Characterization of the cleavage products of human serum immunoglobulin disulphide bonds. II. S-Cyano derivatives

Abstract

The displacement by cyanide ions of S-sulpho substituents from sulphitolysed human serum immunoglobulins yielded S-cyano derivatives, the solubility and sedimentation characteristics of which were examined with respect to pH. Exclusion chromatography gave rise to an aggregated and an unaggregated fraction in proportions similar to those found after oxidative sulphitolysis. Evidence obtained from immunoelectrophoresis, N-terminal amino acid assay, and hexose and amino acid analysis showed that both S-cyano fractions contained polypeptide chains in the same ratios as in the native protein.