Influence of glycosylation on micelle-stabilizing ability and biological properties of C-terminal fragments of cow's kappa-casein

C-terminal fragment of bovine kappa-casein contains glycosidic residues. There are several glycoforms of kappa-casein containing different kinds and numbers of glycosidic residues. Such heterogeneity affects properties of this protein and its fragments. The C-terminal fragment of cow's kappa-casein (residues: 106-169) is the main factor stabilizing casein micelles. Glycosidic moieties connected to this fragment enhance the ability of kappa-casein to stabilize micelles and also the resistance of this protein to the action of proteolytic enzymes and high temperature in simple model systems. kappa-Casein, its C-terminal fragment (macropeptide or glycomacro-peptide) or products of its proteolysis can inhibit proliferation of lymphocytes B, binding Cholera toxin to its receptor, hemagglutination of influenza virus, adhesion of bacteria to cell surface, acid secretion in the stomach, as well as stimulate the release of cholecystokinin in the intestinal cells and the growth of Lactococcus lactis bacteria. Glycosidic moieties may act as an information carrier enabling recognition of compounds (e.g. components of cells) interacting with kappa-casein, glycomacropeptide or its fragments. Copyright (C) 1996 Published by Elsevier Science Limited.