小肠平滑肌胰岛素受体的特征及其蛋白激酶活性  

Characterization of Subunit Structure and Protein Kinase Activity of Insulin Receptor Purified from Smooth Muscle of Small Intestine

作　　者：武海枫[1] 王殿鸿[1] 郑博[1] 刘励 

机构地区：[1]中国医科大学生化教研室

出　　处：《生物化学杂志》1990年第5期408-412,共5页

基　　金：国家自然科学基金资助项目

摘　　要：本实验对狗小肠平滑肌中胰岛素受体的结构和特征进行了分析研究。通过麦胚凝集素琼脂糖和两次Sepharose-CL-6B凝胶层析从平滑肌中纯化胰岛素受体,达到电泳纯。SDS-聚丙烯酰胺凝胶电泳证明胰岛素受体是由两个亚基组成的,分子量分别为135kD和90kD。磷酸化实验证明平滑肌胰岛素受体具有胰岛素依赖性蛋白激酶活性,能催化自身的β亚基磷酸化和底物的磷酸化。Scatchard分析表明胰岛素和受体的结合呈(?)协同效应,最大结合率为13μg胰岛素/mg蛋白质。Subunit structure and protein kinase activity of insulin receptor of canine small intestinal smooth muscle have been studied. The receptor was purified to homogeneity by affinity chromatography on WGA-sepharose column and two sequential gel filtration on Sepharose-CL-6B column. Just as the α and β subunits of the insulin receptor in other tissues, the purified receptor showed two major bands with Mr 135000 and 90000, respectively, on SDS-polyacrylamide electrophoresis. Insulin stimulates autosphorylation of the β -subunit and the phosphorylation of hist-one H2b. Scatchard analysis showed that the competitive binding of insulin to receptor was negatively cooperative and the maximal binding capacity was 13μg/mg protein.

关 键 词：胰岛素受体 蛋白激酶 

分 类 号：Q578[生物学—生物化学]