Castellani L, Elliott B W, Cohen C
Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02254.
J Muscle Res Cell Motil. 1988 Dec;9(6):533-40. doi: 10.1007/BF01738758.
Myosin from a molluscan catch muscle displays unusual properties: when phosphorylated in the rod by an endogenous heavy-chain kinase, myosin solubility is enhanced and the molecule folds (Castellani & Cohen, Proc. natn. Acad. Sci. U.S.A. 84, (1987) 4058-62). We have now localized the sites of phosphorylation to the carboxy-terminal end of the rod by selective proteolytic cleavage. Two major stretches of sequence, 18 and 21 residues long, have been identified, each containing a single residue of phosphoserine. Analysis of the amino-acid sequence of these two peptides indicates that they form a non-helical tailpiece. We discuss how phosphorylation of this tailpiece might influence enzymatic activity in catch muscle thick filaments.
当在杆状区域被内源性重链激酶磷酸化时，肌球蛋白的溶解性增强且分子发生折叠（卡斯特拉尼和科恩，《美国国家科学院院刊》84卷，（1987年）4058 - 62页）。我们现在已通过选择性蛋白水解切割将磷酸化位点定位到杆状区域的羧基末端。已鉴定出两个主要的序列片段，长度分别为18和21个残基，每个片段都含有一个磷酸丝氨酸残基。对这两个肽段氨基酸序列的分析表明，它们形成一个非螺旋的尾段。我们讨论了这个尾段的磷酸化可能如何影响捕捉肌粗肌丝中的酶活性。
