一种不同于碱性磷酸酶的蛋白质酪氨酸磷酸酶，对胰岛素受体具有活性。

A protein phosphotyrosine phosphatase distinct from alkaline phosphatase with activity against the insulin receptor.

作者信息

Strout H V, Vicario P P, Saperstein R, Slater E E

机构信息

Department of Biochemical Endocrinology Merck Institute for Therapeutic Research Rahway, NJ 07065.

出版信息

Biochem Biophys Res Commun. 1988 Mar 15;151(2):633-40. doi: 10.1016/s0006-291x(88)80328-0.

DOI:10.1016/s0006-291x(88)80328-0

PMID:2831899

Abstract

Rat liver plasma membranes were found to have a relatively high ratio of acid to alkaline phosphatase activity when compared to rabbit liver and human placental membranes, respectively. The rat liver plasma membranes contained PPTl phosphatase activity against the soluble autophosphorylated insulin receptor beta-subunit. The PPT phosphatase activity of the membranes, using 32P-histone 2b as a substrate, was inhibited by 100 microM Zn+2, insensitive to 10 mM EDTA, and displayed maximal activity at neutral pH. Dephosphorylation of the insulin receptor beta-subunit by rat liver membranes was inhibited by Zn+2, and stimulated by EDTA. These results prove that the plasma membrane of a physiologically relevant insulin target tissue contains a PPT phosphatase, distinct from alkaline phosphatase, which catalyzes the dephosphorylation of the insulin receptor beta-subunit.

摘要

与兔肝和人胎盘膜相比，发现大鼠肝细胞膜中酸性磷酸酶与碱性磷酸酶活性的比率相对较高。大鼠肝细胞膜含有针对可溶性自磷酸化胰岛素受体β亚基的PPT1磷酸酶活性。以32P-组蛋白2b为底物时，膜的PPT磷酸酶活性受到100 microM Zn+2的抑制，对10 mM EDTA不敏感，并且在中性pH下表现出最大活性。大鼠肝细胞膜对胰岛素受体β亚基的去磷酸化作用受到Zn+2的抑制，并受到EDTA的刺激。这些结果证明，生理相关胰岛素靶组织的细胞膜含有一种与碱性磷酸酶不同的PPT磷酸酶，它催化胰岛素受体β亚基的去磷酸化。