ION-EXCHANGE FAST PROTEIN LIQUID-CHROMATOGRAPHY - OPTIMIZATION OF THE PURIFICATION OF CASEINS USING A NONDENATURING DETERGENT

The separation of bovine milk proteins by fast protein liquid chromatography has been studied by ion-exchange chromatography on Mono S and Mono Q columns. The use of a non-ionic detergent, octyl-glucoside, made possible the separation of the four major casein components αs1, αs2, βand k) as well as minor caseins on the Mono S column using urea containing buffers at pH 3.5. There was, however, considerable overlap between the αs1 and αs2-casein peaks. A good resolution was obtained with a low concentration of urea (3.5 m) and detergent (0.1 %). These conditions allowed the separation of casein components in their native state in less than 50 min. The purity of isolated k-casein was further improved bya second separation on a Mono Q column. © 1990, Proprietors of Journal of Dairy Research. All rights reserved.