Characterization of poly(allylamine) as a polymeric ligand for ion-exchange protein chromatography
Characterization of poly(allylamine) as a polymeric ligand for ion-exchange protein chromatography
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聚（烯丙胺）作为离子交换蛋白色谱聚合物配体的表征
DOI：
10.1016/j.chroma.2016.11.012
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发表时间：
2017
影响因子：
4.1
通讯作者：
Sun Yan
中科院分区：
文献类型：
--
作者：
Li Ming;Li Yanying;Yu Linling;Sun Yan
本文报道了聚烯丙胺（PAA）作为蛋白质色谱的高分子离子交换配体。用聚丙烯酸（PAA）对SepharoseFF进行修饰，制备了6种离子交换剂，离子容量（ICs）为165 ~ 618 mmol/L。进行了反相体积排阻色谱、吸附平衡、吸收动力学和柱洗脱。结果表明，在IC为165-373 mmol/L范围内，吸附容量和有效扩散系数均保持较低的值，当IC达到618 mmol/L时，吸附容量和有效扩散系数开始增加，分别增加了80%和23倍。有趣的是，在IC为373 mmol/L附近观察到孔径急剧减小。结果表明，PAA链通过改变凝胶内部的孔结构，在蛋白质吸附中起着重要的作用。结果表明，PAA分子链从低偶联密度（IC<373 mmol/L）时的多点接枝的不可伸展状态转变为高偶联密度（IC>373 mmol/L）时的更紧密、伸展、柔性的少偶联点接枝状态。接枝链在较高IC值下的这些特性有利于蛋白质通过三维结合进行吸附，并促进了结合蛋白质在链上的“链递送”。在0-500 mmol/L NaCl的离子强度范围内，该离子交换剂均表现出良好的吸附和吸收性能，表明其耐盐性优于目前报道的离子交换剂。此外，pH 5.0的温和条件提供了洗脱色谱中结合蛋白的有效回收。结果表明，具有高IC值的PAA基阴离子交换剂对于处理宽范围离子强度的进料的高容量蛋白质色谱是有希望的。
This work reports poly(allylamine) (PAA), as a polymeric ion-exchange ligand for protein chromatography. Sepharose FF was modified with PAA, and six anion exchangers with ionic capacities (ICs) from 165 to 618 mmol/L were prepared. Inverse size exclusion chromatography, adsorption equilibrium, uptake kinetics and column elution were performed. It was found that both the adsorption capacity and effective diffusivity maintained low values in the IC range of 165–373 mmol/L, but they started to increase beyond 373 mmol/L, and increased by 80% and 23 times, respectively, when the IC reached 618 mmol/L. Interestingly, a drastic decrease of pore size was observed around the IC of 373 mmol/L. The results suggest that the PAA chains played an important role in protein adsorption by altering the inner pore structure of the gels. It is considered that, PAA chains turn from inextensible states with multipoint-grafting on the pore surface at low coupling densities (IC<373 mmol/L) to closer, extended and flexible grafting states with less coupling points at higher coupling densities (IC>373 mmol/L). These characters of the grafted chains at higher IC values benefit in protein adsorption by three-dimensional binding and encouraged the happening of “chain delivery” of bound proteins on the chains. Besides, the ion exchangers showed favorable adsorption and uptake properties in a wide ionic strength range, 0–500 mmol/L NaCl, indicating much better salt tolerance feature than the so-far reported ion exchangers. Moreover, a mild condition of pH 5.0 offered effective recovery of bound proteins in elution chromatography. The results indicate that the PAA-based anion exchanger of a high IC value is promising for high-capacity protein chromatography dealing with feedstock of a wide range of ionic strengths.