas of damaged brain hemispheres and cerebellum tissues were stained with TTC paint. Using Spectrophotometric methods reducing cytochrome c properties of anthocyanins were evaluated. In was discovered that Cy3Gal and Cy3R could effectively reduce cytochrome c. Perfusion of Cy3Gal protects rat brain mitochondrial oxidative phosphorylation system and reduces the cell death of apoptosis and necrosis manner. This work consists of 6 parts: introduction, literature review, methodology, results and discussion, conclusions, references. The size of thesis- 45 p. text without supplements, 15 pictures, 75 bibliographic sources.
 Raktiniai žodžiai: Cerebral ishemia, anthocyanins, apoptosis, necrosis, cyanidin-3-rutinoside, cyanidin-3-galactoside.
 Viačeslav Bedugnis
 Gliukozės biologinių jutiklių kūrimas bei praktinis pritaikymas realiuose objektuose, naudojant vandenyje netirpius mediatorius
 dr. Natalija German
 Pastaraisiais metais nemažai dėmesio yra skiriama gliukozės nustatymui gamtiniuose objektuose elektrocheminių biologinių jutiklių pagalba. Biologinių jutiklių kūrimo strategijos būna įvairios ir yra pastoviai tobulinamos, siekiant sukurti jautresnes sistemas. Baigiamajame bakalauro darbe nagrinėjamas gliukozės biologinių jutiklių kūrimas, naudojant skirtingų formų auksą, vandenyje netirpius mediatorius bei fermentą – gliukozės oksidazę. Darbo tikslas buvo parinkti tinkamesnį elektronų pernešimo tarpininką gliukozės biologiniam jutikliui, parinkti elektrodo padengimo optimalias sąlygas (imobilizavimo metodą, tirpiklio bei elektronų nešiklio koncentraciją ir elektrocheminį potencialą), ištirti pagrindines sukurto biologinio jutiklio analizines charakteristikas (tiesinį koncentracijos intervalą, aptikimo ribą, atsikartojamumą) bei trukdančių komponentų įtaką analizinės sistemos jautrumui. Darbo metu buvo nustatyta, kad tinkamiausias elektronų nešiklis yra N,N,N‘,N‘-tetrametilbenzidinas. Optimaliausiu imobilizavimo būdu buvo parinktas grafito strypelio elektrocheminis modifikavimas aukso nanostruktūromis, padengimas tinkamesniu mediatoriumi ir imobilizavimas gliukozės oksidaze. Didesni gliukozės analiziniai signalai buvo gauti, naudojant 38 mmol L-1 koncentracijos N,N,N‘,N‘-tetrametilbenzidiną, ištirpintą acetonitrile, ir +0.6 V elektrocheminį potencialą. Nustatytas gliukozės tiesinis koncentracijos intervalas (0.1 – 4.48 mmol L-1), aptikimo riba – 0.063 mmol L-1, rezultatų atsikartojamumas, esant gliukozės koncentracijoms 4.48 ir 135 mmol L-1 – 0.254 ir 0.119, atitinkamai. Taip pat nustatyta, kad sukurtas biologinis jutiklis yra atsparus kai kurių angliavandenių ir trukdančių komponentų įtakai bei tinkamas gliukozės nustatymui žmogaus serume. Darbą sudaro 8 dalys: turinys, santrumpos, įvadas, literatūros apžvalga, tyrimų metodika, experimentinės procedūros, išvados, literatūros sąrašas. Darbo apimtis – 39 p. teksto be priedų, 15 iliustr., 2 lent., 37 bibliografiniai šaltiniai.
 Raktiniai žodžiai: aukso nanodalelės, aukso nanostruktūros, biologinis jutiklis, gliukozė, gliukozės oksidazė, netirpus vandenyje mediatorius, žmogaus serumas.
 In recent years a lot of attention is paid to the determination of glucose in natural objects by electrochemical biosensors. The strategies of glucose biosensors creation are various and are constantly improved in order to develope more sensitive systems. This bachelor thesis is about the development of glucose biosensors based on different forms of gold, insoluble in water mediators and enzyme (glucose oxidase). The aim of this work was to choose the appopriate electron transfer mediator for created biosensor, to choose the optimal conditions (the technique of the immobilization, the solvent and the concentration of mediator, electrochemical potential) for the immobilization, to evaluate main analytical characteristics (linear concentration interval, the limit of detection, repeatability) of created biosensors and the influence of interfering substances on the sensitivity of analytical system. It was found that the most appropriate mediator is N,N,N‘,N‘-tethramethylbenzidine. The optimal immobilization is based on modified gold nanostructures, suitable mediator and immobilizied glucose oxidase. The highest glucose analitycal signals were obtained at the +0.6 V potential with 38 mmol L-1 concentration of N,N,N‘,N‘-tethramethylbenzidine, dissolved in acetonitrile. It were obtained: the linear interval of glucose concentration (0.1 – 4.48 mmol L-1), the limit of detection – 0.063 mmol L-1, repeatability of results for glucose concentrations 4.48 and 135 mmol L-1 – 0.254 and 0.119, respectively. It was evaluated that created biosensor is resistant to the influence of carbohydrates and interfering species. Developed system is appopriate for glucose determination in human serum.
 Structure – 8 parts: content, abbreviations, introduction, literature review, the method of investigations, discussion of results, conclusion, the list of literature. Thesis consists of – 39 pgs. of the text without suppliments, 15 figures, 2 tables, 37 bibliographical entries.
 Raktiniai žodžiai: gold nanoparticles, gold nanostructures, biosensor, glucose, glucose oxidase, insoluble in water mediator, human serum
 Skaistė Paulionytė
 Tiazolo dariniai ir jų antibakterinis bioaktyvumas
 Šio darbo tikslas - ištirti naujai susintetintų tiazolo darinių antibakterinį aktyvumą prokariotinėms ląstelėms, naudojant naudojant difuzijos į agarą metodą. Iššifravus naujai susintetintų tiazolo darinių BMR ir IR spektrus, gauti struktūros rezultatai parodė, kad dariniai turi šias funkcines grupes: tiazolo fragmentą (heterociklą), vieną ar du benzeno žiedus su metilo, fluorido ar chlorido pakaitais, karboksilo ir tretinio amino grupes. Taip pat, tiazolo dariniuose identifikuotos hidroksido, karboksilo ir cianido grupės. Difuzijos į agarą tyrimo metu buvo vertinamas bakterijų jautrumas naujai susintetintiems tiazolo dariniams. Gauti rezultatai rodo, kad tiazolo darinių antibakterinis aktyvumas mažai skiriasi tarp gramneigiamų ir gramteigiamų bakterijų. Didžiausias antibakterinis reaktingumas pastebimas tiazolo BAG-6, BAG-8, BAG-4 darinių su 600 μg/ml koncentracija ir veikė visas tyrime naudotas kultūras. Dauguma naujai susintetintų tiazolo darinių pasižymėjo silpnomis antibakterinėmis savybėmis prieš E. coli, B. sphaericus, B. cereus bakterijų kultūras.
 Darbo apimtis – 42 p. teksto be priedų, 29 paveiksliukai, 6 lentelės, 30 bibliografiniai šaltiniai.
 Raktiniai žodžiai: Difuzija į agarą, prokariotinės ląstelės, antibakterinis aktyvumas, tiazolo dariniai, MSK
 The main purpose of this study was to identify antibacterial activity of the newly synthesized derivatives of thiazole on prokaryotic cells. Newly synthesized compounds have been characterized by NMR and IR spectroscopy and then used for agar diffusion method. Analysis of NMR and IR spectrum showed structural differences in each of thiazole derivatives. Identified structures found in thiazole derivatives: thiazole fragment (heterocyclic compound), one or couple of benzene rings with methyl, fluoride or chloride substituents, carboxyl and tertiary amino groups. Bacterial sensitivity was assessed by using agar diffusion method. Antibacterial activity on gram-positive and gram-negative bacterium was basically the same – quite low. Highest antibacterial activity on all tested bacterium was observed with BAG-6, BAG-8 and BAG-4 thiazole derivatives at 600 μg/ml concentration. Most of the newly synthesized thiazole derivatives showed low antibacterial activity on E. coli, B. sphaericus, B. cereus bacterium strains. Structure: introduction, conclusions, literature review, materials and methods, results and discussion, conclusions, references.
 Thesis consist of: 42 p. text without appendixes, 29 pictures, 4 tables, 30 bibliographical entries.
 Raktiniai žodžiai: Agar diffusion, prokaryotic cells, thiazole derivatives, antibacterial activity, MIC.
 Marijus Šerys
 Actinobacter calcoaceticus nuo PQQ priklausomos gliukozės dehidrogenazės katalizuojamos oligosacharidų oksidacijos tyrimai
 Suoksidavus oligosacharidus gaunamos cukrų rūgštys. Jos gali atlikti svarbų vaidmenį kiekvieno gyvenime: statant namus, valant užterštą dirvožemį, gydant žmones. Šiame darbe išanalizuojama oligosacharidų oksidacija draugišku aplinkai – fermentiniu būdu. Sukonstruotos oligosacharidų oksidacinės sistemos paremtos PQQ gliukozės dehidrogenaze, gauta iš Actinobacter calcoaceticus, kuri pasižymi aukštu katalitiniu efektyvumu ir nejautrumu deguoniui. Šiose sistemose, kaip elektronų akceptorius panaudotas geriausias dažas, atsirinktas iš fenotiazininių ir fenoksazininių dažų. Suprojektuota oligosacharidų oksidacijos sistema, išbandyta praktiškai, kurios efektyvumas pasiekė 63 %.
 Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, tyrimo rezultatai ir jų aptarimas, išvados, literatūros sąrašas. Darbo apimtis – 47 p. teksto, 40 paveikslų, 5 lentelės, 23 bibliografiniai šaltiniai.
 Raktiniai žodžiai: oligosacharidai, PQQ gliukozės dehidrogenazė, oksidacija, elektronų akceptorius, regeneracinė sistema.
 Then you oxidize oligosaccharides you get sugar acids. Those acids could perform very important role in our lives – from building houses to treating people. In this bachelor thesis you can find out how oligosaccharides can be oxidized using environment friendly – enzymatic way. Oligosaccharide oxidation systems were build up based on PQQ glucose dehydrogenase extracted from Actinobacter calcoaceticus. This enzyme has a specific high catalytic efficiency and doesn‘t react with oxygen.In these oligosaccharides oxidazing systems as electron acceptor was used a dye, chosen from phenothiazine and phenoxazine dyes. Theoretically modeled oligosaccharides oxidation system was tried practically and its efficiency was 63%.
 Bachelor thesis structure: introduction, review of literature, methods and materials, results, conclusions and references.
 Bachelor thesis consists of 47 pages, 40 pictures, 5 tables, 23 references.
 Raktiniai žodžiai: oligosaccharides, PQQ glucose dehydrogenaze, oxidation, electron acceptor, regeneration system.
 Kamilė Subačiūtė
 Žalioji cinko oksido nanodalelių sintezė ir jų poveikis mielių ląstelių gyvybingumui
 Šio darbo tikslas ištirti cinko oksido nanodalelių toksiškumą mielių Saccharomyces ceverisiae ląstelėms. Žaliosios sintezės metu iš augalų (kinrožės, alavijo, morkų ir bazilikų) lapų ekstraktų, susintetintos didelio optinio tankio cinko oksido nanodalelės. Įvykusią sintezę patvirtino pasikeitųsi tirpalų spalva iš skaidrios į geltoną ir rudą. Panaudojant prašviečiančią elektroninę mikroskopiją buvo nustatyta, kad cinko oksido nanodalelės, turi 30÷40 nm dydį ir yra sferinės formos. UV-RŠ spektroskopijos metu gauti skirtingi sugerties spektrai. Cinko oksido nanodalelių, gautų naudojant alavijo lapų ekstraktą, PPR smailės maksimumas matomas ties 301 nm bangos ilgiu; baziliko lapų ekstraktą, ties 302 nm bangos ilgiu; kinrožių ir morkų lapų ekstraktus PPR gautas ties 303 nm ir 306 nm bangos ilgiais. Gyvybingumo tyrimai leidžia teigti, kad ZnO nanodalelės toksiškai veikia mielių Saccharomyces cerevisiae ląsteles. Naudojant ląstelių skaičiaus kontrolę ir metileno mėlio dažą, tyrimo rezultatai parodė, kad po 24 val. didžiausią poveikį ląstelių gyvybingumui turėjo ZnO nanodalelės, susintetintos naudojant morkų lapų ekstraktą. Ląstelių gyvybingumas buvo 29,09%±3,91. Paveikus ląsteles ZnO Nd, gautomis naudojant alavijo ir baziliko lapų ekstraktus, atitinkamai siekė 52,99%±1,41 ir 38,72%±6,31. Pastebėta, kad, ilginant mielių ląstelių inkubavimo su ZnO Nd trukmę, didėja šviesoje fluorescuojančių mielių Saccharomyces cerevisiae ląstelių skaičius. Tėkmės citometrijos metodas patvirtino toksinį ZnO Nd poveikį mielių ląstelėms. Difuzijos į agarą metodas parodė, kad mielių Saccharomyces ceverisiae ląstelės jautrios ZnO Nd poveikiui taip pat.
 Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, tyrimo rezultatai ir aptarimas, išvados ir literatūros sąrašas. Darbo apimtis – 47 p. teksto be priedų, 15 iliustr., 2 lent., 50 bibliografinių šaltinių. Raktiniai žodžiai: Cinko oksido nanodalelės (ZnO Nd), Fluorescencinė mikroskopija, mielės, Prašviečianti elektroninė mikroskopija (PEM), Saccharomyces ceverisiae, Tėkmės citometrija, UV-Vis spektroskopija.
 The aim of this work was toxicity assessment of Zinc oxide Nanoparticles using Saccharomyces cerevisiae yeast cells. Zinc oxide (ZnO) nanoparticles (Np) have been
 synthesized using various plants (aloe vera, basil, hibiscus and carrot) leaf extracts. Synthesis was confirmed by the change in the colour of the solution from clear to yellow and brown. Using transmission electron microscope was found that ZnO Np size was ~30÷40 nm and their shape was spherical. UV-Vis spectroscopy shown different absorbtion spectra. For ZnO nanoparticles synthesised by aloe vera leaf extract, the SPR was at 301 nm wavelength; synthesised by basil leaf extract, the SPR was at 302 nm wavelenght. The surface plasmon resonance of zinc oxide nanoparticles obtained by carrot and bibiscus leaf extract shown SPR at 306 nm and 303 nm wavelength. The impact of ZnO nanoparticles on the cells were studied using methylene blue dye and the control number of cells monitoring changes in the number of cells in time. The analysis indicated that after 24 hours the viability was most influencend by ZnO nanoparticles synthesized using carrot leaf extract. The viability of yeast cells was 29,09%±3,91. ZnO nanoparticles synthesized using hibiscus and basil leaf extracts viability of yeast cells was respectively 52,99%±1,41 ir 38,72%±6,31. Flow cytometry analysis demonstrate that ZnO nanoparticles affect the yeast viability. Experiments with fluorescence microscope showed that longer incubation with ZnO Np increases fluorescence light in the number of yeast cells. As well diffusion to agar method showed that yeast cells were very sensitive to ZnO Np.
