Physical and Chemical Properties of Bovine Milk and Colostrum Whey M-1 Glycoproteins

Abstract

The M-1 acidic glycoprotein fractions isolated from samples of bovine colostrum and milk whey, although homogeneous by ultracentrifugal and boundary electrophoresis criteria, contained several N-terminal amino acids, and probably consisted of a series of closely related molecular species. Their average molecular weights were near 10,000 with high [beta]-values and negative specific rotations, indicating highly disorganized structures. Amino acid analysis showed high percentages of glutamic acid, proline, threonine, and isoleucine, and unusually low amounts of the basic amino acids. Monosaccharides found in the colostrum M-l glycoprotein fractions were galactose, glucosamine, galacto-samine, and sialic acid, the latter being easily removable by viral neuraminidase.