Translational diffusion coefficients of bovine serum albumin in aqueous solution at high ionic strength
Translational diffusion coefficients of bovine serum albumin in aqueous solution at high ionic strength
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DOI：
10.1006/jcis.1999.6401
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发表时间：
1999-10-01
影响因子：
9.9
通讯作者：
Blackwell, J
中科院分区：
文献类型：
--
作者：
Meechai, N;Jamieson, AM;Blackwell, J
我们报告静态和动态光散射测量牛血清白蛋白（BSA）的解决方案，在高离子强度（I）BSA分子之间的潜在和流体动力学相互作用的强度相当。本文测量了几种溶剂体系的渗透压缩系数（d pi/dc）和平移扩散系数（D-m）的浓度依赖性：（a）在等电点pH = 4.7和I = 0.1时，无长程静电排斥;（B）在pH 7.4和I = 0.15、1.5和3.3时，其中存在良好屏蔽的静电排斥。结果进行了比较与理论预测，其中涉及一个微观硬球治疗的潜力和流体动力学的相互作用。在pH = 7.4和I = 1.5，我们的实验结果d π/dc是在很好的协议与硬球的预测，我们的值为D-m，同样，与硬球流体动力学分析，其中的贡献从速度场中的发散项被忽略。在等电pH值，得到类似的协议与理论，提供了一个吸引力的潜力的贡献包括在内;在pH值7.4和I = 0.15，从一个远程排斥的贡献必须包括在内;在pH值7.4和I = 3.3，开始观察到蛋白质聚集。(C)北京：科学出版社.
We report static and dynamic light scattering measurements on bovine serum albumin (BSA) solutions at high ionic strength (I) where potential and hydrodynamic interactions between BSA molecules are of comparable strengths. Measurements of the concentration dependence of the osmotic compressibility, (d pi/dc), and the translational diffusion coefficient, D-m, are presented for several solvent systems: (a) at the isoelectric pH = 4.7 and I = 0.1, where long-range electrostatic repulsions are absent; (b) at pH 7.4 and I = 0.15, 1.5, and 3.3, where a well-screened electrostatic repulsion is present. The results are compared with theoretical predictions which involve a microscopic hard-sphere treatment of the potential and hydrodynamic interactions. At pH = 7.4 and I = 1.5, our experimental results for d pi/dc are in good agreement with the hard-sphere prediction, and our values for D-m are, likewise, consistent with a hard-sphere hydrodynamic analysis in which contributions from the divergence terms in the velocity field are neglected. At the isoelectric pH, similar agreement with theory is obtained, provided the contribution of an attractive potential is included; at pH 7.4 and I = 0.15, the contribution from a long-range repulsion must be included; at pH 7.4 and I = 3.3, onset of protein aggregation is observed. (C) 1999 Academic Press.