Histidine-rich glycoprotein and alpha 2-plasmin inhibitor in inhibition of plasminogen binding to fibrin.

The plasma proteins alpha 2-plasmin inhibitor and histidine-rich glycoprotein were compared directly with respect to their effectiveness in inhibiting the binding of plasminogen to fibrin under the same experimental conditions. At their physiological concentrations, the presence of alpha 2-plasmin inhibitor more markedly decreased the binding of plasminogen to fibrin than histidine-rich glycoprotein. Significance of these findings in inhibition of fibrinolysis is discussed.