Summary
A procedure is described for partial purification of an inhibitor of the activation
of plasminogen by urokinase and streptokinase. The method involves specific adsorption
of contammants, ion-exchange chromatography on DEAE-Sephadex, gel filtration on Sephadex
G-200 and preparative electrophoresis. The inhibitor fraction contained no antiplasmin,
no plasminogen, no α1-antitrypsin, no antithrombin-III and was shown not to be α2 M or inter-α-inhibitor. It contained traces of prothrombin and cerulo-plasmin. An
antiserum against the inhibitor fraction capable of neutralising the inhibitor in
serum was raised in rabbits.
