Plasmin is an important enzyme () present in blood that degrades many blood plasma proteins, most notable, fibrin clots. The degradation of fibrin is termed fibrinolysis.

Functions

It is a serine protease that is released as plasminogen from the liver into the circulation and activated by tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), thrombin, fibrin, and factor XII (Hageman factor). It is inactivated by alpha 2-antiplasmin, a serine protease inhibitor (serpin).

Apart from fibrinolysis, plasmin proteolyses proteins in various other systems: It activates collagenases, some mediators of the complement system and weakens the wall of the Graafian follicle (leading to ovulation). It cleaves fibrin, fibronectin, thrombospondin, laminin, and von Willebrand factor.

Fibrinolysis (simplified). Blue arrows denote stimulation, and red arrows inhibition.

Pathology

Deficiency in plasmin may lead to thrombosis, as clots are not degraded adequately.

Further reading

External links

de:Plasmin es:Plasminógeno it:Plasmina ja:????? pl:Plazmina pt:Plasmina