 Structure: introduction, literature, materials and methods, results and discussion, conclusions, references. Thesis consists of: 47 p. text without appendixes, 15 pictures, 2 tables, 50 bibliographical entries.
 Raktiniai žodžiai: Flow cytometry, yeast, Saccharomyces ceverisiae, Transmission electron microscopy (TEM) UV-Vis spectroscopy, Zinc oxide nanoparticles (ZnO Np).
 Pelės prioninio baltymo 144 stop mutanto geno konstravimas ir raiška, rekombinantinio baltymo gryninimas ir jo agregacijos tyrimai
 Amiloidai – baltyminės kilmės ne natyvios struktūros dariniai, randami organuose ir audiniuose. Šie baltymai yra siejami su patologiniais veiksniais, sukeliančiais neurodegeneratyvines ligas, tokias kaip transmisinės spongiforminės encefalopatijos (prionų ligos). Vienas iš praktiškai sutinkamų šios ligos pavyzdžių yra Gerstmann-Straussler-Scheinker liga, kurią sukelia įvairios prioninio baltymo mutacijos. Baigiamąjame darbe buvo tirta pelės prioninio baltymo W144STOP (moPrP23-143) mutacija. Atlikti šio baltymo agregacijos tyrimai.
 Įvesta W144STOP mutacija į prioninį baltymą koduojantį geną ir gautas moPrP23-143 konstruktas;
 Gauta moPrP23-143 baltymo raiška E. coli ląstelėse; Išgryninus metalų chelatinės giminingumo chromatografijos metodu iš viso gauta 229,1 ± 0,1 mg rekombinantinio moPrP23-143 baltymo;
 Atlikti moPrP23-143 de novo agregacijos bei inicijuotos agregacijos tyrimai skirtinguose buferiniuose tirpaluose parodė, kad baltymas gali sudaryti fibrilinius agregatus esant 0 M ir 0,5 M GuHCl koncentracijoms. Atliktas 0 M GuHCl formuotų fibrilių stabilumo tyrimas. Iš gautų rezultatų buvo pasirinktos optimalios inicijuotos agregacijos sąlygos tolimesniems tyrimams;
 Inicijuota moPrP23-230, moPrP89-230 agregacija su moPrP23-143 nukleacijos branduoliais bei išnagrinėti pokyčiai atsiradę šios agregacijos metu.
 Darbą sudaro šešios dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, rezultatai ir jų aptarimas, išvados ir literatūros sąrašas.
 Darbo apimtis 41 p. teksto be priedų, 28 paveikslai, 8 lentelės, 52 bibliografinis šaltinis. Atskirai pridedamų darbo priedų nėra.
 Raktiniai žodžiai: Pelės prioninis baltymas, pelės prioninio baltymo mutantas, fibriliniai agregatai, gryninimas, agregacija, inicijuota agregacija.
 Amyloids are proteinatious, non-native structure derivatives that are found in organs and tissues. These proteins are linked to the pathological factors which cause neurodegenerative diseases such as transmissive spongiform encephalopathy (prion diseases). One example of the disease is Gerstmann-Straussler-Scheinker syndrome, which is caused by different mutations of prion protein. The Bachelor‘s work covers the experimental agregation work of mouse prion protein W144STOP (moPrP23-143) mutant.
 Mutation of W144STOP was generated by performing targeted mutagenesis; the construct of moPrP23-143 was generated.
 The moPrP23-143 was expressed in E. coli cells. Using IMAC, recombinant protein was purified (total amount of 229.1 ± 0.1 mg).
 De novo and seed-induced agregation studies of moPrP23-143 were conducted in different buffer solutions, the results showed that moPrP23-143 form fibril agregates without and with 0.5 M of GuHCl. Stability of fibrils, formed without GuHCl, was examined. Cross-seeding of moPrP23-230 and moPrP89-230 using moPrP23-143 fibrils were performed.
 Structure: indtoduction, literature review, materials and methods, results and discussion, conclusions and references.
 Thesis consist of 41 p. Text without appendixes, 28 picture, 8 tables, 52 bibliographical entries.
 Raktiniai žodžiai: Mouse prion protein, mutant of mouse prion protein, fibril agregates, purification, agregation, seed-induced agregation.
 Vario nanodariniai ir jų antibakterinis aktyvumas
 Šio darbo tikslas buvo atlikti biologinę vario nanodarinių sintezę naudojant prokariotinių ląstelių Bacillus subtilis supernatantą, ištirti nanodarinių dydį, formą bei antibakterinį aktyvumą. UV-RŠ spektrofotometrinis tyrimas parodė, kad susintetintų vario nanodarinių optinės sugerties spektro maksimumas matomas ties 600-622 nm bangos ilgiu. PEM tyrimo metu paaiškėjo, kad gauti Cu ND yra 8-30 nm dydžio, sferinės bei kubo formos. Pastebėta tendencija, kad kuo mažesnis nanodarinys, tuo dažniau jo forma panaši į sferinę, ir atvirkščiai, kuo didesnis nanodarinys, tuo dažniau jo forma primena kubą. Difuzijos į agarą metodas buvo naudotas vario nanodarinių antibakteriniam aktyvumui tirti ir buvo gauta, kad jis skiriasi gramteigiamoms ir gramneigiamoms ląstelėms. Didžiausiu antibakteriniu aktyvumu prieš bakterijų kultūras pasižymėjo koloidinis vario nanodarinių tirpalas, susintetintas naudojant 8mM CuSO4 vandeninį tirpalą ir Bacillus subtilis supernatantą, jo pH esant 6,5. Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, tyrimo rezultatai ir aptarimas, išvados ir literatūros sąrašas.
 Darbo apimtis – 42 p. teksto be priedų, 15 iliustr., 4 lent., 36 bibliografiniai šaltiniai.
 Raktiniai žodžiai: UV-RŠ spektroskopija, vario nanodariniai (Cu ND), agaro difuzijos metodas, prašviečianti elektroninė mikroskopija (PEM), Bacillus subtilis
 The aim of this work was to synthesize copper nanoderivatives using the supernatant of prokaryotic Bacillus subtilis cells and to study their size, shape, and antibacterial activity. Optic properties of copper nanoderivatives showed that the peak of absorbtion is visible in the range of 600-622 nm. TEM method showed that the synthesized nanoderivatives had shapes of spheres and cubes, and their size varied in the range of 8-30 nm. The tendency was observed, that the smaller were the nanoderivatives, the more likely their shape was close to spherical form, and conversely, the bigger the nanoderivatives, the more often their shape was similar to nanocubes. Agar well diffusion method showed that bacterial cultures of Gram-positive bacteria are more sensitive to sythesized copper nanoderivatives than Gram-negative bacteria. The best spectrophotometric and antibacterial activity results were observed with copper nanoderivatives synthesized from 8mM CuSO4 aqueous solution and Bacillus subtilis supernatant of pH 6,5. Structure: introduction, literature review, materials and methods, results and discussion, conclusions and references.
 Thesis consists of: 42 p. of text without appendixes, 15 pictures, 4 tables, and 36 bibliographical sources.
 Raktiniai žodžiai: UV-Vis spectroscopy, copper nanoderivatives (Cu ND), agar well diffusion, transmission electron microscopy (TEM), Bacillus subtilis
 Eglė Pleskūnaitė
 Lakazės, imobilizuotos ant magnetinių nanodalelių, veikimo tyrimas
 Baigiamajame bakalauro darbe buvo susintetintos magnetinės nanodalelės ir padengtos auksu. Jų charakterizavimui buvo naudojami spektrofotometrinis ir elektrocheminis metodai. Fermentų imobilizavimo tyrimai atlikti naudojant skirtingas lakazes – dvi rekombinantines ir vieną natyvią. Ištirta lakazių imobilizavimo ant magnetinių nanodalelių priklausomybė nuo inkubavimo laiko, nuo lakazių ir magnetinių nanodalelių kiekio santykio inkubavimo mišinyje. Nustatyta imobilizuotų lakazių desorbcijos priklausomybė nuo plovimui naudojamo acetatinio buferinio tirpalo tūrio. Lakazė buvo imobilizuota ant stiklo anglies elektrodo paviršiaus modifikuoto aukso nanodalelėmis, aukso magnetinėmis nanodalelėmis ar magnetinėmis nanodalelėmis. Atliktas elektocheminis fermentinių elektrodų tyrimas buferiniame tirpale esant slopikliui ir be jo. Nustatyti imobilizuotų ir neimobilizuotų lakazių kinetiniai parametrai. Parodytas halogenidų (fluorido ir chlorido) poveikis imobilizuotoms ir neimobilizuotoms lakazėms, apskaičiotos slopinimo konstantos. Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, medžiagos, įranga ir metodai, rezultatai ir jų aptarimas, išvados, literatūros sąrašas. Darbo apimtis 53 p. teksto, 21 paveikslai, 5 lentelės, 51 bibliografiniai šaltiniai.
 Raktiniai žodžiai: aukso nanodalelės, biokatalizinė srovė, kinetiniai parametrai, lakazė, magnetinės nanodalelės, slopikliai. Anotacija (užsienio k.)
 In the following bachelor thesis magnetic nanoparticles were synthesized and coated with gold. In order to characterize synthesized nanoparticles spectrometric and electrochemical methods were used. The investigation of immobilization of enzymes was performed using various laccases with two of them being recombinant and one being native. The dependences of immobilization of laccase on incubation time and on the ratio of the amounts of laccase and magnetic nanoparticles in the incubation mixture were investigated. The dependence of the desorbtion of the immobilized laccase on the volume of acetate buffer used for washing was determined. Laccase was immobilized on the surface of carbon glass electrodes modified gold nanoparticles, gold coated magnetic nanoparticles or magnetic nanoparticles. The electrochemical measurements of the enzyme electrodes were performed in the buffer solution with an inhibitor and without it. The kinetic parameters of the immobilised and free laccases were determined. The effect of halogenides (fluoride and chloride) on immobilized and non-immobilized laccases was investigated and inhibition constants were calculated.
 Structure: introduction, literature review, materials, tools and methods, results and discussion, conclusions, references. Thesis consist of: 53 pages of text, 21 pictures, 5 tables, 51 bibliographical entries.
 Raktiniai žodžiai: biocatalytical current, gold nanoparticles, inhibitors, kinetic parameters, laccase, magnetic nanoparticles.
 Artūr Oškerko
 Įvairios molekulinės masės beta-1,3-d-gliukanų molekulinių sietų chromatografijos metodu tyrimas
 Beta-gliukanai yra vienas iš labiausiai paplitusių gliukozės polimerų randamų gamtoje. Pastebėta, kad beta-gliukanai stimuliuoja žmogaus imuninę sistemą bei pasižymi teigiamų poveikių naudojant juos vėžio gydymui. Pastaruoju metu atliekama vis daugiau tyrimų su beta-gliukanais todėl, norint gauti daugiau tyrimo medžiagos, optimizuojami frakcionavimo metodai. Baigiamajame bakalauro darbe buvo analizuojamas beta-1,3-D-gliukanų atskyrimas taikant molekulinių sietų chromatografijos metodą bei optimizuojamos atskyrimo sąlygos. Siekiant nustatyti optimaliausias beta-gliukanų atskyrimo sąlygas buvo išanalizuotos skirtingos beta-gliukanų koncentracijos, skirtingi judrios fazės greičiai bei skirtingi mėginio tūriai kolonos atžvilgiu. Pagal gautus rezultatus, buvo nustatyta optimaliausia beta-gliukanų koncentracija, optimaliausias judrios fazės greitis ir optimaliausias mėginio tūris kolonos atžvilgiu. Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, rezultatai ir jų aptarimas, išvados, literatūros sąrašas. Darbo apimtis: 31 psl. teksto be priedų, 12 pav., 1 lent., 20 bibliografinių šaltinių.
 Raktiniai žodžiai: Gel-filtracija, molekulinių sietų chromatografija, beta-gliukanai, atskyrimas, optimizacija.
 Beta-glucan is one of the most common glucose polymers found in the nature. It has been noticed that beta-glucan has positive effects while fighting with various types of cancer and can stimulate human immune system. A lot of research using beta-glucans has been conducted recently, for this reason, in order to get more research material, optimization process is required. In this paper beta-1,3-D-glucan separation with size exclusion chromatography and separation optimization was made. The aim of this work was to analyze various beta-glucan concentration, different flow rates and different analyte volumes. Based on the results, the optimum concentration, optimum flow rate and optimum analyte volume were determined. Structure: introduction, literature review, materials and methods, results and discussion, conclusion, references.
 Thesis consists of: 31 p. text without appendixes, 12 pictures, 1 table, 20 bibliographical entries.
 Raktiniai žodžiai: Gel-filtration, size exclusion chromatography, beta-glucans, separation, optimization.
 Greta Gofmanaitė
 Biologinė sidabro nanodalelių sintezė ir jų įtakos ląstelių gyvybingumui tyrimas
 Baigiamojo bakalaurinio darbo tikslas buvo susintetinti sidabro nanodaleles (Ag Nd), naudojant bakterijų kultūras ir ištirti jų poveikį eukariotinių ląstelių gyvybingumui in vitro.Iš bakterijų Escherichia coli ir Bacillus subtilis kultūrų supernatantų susintetintos didelio optinio tankio sidabro nanodalelės. Tiriant Ag Nd optines sąvybes gauti skirtingi sugerties spektrai patvirtino, kad sidabro nanodalelės skirtinguose koloidiniuose tirpaluose buvo skirtingo dydžio. Ištyrus Ag Nd koloidinius tirpalus nustatyta, kad dalelių dydis siekia 10-50 nm, dauguma jų turi sferinę, ovalo bei daugiabriaunę formas. Gyvybingumo tyrimai leidžia teigti, kad Ag Nd toksiškai veikia mielių Saccharomyces cerevisiae ląsteles. Didžiausiu antibakteriniu aktyvumu pasižymėjo Ag Nd susintetintos naudojant Bacillus subtilis : AgNO3 supernatantą (1:1). Ląstelių gyvybingumas po 24 val. siekė 62,2 ± 3,1 %. Naudojat difuzijos į agarą metodą nustatyta, kad mielių ląstelės buvo jautrios susintetintoms Ag Nd. Jautriausiai reagavo į Bacillus subtilis: AgNO3 (1:1) supernatantą. Gyvybingumo tyrimai fluorescenciniu mikroskopu parodė, kad ilginant inkubavimo su Ag Nd trukmę didėja šviesoje fluorescuojančių mielių Saccharomyces cerevisiae ląstelių skaičius.
