Khramtsov V V, Marsh D
Max-Planck-Institut für biophysikalische Chemie, Abteilung Spektroskopie, Göttingen, Germany.
Biochim Biophys Acta. 1991 Sep 30;1068(2):257-60. doi: 10.1016/0005-2736(91)90218-w.
The concentration dependence of the normalized integral of the saturation-transfer EPR spectrum of human serum albumin spin-labelled on amino groups is found to be sensitive to viscosity and to temperature in aqueous solution and in 60% glycerol. The dependence on protein concentration is consistent with theoretical predictions for a diffusion-controlled Heisenberg spin-exchange interaction and the experimentally derived bimolecular collision rate constants are in reasonable agreement with those calculated theoretically for a diffusion-controlled process. The method is therefore applicable to the determination of translational diffusion coefficients of proteins in solution and, because of the nature of the saturation transfer EPR method, should be ideally suited to the study of local translational diffusion of proteins in membranes.
已发现，在水溶液和60%甘油中，氨基自旋标记的人血清白蛋白饱和转移电子顺磁共振谱归一化积分的浓度依赖性对粘度和温度敏感。对蛋白质浓度的依赖性与扩散控制的海森堡自旋交换相互作用的理论预测一致，实验得出的双分子碰撞速率常数与理论计算的扩散控制过程的速率常数合理吻合。因此，该方法适用于测定溶液中蛋白质的平移扩散系数，并且由于饱和转移电子顺磁共振方法的性质，应该非常适合研究膜中蛋白质的局部平移扩散。
