Protein adsorption to poly(ethylenimine)-modified Sepharose FF: V. Complicated effects of counterions
Protein adsorption to poly(ethylenimine)-modified Sepharose FF: V. Complicated effects of counterions
复制标题
蛋白质对聚（乙烯亚胺）修饰的 Sepharose FF 的吸附：V. 抗衡离子的复杂影响
DOI：
10.1016/j.chroma.2015.05.046
复制
发表时间：
2015
影响因子：
4.1
通讯作者：
Yan Sun
中科院分区：
文献类型：
--
作者：
Na Liu;Linling Yu;Yan Sun
在聚乙烯亚胺（PEI）接枝的Sepharose FF树脂对蛋白质吸附的研究中，发现PEI-Sepharose FF树脂对牛血清白蛋白（BSA）的吸附存在一个临界离子容量（600 mmol/L），超过此值，蛋白质吸附量和吸附速率均显著增加。在这项工作中，用SCN-、Cl-、HPO 42-和SO 42-的钠盐研究了抗衡离子对离子容量为683 mmol/L的PEI-琼脂糖树脂（FF-PEI-L 680）的影响。线性梯度洗脱、间歇吸附和穿透实验表明，SCN-、Cl-、HPO 42-和SO 42-的反离子选择性、有效孔扩散系数（De）和动态结合容量（DBC）依次增大，静态吸附容量依次减小。认为离子交换基团的反离子选择性越高，蛋白质结合强度和吸附量越低，而“链传递”效应（一种表面扩散）的增强使其贬值。此外，DBC值主要取决于贬值。特别是SO 42-是PEI-Sepharose树脂的最佳吸附剂，其最高的Devalue（De/D 0 = 1.17，D 0为蛋白质在自由溶液中的扩散系数）和DBC值（118 mg/mL，停留时间为2 min）。此外，还研究了反离子对非接枝树脂DEAESepharoseFF和QSepharoseFF吸附BSA的影响。结果表明，两种非接枝树脂的共聚反应性不同，且与FF-PEI-L 680的共聚反应性不同。不同国家的偏好归因于离子交换配体化学的差异。此外，DEAE Sepharose FF和Q Sepharose FF的贬值保持不变。对未接枝的树脂，由于没有“链传递”效应，可解释为低的对映体敏感性。结果表明，适当的反离子可以改善蛋白质的吸附和PEI-Sepharose的色谱性能。对于测试的四种抗衡离子，SO 42 −最有利于提供FF-PEI-L 680的最佳吸附和洗脱结果。
In the previous studies on protein adsorption to poly(ethylenimine) (PEI)-grafted Sepharose FF resins, a critical ionic capacity (600 mmol/L) of PEI-Sepharose resins was found for the adsorption of bovine serum albumin (BSA), above which both protein capacity and uptake rate increased drastically. In this work, the influence of counterions on the PEI-Sepharose resin with an ionic capacity of 683 mmol/L (FF-PEI-L680) was investigated with sodium salts of SCN−, Cl−, HPO42−and SO42−. Linear gradient elution, batch adsorption and breakthrough experiments showed that counterion preference, effective pore diffusion coefficient (De) and dynamic binding capacity (DBC) values increased in the order of SCN−, Cl−, HPO42−and SO42−, while static adsorption capacity decreased in this order. It is considered that higher counterion preference of the ion exchange groups resulted in lower protein binding strength and adsorption capacity, while theDevalue increased due to the enhanced “chain delivery” effect (a kind of surface diffusion). Besides, the DBC value was mainly dependent onDevalue. In particular, SO42−was the most favorable counterion for the PEI-Sepharose resin, which gave rise to the highestDevalue (De/D0= 1.17,D0is protein diffusivity in free solution) and DBC value (118 mg/mL at a residence time of 2 min). Moreover, the effects of counterions on BSA adsorption to DEAE Sepharose FF and Q Sepharose FF, which were non-grafted resins, were also studied for comparisons. It was found that the counterion preferences of the two non-grafted resins were different from each other and also different from that of FF-PEI-L680. The different counterion preferences were attributed to the differences in the ion-exchange ligand chemistries. In addition, theDevalues for DEAE Sepharose FF and Q Sepharose FF kept unchanged. The low counterion sensitivity ofDevalues could be interpreted as the lack of “chain delivery” effect for the non-grafted resins. The results indicate that protein adsorption and chromatographic performance with PEI-Sepharose can be improved by proper counterions. For the four counterions tested, SO42−was the most favorable for providing the best adsorption and elution outcomes with FF-PEI-L680.