Thrombomodulin (TM) is an integral membrane glycoprotein expressed on the surface of endothelial cells. Its discovery by Esmon and Owen has focused attention on the importance of the protein C anticoagulant pathway (1,2). TM serves as a cofactor for protein C activation by forming a 1:1 stoichiometric complex with thrombin (Kd=10-10M), which accelerates the rate of protein C activation by 1000-fold relative to the rate with thrombin alone. In addition to facilitating protein C activation, the binding of thrombin to TM drastically alters the procoagulant activity of thrombin. When bound to TM, thrombin no longer clots fibrinogen, activates factor V, inactivates protein S or triggers platelet aggregation.
TM is a single chain protein composed of 5 distinct domains. The domain structure of TM is similar to the low density lipoprotein (LDL) receptor. A short cytoplasmic domain containing a free cysteine is located at the COOH-terminal end and is joined by a membrane spanning region to an O-glycosylation rich domain. The latter is followed by an epidermal growth factor (EGF) homology region and the NH2-terminal hydrophobic domain. The EGF homology region contains 6 EGF-like domains and contains the binding sites for both thrombin and protein C.
Thrombomodulin is isolated from rabbit lung by a modification (3) of the procedure described by Galvin et al. (4) and is supplied as an aqueous solution in 0.02 M Tris, 0.15 M NaCl, pH 7.4, containing 0.05 % polidocanol, and can be stored at -80°C for up to a year. Purity is determined by SDS-PAGE analysis and activity is determined using a chromogenic assay for protein C activation.
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