Search for new aqueous-aqueous two-phase systems for the countercurrent chromatographic separation of proteins

Abstract

Several aqueous-aqueous polymer two-phase systems were searched for the countercurrent chromatographic (CGC) separation of proteins. The selective separation of ovomucin from egg white was performed by CCC using a two-phase system composed of 15% polyethylene glycol (PEG) 1540-dextran T10-100 mM potassium phosphate at pH 7.0. Ovalbumin, conalbumin and lysozyme having small partition coefficients were eluted from the column with dextran-rich lower phase as a mobile phase. On the other hand, ovomucin with the large partition coefficient showed a high affinity to the upper stationary phase. After elution of the ovalbumin, conalbumin and lysozyme, the ovomucin was collected from the column by pushing out with air. After purification, PEG 1540 and dextran T10 were easily eliminated from the CCC fractions by ultrafiltration for a short time. The proteins in the CCC purified fractions were detected by SDS polyacrylamide gel electrophoresis.