AND II: THEIR ACTIVATION BY UROKINASE IN THE PRESENCE OF FIBRIN AND FIBRINOGEN

Two isozymes of a native form of human plasminogen (pig), Glu-plg I and II, were isolated. Glu-plg I or II was activated by urokinase (UK) or streptokinase (SK) in the presence of fibrinogen or fibrin, The activation of Glu-plg I was enhanced more than that of Glu-plg II in the presence of fibrin, Fibrin caused better activation of both Glu-plg I and II than fibrinogen, When fibrinolysis or fibrinogenolysis was measured, fibrin was degraded faster than fibrinogen after the activation of Glu-plg I and II by UK. These results suggest that the activation of Glu-plg I was enhanced more than that of Glu-plg II in the presence of fibrin or to less extent fibrinogen,