Abstract
Gel permeation chromatography (CPC) and temperature solubility were used to isolate different molecular weight fractions of several photographic gelatins. The dependence of the amino acid composition of impurities and metal ion contents on molecular xveight was investigated. The lower molecular weight fraction had an unusual amino acid composition. The difference in amino acid composition was observed according to the raw material species, the methods of manufacture and those of fractionation. This lower molecular weight fraction contained more tyrosine, histidine, methionine, hydroxylysine and hydrophobic amino acids than the original gelatin, while it contained less lysine, alanine and acidic amino acids than the original gelatin. It was considered that the low molecular weight fraction contained a certain amount of telopeptide, peptide from the a2 (1) chain and non- collagenous proteins. High contents of iron and calcium ions as impurities were observed in higher and lower molecular weight fractions.
Notes
Paper presented at the Annual Meeting of SPSTJ held in Tokyo, Japan 30-31 May 1995.