Isolation of the native form of chicken gizzard myosin light-chain kinase.
Isolation of the native form of chicken gizzard myosin light-chain kinase.
复制标题
鸡胗肌球蛋白轻链激酶天然形式的分离。
作者：
P. Ngai;C. A. Carruthers;M. Walsh
描述了一种简单快速的纯化鸡胗肌球蛋白轻链激酶（Mr 136000）的方法，消除了以前遇到的蛋白水解问题。在此过程中，先前与肌球蛋白轻链激酶共纯化的Mr 141000钙调素结合蛋白被去除，并显示出其是一个独特的蛋白，其基础是缺乏激酶活性，不同的凝乳胰蛋白酶图，与火鸡细黄肌球蛋白轻链激酶单克隆抗体缺乏交叉反应性，并且缺乏被纯化的环amp依赖性蛋白激酶催化亚基磷酸化。这个Mr-141000钙调素结合蛋白被鉴定为钙调素，基于钙调素与钙调素的依赖相互作用，亚基Mr，与骨骼肌f -肌动蛋白的Ca2+独立相互作用，钙调素和f -肌动蛋白之间钙调素的依赖竞争，以及组织含量。
A simple and rapid procedure for the purification of the native form of chicken gizzard myosin light-chain kinase (Mr 136000) is described which eliminates problems of proteolysis previously encountered. During this procedure, a calmodulin-binding protein of Mr 141000, which previously co-purified with the myosin light-chain kinase, is removed and shown to be a distinct protein on the basis of lack of kinase activity, different chymotryptic peptide maps, lack of cross-reactivity with a monoclonal antibody to turkey gizzard myosin light-chain kinase, and lack of phosphorylation by the purified catalytic subunit of cyclic AMP-dependent protein kinase. This Mr-141000 calmodulin-binding protein is identified as caldesmon on the basis of Ca2+-dependent interaction with calmodulin, subunit Mr, Ca2+-independent interaction with skeletal-muscle F-actin, Ca2+-dependent competition between calmodulin and F-actin for caldesmon, and tissue content.