磷酸化酶激酶对心肌肌膜（钠 - 钾）ATP酶活性的刺激作用。

Stimulation of cardiac sarcolemmal (Na+--K+) ATPase activity by phosphorylase kinase.

作者信息

St Louis P J, Sulakhe P V

出版信息

Eur J Pharmacol. 1977 Jun 1;43(3):277-80. doi: 10.1016/0014-2999(77)90028-0.

Abstract

Following preincubation with phosphorylase kinase, ATPase activities of heart sarcolemmal membranes were increased: total ATPase from 9.38+/-0.65 to 15.25+/-0.90 and ouabain-sensitive (Na+--K+)ATPase from 1.67+/-0.17 to 3.12+/-0.33 micron moles Pi/mg protein/h (mean +/- S.E. of 3 experiments); (Ca2+)ATPase and (Mg2+--Ca2+)-ATPase activities were not significantly altered due to phosphorylase kinase. Under these conditions, phosphorylase kinase catalyzed phosphorylation of sarcolemmal membranes. The kinase-catalyzed phosphorylation of membranes was increased by Ca2+ ions: at pH 6.8, 30% increase in phosphorylation was observed whereas at pH 8.5, 267% increase was noted due to this action. These findings support the view that Ca2+-dependent phosphorylation of membranes regulates (Na+--K+)ATPase.

摘要

在用磷酸化酶激酶进行预孵育后，心脏肌膜的ATP酶活性增加：总ATP酶从9.38±0.65增加到15.25±0.90，哇巴因敏感的（Na⁺ - K⁺）ATP酶从1.67±0.17增加到3.12±0.33微摩尔无机磷/毫克蛋白/小时（3次实验的平均值±标准误）；（Ca²⁺）ATP酶和（Mg²⁺ - Ca²⁺）-ATP酶活性未因磷酸化酶激酶而发生显著改变。在这些条件下，磷酸化酶激酶催化肌膜的磷酸化。激酶催化的膜磷酸化因Ca²⁺离子而增加：在pH 6.8时，观察到磷酸化增加30%，而在pH 8.5时，由于此作用，磷酸化增加267%。这些发现支持膜的Ca²⁺依赖性磷酸化调节（Na⁺ - K⁺）ATP酶这一观点。