 Darbą sudaro 7 dalys: paveikslėlių, lentelių ir santrumpų sąrašas, įvadas, literatūros apžvalga, medžiagos ir metodai, rezultatai ir jų aptarimas, išvados ir literatūros šaltiniai.
 Darbo apimtis – 49 p. teksto be priedų, 15 pav., 6 lent., 51 bibliografiniai šaltiniai
 Raktiniai žodžiai: Sidabro nanodalelės, biosintezė, prašviečianti elektroninė mikroskopija, antibakterinis aktyvumas
 The aim of bachelor‘s final work is to synthesize silver nanoparticles using different bacteria supernatants and to investigate their influence on the viability of the eukariotic cells in vitro. Using Escherichia coli and Bacillus subtilis supernatants were sythesized high optical absorbtance silver nanoparticles. Different spektroskopy results shown that there were sythesized different sizes silver nanoparticles. The results of TEM shown that silver nanoparticles was between 10 – 50 nm, most of them – spherical, elliptical and polygonal. The vitality research shows that silver nanoparticles have cytotoxic efect for yeasts Saccharomyces cerevisiae cells cultures. The biggest influence on yeasts vitability had silver nanoparticles synthesized using Bacillus subtilis : AgNO3 supernatant (1:1). The vitability after 24 hours was 62,2 ± 3,1 %. Using diffusion into agar method was investigated that yeasts cells were sensitive to all sinthesized silver nanoparticles. The biggest influence had silver nanoparticles synthesized using Bacillus subtilis : AgNO3 supernatant (1:1). Vitability researches using fluorescence microscopy had shown, that making longer incubation time with silver nanoparticles indicates the bigger amounts of fluorescing yeast Saccharomyces cerevisiaecells.
 Structure: list of tables, figures and abbreviations, introduction, literature review, materials and methods, results and discussion, references.
 Thesis consists of – 49 p. of text, 15 figures, 6 tables, 51 bibliographical entries
 Raktiniai žodžiai: Silver nanoparticles, biosynthesis, Transmission electron microscopy, antibacterial activity
 Mingailė Gecevičiūtė
 Anglinių nanostruktūrų taikymas gliukozės biologinių jutiklių kūrime
 Šiais laikais biologiniai jutikliai vis dažniau naudojami biomedicinos tyrinėjimams ir ligų diagnostikai. Biologinis jutiklis yra perspektyviausias analizės metodas, kurio dėka galima sumažinti mėginio tūrį, padidinti biocheminių metodų jautrumą bei analizės greitį, matuoti spalvotuose ar neskaidriuose mėginiuose. Biologinis jutiklis yra sudarytas iš dviejų dalių: biologinio atpažinimo elemento ir signalo vertiklio. Biologinio atpažinimo elementas - tai biologinė molekulė, kuri atpažįsta tiriamą analitę, o vertiklis – paverčia tą atpažinimo reakciją išmatuojamu (dažniausiai elektriniu) signalu.
 Fermentiniai analizės metodai išplito labai greitai, dėl paprastos analizės atlikimo procedūros. Pradėjus plisti cukriniam diabetui, mokslininkai gavo naują iššukį, atrasti kaip galima kontroliuoti gliukozės koncentraciją kraujyje. Taip atrasti pirmieji gliukozės biologiniai jutikliai. Iki šių laikų gliukozės oksidazė yra vienas populiariausių fermentų, naudojamų gliukozės biologiniams jutikliams kūrti, nes gliukozės oksidazė yra stabilus, nebrangus ir aktyvus fermentas .
 Darbą sudaro 8 skyriai, 14 paveikslų, 4 lentelės. Literatūros sąraše 24 šaltiniai, 36 lapai.
 Raktiniai žodžiai: biologinis jutiklis, gliukozės oksidazė, signalo vertiklis, biologinis atpažinimo elementas.
 These days, biosensors are used more frequently in biomedicine studies and disease diagnosis. Biosensors are the most promising method of analyzation, which helped decrease the volume of solutions, increase biochemical methods sensitivity, the speed of the analysis, made it possible to measure in colored and opaque solutions. Biosensors are made out of two parts: a biological sensing material and a transducer. Biological sensing material is a biomolecule, which recognizes the target analyte and the transducer turns that reaction into a measurable (mostly electrical) signal.
 Enzyme methods of analysis spread swiftly, because of its simplicity. When diabetes started to spread, scientist got a new challenge, to find out how to control the concentration of glucose in your blood. And then the first glucose biosensors were created. Up until these days glucose oxidase is one of the most popular enzymes that are used to create glucose biosensors, because glucose oxidase is a stable, inexpensive and active enzyme.
 Thesis consists 8 of chapters, 14 pictures, 4 tables, 24 bibliographical entries, 36 sheets.
 Raktiniai žodžiai: biosensor, glucose oxidase, transducer, biological sensing material
 Marius Pijus Mameniškis
 Elektrokatalizinių gliukozės dehidrogenazės, imobilizuotos ant aukso elektrodo, savybių tyrimas
 Baigiamajame darbe buvo tirta gliukozės dehidrogenazė iš Ewingiella americana (GDH) ant aukso elektrodų, naudojant aukso nanodalelių modifikaciją su aromatinių tiolių junginiais. Buvo nustatytos 4-aminotiofenolio, 4-merkaptobezoinės rūgšties, benzimidazol-2-tiolio, benzoksazol-2-tiolio, benzotiazol-2-tiolio ir chinolin-8-tiolio natrio druskos įtaka fermentui prie pH 4,0 ir pH 7,0, tirpaluose su įdėtu (gliukozės) substratu. Pagal gautas fermento skleidžiamas maksimalias elektrochemines sroves ir didelį aktyvumą abiejuose buferiniuose tirpaluose, buvo atrinkti 4-aminotiofenolio ir benzoksazol-2-tiolio junginiai. Juos naudojant, nustatytas fermento aktyvumas, keičiant tirpalo pH. Buvo pademonstruota imobilizuotos gliukozės dehidrogenazės santykinio aktyvumo priklausomybė nuo pH ir atrinktų elektrodų modifikatorių.
 Raktiniai žodžiai: Aukso nanodalelės, biokatalizė, gliukozės dehidrogenazė, tiolio aromatiniai junginiai
 A study of electrocatalytic function of glucose dehydrogenase using gold electrode was performed in this bachelor thesis. Glucose dehydrogenase, extracted from Ewingiella Americana was immobilized on gold electrode, which was modified by gold nanoparticles and aromatic thiol compounds, such as: 4-aminothiophenol, 2-benzimidazolethiol, 2-benzoxazolethione, 4-mercaptobenzoic acid, 2-mercaptobenzothiazol and 8-mercaptoquinoline sodium salt. The impact of these compounds on glucose dehydrogenase was measured at pH 4,0 and pH 7,0. 4-aminothiophenol and 2-mercaptobenzothiazol was selected for further experiment as enzyme showed significant activity in both pH solutions. Final experiment was carried out by slowly changing solution pH and by recording electric current changes with chronoamperometry. The results showed, that enzyme activity dependence on pH may be changed by using aromatic thiol compounds.
 Raktiniai žodžiai: Biocatalysis, glucose dehydrogenase, gold nanoparticles, thiol aromatic compounds
 Žmogaus karboanhidrazės VA raiška ir gryninimas
 Mitchondrinė žmogaus karboanhidrazė VA yra viena iš 15 žmogaus karboanhidrazių izoformų. Žmogaus karobanhidrazė VA katalizuoja grįžtamą CO2 hidrataciją ir yra svarbi biosintezės procesuose žmogaus organizme: ureagenezėje, gliukoneogenezėje, lipogenezėje. CA VA izoforma generuoja bikarbonato jonus, reikalingus šiems procesams. Žmogaus karboanhidrazė VA yra mažai ištirta, nors jos veiklos sutrikimai sukelia įvairias sveikatos problemas, pavyzdžiui, hiperamonemiją. Dėl baltymo svarbos lipogenezėje, plačiau ištyrus CA VA, ją būtų galima panaudoti kaip taikinį nutukimo problemai spręsti. Šio darbo tikslas - išgryninti aktyvų rekombinantinį žmogaus karboanhidrazės VA katalitinį domeną iš E.coli parenkant optimaliausias raiškos ir gryninimo sąlygas.
 Darbą sudaro 6 dalys: įvadas, literatūros apžvalga ,medžiagos ir metodai, rezultatai ir jų aptarimas, išvados, literatūros sąrašas.
 Darbo apimtis – 40 p. teksto be priedų, 16 pav., 6 lent., 40 bibliografiniai šaltiniai.
 Raktiniai žodžiai: karboanhidrazė, žmogaus karboanhidrazė VA, CA VA, raiška, gryninimas
 Mitochondrial human carbonic anhyrase VA is one the 15 human carbonic anhydrase isoforms. It catalyses a reversible hidration of CO2. Human carbonic anhydrase VA is related to several biosynthesis pathways: ureagenesis, gluconeogenesis, lipogenesis. It does so by providing bicarbonate ions required by these pathways. Human carbonic anhydrase VA is not well understood but is known to cause health problems in patients who have this protein dysfunctioning. Due the protein’s role in the lipogenesis pathway, it has been suggested that it could be a drug target to treat people with obesity.
 The goal of this work is to purify an active recombinant human carbonic anhydrase VA catalitic domain from E.coli with the most optimal expression and purification conditions.
 Thesis structure: introduction, literature review, materials and methods, results and discussion, conclussions, references.
 Thesis consist of 40 p. of text without appendixes, 16 pictures, 6 tables, 40 bibliographical entries.
 Raktiniai žodžiai: human carbonic anhydrase VA, carbonic anhydrase, CA VA, expression, purification.
 Pranas Vidutis
 Archėjų Sulfolobus acidocaldarius mutagenezė elektroporacijos pagalba
 Baigiamajame bakalauriniame darbe tiriamas archėjų Sulfolobus acidocaldarius mutagenezės elektroporacijos pagalba efektyvumas. Siekta sukurti kamienus turinčius taw2 arba taw3 metiltransferazes koduojančių genų delecijas. Mutantinių kamienų kūrimas vykdomas dviem skirtingais metodais. Pirmasis metodas paremtas plazmidžių transformacija atliekant elektroporaciją. Homologinės rekombinacijos būdu, plazmidė įsiterpia į chromosomą, o jai pasišalinant iš chromosomos, įvyksta tikslinio geno delecija. Antrojo metodo metu, vykdoma specifinių DNR fragmentų transformacija į S. acidocaldarius. Homologinės rekombinacijos metu įvyksta tikslino geno delecija, o į jo vietą įterpiamas pyrE genas. Eksperimentų metu nustatyta, jog daugiausia kolonijų susiformuoja elektroporacijos metu elektrinio lauko stipriui esant 15kV/cm-1. Transformuojant plazmides, suformuotų kolonijų skaičius stipriai priklauso nuo elektrinių impulsų serijų, daugiausia kolonijų suformuojama impulsams esant 500μs x 1 ir 1ms x 1ms 5 LV. Transformuojant specifinius DNR fragmentus, skirtingos impulsų serijos didelės įtakos kolonijų susiformavimui neturėjo.
 Bakalaurinį darbą sudaro 6 dalys: įvadas, literatūrinė dalis, metodinė dalis, tyrimo rezultatai ir jų aptarimas, išvados, darbe naudotos literatūros sąrašas.
 Darbo apimtis: 41 psl. be priedų, 16 iliustracijų, 7 lentelės, literatūros sąraše- 34 šaltiniai.
 Raktiniai žodžiai: Elektroporacija, taw2 metiltransferazė, taw3 metiltransferazė, Sulfolobus acidocaldarius, pyrE
 In the Final Thesis, the effectiveness of mutagenesis of archaea Sulfolobus acidocaldarius by the electroporation was studied. The aim is to develop specific strains with taw2 or taw3 methyltransferase coding gene deletions. Creation of mutant strains is carried out by two different methods. The first method is based on the transformation of the plasmid by the electroporation. By the homologous recombination, the plasmid is incorporated into the chromosome, and after its excision, the target gene is deleted. The second method is based on the insertion of specific DNA fragments by the electroporation. During the homologous recombination, the deletion of the target gene occurs, and it is replaced with pyrE gene. Experiments showed that the colonies are formed mostly at the electroporation electric field strength at 15kV/cm-1. When transforming plasmids, the number of colonies formed strongly depends on a series of pulse burst, mainly colonies formed when pulses were at 1 x 500?s and 1ms 1ms x 5 LV. When transforming specific DNA fragments, the different of pulse burst did not have a significant impact on colony formation.
 Structure: introduction, theoretical part, material and methods, results and review of results, conclusions, references. Thesis consist of: 41 p. text without appendixes, 16 pictures, 7 tables, 34 bibliographical entries
 Raktiniai žodžiai: Electroporation, Sulfolobus acidocaldarius, taw2 methyltransferase, taw3 methyltransferase, pyrE
 Katažina Platonova
 Grybinės lakazės izofermentų ir tirozinazės specifiškumo flavonoidams ir fenolinėms rūgštims tyrimas
 Oksidoreduktazių klasės fermentai gyvojoje ląstelėje katalizuoja oksidacijos-redukcijos reakcijas. Lakazės tai monomeriniai tarpląsteliniai glikoproteinai, kurie priklauso daugiavarių oksidazių šeimai. Lakazės plačiai paplitusios tarp grybų, augalų ir bakterijų. Šių oksidazių substratai yra aromatiniai junginiai, metalų jonai ir organiniai junginiai. Dauguma grybinių kamienų gali sintetinti po kelis lakazių izofermentus, kurie paprastai skiriasi savo molekuline mase, fizikocheminėmis bei katalitinėmis savybėmis. Tirozinazė tai polifenolinė oksidazė, katalizuojanti fenolių oksidacijos reakcijas. Oksidazės naudojamos lignino degradacijai, dėmių balinimui, bioremediacijoje, biosensoriams ir pan. Lakazės plačiai taikomos įvairiose srityse. Naujų lakazių, pasižyminčių geromis katalitinėmis savybėmis, galinčių oksiduoti įvairius substratus plačiame pH intervale, paieška ir tyrimai yra labai aktualūs.
