Hirakawa F, Yoshino S, Era S, Kuwata K, Sogami M, Imai N
Department of Physics, Faculty of Science, Nagoya University, Nagoya 464, Japan.
Biophys Chem. 1987 Dec;28(3):251-63.
The charge effect on the translational self-diffusion constant, D, of polyelectrolytes has been quantitatively analyzed based on dynamic light scattering experiments. Perfectly monodisperse bovine mercaptalbumin has been used at low pH as a positively charged polyelectrolyte sample. Completely linear plots of log{g2(t)-1} vs. time t have been obtained for uncharged states of the protein, for the cor relation function of the scattered light intensity, g2(t). The plots deviate from linearity as polyions bear the charges. The D values for various ionic states, obtained from the initial slopes of the plots, have been analyzed using the simple theory of Imai and Mandel (N. Imai and M. Mandel, Macromolecules 15 (1982) 1562) derived based on the Onsager-Navier-Stokes equation for solvent flow with counterion distribution around a polyion. It has turned out that the experimental D values coincide well with the theory and that the characteristic nature of D can be elucidated principally from the charge effect.
基于动态光散射实验，对聚电解质平移自扩散常数D的电荷效应进行了定量分析。在低pH值下，使用完全单分散的牛巯基白蛋白作为带正电的聚电解质样品。对于蛋白质的不带电状态，即散射光强度的相关函数g2(t)，得到了log{g2(t)-1}对时间t的完全线性图。当聚离子带有电荷时，这些图偏离线性。利用基于Onsager-Navier-Stokes方程推导的、考虑聚离子周围反离子分布的溶剂流动的Imai和Mandel的简单理论（N. Imai和M. Mandel，《大分子》15 (1982) 1562），对从这些图的初始斜率获得的各种离子状态的D值进行了分析。结果表明，实验得到的D值与理论值吻合良好，并且D的特征性质主要可以从电荷效应中得到解释。
