Grimaldo Marco, Roosen-Runge Felix, Zhang Fajun, Seydel Tilo, Schreiber Frank
Institut Max von Laue - Paul Langevin (ILL) , B.P.156, F-38042 Grenoble, France.
J Phys Chem B. 2014 Jun 26;118(25):7203-9. doi: 10.1021/jp504135z. Epub 2014 Jun 12.
Dynamics in protein solutions is essential for both protein function and cellular processes. The hierarchical complexity of global protein diffusion, side-chain diffusion, and microscopic motions of chemical groups renders a complete understanding challenging. We present results from quasi-elastic neutron scattering on protein solutions of γ-globulin over a wide range of volume fractions. Translational and rotational diffusion can be self-consistently separated from internal motions. The global diffusion is consistent with predictions for effective spheres even though the branched molecular shape differs considerably from a colloidal sphere. The internal motions are characterized both geometrically and dynamically, suggesting a picture of methyl rotations and restricted diffusion of side chains. We show that the advent of new neutron spectrometers allows the study of current questions including the coupling of intracellular dynamics and protein function.
蛋白质溶液中的动力学对于蛋白质功能和细胞过程都至关重要。全局蛋白质扩散、侧链扩散以及化学基团微观运动的层次复杂性使得全面理解具有挑战性。我们展示了在广泛体积分数范围内对γ-球蛋白蛋白质溶液进行准弹性中子散射的结果。平移扩散和旋转扩散可以与内部运动自洽地分离。尽管分支分子形状与胶体球有很大不同，但全局扩散与有效球体的预测一致。内部运动在几何和动力学上都有特征，表明存在甲基旋转和侧链受限扩散的情况。我们表明，新型中子光谱仪的出现使得研究包括细胞内动力学与蛋白质功能耦合在内的当前问题成为可能。
