The Oxidation of Protein-bound Hydroxylysine by Periodate

Abstract In each of several collagen and gelatin preparations of various origins exposed to the action of 0.06 m alkaline periodate, part of the hydroxylysine resisted destruction by the periodate. The resistant fraction varied from 50% of the total hydroxylysine in bone gelatin to 10% in a citrate-soluble collagen. The resistant fraction was not changed by prolonging the periodate action from 2 min to 2 hours or by digesting gelatin to peptides before the treatment with periodate. It appears that in the periodate-resistant fraction of the hydroxylysine either the hydroxyl group or the amino group of the amino alcohol moiety is bound in covalent combination. Other evidence (20) makes binding of the amino group improbable. Treatment with hydroxylamine under conditions that break ester linkages failed to increase the periodate-resistant fraction of hydroxylysine in bone gelatin, indicating that the resistance was not due to ester linkage of the hydroxyl group.