 Šiame bakalauriniame darbe buvo tirtas grybinės lakazės iš Ulocladium botrytis izofermentų bei tirozinazės specifiškumas flavonoidams ir fenolinėms rūgštims
 Nustatyti Ulocladium botrytis lakazės izofermentų ir tirozinazės kinetiniai parametrai (KM, Vmax), bei apskaičiuotos jų kinetinės konstantos kkat ir koks. UbL1 izofermentas yra specifiškesnis tirtiems substratams nei UbL2. Izofermento UbL2 katalitinis efektyvumas mažesnis nei UbL1. Tirozinazės katalitinis efektyvumas yra mažiausias. Lakazių katalizuojamas oksidacijos procesas efektyvesnis rūgštinėje, o tirozinazės šarminėje pusėje.
 Darbą sudaro šešios dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, rezultatai ir jų aptarimas, apibendrinimas ir literatūros sąrašas. Darbo apimtis – 48 p. teksto, 16 paveikslėlių, 5 lentelės, 35 literatūros šaltiniai.
 Raktiniai žodžiai: fenoliniai junginiai, kinetinės savybės, lakazė, tirozinazė, Ulocladium botrytis.
 Oxidoreductase class enzymes catalyze oxidation-reduction reactions in living cells. Laccases are monomeric extracellular glycoproteins that belong to the copper-containing oxidase family. Laccases are found in many plants, fungi and bacteria. Laccase substrates include aromatic compounds, metal ions and organometallics. Most of fungal strains can synthesize laccase isoforms with different molecular weight, physicochemical and catalytic properties. Tyrosinase is a polyphenolic oxidase, which catalyses phenolic reactions by oxidation. Oxidases are used for lignin degradation, stain bleaching, bioremediation, biosensors and etc. Laccases are widely applied in various fields. Research and discoveries of new types of laccases, having good catalytic properties and being able to oxidize a variety of substrates over a wide pH range, are very important.
 This bachelor thesis provides an investigation of fungal laccase from Ulocladium botrytis isoenzymes and the specificity of tyrosinase with respect to flavonoids and phenolic acids.
 In the process of the thesis, kinetic parameters (KM, Vmax) of Ulocladium botrytis laccase isoenzymes and tyrosinase enzyme have been determined, furthermore, these enzymes kinetic constants kcat ir kox were calculated. UbL1 isoenzyme is more specific than UbL2 for the studied substrates. The catalytic efficiency of UbL2 isoenzyme is lower than that of UbL1. Tyrosinase has the lowest catalytic efficiency. Laccase-catalyzed oxidation process is more effective on the acidic side and the tyrosinase is more effective on the alkaline side. Structure: introduction, literature review, materials and methods, results and discussion, conclusions and literature sources. Thesis consists of: 48 p. of text, 16 pictures, 5 tables, and 35 bibliographical entries.
 Raktiniai žodžiai: phenolic compounds, kinetic properties, laccase, tyrosinase, Ulocladium botrytis.
 Gediminas Plakys
 Kviečių albuminų išskyrimo iš vandens, naudojamo krakmolo gamybos procese, chromatografinio etapo sąlygų parinkimas
 Vienas iš kviečių krakmolo gamybos proceso metu susidarančių šalutinių produktų yra proceso vanduo, kuris šiuo metu utilizuojamas kaip atliekos. Šiame vandenyje lieka ištirpusių vertingų medžiagų, iš kurių svarbiausios – kviečių albuminai, vandenyje tirpūs kviečių baltymai. Dėl perspektyvaus pritaikymo maisto ir farmacijos framonėje, norima kviečių albuminus išskirti iš proceso vandens ir kurti naujus, aukštą pridėtinę vertę turinčius produktus. Šis darbas skirtas parinkti chromatografinio etapo sąlygas kviečių albuminų išskyrimo iš vandens, naudojamo krakmolo gamyboje, procese. Miltų ekstraktas buvo naudojamas kaip proceso vandenį atitinkantis modelis. Tirti šie parametrai: mėginio užnešimo greitis, eliucijos greitis ir užnešamo mėginio pH. Baltymų kiekis po chromatografinio skirstymo gautose frakcijose buvo kontrolinis parametras pagal kurį buvo parenkamos chromatografinio etapo sąlygos. Nustatyta, kad ant 12 ml tūrio sorbento užnešant 100 ml miltų ekstrakto kviečių albuminų išskyrimą geriausia vykdyti šiomis sąlygomis: užnešamo mėginio pH yra 4, mėginio užnešimo greitis – 1,9 cm/min., eliucijos greitis – 4,0 cm/min. Taip pat darbe pateikiami tyrimų metu gauti duomenys apie miltų ekstrakte randamus kviečių albuminus.
 Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, metodika, rezultatai ir jų aptarimas, išvados, literatūros sąrašas.
 Darbo apimtis: 39 p. teksto be priedų, 7 iliustr., 9 lent., 37 bibliografiniai šaltiniai.
 Raktiniai žodžiai: Kviečių baltymai, kviečių albuminai, chromatografija, kviečiai Anotacija (užsienio k.)
 The process water is one of the by-products in starch manufacturing process. At the moment process water is being utilised as waste water. The process water contains valuable soluble components. The most important soluble components that process water contains are water soluble wheat proteins known as wheat albumins. There is an aim to isolate wheat albumins and to create new value added products due to prospective aplications in food and pharmacy industries. The aim of this work was to determine experimental conditions of the chromatographic stage of the wheat albumins isolation from the process water. The flour extract was prepared under laboratory conditions as a model of process water. The conditions that were investigates in this work was the velocity of feeding of the sample, the velocity of elution and sample pH before feeding. Protein concentration was determined in each fraction after the chromatographic separation. According to highest protein concentracion experimental conditions were selected. When 100 mL of sample are applied to 12 mL resin, the suggested conditions that were determined are: sample pH – 4, the velocity of feeding the sample – 1,9 cm/min., the velocity of elution – 4,0 cm/min. Also, there is experimental data about wheat albumins that are found in flour extract.
 Structure: introduction, part of theory, methodology, results and discussion, conclusions, references.
 Thesis consists of: 39 p. text, 7 pictures, 9 tables, 37 bibliographical entries.
 Raktiniai žodžiai: Wheat protein, wheat albumin, chromatography, wheat
 Biokatalizinių magnetinių nanodarinių sintezė ir tyrimas
 Šiame baigiamąjame bakalauro darbe dviem skirtingais metodais buvo susintetintos magnetinės nanodalelės (MND), kurios buvo padengtos auksu trimis skirtingais metodais. Susintetintos MND ir auksu padengtos magnetinės nanodalelės (AuMND) buvo charakterizuotos spektrofotometrijos ir elektrochemijos metodais. Gautos ciklinės voltamperogramos lygintos su aukso nanodalelių cikline voltamperograma. Ant nedengų ir padengtų auksu magnetinių nanodalelių buvo imobilizuota tirpi nuo PQQ priklausoma gliukozės dehidrogenazė (GDH), išskirta iš Acinetobacter calcoaceticus, ir atlikti imobilizuoto fermento aktyvumo tyrimai. Spektrofotometriniu metodu buvo įvertinti natyvios bei imobilizuotos GDH aktyvumai. Parinktas optimalus fermento ir nanodalelių inkubavimo laikas. Nustatyta fermento adsorbuoto ant MND ar AuMND aktyvumo priklausomybė nuo fermento ir MND ar AuMND santykio inkubavimo mišinyje bei įvertintas fermento adsorbcijos efektyvumas ir adsorbuoto fermento nusiplovimas. Nustatyti natyvios ir adsorbuotos GDH kinetiniai parametrai. Darbą sudaro 7 dalys: paveikslų ir lentelių sąrašas, įvadas, literatūros apžvalga, medžiagos, įranga ir metodai, rezultatai ir jų aptarimas, išvados ir literatūros sąrašas.
 Darbo apimtis: 45 p. teksto, 13 pav., 8 lent., 60 bibliografiniai šaltiniai.
 Raktiniai žodžiai: gliukozės dehidrogenazė, magnetinės nanodalelės, auksu dengtos magnetinės nanodalelės, magnetitas, maghemitas
 This bachelor thesis focuses on the synthesis of magnetic nanoparticles (MNP) using two different methods, which were covered with gold by three different methods. Synthesized MNP and gold coated magnetic nanoparticles (AuMNP) were characterized by spectrophotometry and electrochemistry methods. The resulting cyclic voltammograms were compared to gold nanoparticles cyclic voltammogram. Soluble PQQ dependent glucose dehydrogenase (GDH) from Acinetobacter calcoaceticus was immobilized on uncoated and gold coated magnetic nanoparticles and investigation of immobilized enzyme activity was made. Activities of native and immobilized GDH was evaluated by spectrophotometric method. Optimal incubation time of enzyme and nanoparticles was determined. Enzyme adsorbed on MNP or AuMNP activity dependence on enzyme and MNP or AuMNP ratio in incubation mixture was found, also the ablution of adsorbed enzyme and the adsorption efficiency of the enzyme was evaluated. Moreover, kinetic parameters of native and adsorbed GDH was identified.
 Structure: list of figures and tables, introduction, literature review, materials, equipment and methods, results and discussion, conclusions and references.
 Thesis consists of: 45 p. of text, 13 figures, 8 tables, 60 bibliographical entries.
 Raktiniai žodžiai: glucose dehydrogenase, magnetic nanoparticles, gold-coated magnetic nanoparticles, magnetite, maghemite
 Rapolas Jamontas
 Fermentų, dalyvaujančių modifikuotųjų uridinų skaidyme, tyrimas
 RNR funkcijų gausa ir jų specifiškumas molekulei neleidžia apsiriboti kanoniniais nukleozidais, tarp jų ir uridinu. RNR nukleotidai specializuojami atliekant potranskripcines modifikacijas, kurias vykdo ląstelėse esantys fermentai. Kanoninių nukleozidų katabolizmas yra gan plačiai ištirtas, tačiau apie modifikuotųjų skaidymo kelius ir juose dalyvaujančius fermentus žinoma nedaug. Šiame darbe tirti fermentai, susiję su modifikuotų uridino darinių skaidymu. Vienas jų – E. coli pirimidinų oksigenazė RutA, katalizuojanti pirimidino žiedo atidarymą. Tikrinta, ar šis fermentas gali kaip substratą panaudoti modifikuotąją heterociklinę bazę 2-tiouracilą. Kiti du darbe tirti baltymai buvo atrasti metagenominėje bibliotekoje. Tai – viename operone koduojami į deoksiribozės aldolazę ir nukleozidų hidrolazę panašūs fermentai. Darbo metu pademonstruota, jog pirmasis operone koduojamas fermentas neatlieka tokios pačios funkcijos ląstelėje kaip E. coli 2-deoksi-D-ribozės-5-fosfato aldolazė DERA. Taip pat įsitikinta, jog antrasis fermentas yra nukleozidų hidrolazė gebanti nutraukti 2'-O-metiluridino N-glikozidinį ryšį, susidarant uracilui. Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, tyrimo priemonės ir metodai, tyrimo rezultatai ir jų aptarimas, išvados, literatūros sąrašas. Darbo apimtis – 49 p. teksto be priedų, 17 iliustr., 9 lent., 48 bibliografiniai šaltiniai.
 Raktiniai žodžiai: Prasminiai žodžiai: RutA, nukleozidų hidrolazė, deoksiribozės aldolazė, 2'-O-metiluridinas, 2-tiouridinas, modifikuotieji nukleozidai, uridinas.
 RNA specificity and the abundance of its functions does not confine itself to the canonical nucleosides. Uridine is not an exception. The nucleosides of RNA are modified post-transcriptionally by cellular enzymes. The catabolism of canonical nucleosides is widely researched, however much less is known about the fate of modified nucleosides.
 In this study, enzymes that are possibly related to the catabolism of modified uridine derivatives were investigated. The first enzyme was the pyrimidine oxygenase RutA from E. coli. It catalyses the opening of the pyrimidine ring. It was investigated whether a modified heterocyclic base 2-thiouracil could be used as its substrate instead of uracil. The other two proteins were coded in a single operon that was previously discovered in a metagenomic library. Their gene sequences were found to be similar to those of deoxyribose aldolases and nucleoside hydrolases. This research showed that the aldolase enzyme does not act the same as an E. coli 2-deoxy-D-ribose-5-phosphate aldolase DERA in vivo. It was also proven that the hydrolase enzyme is indeed a nucleoside hydrolase that is able to cleave the N-glycosidic bond of 2'-O-methyluridine forming uracil in the process.
 Structure: introduction, analysis of literature, materials and methods, results and discussion, conclusions, references. Thesis consist of: 49 p. text, 17 pictures, 9 tables, 48 bibliographical entries.
 Raktiniai žodžiai: RutA, nucleoside hydrolase, deoxyribose aldolases, 2'-O-methyluridine, 2-thiouracil, modified nucleosides, uridine.
 Grėta Grakauskaitė
 Pelėno rekombinantinio prioninio baltymo sintezė
 Baigiamajame bakalauro darbe nagrinėjamas pelėno rekombinantinis prioninis baltymas, ląstelių auginimo ir baltymo sintezės sąlygų optimizavimas.
 Šiame darbe buvo tiriamos optimalios mitybinės sąlygos, kurioms esant santykinis baltymo kiekis gaunamas didžiausias.
 Darbo metu atlikta plazmidinės DNR, su įklonuotu BvPrP23-231 pelėno baltymą koduojančiu genu, transformacija, augimo sąlygų optimizavimo tyrimas naudojant minimalią M9 druskų mitybinę terpę su E. Coli BL21 kamienu, auginimo su gliukozės primaitinimu tyrimas ir augimo sąlygų optimizavimo tyrimas su BvPrP23-231 plazmide. Taip pat atliktas raiškos įvertinimas baltymų elektroforezės metu ir gautų duomenų apdorojimas „Mathcad“ programa.
 Išnagrinėjus gautus duomenis, buvo gauta, jog didžiausia baltymo išeiga iš gliukozės gauta, kai indukuota esant 0,6 O.V. ir pradinė gliukozės koncentracija 0,3 %. Auginant su papildomu gliukozės pamaitinimu, didžiausia baltymo išeiga iš gliukozės gauta, kai indukuota esant 1 O.V ir pradinė gliukozės koncentracija 0,05 %. Didžiausia baltymo išeiga iš NH4Cl gauta, kai indukuota esant 1 O.V. ir pradinė NH4Cl koncentracija 0,06 %.
 Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, metodinė dalis, rezultatai ir jų aptarimas, išvados ir naudotos literatūros šaltiniai.
 Darbo apimtis – 38 p. teksto be priedų, 19 iliustracijų, 6 lentelės, 31 bibliografiniai šaltiniai.
 Raktiniai žodžiai: prionai, kamienai, tarprūšinis barjeras, pelėno prioniniai baltymai, rekombinantinė technologija.
 Vole recombinant prion protein, conditions optimization of cell culturing and protein synthesis was investigated in the final thesis.
 In this work it was investigated the optimal nutrition conditions in which a relative maximum amount of protein could be produced.
