[Effect of low-molecular peptides on the transformation of fibrinogen into fibrin].

The influence of synthetic peptides on fibrinogen transformation to fibrin under the action of thrombin and fibrin-monomer polymerization was investigated. Peptides Gly-Pro-Arg-Pro; Gly-Pro-Arg-Pro-Lys; Gly-Pro-Arg-Pro-Lys-Boc; Gly-Pro-Arg-Pro-Arg are specific inhibitors of fibrin formation. These peptides interfere with the hydrolysing effect of thrombin due to binding to the central domain of fibrinogen. The interaction of peptides with peripheral D-domains of fibrin-monomer may account for polymerization inhibition. The latter peptide has the largest anticoagulation activity. It is likely that arginine in the fifth position stabilizes the structure of the peptides, with the additional epsilon NH2-group activating its interaction with protein.