31195.嗜酸氧化亞鐵硫桿菌硫氧還蛋白系統(tǒng)的表達純化及定點突變

1、中南大學碩士學位論文嗜酸氧化亞鐵硫桿菌硫氧還蛋白系統(tǒng)的表達純化及定點突變姓名：王億平申請學位級別：碩士專業(yè)：生物工程指導教師：柳建設曾嘉20090501碩士學位論文ABSTRACTThioredoxinsystemconstitutesofthioredoxin(Trx)，thioredoxinreductase(TrxR)，13Nicotinamideadeninedinucleotide2phosphatereducedtetras

2、odiumsalt(NADPH)ThevallcontaindisulfideactivesitesequenceofCysGlyProCysThioredoxinsystemCallstabilizethecellsenvironment，regulatecellgrowthandsignaltransductionprocessestoprotectcellsfromreactiveoxygenspeciesdamagecaused

3、byexternalstimulisuchasvirusinfectionionizingradiation；ItiSalsoareductantinmanycellularreactionssuchasribonucleotidereduction，andplayallimportantroleintheregulationofprotein—proteinexpression，protein—nucleicacidexpressio

4、nItisawidespreadinnaturesystemThioredoxin(Trx)iswidespreadpresenceinanimals，plants，fungiandmicrobes，withamolecularmassof12kDaItisanimportantproteinforregulatingenzymesactivity，playakeyroleinredoxcardersthroughthereversib

5、lethi01disulfideredoxchangeinavarietyofreactions，andplaysseveralkeyrolesinmaintainingtheredoxenvironmentofthecellThegeneofthioredoxinfromAferrooxidansATCC23270wascloned，overexpressedandpurifiedbyonestepaffinitychromatogr

6、aphyWreconstructedthemutantexpressionplasmid(C33A，C33S，C36A，C36S)oftheproteinusingsite—directedmutagenesisTheUvⅥsscanningandactivitytestresultsconfirmedthatresiduesCys33，Cys36ofthioredoxinwereactivesiteresiduesThioredoxi

7、nreductase(TrxR)isaNADPHdependentenzymecontainsFADdomainItisamemberofpyridinenucleotide。disulfideoxidoreductasefamilyTheprimaryfunctionofthioredoxinreductaseistocatalysethereductionofthesmallredoxproteinthioredoxinbyNADP

8、H，andmaintainthereducedstateofT】ⅨThegeneofthioredoxinreductasefromAferrooxidansATCC23270wascloned，expressedandpurifiedbyone—stepaffinitychromatographyThemolecularmassoftherecombinantproteinwas35kDacontainingFADWeconstruc