环磷酸腺苷依赖性蛋白激酶在体外不会使环磷酸鸟苷依赖性蛋白激酶磷酸化。

Cyclic AMP-dependent protein kinase does not phosphorylate cyclic GMP-dependent protein kinase in vitro.

作者信息

Hofmann F, Gensheimer H P

出版信息

FEBS Lett. 1983 Jan 10;151(1):71-5. doi: 10.1016/0014-5793(83)80345-7.

Abstract

The autophosphorylation reaction of purified cGMP-dependent protein kinase has been studied. Apparent initial rates of autophosphorylation in the absence of cyclic nucleotides and in the presence of cGMP and cAMP are 0.006, 0.04, 0.4 mol Pi incorp./min-1. mol cGMP-kinase subunit-1. In the presence of cGMP and cAMP approximately 1 and 2 mol Pi are incorporated/mol enzyme subunit. These values are independent of the enzyme concentration. Stimulation of autophosphorylation by cAMP is not due to activation of a contaminating cAMP-dependent protein kinase since: (a) addition of the heatstable inhibitor protein of cAMP-kinase does not inhibit autophosphorylation; and (b) catalytic subunit of cAMP-kinase added at a 10-fold excess over cGMP-kinase does not phosphorylate cGMP-kinase.

摘要

对纯化的环鸟苷酸依赖性蛋白激酶的自磷酸化反应进行了研究。在不存在环核苷酸、存在环鸟苷酸（cGMP）和环腺苷酸（cAMP）的情况下，自磷酸化的表观初始速率分别为0.006、0.04、0.4摩尔无机磷酸掺入量/分钟 -1·摩尔cGMP激酶亚基 -1。在存在cGMP和cAMP的情况下，每摩尔酶亚基大约掺入1和2摩尔无机磷酸。这些值与酶浓度无关。cAMP对自磷酸化的刺激作用并非由于污染的cAMP依赖性蛋白激酶的激活，因为：（a）添加cAMP激酶的热稳定抑制蛋白不会抑制自磷酸化；（b）以比cGMP激酶过量10倍添加的cAMP激酶催化亚基不会使cGMP激酶磷酸化。