【项目简介】
Histidine-rich glycoprotein, also known as HRG and HPRG, is a glycoprotein located in plasma and platelets, and contains an unusually large amount of histidine and proline. In human, five distinct domains are recognized in the mature HPRG molecule. There are two N-terminal cystatin-like modules (aa 19 - 254) and one His-Pro-rich region (aa 350 - 497) that is flanked by two Pro-rich segments (aa 276 - 321 and 498 - 525). The His-Pro-rich region contains 10 tandem repeats with an HHPHG motif, and the N- and C-termini are linked by a disulfide bond. The specific functions of HRG remain unclear, but it is known that the protein binds heme, dyes and divalent metal ions. It inhibits rosette formation and interacts with heparin, thrombospondin and plasminogen. Two of the protein's effects, the inhibition of fibrinolysis and the reduction of inhibition of coagulation, indicate a potential prothrombotic effect. HPRG is evolutionarily, functionally and structurally related to cleaved high molecular weight kininogen (HKa), an anti-angiogenic polypeptide that stimulates apoptosis of proliferating endothelial cells through binding to cell-surface tropomyosin. 
 
【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HPRG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HPRG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HPRG抗体可与被酶标板捕获的人HPRG结合，形成“包被抗人HPRG抗体+人HPRG+抗人HPRG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HPRG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HPRG的浓度。