[Isolation and properties of acylplasmin].

Plasmin, free of an activator, was obtained after activation of the highly purified human plasminogen by means of trypsin immobilized on Sepharose 4B and after removal of the enzyme from the system. Plasmin was acylated at the active centre using p-amidinophenyl ester of p'-anisic acid to produce the fibrinolytic agent causing a long-term effect. Inactive acyl plasmin was deacylated with the constant rate k3 = 3.10(-4) c-1 (r1/2 = 40 min) at pH 7.4 and 37 degrees. Preliminary studies of the anisoyl-plasmin effect on the system of fibrinolysis in rats showed that in the absence of fibrin clot the fibrinolytic activity was not increased immediately in the euglobulin fraction of blood but after 30 min in result of deacylation of the acyl-enzyme administered into circulation.