肌球蛋白杆状结构中的弯曲运动和内部运动。

Bending motions and internal motions in myosin rod.

作者信息

Highsmith S, Wang C C, Zero K, Pecora R, Jardetzky O

出版信息

Biochemistry. 1982 Mar 16;21(6):1192-7. doi: 10.1021/bi00535a013.

Abstract

Depolarized light scattering and high-resolution 1H NMR measurements were made on solutions of light meromyosin (LMM) and myosin rod in 0.6 M KCl-0.010 M pyrophosphate, pH 9.5, at 20 degrees C. The light scattering data indicated LMM is a rigid molecule. Myosin rod is best described as a once-broken rod with domains that can freely diffuse in conical volumes. The maximum angle that the cone surface makes with the myosin rod axis is 128 degrees, indicating the bending motion of the domains is largely unrestrained. NMR data indicated the fraction of the structure that could be in a random-coil configuration was equal and less than 0.04 for both hydrodynamically rigid LMM and bending myosin rod. Thus, the flexible bending of myosin rod appears to not be due to a random-coil structure.

摘要

在20℃下，对轻酶解肌球蛋白（LMM）和肌球蛋白杆在0.6M KCl-0.010M焦磷酸盐、pH 9.5溶液中的去偏振光散射和高分辨率1H NMR测量进行了研究。光散射数据表明LMM是一种刚性分子。肌球蛋白杆最好描述为一根曾经断裂的杆，其结构域可以在锥形体积内自由扩散。锥面与肌球蛋白杆轴的最大夹角为128度，表明结构域的弯曲运动在很大程度上不受限制。NMR数据表明，对于流体动力学刚性的LMM和弯曲的肌球蛋白杆，可能处于无规卷曲构型的结构比例相等且小于0.04。因此，肌球蛋白杆的柔性弯曲似乎不是由于无规卷曲结构。