Partial purification and characterization of keratokinase, the fibrinolytic activator of the cornea.

Keratokinase (KK) is a fibrinolytic enzyme released by in vitro cultures of cornea. KK converts plasminogen into plasmin producing on the molecule of plasminogen the same pattern of limited proteolysis as urinary activator, urokinase (UK) does. The mol. wt. of KK is around 55 000 daltons, i.e. in the same range of that of UK. Like UK, but unlike tissue activator (TA, derived from vascular endothelium) KK shows a biphasic activity response to increasing concentrations of epsilon aminocaproic acid (EACA) and is scarcely bound to fibrin during clotting.KK may play a role in a number of pathophysiological states of the cornea such as corneal swelling, inflammation and collagen metabolism.