NATURE OF A HYDROXYLAMINE-SENSITIVE BOND IN COLLAGEN

A cyanogen bromide peptide (α1-CB8) from the α1 chain of rat collagen was cleaved with hydroxylamine. Isolation of the relevant tryptic peptides from a resistant fraction of α1-CB8 and from the two hydroxylamine-produced fragments permitted the characterization of the susceptible bond. The data indicate that degradation of α1-CB8 results from cleavage of a cyclic imide, the derivative of a normal peptide bond which forms by condensation of an aspartyl (or asparaginyl) side chain with the subsequent amide nitrogen in the polypeptide chain. Such cyclic imides may represent the bonds presumed to link subunits within collagen chains. © 1969.