分离的肝细胞中支链2-氧代酸脱氢酶复合物的磷酸化作用

Phosphorylation of branched-chain 2-oxo acid dehydrogenase complex in isolated hepatocytes.

作者信息

Jones S M, Sim A T, Hardie D G, Yeaman S J

出版信息

Biochem Biophys Res Commun. 1987 Apr 29;144(2):628-33. doi: 10.1016/s0006-291x(87)80012-8.

Abstract

Hepatocytes, isolated from rats fed a low-protein diet, were incubated with [32P]Pi and the phosphoproteins analysed. Immunoprecipitation using antibody against El of branched-chain 2-oxo acid dehydrogenase complex demonstrated phosphorylation of the alpha-subunit of El. Analysis of the tryptic phosphopeptides from the alpha-subunit indicated that two sites were phosphorylated. 4-methyl 2-oxopentanoate and DL-2-chloro 4-methylpentanoate decreased labelling of both sites. No major direct effects of several hormones on phosphorylation of branched-chain 2-oxo acid dehydrogenase was observed.

摘要

从喂食低蛋白饮食的大鼠中分离出肝细胞，用[32P]Pi进行孵育并分析磷酸化蛋白。使用针对支链2-氧代酸脱氢酶复合体E1的抗体进行免疫沉淀，结果显示E1的α亚基发生了磷酸化。对α亚基的胰蛋白酶磷酸肽分析表明有两个位点发生了磷酸化。4-甲基-2-氧代戊酸酯和DL-2-氯-4-甲基戊酸酯降低了这两个位点的标记。未观察到几种激素对支链2-氧代酸脱氢酶磷酸化有主要的直接影响。