| Abstract: | Three active-site-acylated derivatives of the activator plasmin-streptokinase complex have been synthesized: n-anisoyl-, n-trans-(N,N,N-trimethylamino)-cinnamoyl- and n-guanidine-benzoyl-plasmin-streptokinase. Their diacylation rate constants were 4.2 x 10(-4), 2.0 x 10(-4) and 0.6 x 10(-4) s-1, respectively. Kinetics of lysis of fibrin clots, containing plasminogen or plasminogen and alpha 2-antiplasmin, by acylplasmin, by a free activator complex and by two acylated activator complexes has been studied. It is shown that in the presence of zymogen and inhibitor the effect of acylactivator, as a fibrinolytic, is 163 times more effective than that of acylenzyme and the fibrinolytic response increases with the doze of acylactivator. The rate of fibrinolysis by a free plasmin-streptokinase complex was higher without the inhibitor than that of fibrinolysis by its acylated derivatives; fibrinolytic action of acylactivators was more effective in the presence of the inhibitor. |
