Protein adsorption in anion exchange resins – effects of polymer grafting, support structure porosity, and protein size
Protein adsorption in anion exchange resins – effects of polymer grafting, support structure porosity, and protein size
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DOI：
10.1002/jctb.5410
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发表时间：
2018-07
影响因子：
3.4
通讯作者：
Mimi Zhu;Preston E. Fuks;G. Carta
中科院分区：
文献类型：
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作者：
Mimi Zhu;Preston E. Fuks;G. Carta
阴离子交换树脂广泛用于酸性蛋白质的纯化。将带电聚合物接枝到刚性多孔结构上已显示出在不同条件下改善性能。了解潜在的机制对于材料性能和操作条件的优化设计和选择非常重要。结果在不同的条件下，带正电的接枝聚合物在刚性多孔聚合物骨架结构中对牛血清白蛋白（BSA，Mr~65 kDa）和甲状腺球蛋白（Tg，Mr~660 kDa）的吸附量和动力学均有显著的增强作用。对于较小的BSA，结合增加与接枝聚合物的长度和内容，并与盐浓度降低。对于大得多的Tg，结合随着聚合物接枝树脂的一些盐的添加而增加，但可以低于未添加盐的未接枝树脂所观察到的结合。这种行为是由结合蛋白质的扩散阻碍引起的。增加接枝聚合物的长度或主链的孔径改善Tg吸附动力学。结论蛋白质的吸附受聚合物接枝、骨架结构和吸附蛋白质大小的不同机制控制。需要对树脂性能和条件进行最佳选择，以使吸附能力和传质动力学最大化。
BACKGROUND Anion exchange resins are used extensively for the purification of acidic proteins. Grafting charged polymers to a rigid porous structure has been shown to improve performance under varying conditions. Understanding the underlying mechanisms is important for the optimum design and selection of material properties and operating conditions. RESULTS Positively charged grafted polymers incorporated into a rigid, porous polymeric backbone structure are found to significantly enhance adsorption capacity and kinetics of the proteins bovine serum albumin (BSA, Mr~65 kDa) and thyroglobulin (Tg, Mr~660 kDa) but under different conditions. For the smaller BSA, binding increases with grafted polymer length and content and decreases with salt concentration. For the much larger Tg, binding increases with the addition of some salt for the polymer-grafted resins but can be lower than that observed for ungrafted resins without added salt. This behavior is caused by diffusional hindrance due to the bound protein. Increasing the length of the grafted polymer or the pore size of the backbone improve the Tg adsorption kinetics. CONCLUSION Protein adsorption is controlled by different mechanisms dependent on polymer grafting, backbone structure, and size of the adsorbed protein. Optimum selection of resin properties and conditions is needed to maximize adsorption capacity and mass transfer kinetics.