Factor X is a vitamin K-dependent protein zymogen which is synthesized in the liver and circulates in plasma as a two chain molecule linked by a disulfide bond (1,2). Prior to secretion into plasma, post-translational modifications produce 11 gamma-carboxyglutamic acid (gla) residues and a single b-hydroxyaspartic acid residue, which are located within the NH2-terminal light chain. The light chain also contains two epidermal growth factor (EGF) homology domains. The COOH-terminal heavy chain of factor X contains most of the carbohydrate moieties, as well as the latent serine protease domain. The activation of factor X is catalyzed by either the intrinsic factor Xase complex (factor IXa, factor VIIIa, cellular surface and calcium ions) or the extrinsic factor Xase complex (factor VIIa, tissue factor, cellular surface and calcium ions). Activation of human factor X by either complex results in cleavage at Arg52-Ile53 of the COOH-terminal heavy chain and subsequent release of a 52 amino acid activation glycopeptide. Factor Xa then serves as the enzyme component of the prothrombinase complex which is responsible for the rapid conversion of prothrombin to thrombin. The gla residues enable factor X/Xa to bind phospholipid (i.e. cell surfaces) in a calcium dependent manner; a requirement for assembly of the prothrombinase complex. The first EGF homology domain contains a Ca2+ binding site which acts as a hinge to fold the EGF and GLA domains towards each other (12). This region of the molecule is involved in the recognition of cellular binding domains.

Human factor X is isolated from fresh frozen human plasma by a combination of conventional techniques (3) and immunoaffinity chromatography (4). In addition to the standard human factor X preparation, Gla-domainless human factor X is also available. Bovine factor X is isolated from fresh bovine plasma using a modification of the procedure reported by Bajaj et al. (5,6). The purified zymogen is supplied in 50% (vol/vol) glycerol/H2O and should be stored at -20oC. Purity is determined by SDS-PAGE analysis and activity is measured in a factor X 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