Genetic Polymorphism in Caseins of Cow's Milk. IV. Isolation and Properties of β-Caseins A, B, and C

Abstract

A convenient method is presented for obtaining the genetic variants of [beta]-casein in high purity utilizing DEAE-cellulose chromatography in the presence of 3.3 M as a dissociating agent. Furthermore, the separation of heterozygous mixtures of the [beta]-casein variants may be accomplished with column chromatography by simple manipulation of salt elution gradients. [beta]-caseins A, B and C contained 15.18, 15,33, and 15.45% nitrogen, respectively, and 0.59, 0.57 and 0.50% phosphorus. The genetic forms of [beta]-caseins may be conveniently identified by their relative electrophoretic mobilities on starch-gel and polyacrylamide-gel.