tissue-type plasminogen activator

a natural protein, found in the body and now able to be manufactured by genetic engineering ( see ALTEPLASE ), that can break up a thrombus (see THROMBOLYSIS ). It requires the presence of FIBRIN as a cofactor and is able to activate PLASMINOGEN on the fibrin surface, which distinguishes it from the other plasminogen activators, STREPTOKINASE and UROKINASE .