THE SEPARATION OF MAJOR COMPONENTS OF THE CASEIN OF BOVINE MILK BY ELECTROPHORESIS IN A DENSITY GRADIENT

Abstract

Zonal electrophoresis in a column stabilized by a density gradient has been applied to the small-scale fractionation of the proteins of the casein complex of cow''s milk. The [alpha]s-and [beta] -fractions from the milk of individual Ayrshire cows have been shown to behave as single homogeneous proteins on electrophoresis at two pH values in starch gels. The [alpha]s -fraction has been found to be indistinguishable from [alpha]s -casein prepared by Ca2+ fractionation of the same milk samples. On the evidence of their electrophoretic behavior in starch gels and their elementary analyses, [alpha]1- and [alpha]s-casein are concluded to be substantially the same protein.