Kinetic and mechanistic analysis of prothrombin-membrane binding by stopped-flow light scattering.
Kinetic and mechanistic analysis of prothrombin-membrane binding by stopped-flow light scattering.
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通过停流光散射进行凝血酶原-膜结合的动力学和机制分析。
DOI：
10.1021/bi00537a039
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发表时间：
1982
期刊：
影响因子：
2.9
通讯作者：
Nelsestuen,GL
中科院分区：
文献类型：
--
作者：
Wei,GJ;Bloomfield,VA;Resnick,RM;Nelsestuen,GL
G. Jason Wei，维克托A.放大图片作者：布卢姆菲尔德Resnick和加里L. Nelsestuen* 摘要：我们用停流光散射技术研究了凝血酶原与膜泡相互作用的动力学和机理。在接近生理蛋白浓度（< 3 µ凝血酶原）的条件下，凝血酶原与囊泡的相互作用根据囊泡上具有非相互作用凝血酶原结合位点的简单双分子过程建模。在10 ℃、含3 mM钙的缓冲液中，凝血酶原与含20% α-磷脂酰丝氨酸-80%磷脂酰胆碱的囊泡相互作用的结合速率常数（每个蛋白结合位点）为（1±0.1）× 107 M_1-s_1。这相当于10%的碰撞效率。其逆过程为一级解离，速率常数为3±1 s-1。随着不同的膜组成的协会过程中被发现是有点合作方面的磷脂酰丝氨酸，但解离是不受磷脂酰丝氨酸密度。凝血酶原-膜结合的活化能随膜中酸性磷脂的量而变化。10%磷脂酰丝氨酸膜的活化能约为
G. Jason Wei, Victor A. Bloomfield, Robert M. Resnick, and Gary L. Nelsestuen* abstract: We have investigated the kinetics and mechanism of prothrombin-membrane vesicle interaction byusing stopped-flow light scattering. Under conditions of approximately physiological protein concentration (< 3 µ pro-thrombin), prothrombin interaction with the vesicles was modeled according to a simple bimolecular process with noninteracting prothrombin binding sites on the vesicle. The association rate constant (per protein binding site) for interaction of prothrombin with vesicles containing 20% phos-phatidylserine-80% phosphatidylcholine at 10 C, in buffer containing 3 mM calcium, is (1±0.1) X 107 M_1-s_1. This corresponds to a 10% collision efficiency. The reverse process is a first-order dissociation with a rate constant of 3±1 s-1.Off-rate experiments conducted by sample dilution were consistent with these values. With varying membrane com-positions the association process was found to be somewhat cooperative with respect to phosphatidylserine, but dissociation was unaffected by phosphatidylserine density. The activation energy for prothrombin-membrane association varied with the amount of acidic phospholipid in the membrane. Membranes of 10% phosphatidylserine gave an activation energy of about