Constitutively active human plasminogen activator inhibitor 1, stable mutant 14-1B having a Molecular mass of 43 kDa. This human form of SERPINE1 contains the following four mutations: K154T, Q139L, M354I and N150H. These mutations combine to confer great stability to the otherwise labile molecule essentially locking it into the active conformation. The SERPINE1 is purified by proprietary chromatographic techniques.
Plasminogen activator inhibitor-1 is the principal inhibitor of tissue plasminogen activator(tPA) and urokinase(uPA), the activators of plasminogenand hence fibrinolysis(the physiological breakdown of blood clots). It is a serine protease inhibitor(serpin) protein (SERPINE1). The other PAI, plasminogen activator inhibitor-2(PAI-2) is secreted by the placentaand only present in significant amounts during pregnancy. In addition, protease nexinacts as an inhibitor of tPA and urokinase. PAI-1, however, is the main inhibitor of the plasminogen activators.