Human factor VII is a single chain plasma glycoprotein, and is a zymogen in its native form (1-4). Proteolytic activation of factor VII, yields the enzyme factor VIIa, which when bound to the integral membrane protein tissue factor, forms an enzyme complex that proteolytically converts factor X to factor Xa. This enzyme complex is best known as the extrinsic factor Xase (pronounced ten-ase) complex, since by virtue of its tissue factor component, it is composed of protein normally extrinsic to the plasma environment.
The conversion of factor VII to factor VIIa is catalyzed by a number of proteases including thrombin, factor IXa, factor Xa, factor XIa, and factor XIIa. Rapid activation also takes place when factor VII is combined with tissue factor in the presence of calcium (5-9). This latter event is consistent with autocatalysis, and is likely initiated by a small amount of pre-existing factor VIIa. The activation reaction results in cleavage of the peptide bond between arginine 152 and isoleucine 153.
The resulting factor VIIa consists of an NH2-derived light chain (Mr=20,000), and a COOH-terminal derived heavy chain (Mr= 30,000), which remain associated through a single disulfide bond (cys 135 - cys 262). The light chain contains the membrane binding "Gla domain", while the heavy chain contains the catalytic domain.
Unlike other serine proteases, factor VIIa alone is not readily inhibited by the antithrombin III/heparin complex. However, in the presence of tissue factor, antithrombin III/heparin exhibits significant inhibition of factor VIIa (6).
Human factor VIIa is prepared from affinity purified factor VII, and purified by ion exchange chromatography. The purified protein is supplied in 50% (vol/vol) glycerol/H2O and should be stored at -20°C. The purity is determined by SDS-PAGE analysis, and activity is measured in a factor VII clotting assay.
Haemtech Biopharma可以运行多种分析技术,以提供对蛋白质药物产品或物质的生化分析,或帮助进行污染物鉴定。我们的测定,测试和技术菜单包括:应用领域IVIG药物的血栓形成性过程中杂质分析与止血有关的抗药物抗体测试(免疫原性)例如抗凝血因子抗体宿主细胞蛋白质的鉴定,定量和缓解在制品和在制品中药品的稳定性和释放测试与止血相关的重组蛋白的效力和纯度测定血浆蛋白分析蛋白质的结构表征翻译后修饰二硫键映射构象变化凝血测定试剂(例如凝血活酶)的表征定制的凝血产品检测应用药代动力学研究分析鉴定/验证工艺/产品验证蛋白质纯化方法的发展强迫降解研究方法高效液相色谱反相(RPC)大小排除(SEC)离子交换(IEC)疏水相互作用(HIC)金属亲和力(IMAC)蛋白质A(用于IVIG分析)SDS页面减少和不减少一维和二维考马斯亮蓝染色银染荧光染色免疫印迹多重分析定量化凝血测定因子分析(II,V,VII,VIII,IX,X,XI,XII,XIII等)PTPTPT行动计划福尔摩斯测试其他ELISA法各种显色测定因子分析(II,V,VII,VIII,IX,X,XI,XII,XIII等)其他翻译后修饰分析糖基化,硫酸化,磷酸化,羟基化,脱酰胺,乙酰化,氧化,氨基甲酸酯化和γ-羧化凝血酶生成测定对于IVIG和其他抗药物抗体ELISA(ADA)抗原料药抗体抗宿主细胞蛋白的抗体抗污染物或分解产物的抗体鉴定未知质谱N端测序残留水分测定顶空真空测量pH值渗透压折光率总蛋白质配方评估