Isoelectric Focusing Studies on the Distribution of Uroproteins with Plasminogen Activator Activity

ABSTRACT By means of isoelectric focusing and gel filtration uroprotein concentrates as well as urokinase preparations were investigated. The distribution of molecular weights with UK activity was found different when the native uroprotein concentrate was analysed in comparison to the analysis of uroprotein fractions obtained by isolectric focusing. In the latter material the S 2 type of UK with molecular weight 54, 700 was no more detectable. It is assumed that S 2 UK is composed of the S 1 and an inert protein. Uroproteins obtained after physical exertion showed a predominance of the S 1 type of UK, while the concentrations of uroproteins with pI = 5.0 or below and their plasminogen activator activities remained unaltered.