Hearn M T, Hodder A N, Aguilar M I
Department of Biochemistry, Monash University, Clayton, Victoria, Australia.
J Chromatogr. 1988 Jun 29;443:97-118. doi: 10.1016/s0021-9673(00)94786-1.
The influence of different displacer salts on the retention behaviour of seven globular proteins ranging in molecular weight from 12,000 to 69,000 was investigated using the Mono Q anion-exchange resin as the stationary phase. Isocratic retention data were collected using several different alkali metal halides as the displacing salt, thereby systematically varying the anion and cation species in the series F-, Cl- and Br- and Li+, Na+ and K+. The different anions were found to reduce protein retention in order of their decreasing hydrated ionic radii. Protein Zc values were found to be lower for fluoride and bromide than for chloride. It was demonstrated that the cationic co-ions also influence solute retention properties with this anion-exchange resin through, inter alia, preferential interactions with the protein solute. Protein band-broadening was found to systematically vary with the choice of displacer salt. These changes were related to known Hofmeister effects on protein aggregation kinetics and solubility and the degree of ion penetration at the double layer of the stationary phase-mobile phase interface. These studies now provide a rapid comparative basis for evaluating the mechanism of co- and counter-ion interactions with proteins in high-performance ion-exchange chromatographic systems.
以Mono Q阴离子交换树脂作为固定相，研究了不同置换盐对七种分子量在12,000至69,000之间的球状蛋白质保留行为的影响。使用几种不同的碱金属卤化物作为置换盐收集等度保留数据，从而系统地改变F-、Cl-和Br-以及Li+、Na+和K+系列中的阴离子和阳离子种类。发现不同的阴离子按照其水合离子半径减小的顺序降低蛋白质保留率。发现氟化物和溴化物的蛋白质Zc值低于氯化物。结果表明，阳离子共离子也通过与蛋白质溶质的优先相互作用等方式影响这种阴离子交换树脂的溶质保留特性。发现蛋白质条带展宽随置换盐的选择而系统变化。这些变化与已知的霍夫迈斯特效应有关，该效应涉及蛋白质聚集动力学和溶解度以及固定相 - 流动相界面双层处的离子渗透程度。这些研究现在为评估高效离子交换色谱系统中蛋白质与共离子和反离子相互作用的机制提供了快速比较基础。
