Variants of κ-Casein Revealed by Improved Starch Gel Electrophoresis

Abstract

Addition of low concentrations of cysteine or mercaptoethanol to the concentrated urea solutions for zone electrophoresis in starch gel markedly improved the resolution of K-casein zones in both unfractionated acid casein and various preparations of K-casein permitting demonstration of variation of K-casein in individual milks. Zones (2) occur (singly and in combination) in variable proportions. Stable differences in the protein moieties may represent genetically controlled variant forms of K-casein.