Similarities in properties and a functional difference in purified leucyl-tRNA synthetase isolated from two developmental stages of Tenebrio molitor☆
[摘要] InTenebriomolitor,aswellasinotherbiologicalsystems,thereareindicationsthatdifferencesinleucyl-tRNAsynthetaseactivitymayplayaroleintranslationalcontrol.However,ithasnotbeenclearwhetherthedifferenceinactivityisduetotheappearanceofamultiplicityofenzymesduringdevelopmentortothealterationofasingleenzyme.Thepurificationofleucyl-tRNAsynthetasefromday1andday7afterthelarvalpupalmoltofTenebriomolitorisdescribed.Theenzymefrombothdevelopmentalstageswaspurifiedovera1000-fold.Thetwoenzymepreparationsareidenticalinmolecularweight(99,000).Theyshowthesamecharacteristicsafteraging.ThepHoptimum,heatinactivationbehavior,anddependencyondivalentcationsarethesameforbothenzymes.TheyalsoshowidenticalkineticswithsimilarvaluesofKmforleucine,ATP,Mg2+,andtRNAday1.However,leucyl-tRNAsynthetasepurifiedfromday7exhibitsanadditionalfunctioninrecognizinganewspeciesofisoacceptingtRNAinday7tRNA.Wehavetentativelyconcludedthatthetwoenzymesareprobablydifferentformsofthesameenzymeandtheadditionalactivityisduetoalterationoftheenzymeatthemacromolecularlevelduringdevelopment.
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[效力级别] [学科分类] 生物科学(综合)
[关键词] [时效性]