Involvement of thrombin anion-binding exosites 1 and 2 in the activation of factor V and factor VIII
Involvement of thrombin anion-binding exosites 1 and 2 in the activation of factor V and factor VIII
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DOI：
10.1074/jbc.271.23.13882
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发表时间：
1996-06-07
影响因子：
4.8
通讯作者：
Lollar, P
中科院分区：
文献类型：
--
作者：
Esmon, CT;Lollar, P
利用凝血酶Arg(93) -> Ala、Arg(97) -> Ala和Arg(101) -> Ala（凝血酶RA）研究了阴离子结合凝血酶外源性位点在V和VIII因子活化中的作用。Arg(93) -> Ala是一种重组外源性2缺陷突变体，是一种合成的m -乙酰化12肽ac - asn - gly - asp - pheu - glul - glul - il - pre - glul - tyr - o- so4 - leu (hirugen)，可竞争性地抑制大分子与外源性1的结合。凝血酶RA活化因子VIII或第一步活化因子V的催化效率约为野生型凝血酶的10%。对Va因子的总转化率不受突变的影响。与因子V相比，凝血酶RA对因子VIII的缓慢激活与所有三个蛋白水解位点(Arg（372), Arg（740）和Arg(1689)）的裂解率降低有关。这些结果表明凝血酶阴离子结合的外源位点都参与了凝血酶V和凝血因子VIII的识别。
The role of anion-binding exosites of thrombin in the activation of factor V and factor VIII was studied using thrombin Arg(93) --> Ala, Arg(97) --> Ala, and Arg(101) --> Ala (thrombin RA), a recombinant exosite 2 defective mutant and a synthetic M-acetylated dodecapeptide, Ac-Asn-Gly-Asp-Phe-Glu-Glu-Ile-Pro-Glu-Glu-Tyr-O-SO4-Leu (hirugen), which competitively inhibits binding of macromolecules to exosite 1. The catalytic efficiency of the activation of factor VIII or of the first step of factor V activations by thrombin RA was approximately 10% that of wild-type thrombin. The overall rate of conversion to factor Va was not influenced by the mutation. in contrast to factor V, the slow activation of factor VIII by thrombin RA was associated with a decreased rate of cleavage at all three proteolytic sites (Arg(372), Arg(740), and Arg(1689)). Hirugen inhibited factor V and factor VIII activation, These results indicate that both anion-binding exosites of thrombin are involved in the recognition of factor V and factor VIII.