Factor XIII‐mediated cross‐linking of NH2‐terminal peptide of α2‐plasmin inhibitor to fibrin

Abstract

The NH₂-terminal 12-residue peptide of α₂-plasmin inhibitor, Asn—Gln—Glu—Gln—Val—Ser—Pro—Leu—Thr—Gly—Leu—Lys—NH₂ ·AcOH, was found to be a good substrate for plasma transglutaminase (activated blood coagulation factor XIII) and rapidly incorporated into fibrin by the enzyme. A high concentration of the peptide inhibited the enzyme-mediated cross-linking of α₂-plasmin inhibitor to fibrin probably by competing with the inhibitor for the same site of fibrin α-chain.