Abstract: Method for the isolation of urokinase from human urine in which the urokinase is adsorbed and thereafter eluted with aqueous cation surfactant mixture. Novel carboxyalkyl cellulose is utilized as a preferred adsorbent.

Abstract: A novel plasminogen activating enzyme-specific competitive inhibitor is disclosed consisting of an amino-terminated .alpha.-N-substituted aminocarboxylic acid, such as .alpha.-N-benzylsulfonyl-p-aminophenylalanine, or the acid derivatives thereof. The competitive inhibitor ligand, when covalently coupled to the surface of a water-insoluble solid support material through a spacer chain of at least 4 carbon atoms, is useful as a biospecific extracting agent for use in affinity chromatography of plasminogen activating enzymes, such as urokinase, cytokinase, and the like, from crude aqueous preparations thereof, such as mammalian urine, mammalian body tissue preparations, mammalian plasma and spent tissue culture growth medium.