Molt cycle-associated changes in calcium-dependent proteinase activity that degrades actin and myosin in crustacean muscle☆
[摘要] Theroleofcalcium-dependentproteinase(CDP)intheproecdysialatrophyofcrustaceanclawmusclehasbeeninvestigated.Duringatrophythemolarratioofactintomyosinheavychaindecreased31%,confirmingearlierultrastructuralobservationsthattheratioofthin:thickmyofilamentsdeclinedfrom9:1to6:1(D.L.MyklesandD.M.Skinner,1981,J.Ultrastruct.Res.,75,314–325).ThereleaseofTCA-solublematerialinmusclehomogenatesatneutralpHwasstimulatedbyCa2+andcompletelyinhibitedbyEGTA.Thespecificdegradationofthemajormyofibrillarproteins(actin,myosinheavyandlightchains,paramyosin,tropomyosin,troponin-T,andtroponin-I)wasdemonstratedbySDS-polyacrylamidegelelectrophoresis.Proteolyticactivitywasmorethantwofoldgreaterinproecdysialmusclehomogenates.DegradationofmyofibrillarproteinswasinhibitedbyEGTA,andthetwoinhibitorsofcysteineproteinases,leupeptinandantipain,butnotpepstatin,aninhibitorofasparticproteinases.UnlikeCDPsfromvertebratemuscle,theCDP(s)incrabclawmuscledegradesactinandmyosininadditiontoothermyofibrillarproteins.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
