Mechanism of inhibition of fibrinolysis and fibrinogenolysis by the end fibrinogen degradation products.

Influence of the end fibrinogen-derived DH, DL and E fragments on fibrinolysis and fibrinogenolysis has been studied. Electrophoresis of the plasmin-digested unstabilized fibrin and fibrinogen showed that fragment E was the only inhibitor of plasmin hydrolysis of fibrinogen, the antifibrinolytic activity of the fragments being increased in a DL < E < DH series. The fragments were revealed by means of elastic light scattering and analytical ultracentrifugation to be arranged in a E > DL > DH series by their ability to form a complex with plasminogen. It was concluded that the complex formation did not greatly contribute to the mechanism of fibrinolysis inhibition. Antifibrinolytic effect of fragment DH is due to its antipolymerization activity. The paper discusses the competitive protein-protein interactions occurring on a polymeric matrix of fibrin.