皂素通透的人血小板中花生四烯酸释放和1,2 -二酰甘油形成对百日咳毒素、GDPβS和NaF的差异敏感性：涉及磷脂酶C和A2激活的不同GTP结合蛋白的可能证据。

Differential sensitivity of arachidonic acid release and 1,2-diacylglycerol formation to pertussis toxin, GDP beta S and NaF in saponin-permeabilized human platelets: possible evidence for distinct GTP-binding proteins involving phospholipase C and A2 activation.

作者信息

Nakashima S, Hattori H, Shirato L, Takenaka A, Nozawa Y

机构信息

Department of Biochemistry, Gifu University School of Medicine, Japan.

出版信息

Biochem Biophys Res Commun. 1987 Nov 13;148(3):971-8. doi: 10.1016/s0006-291x(87)80227-9.

DOI:10.1016/s0006-291x(87)80227-9

PMID:3120720

Abstract

Human platelets labeled with [3H]arachidonic acid and permeabilized with saponin produced [3H]1,2-diacylglycerol (DG) by phospholipase C and released [3H]arachidonate by phospholipase A2, when activated with thrombin. Thrombin-induced arachidonate liberation was almost completely inhibited with pretreatment of pertussis toxin (10 micrograms/ml), whereas DG formation was decreased by only 20-40% in the toxin-treated platelets. Although guanosine 5'-o-(2-thiodiphosphate) (GDP beta S) suppressed arachidonate release and DG production in a dose-dependent manner, the half maximal inhibition required less than 10 microM for arachidonate release but more than 100 microM for DG production. Moreover, the dose-response effects of NaF on arachidonate release and DG formation were different. These results indicate that arachidonate release and DG formation are differently affected by these agents acting on guanine nucleotide binding proteins (G-proteins), suggesting that the distinct G proteins modulate the activity of phospholipase C and phospholipase A2.

摘要

用[3H]花生四烯酸标记并用皂素通透处理的人血小板，在用凝血酶激活时，通过磷脂酶C产生[3H]1,2 - 二酰甘油（DG），并通过磷脂酶A2释放[3H]花生四烯酸。百日咳毒素（10微克/毫升）预处理几乎完全抑制了凝血酶诱导的花生四烯酸释放，而在毒素处理的血小板中，DG形成仅减少了20 - 40%。尽管5'-O-(2-硫代二磷酸)鸟苷（GDPβS）以剂量依赖方式抑制花生四烯酸释放和DG产生，但花生四烯酸释放的半数最大抑制所需浓度小于10微摩尔，而DG产生则需大于100微摩尔。此外，NaF对花生四烯酸释放和DG形成的剂量反应效应不同。这些结果表明，花生四烯酸释放和DG形成受作用于鸟嘌呤核苷酸结合蛋白（G蛋白）的这些试剂的影响不同，提示不同的G蛋白调节磷脂酶C和磷脂酶A2的活性。