Effects of Salts on the Partition of Proteins in Poly (ethylene glycol)-Dextran Aqueous Two Phase System

Poly(ethylene glycol)-dextran 수용액 2상계에서 단백질 분획계수에 미치는 금속염의 효과

  • Lee, Sam-Pin (Department of Food Technology, Korea University) ;
  • Lee, Cherl-Ho (Department of Food Technology, Korea University)
  • 이삼빈 (고려대학교 식품공학과) ;
  • 이철호 (고려대학교 식품공학과)
  • Published : 1987.04.01


The effects of pH and added salts on the partition coefficients of proteins in a polyethylene glycol)-dextran aqueous two-phase system were investigated. The partition coefficients attained the lowest value at the isoelectric point of proteins in an equal volume aqueous two-phase system containing 5% PEG and 9.5% dextran in 5 mM phosphate buffer solution. The coefficients increased dramatically at pH 11; BSA which had highest effective hydrophobicity marked 50-fold increase, while ${\beta}-lactoglobulin$ and ovalbumin which had low hydrophobicity 10-fold increase, respectively. The effect of added salts varied with the pH. The partition coefficient increased by the addition of salt at pH 3.0 but decreased drastically at pH 7.0. The partition coefficient increased in the order of added Li < Na < K at pH 3.0 and decreased in the order of added Li < Na < K at pH 11.0.