【项目简介】
uPA is a serine protease with an extremely limited substrate specificity, cleaving the sequence CysProGlyArg560Val561ValGlyGlyCys in plasminogen to form plasmin. uPA is a potent marker of invasion and metastasis in a variety of human cancers associated with breast, stomach, colon, bladder, ovary, brain and endometrium. For example, the combination (both low vs. either or both high) of uPA and its inhibitor, plasminogen activator inhibitor1 (PAI1), outperforms the single factors as well as other traditional prognostic factors with regard to risk group assessment for breast cancer, particularly in nodenegative breast cancer. The human uPA is initially synthesized as 431 amino acid precursor with a Nterminal signal peptide (20 residues). The single chain molecule is processed into a disulfidelinked twochain molecule. The B chain starting at Ile179 corresponds to the catalytic domain. Two forms of the A chain exist, one starting at Ser21 (the long form) and the other at Lys156 (the short form). The resulting twochain forms have different molecular weights (MW). The B chain is common for both forms whereas the long and short A chains are unique to the high and low MW forms, respectively.
 
【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Urokinase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Urokinase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Urokinase抗体可与被酶标板捕获的人Urokinase结合，形成“包被抗人Urokinase抗体+人Urokinase+抗人Urokinase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Urokinase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Urokinase的浓度。