Plasminogen (whether Glu-1, Lys-77 or Val-442) is converted to the active serine protease plasmin by hydrolysis of the Arg560-Val561 peptide bond yielding an NH2-terminal heavy (A) chain and a COOH-terminal light (B) chain linked by 2 disulfide bonds (1-3). This conversion is catalyzed by a variety of physiological and pathological activators, including urinary type plasminogen activators, tissue type plasminogen activators, streptokinase, staphylokinase, kallikrein, factors IXa and XIIa. The COOH-terminal derived light chain (Mr=26,000) contains the catalytic triad (His42, Asp85 and Ser180) as well as the streptokinase binding site. The NH2-terminal derived heavy chain ranges in molecular weight from 63,000 to 12,000 depending on the type of plasminogen from which it originated. In the absence of inhibitors, plasmin cleaves the amino-terminal Glu1 to Lys76 peptide from plasmin (plasminogen) to yield Lys-plasmin, which has a greater affinity for fibrin than the Glu form. The heavy chain of Lys-plasminogen contains 5 triple loop disulfide bridged regions of internal sequence homology known as kringles. Kringles 1-4 contain the ω-aminocarboxylic acid and fibrin binding sites.

Plasmin is a serine protease with broad specificity which, in addition to cleavage of fibrin, is capable of activation and/or degradation of compounds of the coagulation, kinin generation and complement systems. Although plasmin can be inhibited by a number of plasma protease inhibitors in vitro, regulation of plasmin in vivo is thought to occur mainly through its interaction with α2-antiplasmin, and to a lesser extent, α2-macroglobulin.

Human Lys-plasmin is prepared from homogeneous Glu-plasminogen using urokinase, as described by Robbins et al. (3). Plasmin is supplied in 50% (vol/vol) glycerol/H2O and should be stored at -20°C. Activity is measured by chromogenic substrate assay and purity is judged by SDS gel electrophoresis.

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