牛血清清蛋白(BSA)在双水相体系中分配特性的研究

Partition of BSA in Aqueous Two phase System

采用聚乙二醇／硫酸盐体系：ＰＥＧ／（ＮＨ４）２ＳＯ４研究成相条件、始加ＢＳＡ总浓度、ｐＨ值及外加盐ＮａＣｌ对ＢＳＡ在双水相体系中的分配特性的影响．结果表明，一般情况下，ＢＳＡ适宜于分配在下相；ｐＨ值的变化对分配系数影响不大；外加ＮａＣｌ对ＢＳＡ在两相中的分配产生很大的影响，由通常的ＢＳＡ宜分配于下相转变成宜分配于上相及上相表层；通过改变起始ＢＳＡ在溶液中的总浓度，得到平衡时上、下相ＢＳＡ浓度随起始ＢＳＡ总浓度变化的曲线方程，上相宜用“饱和型”方程表示，下相适合用线性方程表示，将上、下相ＢＳＡ浓度之比得到的平衡常数Ｋ的表达式与实验数据拟合较好．

The partition of BSA in polyethylene glycol(PEG) sulphate aqueous two phase system has been investigated at different concentrations of PEG,sulphate and neutral salt,at different pH values,and at varying overall BSA concentrations.Ordinarily,BSA favors to exist in bottom phase.The BSA partition coefficient is increased with the increasing of NaCl concentrations.pH values have a slight effect on BSA partition coefficient.The BSA concentration in top phase has been correlated with a ″saturation″ type equation and the BSA concentration in bottom phase has been correlated with a linear type equation.The partition coefficient could be satisfactorilly predicted,as a function of the overall BSA concentration,by the ratio between the ″saturation″ equation of the top phase and the linear equation of the bottom phase.