Cross-linking site in fibrinogen for alpha 2-plasmin inhibitor.

摘要: A plasma proteinase inhibitor, alpha 2-plasmin inhibitor (alpha 2PI), is cross-linked with chain of fibrin(ogen) by activated coagulation Factor XIII (plasma transglutaminase). 2PI serves only as a glutamine substrate (amine acceptor) for in the cross-linking reaction, and occurs between Gln-2 molecule lysine residue donor) chain, whose position was investigated. fibrinogen were reacted XIII. The resulting complex separated subjected to two cycles Edman degradation using phenyl isothiocyanate first cycle dimethylaminoazobenzene-isothiocyanate second cycle. aqueous phase after cleavage stage cycle, containing dimethylaminoazobenzene-thiohydantoin-Gln CNBr fragmentation tryptic digestion. Only one peptides found have peak absorbance at 420 nm, indicating presence that peptide. peptide identified corresponding residues Asn-290-Arg-348 analyses NH2-terminal amino acid sequence composition. contains single 303, Lys-303 forms cross-link 2PI.