【项目简介】
Apolipoprotein H (ApoH), also known as β2Glycoprotein I/β2GPI, is a 50 kDa variably glycosylated member of the complement control superfamily of proteins. Mature human ApoH consists of four tandem Sushi/SCR repeats followed by one Sushilike repeat. Mature human ApoH shares 76% and 82% aa sequence identity with mouse and rat ApoH, respectively. Hepatocytederived ApoH binds directly to negatively charged phospholipids. It circulates as a component of lipoprotein particles and as a lipidfree serum protein. ApoH also associates with liposomes and apoptotic cell debris, thereby enabling their renal clearance via Megalin uptake. Circulating levels of ApoH are postively correlated with triglyceriderich lipoprotein (VLDL) components in type II diabetes. ApoH inhibits thrombosis by blocking the activation of Coagulation Factor XI but also shows procoagulant activity by inhibiting the activation of Protein C. ApoH can be cleaved by Plasmin at Lys317 Thr318, an action that is enhanced by heparin. ApoH cleavage reduces its ability to bind phospholipids and inhibit Factor XI activation but confers the ability to bind Plasminogen. 

【检验原理】
本试剂盒采用双抗体夹心ELISA法。酶标微孔板上预包被有抗人ApoH抗体，当加入标准品和待测样本时，标准品和待测样本中的人ApoH会和该抗体结合。洗板后，游离的其他成分被洗去，加入辣根过氧化物酶标记的的抗人ApoH抗体可与被酶标板捕获的人ApoH结合，形成“包被抗人ApoH抗体+人ApoH+抗人ApoH抗体-HRP”免疫复合物。当加入TMB显色底物后，复合物上连接的HRP催化底物反应，生成蓝色产物，终止反应后变为黄色。在450nm处测定OD值，人ApoH浓度与OD450值之间呈正比，可通过绘制标准曲线求出标本中人ApoH的浓度。