Amino acid sequence and posttranslational modifications of human factor VIIa from plasma and transfected baby hamster kidney cells.
Amino acid sequence and posttranslational modifications of human factor VIIa from plasma and transfected baby hamster kidney cells.
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DOI：
10.1021/bi00420a030
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发表时间：
1988-10
期刊：
影响因子：
2.9
通讯作者：
L. Thim;S. Bjoern;M. Christensen;E. Nicolaisen;T. Lund-Hansen;A. Pedersen;U. Hedner
中科院分区：
文献类型：
--
作者：
L. Thim;S. Bjoern;M. Christensen;E. Nicolaisen;T. Lund-Hansen;A. Pedersen;U. Hedner
凝血因子VII是维生素K依赖性糖蛋白，其活化形式因子VIIa通过在Ca 2+和组织因子存在下活化因子X和/或因子IX参与凝血过程。在人因子VIIa分子中存在三种类型的潜在翻译后修饰，即10个γ-羧基化的、位于N-末端的谷氨酸残基、1个β-羟基化的天冬氨酸残基和2个N-糖基化的天冬酰胺残基。在本研究中，已将从转染的幼仓鼠肾细胞系的培养基中纯化的重组因子VIIa的氨基酸序列和翻译后修饰与人血浆因子VIIa进行了比较。通过使用HPLC、氨基酸分析、肽图谱和自动Edman降解，发现重组因子VIIa的蛋白质骨架与人因子VIIa相同。重组因子VIIa和人血浆因子VIIa均不含β-羟基天冬氨酸。在人血浆因子VIIa中，发现10个位于N-末端的谷氨酸残基被完全γ-羧化，而在重组因子VIIa分子的相应位置发现9个完全和1个部分γ-羧化残基。天冬酰胺残基145和322被发现是完全N-糖基化的人血浆因子VIIa。在重组因子VIIa中，天冬酰胺残基322被完全糖基化，而天冬酰胺残基145仅被部分（约66%）糖基化。除了唾液酸和岩藻糖含量的微小差异外，重组凝血因子VIIa和人血浆凝血因子VIIa的总体碳水化合物组成几乎相同。（250字处删节）
Blood coagulation factor VII is a vitamin K dependent glycoprotein which in its activated form, factor VIIa, participates in the coagulation process by activating factor X and/or factor IX in the presence of Ca2+ and tissue factor. Three types of potential posttranslational modifications exist in the human factor VIIa molecule, namely, 10 gamma-carboxylated, N-terminally located glutamic acid residues, 1 beta-hydroxylated aspartic acid residue, and 2 N-glycosylated asparagine residues. In the present study, the amino acid sequence and posttranslational modifications of recombinant factor VIIa as purified from the culture medium of a transfected baby hamster kidney cell line have been compared to human plasma factor VIIa. By use of HPLC, amino acid analysis, peptide mapping, and automated Edman degradations, the protein backbone of recombinant factor VIIa was found to be identical with human factor VIIa. Neither recombinant factor VIIa nor human plasma factor VIIa was found to contain beta-hydroxyaspartic acid. In human plasma factor VIIa, the 10 N-terminally located glutamic acid residues were found to be fully gamma-carboxylated whereas 9 full and 1 partial gamma-carboxylated residues were found in the corresponding positions of the recombinant factor VIIa molecule. Asparagine residues 145 and 322 were found to be fully N-glycosylated in human plasma factor VIIa. In the recombinant factor VIIa, asparagine residue 322 was fully glycosylated whereas asparagine residue 145 was only partially (approximately 66%) glycosylated. Besides minor differences in the sialic acid and fucose contents, the overall carbohydrate compositions were nearly identical in recombinant factor VIIa and human plasma factor VIIa.(ABSTRACT TRUNCATED AT 250 WORDS)