 In this work was carried out transformation of plasmid DNA with cloned BvPrP23-231 voles protein encoding gene, study of optimal growth conditions using minimal M9 nutrition medium with E. Coli Bl21 strain, study of growth with a glucose fed–batch and analysis of optimal growth conditions with BvPrP23-231 plasmid.
 It was found that the biggest amount of protein yield by glucose was when induction was carried out at 0,6 OD and initial gluocose concentration was 0,3 %. Growing with glucose fed–batch gave also great amount of protein yield when induction was carried out at 1 OD and initial gluocose concentration was 0,05 %. The highest amount of protein yield by NH4Cl was when induction was carried out at 1 OD and initial NH4Cl concentration was 0,06 %.
 Structure: introduction, literature review, methodology, results and discussion, conclusions and suggestions, references. Thesis consist of: 38 p. text without appendixes, 19 pictures, 6 tables, 31 bibliographical entries.
 Raktiniai žodžiai: prions, strains, species barrier, vole prion protein, recombinant technology.
 Ląstelių mikroaplinkos vaidmuo žmogaus storosios žarnos karcinomos HT29 linijos ląstelių atsakui į chemoterapinio agento 5-fluorouracilo poveikį
 Vėžinių ląstelių savybės priklauso ne tik nuo heterogeniškos naviko ląstelių populiacijos, bet ir nuo jas supančios mikroaplinkos struktūros ir standumo. Šio darbo tikslas buvo sukurti 3D modelinę žmogaus storosios žarnos karcinomos HT29 linijos ląstelių sistemą in vitro, tam naudojant sintetinį polimerą metilceliuliozę. Darbo metu buvo nustatyta aplinkos standumo įtaka HT29 ląstelių morfologijai, proliferacijai bei genų raiškai, pakeitus šių ląstelių auginimo sąlygas iš 2D į 3D. Taip pat buvo nustatyta, kad HT29 ląstelių išgyvenamumas po poveikio chemoterapiniu agentu 5-fluorouracilu yra didesnis erdvinėse (3D) nei monosluoksnio (2D) ląstelių kultūrose. Raktiniai žodžiai: HT29, 2D ir 3D modelinė sistema, metilceliuliozė, standumas, 5-fluorouracilas.
 Cancer cells characteristics depend not only on heterogeneous tumor cells population, but also on the surrounding microenvironment structure and stiffness. The aim of this reaseach was to develop a 3D cell culture system of human colon carcinoma cell line HT29 in vitro, using a synthetic polymer methylcellulose. This research revealed that changing the cell culture conditions from two-dimensional (2D) to 3D cell culture format alter environmental stiffness and induce changes in HT29 cell morphology, proliferation and gene expression. Moreover, the exposure of HT29 cells to chemotherapeutic agent 5-fluorouracil revealed that the survival increased in 3D cell culture, as compared to the traditional two-dimensional (2D) monolayer cell culture systems.
 Raktiniai žodžiai: HT29, 2D and 3D cell culture systems, methylcellulose, stiffness, 5-fluorouracil.
 Arnoldas Matulevičius
 Sidabro nanodalelių citotoksiškumo vertinimas ląstelėms, naudojant Ramano spektroskopiją
 Šio bakalaurinio darbo tikslas – susintetinti sidabro nanodaleles (AgNd), naudojant augalų ekstraktus, ir ištirti jų citotoksiškumą eukariotinėms ląstelėms, naudojant Ramano spektroskopiją. Iš augalų (beržų ir pienių žiedų bei dilgėlių lapų) ekstraktų susintetintos sidabro nanodalelės. Tiriant AgNd optines savybes, gauti skirtingi sugerties spektrai patvirtino, kad sidabro nanodalelės yra įvairaus dydžio. Prašviečiančiu elektroniniu mikroskopu nustatyta, kad AgNd dydis siekia 5–80 nm, dauguma jų turi ovalo, sferinę ir daugiabriaunę formas.
 Gyvybingumo tyrimai teigia, kad AgNd toksiškai veikia mielių Saccharomyces cerevisiae ląsteles. Didžiausiu citotoksiškumu pasižymėjo AgNd, susintetintos naudojant pienių žiedų ekstraktą. Ląstelių gyvybingumas po 24 valandų siekė 29,88 % ± 1,03. Naudojant difuzijos į agarą metodą buvo nustatyta, kad mielių ląstelės jautrios susintetintoms AgNd. Atlikus Ramano spektroskopijos tyrimą buvo įsitikinta, kad paveikus AgNd mielių ląsteles, keičiasi ląstelių sienelės struktūra ir cheminės sudėtis.
 Raktiniai žodžiai: mielės, Saccharomyces cerevisiae, sidabro nanodalelės (AgNd), UV–RŠ spektroskopija, paviršiaus plazmonų rezonansas, Ramano spektroskopija.
 The aim of this work was to synthesize silver nanoparticles (AgNPs) by using different plant extracts and to evaluate they cytotoxicity on eukariotic cells using Raman spectroscopy. Silver nanoparticles were synthesized by biological synthesis using birch blossom, dandelion blossom and nettle leaves extracts. The optical properties of silver nanoparticles have been investigated by using UV–Visible spectroscopy. By the different absorption spectrums obtained, it was confirmed that various sizes of silver nanoparticles were produced. By using transmission electron microscopy (TEM) it was found that AgNPs obtained by using different plant extracts sizes ranging from 5 nm to 80 nm. The majority of silver nanoparticles was found to have an oval, spherical and polyhedral shapes.
 Yeast Saccharomyces cerevisiae viability was tested by using control number of cells monitoring changes in the number of cells in time and methylene blue dye. The results showed that the highest citotoxic activity against Saccharomyces cerevisiae had AgNPs synthesized by using dandelion blossom extract – after 24 hours cells viability was 29,88 % ± 1,03. Using the agar well diffusion method, it was found that yeast Saccharomyces cerevisiae cells are sensitive to synthesized silver nanoparticles. Raman spectroscopy results proved that after the affection of AgNPs on the yeast cells the changes in cell wall structure and chemical composition were made.
 Raktiniai žodžiai: yeast, Saccharomyces cerevisiae, silver nanoparticles (AgNp), UV–Vis spectroscopy, surface plasmon resonance, Raman spectroscopy.
 Agnė Kriaučiūnaitė
 Alksnių džiūtį sukeliančių Phytophthora rūšių įvairovės tyrimai
 Phytophthora genties augalų patogenai sukelia nemenką žalą natūralioms ekosistemoms. Šiai genčiai priskiriamas ir alksnių džiūtį sukeliantis mikroorganizmas Phytophthora alni s. l. Lietuvoje alksnių fitoftorozės sukėlėjas yra mažai ištirtas: neaiški ligą sukeliančių mikroorganizmų įvairovė, jų pasiskirstymas bei virulentiškumas (agresyvumas). Baigiamojo bakalauro darbo metu buvo atlikti Phytophthora rūšinės įvairovės, aptinkamos alksnių dirvožemyje, bei APU (P. x alni, P. plurivora, P. uniformis) patogenų grupe užkrėstų juodalksnių sėjinukų virulentiškumo tyrimai. Atlikti patogenų izoliavimo, mikroorganizmų atrinkimo mikroskopine analize, DNR išskyrimo iš grynųjų patogenų kultūrų, dirvožemio ir šaknų, polimerazinės grandininės reakcijos sąlygų optimizavimo, kokybinio virulentiškumo įvertinimo, DNR sekų analizės darbai. Nustatyta, jog iš 130 izoliatų, alksnių dirvožemyje vyrauja 8 grybų rūšys, tačiau nei viename neaptikta Phytopthora gentis. Virulentiškumo testas patvirtino APU patogenų grupės agresyvumą juodalksnių sėjinukams. Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, įranga, medžiagos ir metodai, rezultatai ir jų aptarimas, išvados, literatūros sąrašas. Darbo apimtis – 46 p. teksto be priedų, 11 paveikslai, 6 lentelės, 76 bibliografiniai šaltiniai.
 Raktiniai žodžiai: Alnus spp. dirvožemis, P. x alni, P. uniformis, P. plurivora, mikroorganizmai, oomicetai, grybai, virulentiškumo testas, izoliavimas, identifikavimas.
 Phytophthora is genus of plant patogens responsible for worldwide damage to naturals ecosystems. Phytophthora alni s. l. is a causal agent of alder decline. In Lithuania little is known about this disease: diversity and distribution of microorganisms and their virulence to alder trees. The aim of this thesis was identification of Phytophthora species in alder rizosphere soil and virulence test of APU (P. x alni, P. plurivora, P. uniformis) patogen group in black alder seedlings. In this study isolation of pathogens, selection of isoliates by morphological-microscopy analise, DNA extraction from, microorganism cultures, rizosphere soil and roots, polymerase chain rection optimisation, quantification virulence assessment and DNA sequences analysis were performed. During the reseach 130 samples were isolated, no Phytophthora isolates were identified. In total 8 fungi were observed. Virulence test confirme APU patogen group aggressiveness for black alder seedlings.Structure: introduction, literature, equipment, materials and methods, results and discussion, conclusions, references.Thesis consist of: 46 p. text without appendixes, 11 pictures, 6 tables, 76 bibliographical entries.
 Raktiniai žodžiai: Alnus spp. rizosphere, P. x alni, P. uniformis, P. plurivora, microorganisms, Oomycetes, Fungi, virulence test, isolation, identification.
 Eco88I restrikcijos endonukleazės gryninimo technologijos tobulinimas
 Restrikcijos endonukleazės – tai fermentai, kurie atpažįsta specifines DNR grandinės sekas ir hidrolizuoja kovalentinį ryšį. Šie fermentai yra plačiai naudojami genų klonavimo bei DNR modifikavimo eksperimentuose. Iš grubaus ląstelinio ekstrakto šie baltymai yra gryninami chromatografiniu metodu. Gryninimo metu iš preparato turi būti pašalintos nespecifinės egzo- ir endonukleazės ir gaunamas funkciškai specifiškas fermentas. Darbo objektu pasirinkta rekombinantinė restrikcijos endonukleazė Eco88I, kurios gryninimo procesas yra sudėtingas dėl didelio chromatografinių stadijų skaičiaus. Procesas užtrunka ilgai, o produktas ne visada atitinka kiekybės ir kokybės reikalavimus.
 Darbo metu atlikta sorbentų analizė, parinktos chromatografinio gryninimo sąlygos. Eco88I gryninimo schema sutrumpinta iki keturių chromatografinių stadijų, išvengta nukleorūgščių išsodinimo ir baltymų išsodinimo stadijų. Produkto išeiga padidinta 10 kartų, o gautas preparatas atitinka visus kokybės testų reikalavimus.
 Darbo apimtis 59 p. teksto be priedų, 28 paveikslėliai, 7 lentelės, 24 bibliografiniai šaltiniai. Raktiniai žodžiai: Chromatografija, Eco88I, restrikcijos endonukleazė, pseudo-giminingumo, sorbentas.
 Restriction endonucleases are enzymes that recognize specific DNA sequences and hydrolyze covalent bonds. These enzymes are widely used in gene cloning and DNA modification experiments. Restriction endonucleases are purified by chromatographic techniques from crude cell extract, non-specific exo- and endonucleases are removed during the process to obtain functionally-specific enzymes.
 The purification process of recombinant restriction endonuclease Eco88I is complicated due to the large number of chromatographic steps. The process takes a long time and the product does not always meet the requirements in terms of quantity and quality.
 In our study we performed analysis of sorbents and selected conditions for individual chromatographic purification step. Eco88I purification process was reduced to four chromatographic steps and the precipitation of nucleic acids and proteins was avoided. Yield of the product was increased by 10 times and the purified enzyme meets all quality requirements.
 Thesis consists of: 59 p. without appendixes, 28 pictures, 7 tables and 24 bibliographical entries.
 Raktiniai žodžiai: Chromatography, Eco88I, restriction endonuclease, pseudo-affinity, resin. Žilvinas Daučionas
 Restrikcijos endonukleazių gryninimo technologijų tobulinimas
 Daugumos analizuotų restrikcijos endonukleazių chromatografinio gryninimo technologijos sukurtos dar prieš 20 metų, naudojant naujausius to laikmečio sorbentus. Patobulėjus chromatografinio gryninimo technologijoms, atsiradus pažangesniems sorbentams, atsirado galimybė sukurti efektyvesnes gryninimo schemas. Darbo tikslas: pakeisti ir optimizuoti restrikcijos endonukleazių, kurių gryninimo schemose yra seni dažiklių-ligandų sorbentai, chromatografinio gryninimo technologijas. Ieškant alternatyvų šiuo metu naudojamiems sorbentams, analizuotas panašiomis sorbcinėmis savybėmis pasižymintis dažiklių-ligandų sorbentas. Patikrintas pastarojo sorbento tinkamumas 17 restrikcijos endonukleazių. Optimizuotos trijų restrikcijos endonukleazių gryninimo schemos. Nustatyta gryninimo schemų keitimo įtaka fermentiniam stabilumui.
 Darbą sudaro septynios dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, eksperimentų rezultatai ir jų aptarimas, išvados, padėka ir literatūros sąrašas. Darbo apimtis – 70 p. teksto be priedų, 32 iliustr., 4 lent., 63 bibliografiniai šaltiniai, 3 priedai.
 Raktiniai žodžiai: chromatografija, fermentinis aktyvumas, gryninimas, restrikcijos endonukleazė, sorbentai.
 The majority of studied restriction endonucleases purification technologies were developed more than 20 years ago and were based on the properties of sorbents available at the time. Nowadays chromatographic purification is more advanced and a variety of different sorbents could be adapted for more efficient protein purification. The main aim of this technology improvement was to find the replacement for currently used dye-ligand sorbents and to optimize enzyme purification schemes. In order to fulfill the task, the most common sorbent having similar properties were investigated. Suitability of selected sorbent was tested in purification process of 17 restriction endonuclease enzymes. Chromatographic purification techniques of three restriction endonucleases were optimized. Furthermore, the influence of modified chromatographic purification scheme on purified enzyme stability was studied.
 Thesis consist of: 70 p. text without appendixes, 32 pictures, 4 tables, 63 bibliographical entries, 3 appendixes.
 Raktiniai žodžiai: chromatography, enzyme activity, purification, restriction endonuclease, sorbent.
