Alpert S S, Banks G
Biophys Chem. 1976 May;4(3):287-96. doi: 10.1016/0301-4622(76)80077-4.
Laser correlation spectroscopy was used to measure the mutual diffusion coefficient, D, of human cyanomethemoglobin (Fe+++:CN) at varying protein concentrations. These measurements were made at 20 degrees C in a 0.1 M phosphate buffer solution at pH 7.0. For low protein concentrations we find D = (6.43 +/- 0.26) X 10(-7) cm2/s and that there is a near linear decrease from this value at higher concentrations. The linear relation between the diffusion coefficient and protein concentration allows us to deduce the value of the linear frictional volume fraction coefficient, Kf=7.75, and to extrapolate to hemoglobin concentrations equivalent to that in the red blood cell where we estimate D = 4.25 X 10(-7) cm2/s. Various theoretical predictions of the dependence of the mutual diffusion coefficient on concentration are tested; we find that the generalized Stokes-Einstein relation can be made to fit our high concentration data if we assume a hard-sphere model and if we include a term involving a hydrodynamic interaction integral.
采用激光相关光谱法测量了不同蛋白质浓度下人体氰化高铁血红蛋白（Fe+++:CN）的互扩散系数D。这些测量是在20℃、pH值为7.0的0.1M磷酸盐缓冲溶液中进行的。对于低蛋白质浓度，我们发现D = (6.43 ± 0.26) × 10(-7) cm2/s，并且在较高浓度下该值近似呈线性下降。扩散系数与蛋白质浓度之间的线性关系使我们能够推导出线性摩擦体积分数系数Kf = 7.75的值，并外推至与红细胞中血红蛋白浓度相当的浓度，在此我们估计D = 4.25 × 10(-7) cm2/s。测试了互扩散系数对浓度依赖性的各种理论预测；我们发现，如果假设为硬球模型并且包含一个涉及流体动力学相互作用积分的项，广义斯托克斯 - 爱因斯坦关系式可以拟合我们的高浓度数据。
