Effect of dextran layer on protein uptake to dextran-grafted adsorbents for ion-exchange and mixed-mode chromatography.
Effect of dextran layer on protein uptake to dextran-grafted adsorbents for ion-exchange and mixed-mode chromatography.
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DOI：
10.1002/jssc.201100394
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发表时间：
2011-11
影响因子：
3.1
通讯作者：
Linling Yu;Qinghong Shi;Y. Sun
中科院分区：
文献类型：
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作者：
Linling Yu;Qinghong Shi;Y. Sun
以磺丙基和4-（1H-咪唑-1-基）苯胺为色谱配体，制备了一系列葡聚糖接枝的吸附剂，分别用于离子交换色谱（IEC）和混合模式色谱（MMC），考察葡聚糖层对γ-球蛋白吸附的影响。静态吸附实验结果表明，葡聚糖接枝IEC吸附剂对γ-球蛋白的吸附量随葡聚糖含量的增加而增加。这可能归因于带电蛋白质在葡聚糖层中的多层吸附，从而进一步在吸附区域的边界及其附近诱导显著的电势梯度，从而改善了与浓度梯度相结合的传质。与IEC吸附剂相比，葡聚糖接枝MMC吸附剂的吸附容量和有效扩散系数没有明显变化。有人认为，固定在葡聚糖接枝MMC吸附剂上的疏水配体在pH 8.0时粘在一起，导致葡聚糖层的塌陷。与在pH 4.0时测定的γ-球蛋白的有效孔隙率一致，证实MMC吸附剂中葡聚糖层更为复杂，受缓冲液pH的影响显著，在不同pH下对蛋白质的吸附也表现出来。因此，它揭示了在葡聚糖接枝MMC吸附剂中的蛋白质的颗粒内传质的复杂性。
In the current research, a series of dextran-grafted adsorbents were prepared using sulfopropyl and 4-(1H-imidazol-1-yl) aniline as chromatographic ligands for ion-exchange (IEC) and mixed-mode chromatography (MMC) to respectively investigate the influence of dextran layer on adsorption of γ-globulin. Experimental evidences of static adsorption on dextran-grafted IEC adsorbents showed that adsorption capacity of γ-globulin increased with dextran content. It could be attributed to the multilayer adsorption of charged protein in dextran layer and thus further induced a significant electrical potential gradient at the boundary of adsorbed area and its proximity, improving mass transfer in combination with concentration gradient. In contrast to IEC adsorbents, adsorption capacity and effective diffusivity of dextran-grafted MMC adsorbents did not change obviously with dextran grafting. It was considered that hydrophobic ligands immobilized onto dextran-grafted MMC adsorbents were stuck together at pH 8.0, resulting in the collapse of dextran layer. In concert with measured effective porosity for γ-globulin at pH 4.0, it was confirmed that dextran layer in MMC adsorbent was more complicated and influenced significantly by buffer pH. It was also manifested by protein adsorption at different pHs. Thus, it revealed the complexity in intraparticle mass transfer of the protein in dextran-grafted MMC adsorbent.