 Simonas Baronas
 Fosfoceliuliozės sorbento, naudojamo chromatografijoje, gamybos technologijos tobulinimas
 Fosfoceliulioziniai sorbentai dažnai naudojami jonų mainų chromatografijoje bei tokių baltymų kaip kinazės, endonukleazės, nukleazės gryninime. Jonitai su celiuliozinėmis matricomis pasižymi stipria jonine sąveika su baltymais, nes hidrofobinės ir kitos ne joninės sąveikos tarp sorbento ir baltymo yra mažos. Šio magistrinio darbo tikslas – patobulinti P11 fosfoceliuliozės gamybos technologiją. Darbo metu pastebėta, kad didžiausią įtaką fosfatų (fosforo rūgšties liekanų) kiekiui fosfoceliulioziniuose sorbentuose turi vandens kiekis fosforilinimo reakcijos mišinyje. Taip pat, parinktas geriausiai fosfoceliuliozinių sorbentų gamybai tinkantis karbamidas. Eksperimentiniai sorbentai charakterizuoti ir palyginti su šiuo metu naudojamu, nustatyti šių sorbentų privalumai ir trūkumai.
 Darbo apimtis 54 p. teksto be priedų, 40 paveikslėliai, 4 lentelės, 31 bibliografiniai šaltiniai.
 Raktiniai žodžiai: Fosfoceliuliozė, chromatografija, fosforilinimas, fosfatų kiekis
 Cellulose phosphate resins are often used in ion exchange chromatography for purification of enzymes such as kinase, endonuclease, exonuclease. Cellulose matrix ion exchangers exhibit strong ionic interaction with the protein since hydrophobic and other non-ionic interactions between the resin and the protein are weak. The aim of this study is to improve the technology of cellulose phosphate production. Produced cellulose phospate resins were characterized, their properties compared with currently used resin. The most suitable urea was selected for cellulose phosphate production. Moreover, we observed that water content in phosphorylation reaction mixture has greatest influence on quantity of phosphoric acid residue in cellulose phosphate resin. Thesis consists of: 54 p. without appendixes, 40 pictures, 4 tables and 31 bibliographical entries.
 Raktiniai žodžiai: Cellulose phosphate, chromatography, phosphorylation, quantity of phosphates Gertrūda Šeškutė
 Fermentų sistemų, imobilizuotų ant nanostruktūrizuotų paviršių, elektrocheminio aktyvumo pH profilių tyrimas
 Baigiamajame magistro darbe buvo susintetintos trys tiesioginės elektronų pernašos principu veikiančios Ewingella americana gliukozės dehidrogenazės bioelektrokatalitinės sistemos, sudarytos iš aukso nanodalelių, dengtų 4-aminotiofenoliu (4-ATF), 4-merkaptobenzoine rūgštimi (4-MBR) ir šių tiolinių junginių mišiniu, ir ištirta fermentų elektrocheminio aktyvumo priklausomybė nuo buferinio tirpalo joninės jėgos ir pH. Sistemų elektrocheminis aktyvumas buvo tiriamas 10 mM ir 50 mM joninės jėgos buferiniuose tirpaluose,o pasirinktas buferinių tirpalų pH 3–8 . Atlikus tyrimą nustatyta, kad elektrodo paviršiaus modifikavimas 4-ATF ir 4-MBR bei šių medžiagų mišiniu ir darbinio tirpalo joninė jėga daro įtaką biokatalitinės srovės stiprio priklausomybei nuo buferinio tirpalo pH. Pastebėta, kad sistemos, kuriose aukso nanodalelės buvo modifikuotos 4-ATF, generavo didesnes biokatalitis sroves, nei sistemos, kurių modifikavimui buvo naudota 4-MBR ir tiolinių junginių mišinys. Iš analizavus gautas srovės stiprio priklausomybes nuo buferinio tirpalo pH buvo pastebėta, kad šios priklausomybės buvo labiau išreikštos matavimus atliekant 50 mM joninės jėgos buferiniuose tirpaluose, tačiau sistemos, kuriose aukso nanodalelės modifikuotos 4-ATF ar 4-MBR didesnę biokatalitinę srovę generuoja 10 mM joninės jėgos buferiniuose tirpaluose. Be to, mažesnės joninės jėgos buferiniuose tirpaluose visos trys sistemos efektyviai veikė pH 3-5 aplinkoje. Raktiniai žodžiai: gliukozės dehidrogenazė, bioelektrokatalitinės sistemos, tiesioginė elektronų pernaša, elektrocheminio aktyvumo priklausomybė nuo pH, buferinio tirpalo joninė jėga
 In master thesis three direct electron transfer based Ewingiella americana glucose dehydragenase bioelectrocatalitic systems consisting of gold nanoparticles, coated with 4-aminothiophenol (4-ATP), 4-mercaptobenzoic acid (4-MBA), and mixture of these thiol compounds, were synthesized and enzyme electrochemical activity dependence on the buffer solution pH and ionic strength were investigated. Electrochemical activity of the systems was determined using 10 mM and 50 mM ionic strength buffer solutions pH 3-8. The results showed, that electrochemical activity dependence on the buffer solution pH has been influenced by surface modification using 4-ATF and 4-MBA, and ionic strength of buffer solution. It was observed, that systems generated higher biocatalytic currents, when gold nanoparticles was modified with 4-ATP. Analysis of electrochemical activity dependence of buffer solution pH showed that this dependence was more pronounced when measurments were perforemed in 50 mM ionic strength buffer solutions. However, systems where gold nanoparticles was modified only with 4-ATP or 4-MBA generated higher biocatalytic currents in 10 mM ionic strength working solutions. Also all three systems effeciently operated in an acidic pH range, when buffer solution ionic strength was 10 mM. Raktiniai žodžiai: glucose dehydrogenase, bioelectrocatalytic systems, direct electron transfer, electrochemical activity dependence on pH, buffer solution ionic strength
 Anželika Lopato
 Žymėtų krienų pereksidaze antikūnų, specifinių vištų imunoglobulinams Y, paruošimas ir jų pritaikymas imunofermentinėje ir imunobloto reakcijoje
 Baigiamajame magistro darbe nagrinėjamas imunotechnologinių metodų pritaikymas diagnozuojant Niukaslio ligą. Nuo 1926 metų paplitusi paukščių patogeninė virusinė liga iki šiol yra didelė problema tiek ekonomiškai išsivysčiusioms, tiek trečiojo pasaulio šalims.
 Niukaslio ligos virusas gali būti panaudotas kaip antigenas įvairiuose serologiniuose tyrimuose. Šiuo metu tradiciniai testai sėkmingai pakeičiami imunofermentiniu metodu. Baigiamojo darbo metu nagrinėjamas imunofermentinei sistemai sukurti tinkamo konjugato – specifinių vištų imunoglobulinams Y antikūnų, paruošimas ir jų konjugavimas su krienų peroksidaze, virusinio antigeno paruošimas ir plokštelės padengimas, kitų imunofermentinio metodo etapų sąlygų parinkimas: plovimo, stabdymo, blokavimo buferių bei kontrolinių serumų darbinių titrų parinkimas. Pateikiamas imunofermentinio metodo pagrindu diagnostinės sistemos, tinkančios aptikti Niukaslio ligos virusui specifinius antikūnus infekuotų vištų serumuose, sukurimas ir technikos atidirbimas. Išnagrinėjus teorinius ir praktinius aspektus, pateikiamos baigiamojo darbo išvados ir siūlymai. Darbą sudaro šešios dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, rezultatai ir jų aptarimas, išvados, literatūros sąrašas.
 Darbo apimtis – 73 p. teksto be priedų, 30 iliustr., 14 lent., 53 bibliografiniai šaltiniai.
 Raktiniai žodžiai: Niukaslio liga, imunoglobulinai Y, krienų peroksidazė, Niukaslio ligos virusas, imunofermentinė analizė
 The purpose of this paper work is the application of immune technologies in Newcastle disease diagnosis. A common birds pathogenic viral disease is a major problem both economically developed and pour countries since 1926.
 Newcastle disease virus can be used as an antigen in various serological tests. Nowadays more and more tests are successfully replaced by enzyme immunoassay. During this paper work a production of appropriate antibodies, conjugated with horseradish peroksidase, wich are specific to chickens immunoglobulins Y, viral antigen preparation and plate coating, selection of wash buffer, bloking buffer, ant control serum titre is examined. The enzyme immunoassay based diagnostic system, suitable for the detection of Newcastle disease virus specific antibodies in sera from infected hens and technology work-off is presented. After the theoretical and practical aspects, conclusions and recommendations are given.
 This thesis consists of the introduction, review of the literature, materials and methods, results and discussions, conclusions, references.
 This thesis consists of 73 pages without appendixes, 30 pictures, 14 tables, 53 bibliographical entries.
 Raktiniai žodžiai: Newcastle disease, immunoglobulins Y, horseradish peroxidase, Newcastle disease virus, enzyme-linked immunoassay
 Viktorija Voitovič
 Fizikocheminių metodų pritaikymas biotechnologinių produktų kokybei užtikrinti
 dr. Saulius Serva
 Šiuo metu platus biotechnologinių produktų naudojimas reikalauja turėti jų kokybę užtikrinančias sistemas. Vieni iš kokybės vertinimo parametrų – funkciniai testai. Tai metodai, kurių tikslas yra išmatuoti sistemos funkcinių komponentų kokybę. Viena iš biotechnologinių produktų grupių, kurios kokybė yra tikrinama atliekant funkcinius testus, yra magnetinių dalelių nukleorūgščių gryninimo rinkiniai. Platus šių rinkinių pritaikymas suteikia galimybę išgryninti nukleorūgštis iš įvairių šaltinių. Kadangi biologinių šaltinių įvairovė yra didelė (pienas, kraujas, augalai, ląstelės ir kt.), todėl gryninimo rezultatai gali varijuoti. Taip pat funkcinis testavimas reikalauja specifinių darbuotojo įgūdžių, trunka ilgai (1–5 dienos) ir kartais neparodo svarbių išgrynintos nukleorūgšties kokybei parametrų – priemaišų. Darbo metu pasiūlyta išspręsti šią problemą pritaikant fizikocheminius metodus tirpalų kokybei užtikrinti. Atlikti eksperimentai parodė, kad dauguma reagentų gali būti apibūdinami pagal fizikocheminius parametrus – pH, laidumą, tankį ir lūžio rodiklį. Įrodytas fizikocheminių metodų panaudojimo tirpalų kokybei užtikrinti tinkamumas bei pranašumas prieš funkcinius testavimo metodus.
 Darbą sudaro septynios dalys: įvadas; literatūros apžvalga; medžiagos ir metodai; rezultatai ir jų aptarimas; išvados; padėka bei literatūros sąrašas.
 Darbo apimtis – 71 p., 17 paveikslų, 21 lentelė, 71 bibliografinis šaltinis, 1 priedas.
 Raktiniai žodžiai: fizikocheminiai metodai, funkciniai testai, nukleorūgščių gryninimo rinkiniai
 Extensive use of the biotechnology products requires having precise quality assurance systems. Often quality of the product is assessed by performing functional tests. The quality of such biotechnology products as nucleic acid purification kits is tested by functional tests. Magnetic bead-based nucleic acid isolation kits allow extracting nucleic acid from various sample sources including cells, tissues, blood, and cell-free media. However, due to its applicability to extract nucleic acids from diversity of sources, the purification yield varies depending on the source. Performing complexed functional tests requires specific employee skills, the process is time-consuming and these tests do not always indicate the presence of impurities in the solutions.
 The purpose of this work is to solve the magnetic bead-based nucleic acid purification kits solutions quality assurance problem by adapting physicochemical methods. Experiments indicated that most of the reagents can be characterized by the physicochemical parameters such as pH, conductivity, density and refractive index. The suitability of these physicochemical methods for quality assurance of the kit solutions was analyzed and their advantages over functional testing described.
 Raktiniai žodžiai: physicochemical methods, functional tests, nucleic acid purification kits
 Erika Beliavciv
 Baltymų konjugavimo su magnetinėmis dalelėmis tyrimai
 RNR naudojama įvairiuose tyrimuose biotechnologijos, genetikos, biochemijos, medicinos ir kitose srityse, atliekant atvirkštinės transkripcijos polimerazinę grandininę reakciją, genų raiškos tyrimus ir t.t. Darbas su RNR reikalauja švaros ir atsargumo, nes RNR yra linkusi degraduoti. Pagrindinė RNR degradavimo priežastis – RNazės. Yra žinoma būdų, kaip iš tirpalų pašalinti RNazes, tačiau jie ilgai užtrunka, yra sudėtingi, brangūs ir ne visada veiksmingi. Ypač sunku ribonukleazes pašalinti iš baltyminių tirpalų. Ribonukleazių inaktyvavimui dažnai naudojami ribonukleazių slopikliai, kurie susijungdami su ribonukleazėmis slopina jų veiklą, tačiau po inaktyvacijos tirpale lieka slopiklio priemaišos, kurios gali trukdyti tolimesniam darbui su baltymais. Vienas iš būdų išvengti šių priemaišų yra konjuguoti ribonukleazių slopiklį su magnetinėmis dalelėmis. Konjuguotam slopikliui specifiškai susirišus su ribonukleazėmis, magnetinės dalelės kartu su slopikliu ir RNazėmis pašalinamos iš baltyminių tirpalų magneto pagalba nepaliekant papildomų priemaišų. Baigiamojo magistro darbo metu buvo parinktas tinkamas konjugavimui ribonukleazių slopiklis ir konjuguotas su magnetinėmis dalelėmis. Darbo metu tirtas konjugavimas su skirtingas funkcines grupes turinčiomis magnetinėmis dalelėmis, optimizuotas konjugavimo procesas ir atrinktas daugiausiai ribonukleazių surišantis slopiklio ir dalelių konjugatas.
 Raktiniai žodžiai: ribonukleazės, ribonukleazių slopiklis, RNR, magnetinės dalelės, konjugavimas.
 In biotechnology, genetics, biochemistry, medicine and other fields, RNA is used in the reverse transcription polymerase chain reaction, gene expression studies and etc. RNA tends to easily degrade therefore work with it should be careful and clean. Main cause of RNA degradation are RNases. There are known several ways how to remove RNases from solutions, but they are long-lasting, complex, expensive and not always effective. It is extremely difficult to remove ribonucleases from protein solution. Commonly RNase inhibitors are used to inactivate RNases, but after RNase inactivation inhibitor impurities remains in solution and afterwards these impurities can interfere further work with proteins. One way to avoid these impurities is to conjugate ribonucleases inhibitor with magnetic beads. After specific binding of inhibitor with RNases, magnetic beads together with inhibitor and RNases are separated from protein solutions using magnetic field. This approach allows to avoid of remaining contaminants in protein solution. In the master thesis suitable RNase inhibitor was selected and conjugated with magnetic beads. Conjugation of inhibitor with magnetic beads containing different functional groups was investigated, optimal conjugation conditions determined and magnetic bead and inhibitor conjugate with largest capacity to bind ribonucleases was selected. Raktiniai žodžiai: ribonuclease, ribonuclease inhibitor, RNA, magnetic beads, conjugation.
