Biochemical and Biophysical Research Communications 2015-01-01

Inhibition of GDP beta S of agonist-activated phospholipase C in human platelets requires cell permeabilization.

Liting Guo, Haijun Zhang, Fei Wang, Ping Liu, Yonglu Wang, Guohua Xia, Ran Liu, Xueming Li, Haixiang Yin, Hulin Jiang, Baoan Chen

Index: Biochem. Biophys. Res. Commun. 153 , 417-421, (1988)

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Abstract

The inhibition by guanosine 5'-[beta-thio]diphosphate (GDP beta S) of phospholipase C was compared in intact and saponin-permeabilized human platelets in order to assess whether effects of GDP beta S on phospholipase C activation unrelated to guanine nucleotide binding function were occurring. GDP beta S exhibited no effect on phospholipase C activity, monitored by phosphatidic acid formation, in intact platelets that were unstimulated or stimulated with 0.5 U/ml thrombin or 20 nM ONO-11113 (a stable thromboxane A2 analogue). However, GDP beta S did cause a marked decrease in the activity of phospholipase C in saponin-permeabilized platelets. Thus GDP beta S is a viable tool for studying the role of G-proteins in transducing receptor-mediated activation of phospholipase C in platelets.