BLOOD-COAGULATION INDUCED BY THE VENOM OF BOTHROPS-ATROX .2. IDENTIFICATION, PURIFICATION, AND PROPERTIES OF 2 FACTOR-X ACTIVATORS
BLOOD-COAGULATION INDUCED BY THE VENOM OF BOTHROPS-ATROX .2. IDENTIFICATION, PURIFICATION, AND PROPERTIES OF 2 FACTOR-X ACTIVATORS
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DOI：
10.1021/bi00377a019
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发表时间：
1987-02-10
期刊：
影响因子：
2.9
通讯作者：
BON, C
中科院分区：
文献类型：
--
作者：
HOFMANN, H;BON, C
我们已经鉴定并纯化了激活凝血因子X的Bothrops atrox毒液的两种组分。活化剂I和活化剂2通过离子交换色谱分离，但在其他方面呈现相似的特性。它们由Mr 59，000的重链多肽和一条或两条轻链组成，形成M4 14，000 - 15，000的双联体。它们对合成底物和凝血酶原或纤维蛋白原无活性，因此似乎特异性作用于因子X。它们对丝氨酸蛋白酶或硫醇酯酶的抑制剂不敏感。因子X的激活被具有HI 11系数为2.4的Ca 2+离子激活，并且被Hg 2+、Ba 2+和Cd 2+抑制。其pH依赖性表明活性取决于表观pK为6.9的基团的电离。我们研究了B对纯化的牛X因子的切割作用。atrox激活剂，并将其与用来自蝰蛇毒液的因子X激活剂获得的结果进行比较。与生理活化剂一样，毒液的活化剂切割因子X的重链，产生活化的因子Xa α。然而，它们产生两个裂解：一个在因子X重链的N-末端附近，产生因子X μ，第二个位于因子Xa α重链的一端，生成因子Xav.
We have characterized and purified the two components of the venom of Bothrops atrox that activate the coagulation factor X. Activator I and activator 2 were separated by ion-exchange chromatography but otherwise presented similar characteristics. They consist of a heavy polypeptide of Mr 59,000 and either one or two light chains forming a doublet of M4 14,000-15,000. They are inactive on synthetic substrates and on prothrombin or fibrinogen and thus appear to act specifically on factor X. They are not sensitive to inhibitors of serine proteases or thiol esterases. The activation of factor X is activated by Ca2+ ions with a HIll coefficient of 2.4 and is inhibited by Hg2+, Ba2+, and Cd2+. Its pH dependency suggests that the acivity depends on the ionization of a group with an apparent pK of 6.9. We studied the cleavage of purified bovine factor X by B. atrox activators and compared it to that obtained with the factor X activator from Vipera russelli venom. Like the physiological activators, the venom''s activators cleave the heavy chain of factor X, producing the activated factor Xa.alpha.. They produce however two cleavages: one near the N-terminal end of the heavy chain of factor X, generating factor X.mu., and a second one located at one extremity of the heavy chain of factor Xa.alpha., generating factor Xav.