Preparation of κ-Casein by Gel Filtration

Abstract

A procedure for the preparation of pure K-casein by Sephadex gel filtration is described. Unreduced casein is filtered through a 2.5-by 95-em colmnn of Sephadex G-150 equilibrated with 0.005 ~ triscitrate buffer, pit 8.6, containing 6 urea. K-Casein is excluded from the gel and emerges as a sharp peak at the void volume; all other caseins are retarded by the gel. The method is particularly suitable for preparing pure Kicasein in good yield from small quantities of whole casein, but larger amounts of n-casein are readily prepared. The method is also suitable for the purification of K-casein-rich preparations.