Biochemical characteristics of the Mr 52,000 component of Akazara scallop troponin.
Some biochemical properties of the Mr 52,000 component of Akazara scallop striated adductor troponin, which had been tentatively identified as troponin-I, were compared with those of rabbit troponin-I. Both the Mr 52,000 component and rabbit troponin-I together with rabbit tropomyosin inhibited the Mg-ATPase activity of rabbit reconstituted actomyosin to 1/10 of the original activity. The inhibition was neutralized by the addition of Akazara scallop and rabbit troponin-C or Patinopecten scallop calmodulin. The Mr 52,000 component and rabbit troponin-I were insoluble below 0.15 M KCl, but were solubilized by complexing with an equimolar amount of troponin-C or calmodulin. On alkaline urea-polyacrylamide gel electrophoresis, the Mr 52,000 component as well as rabbit troponin-I was found to form a stable complex with troponin-C or calmodulin in the presence of Ca2+.
Ojima
T
T
Department of Chemistry, Faculty of Fisheries, Hokkaido University.
Nishita
K
K
D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000032:analysis / Q000037:antagonists & inhibitors; D002135:Calcium-Binding Proteins / Q000494:pharmacology; D002147:Calmodulin / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D008974:Mollusca / Q000032:analysis*; D009218:Myosins / Q000037:antagonists & inhibitors; D012995:Solubility; D014336:Troponin / Q000032:analysis* / Q000302:isolation & purification / Q000494:pharmacology; D019209:Troponin C
D002135:Calcium-Binding Proteins; D002147:Calmodulin; D014336:Troponin; D019209:Troponin C; D017301:Ca(2+) Mg(2+)-ATPase; D009218:Myosins