反离子对部分电荷中和的聚乙烯亚胺接枝介质的蛋白质色谱行为的影响

Effect of counterions on protein adsorption to partial neutralization poly(ethylenimine)-grafted Sepharose FF

前期研究表明部分电荷中和的聚乙烯亚胺接枝琼脂糖介质FF-PEI-R440具有较高静态吸附容量和快速传质速率。本文选取硫氰酸根离子、氯离子、磷酸氢根离子以及硫酸根离子这4种反离子,在离子强度为0.03、0.06mol·L^(-1)下,研究其对FF-PEI-R440吸附与洗脱行为的影响。结果表明:在两种离子强度下,饱和吸附容量的增加顺序均为SCN-<SO_4^(2-)<HPO42-<Cl^-;在低离子强度下,除SCN-外,反离子种类对传质速率和动态结合容量没有显著影响;在高离子强度下,传质速率的增加顺序为SCN-<SO_4^(2-)≈Cl^-<HPO42-,而动态结合容量的增加顺序与饱和吸附容量序列一致;两种离子强度下Cl^-均保持最高的动态结合容量;反离子种类对蛋白质洗脱行为没有显著影响。上述结果说明反离子主要影响FF-PEI-R440的吸附性能,而不影响洗脱,且流动相中选择Cl^-为反离子最利于FF-PEI-R440的实际柱色谱操作。

The partially neutralized poly（ethylenimine）-grafted Sepharose FF,FF-PEI-R440,exhibited higher protein capacity and faster uptake rate than its starting resin FF-PEI-L740.In this work,the influence of counterions on protein adsorption onto and elution from the FF-PEI-R440 resin was investigated with sodium salts of SCN^-,Cl^-,HPO4^2-and SO4^2-at ionic strengths of 0.03 mol·L^-1 and 0.06 mol·L^-1.It was found that the static adsorption equilibrium of FF-PEI-R440 was significantly influenced by the counterions,and the adsorption capacity increased in the order of SCN^-SO4^2-HPO4^2-Cl^-at the two ionic strengths.At the low ionic strength,the counterions had no significant effect on the uptake rate and dynamic binding capacity except for SCN^-.At high ionic strength,the uptake rate increased in the order of SCN^-SO4^2-≈Cl^-HPO4^2-.Dynamic binding capacity increased in the order of SCN^-SO4^2-HPO4^2-Cl^-,the same of the order of adsorption capacity.The dynamic binding capacity kept the highest values when Cl^-existed at the two ionic strengths.Protein elution was little affected by counterions.The results indicated that the adsorption performance of FF-PEI-R440 was affected by counterions and the Cl^-was the most favorable couterion for column operation.