The N-terminal pentapeptide of α2-plasmin inhibitor, H-Asn-Gln-Glu-Gln-Val-OH, and its analogue, H-Asp-Gln-Glu-Gln-Val-OH, were synthesized and their inhibitory effects on the cross-linking reaction of α2-plasmin inhibitor to fibrin mediated by factor XIIIa were examined. The synthetic peptides were inhibitory at high concentration.
