【项目简介】
Hemopexin (HPX) is a 60 kDa plasma glycoprotein with two four-bladed β-propeller folds. This structural motif has been found in other proteins including collagenases and provides sites for proteinprotein interactions . The liver is the major synthesizing organ. Expression in the central nervous system, in the retina, and in peripheral nerves has also been observed. Hemopexin belongs to the family of the acutephase proteins whose synthesis is induced after an inflammatory event. Hemopexin participates in maintaining and recycling the iron pool by utilizing its high binding affinity toward heme composed of protoporphyrin IX and iron. It also functions in preventing oxidation caused by heme after hemolysis. Hydrophobic heme molecules can intercalate into lipid membranes and participate in the oxidation of lipid membrane components through the Fenton reaction resulting in lipid peroxidation. Hemopexin undergoes a conformational change upon the binding of heme. The conformational change allows hemopexin to interact with a specific receptor, forming a complex which is then internalized. In the plasma, it is likely that heme binds albumin (35-55 g/L) first because of the higher concentration of albumin in plasma than hemopexin (0.5-1.2 g/L), and is then transferred to hemopexin, which has a much higher affinity (Kd ~1 pM) toward heme.
 
【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Hemopexin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Hemopexin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Hemopexin抗体可与被酶标板捕获的人Hemopexin结合，形成“包被抗人Hemopexin抗体+人Hemopexin+抗人Hemopexin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Hemopexin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Hemopexin的浓度。