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《擴(kuò)展青霉脂肪酶“蓋子”結(jié)構(gòu)域突變對(duì)其活性影響的分析》由會(huì)員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在行業(yè)資料-天天文庫。
1、福建師范大學(xué)林瑞鳳碩士論文IIAbstractAbstractInordertobringfacilityformoleculardesigningandalteratingPenicilliumexpansumlipasegene,weamplifythematurepeptideofPenicilliumexpansumlipase,andinsertintopPIC9Kvectortoconstructrecombinantexpressionplasmid.ByaligningPenicilliumexp
2、ansumlipasewithferuloylesterase,wemutagenesisthesixty-sixth,^eihty-first,ninty-fourthaminoacids,the”lidt.,therightsideofhingeregionof-.IPenicilliumexpansumlipase,SOaStostudytheireffectonlipaseactivity.Firstly,bymeansofthepreviousconstructedrecombinantexpressi
3、onplasmidtemplate,wesite—directedmutagenesisthreeaminoacidsinbothsidesofthehingeregionof”lidf’(T66G,T81P,K94E)bycircuLarplasmidsstepPCR,andabtainthreerecombinantexpressionplasmidscontainingmutantaminoacids.AfterexpressedinHchiapastorisGSll5strain,wepurifiythe
4、expressionproductbyNi—column,thenmeasuretheirhydrolysisactivityon4·nitrophenyldecanoatelaurate.Theresultsshowthat:PELT66Grecombinantlipaserelativeactivity(5.09U/mg)issimilartothewild-typePELlipase,whilePELT81PandPELK94Erecombinantlipaserelativeactivityhavebee
5、nimproved2.95timesand2.57times,respectivelyupto19.08966U/mgand17.2391U/mg·Secondly,weexchangethe”lid”domainbythewayofintroducingrestrictionsitesthenbackmutationbycircuLarplasmidstepPCRandconstructrecombinantexpressionplasmidwithpPIC9Kvector.However,afterexpre
6、ssedinPichiapastorisGSll5strain,itdoesnotshowanylipaseactivityonoliveoil-rhodamineBagarplate.WhilethepurifiedlipasebyNi.columncanbeseenonestrapabout28KDabySDS-PAGEelectrophoresis.Atlastwealsoreplacetherighthingeregionoflipase”lid”byoverlapextensionPCR.Asthe“l(fā)
7、id”mutantlipase,theconcentratedfermentationbrothofthisrecombinant^鈺jlipasedonotshowanylipaseactivity.■Inaword,Penicilliumexpansumlipase”lid-’domainplayveryimportantroleinitsactivity,especiallythemutationson”lid”,therighthingeregion,T81P,K94E,whichwillresuLtin
8、thelossorwhole-foldimprovementoflipaseactivityKeywords:Penicilliumexpansumlipase,circularplasmidstepPCR,overlapextensionPCR,liddomainIIIr福建師范大學(xué)林瑞鳳碩士論文,"'a隊(duì)J-1IV中文文摘中文文摘擴(kuò)展青霉脂肪酶是一類中溫堿性脂肪酶,能