Concentration dependence of translational diffusion coefficients for globular proteins.
Concentration dependence of translational diffusion coefficients for globular proteins.
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DOI：
10.1039/c4an01060d
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发表时间：
2014-10
期刊：
影响因子：
--
通讯作者：
D. Scott;S. Harding;D. Winzor
中科院分区：
文献类型：
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作者：
D. Scott;S. Harding;D. Winzor
本调查研究发表的卵清蛋白和牛血清白蛋白的传统扩散实验的结果，以确定在何种程度上假设浓度的平移扩散系数的独立性是一个合理的近似在分析蛋白质的沉降速度实验中的边界扩散。虽然目前的理论预测这两种蛋白质的扩散系数（D）具有显著的正浓度依赖性，但在恒温和溶剂化学势（也与沉降速度有关）的约束下进行的这些实验扩散研究中未检测到任何相关性。相反，结果更好地描述了相对较小的浓度依赖性预测考虑溶液粘度是一个额外的来源的D-C依赖性。由于浓度低于10 mg mL（-1）的溶液中D的预测变化在实验估计的不确定性范围内，因此这些发现支持使用Fujita开发的Lamm方程的近似解来定量分析蛋白质沉降速度实验中的边界扩展。
This investigation examines published results of traditional diffusion experiments on ovalbumin and bovine serum albumin to determine the extent to which assumed concentration independence of the translational diffusion coefficient is a reasonable approximation in the analysis of boundary spreading in sedimentation velocity experiments on proteins. Although significant positive concentration dependence of the diffusion coefficient (D) for both proteins is predicted by current theories, none has been detected in these experimental diffusion studies performed under the constraints of constant temperature and solvent chemical potential (those also pertinent to sedimentation velocity). Instead, the results are better described by the relatively minor concentration dependence predicted by considering solution viscosity to be an additional source of D-c dependence. Inasmuch as the predicted variation in D for solutions with concentrations below 10 mg mL(-1) is within the uncertainty of experimental estimates, these findings support use of the approximate solution of the Lamm equation developed by Fujita for the quantitative analysis of boundary spreading in sedimentation velocity experiments on proteins.