 Sclerotinia sclerotiorum lakazės izofermentų gryninimas, savybių tyrimas ir imobilizavimas nanodariniuose
 Išgryninti nauji Sclerotinia slerotiorum lakazės L241-1 ir L241-2 izofermentai, kurių molekulinės masės (nustatytos SDS-PAGE metodu) atitinkamai lygios 110±10 kDa ir 66±5 kDa. L241-1 izofermentas pasižymi geltonųjų lakazių spektrinėmis savybėmis, sugerties spektre jos neturi smailės 550–700 nm intervale, o L241-2 turi smailę šiame intervale, kas būdinga mėlynosioms lakazėms. Ištirtos L241-1 ir L241-2 izofermentų fiziko-cheminės savybės. L241-1 izofermentas pakankamai stabilus, o L241-2 aktyvumas priklauso nuo terpės, kurioje jis laikomas, ir temperatūros.
 Ištirtos L241-1 ir L241-2 izofermentų kinetinės savybės, t. y., substratinis specifiškumas tradiciniams lakazių substratams, flavonoidams, hidroksicinaminėms ir hidroksibenzoinėms rūgštims. Nustatytos reakcijos greičio priklausomybės nuo buferinių tirpalų pH. Atlikti įvairių druskų poveikio tyrimai L241-1 ir L241-2 izofermentų aktyvumui ir gauti rezultatai palyginti tarpusavyje. Pastebėta, kad L241-1 labiau atsparus įvairių druskų poveikiui nei L241-2 izofermentas.
 L241-1 ir L241-2 izofermentai imobilizuoti ant AuND dengtų Au elektrodų ir dengtų nanovamzdeliais anglies elektrodų. Tiesioginė elektronų pernaša nebuvo stebima imobilizavus šiuos izofermentus ant elektrodų. Imobilizavus L241-1 ir L241-2 izofermentus ant FeMND, nustatyta, kad šis metodas labiau tinka L241-1 lakazei, nes yra išsaugomos natyvaus izofermento savybės, priešingai nei L241-2 atveju. Darbą sudaro šešios dalys: įvadas, literatūros apžvalga, eksperimentinė dalis, rezultatai ir jų aptarimas, išvados, literatūra ir priedai.
 Darbo apimtis 69 p. teksto be priedų, 32 paveikslai, 11 lentelių, 45 bibliografiniai šaltiniai.
 Raktiniai žodžiai: lakazė, Sclerotinia slerotiorum, izofermentas, fiziko-cheminės savybės, kinetinės savybės, pH, nanodalelės.
 New Sclerotinia slerotiorum laccase (L241-1 and L241-2) isoenzymes were purified, molecular weights were determined and equal 110 ± 10 kDa and 66 ± 5 kDa respectively. L241-1 isoenzyme is yellow laccase, because absorption spectrum peak in the range 550–700 nm was not observed, but the L241-2 isoenzyme absorption spectra has a peak in this range which is characteristic for blue laccases. Physico-chemical properties of L241-1 and L241-2 isoenzymes were investigated. L241-1 isoenzyme is enough stable and L241-2 activity depends on the medium in which it is stored, and temperature.
 L241-1 and L241-2 isoenzymes kinetic properties, i. e., the substrate specificity of traditional laccase substrates, flavonoids, hydroxycinnamic and hydroxybenzoic acids were investigated. The reaction rate dependence on the buffer solutions pH were determined. Investigations of different salts influence on L241-1 and L241-2 isoenzymes activity were performed and the results were compared with each other. It was observed that L241-1 is more resistant to the influence of various salts than L241-2 isoenzyme.
 L241-1 and L241-2 isoenzymes were immobilized on the Au electrode coated by AuNP and on the carbon electrodes coated by nanotubes. Direct electron transfer was not observed when isoenzymes were immobilized on the electrodes. Also L241-1 and L241-2 isoenzymes were immobilized on FeMND, and it was determined that this method is more suitable for L241-1 laccase, because the native isoenzyme properties were saved, unlike the L241-2.
 Structure: introduction, literature analysis, experimental part, discussion of the results, conclusion, references, appendices.
 Thesis consist of: 69 p. of text, 32 pictures, 11 tables, 45 bibliographical entries.
 Raktiniai žodžiai: laccase, Sclerotinia slerotiorum, isoenzyme, physico-chemical properties, kinetic properties, pH, nanoparticles.
 Viktorija Brasaitė
 Kapsaicino poveikio dvisluoksnėms fosfolipidų membranoms tyrimas
 Baigiamajame magistro darbe buvo suformuotos ir tirtos modelinės biologinių ląstelių membranų struktūros – paviršiuje imobilizuotos fosfolipidinės dvisluoksnės membranos (tBLM). Šie modeliai panaudoti siekiant ištirti kapsaicino įtaką fosfolipidinėms membranoms bei poras formuojančių citolizinų pažaidos mastui. tBLM formuotos liposomų liejimosi metodu ant lygaus, magnetroniškai užgarinto aukso paviršiaus, modifikavus jį savitvarkiu monosluoksniu. Membranos elektriniai parametrai registruoti elektrocheminio impedanso spektroskopijos (EIS) metodu. Darbo metu nustatyta, jog kapsaicinas įsiterpia į dvisluoksnes lipidų membranas jų formavimo metu. Ištirtas kapsaicino poveikis tBLM elektriniams parametrams bei kapsaicino įtaka nuo cholesterolio priklausomų citolizinų sukeltai cholesterolio turinčių dvisluoksnių membranų pažaidai. Nustatyta, jog kapsaicinas sustiprina pažaidą poras formuojančio toksino – vaginolizino atveju, tačiau beveik neturi poveikio pneumolizino sukeliamai membranos pažaidai. Kapsaicino įtaka stebėta ne tik cholesterolio, bet ir sfingomielino turinčiose dirbtinėse membranose.
 Darbą sudaro šios pagrindinės dalys: įvadas; literatūros apžvalga; medžiagos, įranga, metodai; tyrimo rezultatai ir jų aptarimas; išvados; literatūra.
 Raktiniai žodžiai: cholesterolis, EIS, kapsaicinas, pneumolizinas, tBLM, vaginolizinas.
 In this master thesis, there were one of synthetic biological cell membrane models – tethered bilayer lipid membranes (tBLMs) – formed and investigated. These models were used to examine the capsaicin effect on bilayer phospholipid membranes as well as to the extent of damage of pore-forming cytolysins. tBLMs were formed by multilamellar vesicles fusion method on a flat gold nanolayer, vaporized using magnetron, and modified with self-assembled monolayer. Electrical parameters of membranes were recorded using electrochemical impedance spectroscopy (EIS) method. Study has shown that capsaicin inserts into bilayer lipid membranes during formation process. Capsaicin effect to the electrical parameters of tBLM was investigated. Capsaicin influence of cholesterol-dependent cytolysins binding to membrane and pore forming was obtained as well. It was found that capsaicin enhances the damage of a pore forming toxin – vaginolysin case, but has almost no impact on pneumolysin-induced membrane damage. Influence of capsaicin was observed by monitoring not only cholesterol, but also sphingomyelin containing artificial membranes.
 The work consists of these main parts: introduction; literature review; materials, equipment, methods; results and discussion; conclusions; references.
 Raktiniai žodžiai: cholesterol, EIS, capsaicin, pneumolysin, tBLM, vaginolysin.
 Sandra Gandzelytė
 L-askorbo rūgšties imobilizavimo į chitozano nanodaleles efektyvumo tyrimas
 Erikas Treskovskis
 L-askorbo rūgštis turi nemažai biologinių, farmakologinių ir dermatologinių funkcijų. Tačiau askorbo rūgštis yra labai nestabili. Vitamino C kapsuliavimas gali padėti jį stabilizuoti, kontroliuoti jo paleidimą į norimą aplinką ir užmaskuoti jo rūgštų skonį. Baigiamajame magistro darbe nagrinėjama chitozano ir TPP koncentracijų, vitamino C pridėjimo į nanodalelių sintezės mišinį eigos ir skirtingų chitozano molekulinių savybių įtaka imobilizacijos efektyvumui. Atlikus tiriamąjį darbą galima teigti, kad imobilizavimo efektyvumą įtakoja chitozano tirpalo koncentracija ir skirtingos chitozano molekulinės savybės, taip pat nustatyta, kad nanodalelių sintezei su chitozanu, kurio MM 100000 – 300000 Da reikalinga didesnė TPP koncentracija, nei kai nanodalelių sintezei naudojamas chitozanas, kurio DL 75,5 – 85,5 %. Imobilizacijos efektyvumo maksimumas (76,7 %) pasiektas, kai sintezei naudotas 4 % chitozanas, kurio DL 75,5 – 85,5 % ir 2 % TPP tirpalas. Atlikus nanodalelių TEM analizę, galima teigti, kad dalelės netvarkingos formos, o jų dydis apie 200 nm. Išanalizavus nanodaleles su FTIR spektroskopu galima teigti, kad vitaminas C nanodalelėse ou imobilizacijos yra stabilus ir nepakitęs.
 Darbą sudaro 6 dalys: įvadas, literatūros apžvalga, tyrimų medžiagos ir metodai, tyrimo rezultatai, išvados, literatūros sąrašas. Darbo apimtis – 55 p. teksto be priedų, 28 iliustr., 61 bibliografinis šaltinis.
 Raktiniai žodžiai: Askorbo rūgštis, chitozanas, imobilizacijos efektyvumas, joninė gelfiksacija, nanodalelės, TPP, vitaminas C
 L-Ascorbic acid (AA) known as vitamin C has a variety of biological, pharmaceutical, and dermatological functions. However, AA is very unstable in many conditions. To overcome some of such shortcomings of AA, the nanoparticle technique may be suitable for maintenance of AA bioactivity. In master thesis the stability and characteristics of L-ascorbic acid (AA)-loaded chitosan nanoparticles are investigated. In research work is shown that immobilization efficiency is influenced by chitosan solution concentration and various chitosan molecular characteristics. The research showed that for nanoparticles of chitosan (MW 100000-300000 Da) there is need for more TPP concentration than chitosan (DL 75,5 - 85.5%) to get the same efficiency. Maximum of immobilization efficiency (76.7%) was reached when 4% chitosan (DL 75.5 - 85.5%) solution was used with 2% solution of TPP. The TEM analysis of the nanoparticles, showed that the particles of irregular shape with a size of about 200 nm was formed. After FTIR spectroscopy analysis it clear that vitamin C in nanoparticles are stable and unchanged.
 Structure: introduction, literature review, materials and methods, results, conclusions, references. Thesis consist of: 55 p. text without appendixes, 28 pictures, 61 bibliographical entries.
 Raktiniai žodžiai: Ascorbic acid, chitosan, ionic gelation, loading efficiency, nanoparticles, TPP, vitamin C
 Gintarė Juškaitė
 Suaugusio žmogaus raumens mezenchiminių kamieninių ląstelių miogeninės diferenciacijos reguliavimo technologijos in vitro
 Mezenchiminės kamieninės ląstelės (MKL) yra vienos iš labiausiai aptinkamų suaugusio žmogaus organizmo kamieninių ląstelių, kurios in vitro sąlygomis gali diferencijuoti įvairiomis kryptimis. Keičiant MKL augimo aplinką ir išorinius signalus, galima tikslingai MKL paversti funkcionaliomis tam tikro audinio ląstelėmis. Šiame darbe buvo išskirtos žmogaus raumens MKL (rMKL) ir tirtas šių ląstelių proliferacinis bei difereciacinis potencialai kreipiant ypatingą dėmesį į miogeninės diferenciacijos reguliaciją bei stimuliavimo išoriniais poveikiais galimybes. Kadangi miogeninės diferenciacijos sutrikimai sukelia įvairias raumenų miopatijas ir jų funkcijų sutrikimus, šių ligų gydymui gali būti naudojamos įvaikios kamieninės ląstelės, tačiau labiausiai tinka rMKL, kurios turi didžiausią potencialą greitai diferencijuoti į miocitus ir atstatyti, atnaujinti bei regeneruoti pažeistą raumenį. Šiame darbe tyrėme žmogaus rMKL populiacijų miogeninės diferenciacijos galimybes bei jų stimuliavimo biotechnologijas. Nustatėme, kad bendra rMKL kultūra silpnai diferenciavo miogenine kryptimi bei rodė silpną atsaką į elektrinius bei temperatūrinius stimulus. rMKL išskirstymas pagal CD56 žymenį į dvi atskiras populiacijas parodė, kad CD56 žymenį turinti populiacija patikimai geriau diferenciavo miogenine kryptimi ir efektyviau reagavo į išorinius stimulus. Taigi, žmogaus rMKL populiacija nėra vienalytė, tačiau miogeninės diferenciacijos efektyvumą skirtingose populiacijose galima tikslingai reguliuoti išoriniais stimulais. Gauti šiame darbe rezultatai gali prisidėti tiriant žmogaus rMKL miogeninės diferenciacijos reguliaciją bei praplėsti įvairių raumens funkcijų sutrikimų gydymo galimybes neinvaziniais gydymo metodais. Darbą sudaro 6-ios dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, rezultatai ir aptarimas, išvados ir literatūros sąrašas. Darbo apimtis – 85 p. teksto be priedų, 26 iliustr., 3 lent., 159 bibliografiniai šaltiniai.
 Raktiniai žodžiai: elektrinis stimuliavimas, karščio šokas, mezenchiminės kamieninės ląstelės, miocitai, miogeninė diferenciacija, raumuo.
 Mesenchymal stem cells (MSC) are one of the most common adult stem cells that can differentiate into variety of cell types in vitro. Under special growth conditions or external signals MSC can be purposefully directed to become functional given tissue cells. In this work adult skeletal muscle MSC (mMSCs) have been isolated and their proliferative and differentiation potentials have been studied paying particular attention to the regulation of myogenic differentiation and its stimulation abilities by external impacts.
 Since mulfunction of myogenic diferentiation promote myopathies and muscle functional disabilities, various types of stem cells can be used for therapeutic purposes. However, the most appropriate are mMSC that have the greatest potential to rapidly differentiate into myocytes and restore, renew and/or regenerate damaged muscle. In this study, we investigated the myogenic differentiation potencial of human mMSC populations and their stimulation biotechnologies. Data of this study show that general culture of mMSC had week myogenic differention potential and weekly responded to the external electrical and thermal stimuli. The sorted mMSC according to the CD56 biomarker showed that CD56 positive cell significantly better differentiated to myogenic direction and more efficiently responded to external stimuli. CD56 negative cells did not show myogenic differentiation potencial. In summary, general human muscle-derived MSCs population is heterogeneous and myogenic diferentiation in individual populations can be purposely stimulated by external stimuli. The results obtained in this study can contribute to the investigation of regulation of human mMSC myogenic differentiation and expand the treatment of various muscle disfunctions by non-invasive therapeutic methods. Structure: introduction, literature review, reagents and methods, results and discussion, conclusions, references. Thesis consist of: 85 p. text without appendixes, 26 pictures, 3 tables, 159 bibliographical entries.
