AssayPro—Human PAI-1 Chromogen

Introduction
Type I plasminogen activator inhibitor (PAI-1) is a 50 kDa serpin family member that inhibits tissue- and urokinase-type plaminogen activators (t-PA, u-PA). This protein appears to be an important regulator of plasminogen activation by t-PA and extracellular proteolysis by u-PA (1, 2, 3). The plasminogen activator proteolytic enzyme systems are important not only for fibrinolysis but also for extracellular matrix remodeling, and have been implicated in a number of normal and pathological processes including angiogensis, ovulation and embryogenesis, thrombotic and hemorrhagic disorders, connective tissue diseases, neoplasm and sepsis (4, 5). PAI-1 is a prognosticator in breast cancer (6), gastric cancer (7), various forms of lung cancer (8) and cervical cancer (9).

【介绍】
纤溶酶原激活剂抑制物（PAI-1）是一种分子量为43KDa丝氨酸蛋白酶抑制物家族成员，主要作用是抑制组织型和尿激酶型纤溶酶原活化剂（t-PA，uPA）。PAI-1在调节t-PA活化纤溶酶原和uPA在细胞外间质的蛋白水解有重要作用。纤溶酶原激活剂的蛋白水解酶系统不仅对纤溶是重要的，对下面过程也是很重要的：即细胞外间质的再生；参与许多正常和病理的过程如血管的生成、排卵、胚胎的形成、血栓和出血的疾患；结缔组织病变，瘤和败血症等。
PAI-1是乳房癌、胃癌、各种肺癌和子宫颈癌的一个预后指标。

Principle of Assay
The AngioSense Human PAI-1 Chromogenic Activity Assay Kit is developed to determine human PAI-1 activity in cell culture supernatants. A fixed amount of tPA is added in excess to undiluted sample, which allows PAI-1 and tPA to form an inactive complex. The assay measures plasminogen activation by residual tPA in coupled assays that contain tPA, plasminogen, and a plsmin-specific synthetic substrate. The amount of plasmin produced is quantitated using a highly specific plasmin substrate releasing a yellow para-nitroaniline (pNA) chromophore. The absorbance of the pNA at 405 nm is inversely proportional to the PAI-1 enzymatic activity.