A member of the serpin superfamily found in plasma that inhibits the lysis of fibrin clots which are induced by plasminogen activator. It is a glycoprotein, molecular weight approximately 70,000 that migrates in the alpha 2 region in immunoelectrophoresis. It is the principal plasmin inactivator in blood, rapidly forming a very stable complex with plasmin.

Synonyms: 0, Serpin F2, alpha 2 Plasmin Inhibitor, alpha 2-Plasmin Inhibitor, alpha(2)-Plasmin Inhibitor, alpha-2-Antiplasmin, alpha 2 Antiplasmin, alpha-2 Antiplasmin