Structural variability of the neutral carbohydrate moiety of cow colostrum kappa-casein as a function of time after parturition. Identification of a tetrasaccharide with blood group I specificity

Abstract

New neutral oligosaccharides from cow colostrum -casein were identified and characterized by 500-MHz 1H-NMR spectroscopy. Their structures are Galbeta(1->3)GalNAc-ol, Galbeta(1->3)[GlcNAcbeta(1->6)]GalNAc-ol, Galbeta(1->3)[Galbeta(1->4)GlcNAc(beta1->6)]GalNAc-ol, Galbeta(1->3){Fucalpha(1->3)[Galbeta(1->4)]GlcNAcbeta(1->6)}Gal-NAc-ol. The tetrasaccharide and the cow colostrum kappa-caseinoglycopeptide which contains this oligosaccharide inhibit the hemagglutination of blood group I human erythrocytes. In cow mature milk only the disaccharide is characterized. The variability of these neutral oligosaccharides in cow kappa-casein as a function of time after calving is studied.