High performance gel and ion-exchange chromatography of buffalo casein

Abstract

Buffalo casein was separated into 3 fractions by high performance gel chromatography on a TSK-GEL G3000SW column using 50 mM phosphate buffer (pH 6·7) containing 6 m urea and 0·3 m NaCl. The first and second eluted fractions contained κ- and α s 2 -caseins, respectively. Buffalo casein was also separated into 5 fractions (κ-, unidentified, β-, α s 2 - and α s 1 -caseins) by high performance ion-exchange chromatography on a TSK-GEL DEAE-5PW column, although the α s 1 - and α s 2 -casein fractions overlapped. The relative composition of Egyptian buffalo casein was 36·9% α s 1 -casein, 9·3% α s 2 -casein, 35·8% β-casein, 13·2% κ-casein and 4·8% unidentified casein when κ- and α s 2 -casein contents were estimated by high performance gel chromatography and the other caseins by high performance ion-exchange chromatography.