Protein adsorption on novel acrylamido-based polymeric ion-exchangers - IV. Effects of protein size on adsorption capacity and rate
Protein adsorption on novel acrylamido-based polymeric ion-exchangers - IV. Effects of protein size on adsorption capacity and rate
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DOI：
10.1016/s0021-9673(02)01027-0
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发表时间：
2002-09-20
影响因子：
4.1
通讯作者：
Carta, G
中科院分区：
文献类型：
--
作者：
Hunter, AK;Carta, G
研究了蛋白质粒径对丙烯酰胺基高分子阴离子交换剂吸附容量和吸附速率的影响。蛋白质乳白蛋白，肌红蛋白，卵清蛋白，BSA，伴清蛋白，IgG，和铁蛋白的分子量范围从15 000至450 000进行了研究。在高盐浓度（50 mM Tris-HCl，含500 mM NaCl）下，只有较小的蛋白质乳白蛋白和肌红蛋白获得了相当大部分的颗粒体积。较大的蛋白质几乎完全排除，在中性大分子获得的结果一致。相比之下，在低盐浓度（50 mM Tris-HCl）下，对于所研究的所有蛋白质，吸附容量非常大（280-400 mg/ml颗粒体积），除了铁蛋白，其容量低得多。这表明，只要溶质不是太大，有利的静电相互作用克服了尺寸排阻效应。吸附速率的测量表明，传质速率也相当快，在低盐浓度。有效扩散系数由匹配模型和实验结果确定，并发现随着蛋白质尺寸的增加而大幅降低。如前所述，发现均匀扩散模型预测实验观察到的蛋白质浓度和边界层传质效应的趋势。(C)2002 Elsevier Science B. V.保留所有权利。
The effects of protein size on the adsorption capacity and rate is determined for an acrylamido-based polymeric anion-exchanger. The proteins lactalbumin, myoglobin, ovalbumin, BSA, conalbumin, IgG, and ferritin with molecular masses ranging from 15 000 to 450 000 were investigated. At high salt concentration (50 mM Tris-HCl containing 500 mM NaCl), only the smaller proteins lactalbumin and myoglobin gained access to a significant portion of the particle volume. The larger proteins were nearly completely excluded, in agreement with the results obtained for neutral macromolecules. By contrast, at low salt concentration (50 mM Tris-HCl), the adsorption capacity was very large (280-400 mg/ml of particle volume) for all the proteins studied except for ferritin, for which the capacity was much lower. this suggests that, provided the solute is not too large, the favorable electrostatic interaction overcomes the size exclusion effect. Adsorption rate measurements showed that mass transfer rates are also quite fast at low salt concentration. Effective diffusivities were determined by matching model and experimental results and were found to decrease substantially as the protein size increased. As previously observed, the homogeneous diffusion model was found to predict the experimentally observed trends with respect to protein concentration and boundary layer mass transfer effects. (C) 2002 Elsevier Science B.V. All rights reserved.