THE MOLECULAR-WEIGHT DISTRIBUTION AND THE HYDROLYSIS MECHANISM OF GELATIN BY DILUTE HYDROCHLORIC-ACID

Hydrolysis of gelatin by diluted hydrochloric acid has been believed to proceed through random breakdown of the polypeptide. This standpoint was examined through determination of the molecular weight distribution of the hydrolytic product of alkali-processed gelatin (isoionic point, pH 4.8 ; alpha-gelatin rich) by gel permeation chromatography using Asahipak GS-620 and GS-310 columns. The GPC chromatogram obtained at the middle stage of hydrolysis was bell-shaped, and agreed well with that drawn based on the theory of Sakurada and Okamura in which the hydrolytic rupture is assumed to proceed with equal probability for all main chain bonds linking the monomers.