PREPARATION AND FRACTIONATION OF GOAT KAPPA-CASEIN - ANALYSIS OF GLYCAN AND PEPTIDE COMPONENTS

Whole goat .kappa.-casein was prepared by chromatography of whole casein on hydroxyapatite. Chromatography of whole .kappa.-casein on DEAE-cellulose separated 5 fractions. All of them were sensitive to chymosin. Their amino acid and carbohydrate composition, phosphate content and molecular weight were determined. Galactose, N-acetylgalactosamine, N-acetyl and N-glycolyl neuraminic acids were identified in whole .kappa.-casein. It appears that goat .kappa.-casein, like cow, buffalo and ewe .kappa.-caseins, is composed of several fractions having identical peptide chains and differing in their carbohydrate contents. The main fraction, devoid of carbohydrate, was treated with chymosin. The p-.kappa.-casein and caseinomacropeptide were isolated. Their amino acid composition and phosphate content were determined.