ホタテガイ・トロポニンＣのＣＮＢｒ‐フラグメントの性質と部分アミノ酸配列

Abstract

Troponin C of the striated adductor muscle of Ezo-giant scallop Patinopecten yessoensis was split with CNBr into 3 fragments named CB1, CB2 and CB3 which consisted of about 80, 50 and 4 amino acid residues, respectively. CB1 was shown to contain Ca2+-binding and TnI-binding domains. While CB2 is the N-terminal fragment which was incapable of binding of Ca2+ though it was expected to contain at least one Ca2+-binding domain in view of the structural homology with other Ca2+-binding proteins. Amino acid sequence of the CB2 was determined as QFTEERSAKQILNAKEAFDNVCKLKEGTVSCKDLGAIFKSLGLLVKSDAM. Thus the sequential homology was considerably low in the CB2 and the N-terminal regions of the other Ca2+-binding proteins especially in the possible Ca2+-binding domains.