PROTHROMBIN CONTRIBUTES TO THE ASSEMBLY OF THE FACTOR VA-FACTOR XA COMPLEX AT PHOSPHATIDYLSERINE-CONTAINING PHOSPHOLIPID-MEMBRANES
PROTHROMBIN CONTRIBUTES TO THE ASSEMBLY OF THE FACTOR VA-FACTOR XA COMPLEX AT PHOSPHATIDYLSERINE-CONTAINING PHOSPHOLIPID-MEMBRANES
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DOI：
10.1074/jbc.270.45.26883
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发表时间：
1995-11-10
影响因子：
4.8
通讯作者：
LINDHOUT, T
中科院分区：
文献类型：
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作者：
BILLY, D;WILLEMS, GM;LINDHOUT, T
凝血酶原酶的激活是由凝血酶原酶催化的，凝血酶原酶是凝血因子Xa和凝血因子Va的复合体，组装在带负电荷的磷脂膜上。我们用管式流动反应器研究了凝血因子Va、凝血酶原和带负电的磷脂酰丝氨酸对凝血酶原酶组装的相对贡献。用凝血因子Xa、凝血因子Va和凝血酶原混合物灌流磷脂涂层的毛细血管产生凝血酶的稳态速率，其随(I)磷脂双层的磷脂酰丝氨酸含量、(Ii)凝血因子Va浓度以及(Iii)灌注液的凝血酶原浓度而增加，其中将20mol%的磷脂酰乙醇胺(一种促进凝血酶原酶活性的能力较差的磷脂)加入到5mol%的磷脂酰丝氨酸膜中也增加了凝血酶的稳态生成速率，对流动反应器中凝血酶原酶数量的直接测量表明，催化活性的增加是膜相关凝血酶原酶的稳态数量增加的结果。因此，计算出相似的凝血酶原激活周转次数(3100分钟(-1))，而不考虑膜的磷脂酰丝氨酸含量，我们为低磷脂酰丝氨酸含量的膜(
The activation of prothrombin is catalyzed by prothrombinase, a complex of factor Xa and factor Va assembled on a negatively charged phospholipid membrane, We used a tubular flow reactor to identify the relative contributions of factor Va, prothrombin, and the negatively charged phosphatidylserine to the assembly of prothrombinase. Perfusion of phospholipid-coated capillaries with a mixture of factor Xa, factor Va, and prothrombin resulted in a steady-state rate of thrombin production that increased with (i) the phosphatidylserine content of the phospholipid bilayer, (ii) the factor Va concentration, and, most interestingly, (iii) the prothrombin concentration of the perfusion solution, Incorporation of 20 mol % phosphatidylethanolamine, a phospholipid with poor ability to promote prothrombinase activity, into a 5 mol % phosphatidylserine membrane also increased the steady-state rate of thrombin production, Direct measurements of the amount of prothrombinase in the flow reactor demonstrated that increased catalytic activities were the result of an increased steady-state amount of membrane associated prothrombinase. Thus, similar turnover numbers of prothrombin activation (3100 min(-1)) were calculated, irrespective of the phosphatidylserine content of the membrane, We established for membranes with low phosphatidylserine content (