兔肌肉组织组织蛋白酶D对肌原纤维蛋白的降解模式

Mode of degradation of myofibrillar proteins by rabbit muscle cathepsin D.

作者信息

Matsumoto T, Okitani A, Kitamura Y, Kato H

出版信息

Biochim Biophys Acta. 1983 Jan 4;755(1):76-80. doi: 10.1016/0304-4165(83)90275-1.

Abstract

The mode of degradation of myofibrillar proteins by the action of highly purified rabbit muscle cathepsin D (EC 3.4.23.5) was studied using SDS-polyacrylamide gel electrophoresis. Cathepsin D optimally degraded myosin heavy chain, alpha-actinin, tropomyosin, troponin T and troponin I at around pH 3. It did not degrade actin or troponin C. Degradation of myosin heavy chain produced four major fragments of 155000, 130000, 110000 and 90000 daltons. Troponin T was hydrolyzed to 33000-, and 20000- and 11000-dalton fragments. Troponin I was degraded into fragments of 13000 and 11000 daltons. Degradation of alpha-actinin and tropomyosin was not as rapid as that of myosin and troponins T and I. Tropomyosin gave a fragment of 30000 daltons, but alpha-actinin showed no distinct band of this fragment on gels.

摘要

利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳研究了高纯度兔肌肉组织蛋白酶D（EC 3.4.23.5）作用下肌原纤维蛋白的降解模式。组织蛋白酶D在pH值约为3时能最佳地降解肌球蛋白重链、α-辅肌动蛋白、原肌球蛋白、肌钙蛋白T和肌钙蛋白I。它不会降解肌动蛋白或肌钙蛋白C。肌球蛋白重链的降解产生了155000、130000、110000和90000道尔顿的四个主要片段。肌钙蛋白T被水解为33000、20000和11000道尔顿的片段。肌钙蛋白I被降解为13000和11000道尔顿的片段。α-辅肌动蛋白和原肌球蛋白的降解不如肌球蛋白以及肌钙蛋白T和I的降解迅速。原肌球蛋白产生了一个30000道尔顿的片段，但α-辅肌动蛋白在凝胶上未显示出该片段的明显条带。