PARTIAL CHEMICAL CHARACTERIZATION OF ISOLATED GAMMA-CHAIN OF HUMAN FIBROGEN

The S-sulfo-γ-chain of human fibrinogen has been isolated and characterized with respect to end terminal groups, molecular weight, and amino acid and carbohydrate composition. The molecular weight, as determined by the isotopic recovery of the N-terminal amino acid, tyrosine, was 47,000-50,000. The C-terminal sequence revealed by the action of carboxypeptidase A was -(Ser, Ala, Gly)-Asp-Val. Two glycopeptides isolated from a tryptic digest of S-sulfo-γ-chain were found to contain essentially all of the solubilized carbohydrate. A single site of attachment of the carbohydrate moiety (3 glucosamine and 7 hexose residues) to the peptide chain is postulated. © 1969.