Institut für Biotechnologie, FG Bioverfahrenstechnik, Technische Universität Berlin, Berlin, Germany.
Colloids Surf B Biointerfaces. 2011 Oct 15;87(2):217-25. doi: 10.1016/j.colsurfb.2011.05.021. Epub 2011 May 19.
In this study, the potential use of a synthetic Mg/Al hydrotalcite (layered double hydroxide) as a novel chromatography material for protein purification was investigated. The hydrotalcite is present in its carbonate form and is characterized by an Al/Mg-ratio of 1.85. Zetapotential measurements confirm a positive surface potential up to pH 10 suggesting applicability as anion exchanger. The binding of model proteins covering a broad range of isoelectric points and molecular weights was performed at different pH-values under batch conditions to evaluate the binding behaviour of the hydrotalcite. Furthermore, static binding capacities were exemplarily determined for hemoglobin and human serum albumin. Additionally, the adsorption and elution of hemoglobin was studied under dynamic conditions. The binding behaviour of the hydrotalcite was compared to commercially available anion exchangers and was found to be a function of pH, depending on the model protein. Variant adsorption behaviour is explained by further interactions like hydrogen bonds and by an unequal charge distribution over the protein surfaces. The hydrotalcite reveals high adsorption capacities under static (260 mg/g) as well as under dynamic conditions (88 mg/g at 34 cm/h; 61 mg/g at 340 cm/h). With appropriate buffers like 500 mM carbonate (pH 10) the adsorbed proteins can be nearly completely desorbed making regeneration possible. Due to the binding and elution properties it is concluded, that the hydrotalcite can serve anion exchange material for chromatographic protein separations.
在这项研究中，研究了一种合成的 Mg/Al 水滑石（层状双氢氧化物）作为新型蛋白质纯化色谱材料的潜在用途。水滑石以碳酸盐形式存在，其 Al/Mg 比为 1.85。Zeta 电位测量证实，表面电位在 pH 值为 10 时呈正电性，表明其可用作阴离子交换剂。在批处理条件下，在不同 pH 值下进行了覆盖广泛等电点和分子量的模型蛋白质的结合实验，以评估水滑石的结合行为。此外，还对血红蛋白和人血清白蛋白进行了静态结合容量的测定。此外，还研究了血红蛋白在动态条件下的吸附和洗脱。将水滑石的吸附行为与市售的阴离子交换剂进行了比较，发现其吸附行为是 pH 的函数，取决于模型蛋白质。不同的吸附行为可以用氢键和蛋白质表面上不均匀的电荷分布等进一步相互作用来解释。水滑石在静态（260mg/g）和动态条件下（34cm/h 时 88mg/g；340cm/h 时 61mg/g）均显示出较高的吸附容量。使用适当的缓冲液，如 500mM 碳酸盐（pH 10），可以几乎完全洗脱吸附的蛋白质，从而实现再生。根据结合和洗脱特性，得出结论，水滑石可以作为用于蛋白质色谱分离的阴离子交换材料。
