Studies on Activator Formation in Human Plasma with Streptokinase

Summary The plasminogen-streptokinase complex called “activator” was present in diluted plasma in the form of a largely dissociated mixture. More than ⅞ of the streptokinase and plasminogen molecules were available for further activator formation. The activator is probably a dissociated complex of the formula Streptokinase + Plasminogen ⇄ Activator. The fact that an increase in activator concentration by x times is obtained by multiplying either the streptokinase content by the factor y or the plasminogen concentration by the same factor y would point to a kinetic effect along the lines of the mass action law.