Purification of human plasminogen and plasmin by gel filtration on Sephadex and chromatography on diethylaminoethyl-Sephadex.

Highly purified human plasminogen has been prepared from a variety of plasma fractions and by different purification methods. The two major fractions used have been serum or plasma euglobulin and Cohn plasma Fraction III. The purification methods (1-14) have all yielded products of high purity. Plasminogen useful for further purification and isolation studies can be prepared by the Kline method (3). High purity plasmin can be prepared from Kline method plasminogen by activation with streptokinase (15). The purpose of this study was to develop new methods for the preparation of pure plasminogen and plasmin. The Kline method was first modified to give a more reproducible procedure, with better yields. Plasminogen was precipitated, in the final step, at pH 6.0, with NaH2P04. The use of plasma Fraction IIT2,3 instead of Fraction III as the starting material resulted in higher yields of proenzyme and gave preparations with higher specific activities. Gel filtration through Sephadex columns and chromatography on diethylaminoethyl-Sephadex columns resulted in preparations of highly purified proenzyme and enzyme. Ultracentrifugal and electrophoretic analysis, gel diffusion (Ouchterlony), and immunoelectrophoretic studies were carried out to characterize and to determine homogeneity of the proenzyme and enzyme.