Human genes for factor IX and other vitamin K dependent blood proteins.
Human genes for factor IX and other vitamin K dependent blood proteins.
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人类基因 IX 和其他维生素 K 依赖性血液蛋白。
DOI：
10.1007/978-1-4757-5985-3_6
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发表时间：
1987
影响因子：
--
通讯作者：
Chen,SH
中科院分区：
文献类型：
--
作者：
Kurachi,K;Chen,SH
因子IX是具有m.w. 57,000.它是参与血液凝固中期的丝氨酸蛋白酶的单链前体。它被因子XIa（活化因子XI）以及因子VII-组织因子的复合物活化为双链形式丝氨酸蛋白酶，因子IXa。因子IX是六种血液蛋白质之一，它们的正常生物合成需要维生素K。这些蛋白质包括因子VII、因子IX、因子X、凝血酶原、蛋白质C、蛋白质S和蛋白质Z。前四种蛋白质是凝血因子。蛋白C通过在蛋白S存在下灭活因子Villa和Va而作为血液凝固的有效调节剂发挥作用。蛋白S也可能通过与C4 b结合蛋白2结合而在补体系统中发挥调节作用。蛋白质Z的功能目前尚不清楚。位于这些蛋白质的氨基末端约40个氨基酸序列内的前约10个谷氨酸残基在膜结合羧化酶催化的反应中在维生素K作为辅因子3的存在下转化为γ羧基谷氨酸残基（gla残基）。蛋白质中的这些gla残基作为结合钙离子的位点，这是这些蛋白质的最佳活性所需的。
Factor IX is a plasma glycoprotein with m.w. 57,000. It is a single chain precurser to a serine protease which participates in the middle phase of blood coagulation. It is activated by factor XIa (activated factor XI) as well as by a complex of factor VII-tissue factor to a two chain form serine protease, factor IXa. Factor IX is one of the half a dozen blood proteins which require vitamin K for their normal biosynthesis. These proteins include factor VII, factor IX, factor X, prothrombin, protein C, protein S and protein Z. The first four proteins are blood coagulation factors. Protein C functions as an efficient regulator of blood coagulation by inactivating factors Villa and Va in the presence of protein S. Protein S also has a possible regulatoryrolein the complement system by binding to C4b binding2protein. The function for protein Z is not known at the present time. The first about ten glutamic acid residues which are located within the amino-terminal about 40 amino acid sequence of these proteins are converted to gamma carboxylglutamic acid residues (gla residues) in a reaction catalyzed by a membrane-bound carboxylase(s) in the presence of vitamin K as a cofactor3. These gla residues in the proteins serve as the sites to bind calcium ions which are required for the optimal activities for these proteins.