Chou K C
Biophys J. 1985 Aug;48(2):289-97. doi: 10.1016/S0006-3495(85)83782-6.
Low-frequency internal motions in protein molecules play a key role in biological functions. Based on previous work with alpha-helical structure, the quasi-continuum model is extended to the beta-structure, another fundamental element in protein molecules. In terms of the equations derived here, one can easily calculate the low-frequency wave number of a beta-sheet in an accordionlike motion, and the low-frequency wave number of a beta-barrel in a breathing motion. The calculated results for immunoglobulin G and concanavalin A agree well with the observations. These findings further verify that the observed low-frequency motion (or the so-called dominant low-frequency mode) in a protein molecule is essentially governed by the collective fluctuations of its weak bonds, especially hydrogen bonds, and the internal displacement of the massive atoms therein, as described by the quasi-continuum model.
蛋白质分子中的低频内部运动在生物功能中起着关键作用。基于先前对α螺旋结构的研究工作，准连续介质模型被扩展到β结构，这是蛋白质分子中的另一个基本元素。根据这里推导的方程，可以很容易地计算出在类似手风琴运动的β折叠片中的低频波数，以及在呼吸运动的β桶中的低频波数。对免疫球蛋白G和伴刀豆球蛋白A的计算结果与观测结果吻合良好。这些发现进一步证实，蛋白质分子中观测到的低频运动（或所谓的主导低频模式）本质上是由其弱键，特别是氢键的集体涨落以及其中大质量原子的内部位移所支配的，正如准连续介质模型所描述的那样。