 Raktiniai žodžiai: electric stimulation, heat shock, mesenchymal stem cells, muscle, myocites, myogenic differentiation.
 Vlada Ganytė Oginskytė
 GsuI restrikcijos endonukleazės gryninimo technologijos tobulinimas
 Darbo metu nagrinėjamos anksčiau sukurtos restrikcijos endonukleazės technologijos neatsikartojamumo priežastys ir kuriama nauja gamybinio gryninimo schema. Optimizuotos ardymo sąlygos – parinktas optimalus biomasės kiekio ir jos suspendavimo buferinio tirpalo tūrio santykis, ištirta pridedamų medžiagų skirtingų koncentracijų įtaka tikslinio produkto išeigai. Tobulinama chromatografinio gryninimo schema. Parinkti tinkami sorbentai ir buferiniai tirpalai. Optimizuoti parametrai su tikslu gauti kokybišką ir su gera išeiga produktą. Nustatytas sorbentų dinaminis sorbcinis imlumas baltymui GsuI. Atliktas išgryninto baltymo stabilumo tyrimas. Darbą sudaro šešios dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, tyrimo rezultatai ir jų aptarimas, išvados , literatūros sąrašas. Darbo apimtis – 59 p., 29 paveikslai, 6 lentelės, 54 bibliografiniai šaltiniai.
 Raktiniai žodžiai: restrikcijos endonukleazė, ląstelių ardymas, chromatografinis gryninimas, buferinio tirpalo optimizavimas, dinaminis sorbcinis imlumas.
 Manufacturing technology of restriction endonuclease GsuI was analysed and new purification technology of GsuI was designed, in the present work. In order to increase the yielding amount of target protein, in the clarification step homogenisation and cell disruption were optimised. With regard to improve cell disruption the buffer solution and optimal ratio of cells and buffer solution were set on.
 Moreover, different sorbents were tested during the optimization of the chromatography purification. The most suitable sorbents for chromatography purification were chosen to achieve the best yield of the enzyme. The GsuI functional purity was tested using standard methods. For the further optimization dynamic binding capacity of sorbents was estimated. The next step of the research was to investigate the GsuI protein stability. Structure: introduction, literature review, materials and methods, results and discussion, conclusions, references. Thesis consist of – 59 p., 29 pictures, 6 tables, 54 bibliographical entries. Raktiniai žodžiai: restriction endonuclease, disintegration, buffer solution optimization, chromatography purification, dynamic binding capacity.
 Karolina Kriaučiūnaitė
 Mezenchiminių kamieninių ląstelių sekretuojamų ekstraląstelinių vezikulių neuroprotekcinio poveikio tyrimai
 Daugeliui neurodegeneracinių ligų būdingas lėtinis uždegimas. Centrinėje nervų sistemoje uždegiminius procesus reguliuoja funkciniai audinių makrofagai, vadinami mikroglija. Fiziologinėmis sąlygomis mikroglija yra ramybės būsenos, tačiau neurouždegimo metu ji aktyvuojama ir atlieka kritinę funkciją diferencijuodama į uždegiminį M1 arba antiuždegiminį M2 imunofenotipą.
 Šio darbo tikslas yra ištirti kaip pieninio danties pulpos kamieninių ląstelių (PDPKL) sekretuojamos ekstraląstelinės vezikulės veikia žmogaus mikroglijos ląstelių uždegiminę aktyvaciją in vitro. Nustatyta, kad šiame darbe naudojamas in vitro poliarizavimo protokolas padeda efektyviai indukuoti M1 ir M2 imunofenotipą žmogaus mikroglijos ląstelėse. Taip pat identifikuoti potencialūs egzosomų taikiniai žmogaus mikroglijos ląstelėse. Eksperimento duomenys rodo, kad PDPKL egzosomos veikia uždegimą (ARG1, iNOS, VEGFA), fagocitozę (CD11b, TREM2), bei nespecifinį imuninį atsaką (CD14, TLR4) reguliuojančių genų ir miR-124-3p bei miR-145-5p raišką M0, M1 ir M2 žmogaus mikroglijos ląstelėse. Kitas svarbus rezultatas – PDPKL sekretuojamos egzosomos skatina mikroglijos ląstelių migraciją ir fagocitinį aktyvumą. Šie rezultatai suteikia naujų žinių apie priešuždegiminį ir neuroprotekcinį PDPKL sekretuojamų egzosomų poveikį ir potencialiai gali būti panaudoti kuriant naujus neurodegeneracinių ligų metodus.
 Darbą sudaro šešios dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, tyrimų
 rezultatai ir jų aptarimas, išvados ir literatūros sąrašas.
 Darbo apimtis – 54 p., 14 paveikslų, 4 lentelės, 79 bibliografiniai šaltiniai.
 Raktiniai žodžiai: mikroglija, ekstraląstelinės vezikulės, egzosomos, neurodegeneracija, neurouždegimas
 Acute inflammation is associated with many neurodegenerative diseases. In central nervous system inflamatory process is regulated by resident tissue macrophages, named microglia. In physiology conditions microglial cells are ramified, but during neuroinflammation microglia become activated. During microglial activation cell morphology is changed either to M1, the typically activated phenotype, or to M2, an alternatively activated phenotype.
 The aim of this study is to investigate the exosomes effect on the activation of human microglial cells. Exosomes were obtained from the stem cells derived from the dental pulp of human exfoliated deciduous teeth (SHEDs). During this study effective in vitro polarization of human microglial cells into M1 and M2 states was established. In addition, potential targets of exosomes in human microglial cells were identified. Obtained results indicate that exosomes affect expression of genes involved in the regulation of inflammatory response (ARG1, iNOS, VEGFA), phagocytosis (CD11b, TREM2) and also unspecific immune response (CD14, TLR4). Moreover, exosomes significantly affected expression of miR-124-3p and miR-145-5p in M0, M1 and M2 microglial cells. Another important finding of this study was that exosomes activate migration and phagocytic activity of human microglial cells.
 In conclusion, it demonstrates that exosomes derived from SHEDs can act as potent immunomodulators of human microglial cells. Herein, successful implementation of this project provides knowledge about neuroprotective and anti-inflammatory properties of exosomes which might be helpful for the development of new therapeutic strategies against neurodegenerative disorders.
 Structure: introduction, literature review, materials and methods, results and discussion,
 Thesis consist of: 54 p. text without appendixes, 14 pictures, 4 table, 79 bibliographical
 Raktiniai žodžiai: microglia, extracellular vesicles, exosomes, neurodegeneration, neuroinflammation
 Gytis Paškauskas
 Žmogaus mezenchiminių kamieninių ląstelių panaudojimas plaučių epitelio atkūrimui in vitro
 Su oro tarša siejamas žmogaus plaučių audinio irimas ir sutrikę regeneracijos procesai neramina mokslininkus ir gydytojus visame pasaulyje. Šiam audiniui atkurti bandoma pasitelkti ir kamienines ląsteles. Mes darbe naudojome mezenchimines kamienines ląsteles išskirtas iš įvairių žmogaus audinių. Ląstelės buvo išskirtos iš kaulų čiulpų, riebalinio audinio, pagausintos, charakterizuotos, augintos skirtingomis sąlygomis: trimatėje ir dvimatėje kultūrose. Taip pat augintos plaučių alveolinio epitelio ląstelės. Tirtas pastarųjų ląstelių gyvybingumas veikiant įvairiais oro taršos elementais: policiklinių aromatinių angliavandenilių mišiniu iš kietųjų oro taršos dalelių, cigarečių dūmų ekstraktu. Tokio pažeidimo fone stebėjome kamieninių ląstelių terpės apsauginius poveikius: gyvybingumui, epitelio ląstelių mobilumui, epitelio baltymų sintezei. Lyginome skirtingai augintų kamieninių ląstelių poveikius. Kamieninės ląstelės ir jų gaminami faktoriai gali būti panaudojami plaučių kvėpuojamam epiteliui atkurti ir oro taršos efektams sumažinti. Jų galimybės priklauso ir nuo to, kokiose kultūrose ir sąlygose kamieninės ląstelės buvo auginamos in vitro. Sėkmingam šių produktų panaudojimui dar reikia tolesnių eksperimentų bei patvirtinimo in vivo bei klinikiniuose tyrimuose.
 Raktiniai žodžiai: MKL, mezenchiminės kamieninės ląstelės, plaučio epitelis, in vitro.
 Air pollution-associated human lung diseases, i.e. tissue destruction and degeneration processes, raise concern for scientists and physicians around the world. In the attempts to restore or repair lung tissue stem cells are often used. In this work we have used mesenchymal stem cells derived from various human tissues. The cells were isolated from bone marrow, adipose tissue, expanded in vitro, characterized and cultivated at different conditions: in three-dimensional and two-dimensional cultures. Lung alveolar epithelial cells in monolayer were also cultivated. Cell viability was tested at different time points using different air pollution components: a mixture of polycyclic aromatic hydrocarbons from solid particles of air pollution, cigarette smoke extract. In this toxicity model we have observed some protective effects of mesenchymal stem cells on epithelial cell viability, mobility and protein synthesis. Comparisons of differently cultivated stem cell effects were done.
 Stem cells and their produced factors can be used to restore alveolar epithelium of the lungs and reduce some effects of air pollution. The possibilities depend on stem cell culture type and conditions used in vitro. The successful use of these products still need further validation experiments and in vivo and clinical studies.
 Raktiniai žodžiai: MSC, mesenchymal stem cells, in vitro, lung epithelium.
 Biomolekulių cheminio prijungimo prie magnetinių dalelių paviršiaus ypatumų tyrimai
 Baigiamajame darbe buvo tiriami magnetinių dalelių-antikūnų konjugatų gamybos parametrai ir tobulinama gamybos technologija. Nustatyta, kokiomis sąlygomis susidaro dalelių-baltymų agregatai ir kaip jų išvengti. Įvertinta magnetinių dalelių koncentracijos ir dalelių veikimo ultragarsu įtaka pagaminamų konjugatų kokybei. Įvertinta optimali druskų koncentracija konjugavimo proceso metu. Analizuojant konjuguojamo antikūno kiekį ir gaunamų konjugatų funkcionalumą, optimizuota konjugavimo proceso temperatūra. Tiriant įvairias dalelių blokavimo nespecifiniais baltymais sąlygas, nustatyta šio veiksnio įtaka produkto kokybei. Taip pat optimizuotas konjuguojamo antikūno kiekis ir konjugavimo laikas.
 Raktiniai žodžiai: magnetinės dalelės, antikūnai, konjugavimas, ląstelių atskyrimas.
 In the present work parameters of conjugation reaction between magnetic beads and antibodies were analyzed and the production technology was improved. The cause of bead-protein aggregate formation was determined. Also, the concentration of the magnetic beads during conjugation and impact of sonication process for the quality of conjugates were evaluated. Optimal salt concentration during conjugation process was selected. Conjugation reaction temperature was optimized after measuring quantity of conjugated antibody and testing functionality of conjugates. Moreover, the impact of blocking the beads with unspecific proteins to the quality of final conjugate was examined. In addition, optimal quantity of antibody and duration of conjugation process were determined.
 Raktiniai žodžiai: magnetic beads, antibodies, conjugation, cell purification.
 Perprogramuotų žmogaus gaubtinės žarnos epitelinių ląstelių reakcija į poveikį jonizuojančiąja spinduliuote 3D modelinėje sistemoje
 Naujų ir modernių tyrimo modelių kūrimas ir taikymas yra būtinas norint nustatyti geriau suprasti vėžinių ir vėžio panašių į kamienines ląstelių atsparumo jonizuojančiajai spinduliuotei išsivystymo mechanizmus. Šio darbo metu buvo sukurta perprogramuotų žmogaus gaubtinės žarnos epitelinių FHC ląstelių (iDKL-FHC) modelinė 3D kultivavimo sistema in vitro bei ištirtas molekulinis šių ląstelių augintų 3D kultūroje atsakas į vienkartinės bei frakcionuotos dozės poveikį jonizuojančiąja spinduliuote (JS).
 Optimizavus sąlygas iDKL-FHC ląstelių kultivavimui erdvinėje ląstelių kultūroje, pastebėta, kad šioje sistemoje keičiasi ląstelių morfologija, augimo dinamika bei ląstelių atsakas į JS. Pasitelkus bioinformatinius analizės metodus buvo įvertinti ląstelių visuminiai genų raiškos pokyčiai pakeitus auginimo sąlygas iš monosluoksnio (2D) į erdvinę (3D) kultivavimo sistemą. Reikšmingi genų pokyčiai pastebėti genuose priskirtuose su ląstelių tarpusavio sąveikomis ir už kamieniškumą atsakingų signalinių kelių grupėms. Po poveikio JS atliktos bioinformatinės analizės metu nustatyta, kad iDKL-FHC reikšmingai keitėsi genai susiję su ląstelės ciklo reguliacija, DNR pažaidų taisymu, ląstelių sąveikomis bei atsako į stresą signaliniais keliais.
 Darbą sudaro šešios dalys: įvadas, literatūros apžvalga, medžiagos ir metodai, rezultatai ir jų aptarimas, išvados, literatūros sąrašas. Darbo apimtis: 70 puslapiai teksto (su priedais), 17 paveikslų, 15 lentelių, 130 bibliografinių šaltinių.
 Raktiniai žodžiai: 3D ląstelių kultūros, jonizuojančioji spinduliuotė, FHC, perprogramavimas, indukuotos daugiagalės kamieninės ląstelės, iDKL, visuminė genų raiškos analizė.
 Resistance of cancer and cancer stem-like cells to ionizing radiation reduces the effectiveness of anti-cancer radiotherapy and requires new studies based on modern methods. This Master’s degree project allowed us to create 3D cell culture model in vitro from reprogrammed human colon epithelial FHC cells (iPSC-FHC) and investigate their molecular response to single and fractionated dose of ionizing radiation (IR). We observed that iPSC-FHC, grown in 3D microenvironment, changed cell morphology and proliferation rate. Genome-wide analysis of gene expression enabled us to identify significant changes in genes associated with cell interactions and stemness signaling pathways. The results of cellular response to ionizing radiation, obtained from 3D cell cultures, revealed that genes of iPSC-FHC responsible for cell cycle regulation, DNA repair, cell interaction and response to stress signaling pathways were significantly altered.
 Structure: introduction, literature overview, materials and methods, results, conclusion and references. Thesis consists of: 70 page of text (with supplement), 17 pictures, 15 tables, 130 references.
 Raktiniai žodžiai: 3D cell culture, ionizing radiation, FHC, reprogramming, induced pluripotent stem cells, iPSC, genome-wide analysis of gene expression. Puslapio administratoriai: