Müller J J
Institut für Molekularbiologie, Berlin, Federal Republic of Germany.
Biopolymers. 1991 Feb 5;31(2):149-60. doi: 10.1002/bip.360310203.
Two low structure-resolution methods are proposed for prediction of rotational diffusion parameters. The indirect procedure is based on the structure of a molecule in solution or in crystal, and uses the structure parameters of radius of gyration, and low-resolution molecular surface and volume, determined from measured or theoretically calculated small-angle x-ray scattering intensities, to estimate a frictional equivalent ellipsoid of revolution. The direct method starts mainly from the crystallographic structure of a molecule and calculates the triaxial inertia equivalent ellipsoid, experimentally calibrated by translation diffusion data, to simulate the frictional behavior. The predicted harmonic mean of the rotational correlation times of compact globular macromolecules with molar masses of 14,000-65,000 g/mol agree with experimental results within the error limits. The prediction method is recommended for expert systems in structure research and for detection of internal protein flexibility or marker mobility by nmr and electron paramagnetic resonance experiments.
提出了两种低结构分辨率方法来预测旋转扩散参数。间接方法基于溶液或晶体中分子的结构，并使用由测量或理论计算的小角x射线散射强度确定的回转半径、低分辨率分子表面和体积等结构参数，来估计一个摩擦等效旋转椭球体。直接方法主要从分子的晶体结构出发，计算经平移扩散数据实验校准的三轴惯性等效椭球体，以模拟摩擦行为。预测的摩尔质量为14,000 - 65,000 g/mol的紧密球状大分子的旋转相关时间的调和平均值在误差范围内与实验结果相符。该预测方法推荐用于结构研究的专家系统以及通过核磁共振和电子顺磁共振实验检测蛋白质内部柔性或标记物流动性。
