Rosing J, Govers-Riemslag J W, Yukelson L, Tans G
Department of Biochemistry, Cardiovascular Research Institute, University of Maastricht, PO Box 616, NL-6200 MD Maastricht, The Netherlands.
Haemostasis. 2001 May-Dec;31(3-6):241-6. doi: 10.1159/000048069.
Blood coagulation factor V is a single-chain glycoprotein with M(r) = 330,000 which plays an important role in the procoagulant and anticoagulant pathways. Thrombin activates factor V into factor Va, a two-chain molecule which is composed of a heavy (M(r) = 105,000) and a light chain (M(r) = 71,000/74,000). Factor Va accelerates factor Xa-catalysed prothrombin activation more than 1,000-fold and under physiological conditions the cofactor activity of factor Va in prothrombin activation is down-regulated by activated protein C. Factor V can also be activated by a wide variety of snake venoms (e.g. from Vipera species, Naja naja oxiana, Bothrops atrox) and by proteases present in the bristles of a South American caterpillar (Lonomia achelous). Some venoms, notably of Vipera lebetina turanica and Lonomia achelous, contain proteases that are able to inactivate factor V or factor Va. Venom factor V activators are excellent tools in studying the structure-function relationship of factor V(a) and they are also used in diagnostic tests for quantification of plasma factor V levels and for the screening of defects in the protein C pathway. In this review, the structural and functional properties of animal venom factor V activators and inactivators is described.
血液凝固因子V是一种单链糖蛋白，相对分子质量（M(r)）为330,000，在凝血和抗凝途径中起重要作用。凝血酶将因子V激活为因子Va，后者是一种双链分子，由重链（M(r)=105,000）和轻链（M(r)=71,000/74,000）组成。因子Va使因子Xa催化的凝血酶原激活加速1000多倍，在生理条件下，凝血酶原激活过程中因子Va的辅因子活性受到活化蛋白C的下调。因子V也可被多种蛇毒（如蝰蛇属、中亚眼镜蛇、矛头蝮蛇的蛇毒）以及一种南美毛虫（螯蛱蝶）刚毛中的蛋白酶激活。一些毒液，特别是草原蝰蛇和螯蛱蝶的毒液，含有能够使因子V或因子Va失活的蛋白酶。蛇毒因子V激活剂是研究因子V(a)结构 - 功能关系的优秀工具，它们也用于血浆因子V水平定量以及蛋白C途径缺陷筛查的诊断测试。在这篇综述中，描述了动物毒液因子V激活剂和失活剂的结构和功能特性。
