生物反应工程chap2enzyme1ppt课件

《生物反应工程chap2enzyme1ppt课件》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、Chapter2EnzymesReducedDsbAfromE.coliLysozyme§2.1IntroductionDefinitionHistoryBüchner,1897:AbreakthroughinEnzymology.Catalystsatworkinalivingorganismcouldalsofunctioncompletelyindependentlyofanylifeprocess.EffortstoisolateandpurifyindividualenzymeswereBüchner’sdiscoveries.Sumner,1926:Firstisolati

2、onofapureenzyme.Enzymesareusuallyproteinsofhighmolecularweight(15,000

3、owertheactivationenergyofthereaction,butDoesn’taffectFree-energychangeEquilibriumconstant8/6/20213EnzymeExample:Thedecompositionofhydrogenperoxide(H2O2):18kcal/molUncatalyzedreactionat20℃ColloidalplatinumChemicallycatalyzedHydrogenperoxidaseEnzymaticallycatalyzed13kcal/mol7kcal/molFromArrheniuse

4、quation:Wehave,8/6/20214EnzymeTheinteractionbetweentheenzymeanditssubstrate——weakforce:vanderWaalsforcesHydrogenbondingSpecific:CatalyzeonekindofreactionInvolvingcertainsubstratesNeedforcofactorsorcoenzyme:Cofactors:metalions:Mg,Zn,Mn,FeCoenzyme:acomplexorganicmolecule:NAD,FAD,CoA,somevitamins8/

5、6/20215EnzymeEnzymesarenamedbyaddingthesuffix–asetothe:EndofthesubstrateSuchasureaseThereactioncatalyzedSuchasalcoholdehydrogenaseNomenclatureEnzymesusingfamiliarnames:PepsininthedigestivetractTrypsininthedigestivetractRenninusedincheesemaking“Oldyellow”,whichcausedbrowningofslicedapples8/6/2021

6、6EnzymeEC(EnzymeCommission)SIXclassesnumberedinFOURdigitsClassificationThefirstdigitalTheseconddigitalThethirddigitalThefourthdigitalTypeofreactioncatalyzed——mainclasses——actualsubstance8/6/20217EnzymeOxidoreductasesFirstdigit1––theclassoxidoreductases.Seconddigit––thedonorofhydrogenatomorelectr

7、oninvolved.AlcoholAldehydeorketoneAlkene–CH=CH-PrimaryamineSecondaryamineNADH,NADPHThirddigit––hydrogenatomorelectronacceptor.NAD+,NADP+Fe3+O2OtherwiseunclassifiedFourthdigit––numberforfurtheridentification.8/6/20218EnzymeTr