Neves D E, Scott R A
Macromolecules. 1977 Mar-Apr;10(2):339-46. doi: 10.1021/ma60056a021.
A stochastic model of the kinetics of the helix--coil transition based on the equilibrium statistical mechanical theory of Lifson and Roig is presented. A Monte Carlo simulation of the kinetics based on the stochastic model was used to study the kinetics of the helix--coil transition. Kinetics simulations were conducted from several initial values of the fractional hydrogen bonding parameter theta to each equilibrium value of theta. A spectrum of relaxation times and characteristic weighting constants is reported for each kinetics simulation. The chain lengths used in this study were 15, 34, and 85 residues. It was found that at each chain length the relaxation times depend only on the equilibrium value of 0 while the characteristic weighting constants depend on both the initial and equilibrium values of theta. The mean relaxation time was calculated for several relaxations at chain lengths 15, 34, and 85. It was found that the mean relaxation time does not reflect the correct order of magnitude of the slowest relaxation process. In addition, it was found that pure random coil species do not survive long enough to be measured by nmr spectroscopy and therefore values of t greater than or equal to 10(-1)s do not reflect a relaxation time of the helix--coil transition.
提出了一种基于利夫森和罗伊格平衡统计力学理论的螺旋-线团转变动力学随机模型。基于该随机模型对动力学进行了蒙特卡罗模拟，以研究螺旋-线团转变的动力学。从分数氢键参数θ的几个初始值到θ的每个平衡值进行了动力学模拟。报告了每次动力学模拟的一系列弛豫时间和特征加权常数。本研究中使用的链长为15、34和85个残基。结果发现，在每个链长下，弛豫时间仅取决于θ的平衡值，而特征加权常数则取决于θ的初始值和平衡值。计算了链长为15、34和85时几次弛豫的平均弛豫时间。结果发现，平均弛豫时间没有反映出最慢弛豫过程的正确数量级。此外，还发现纯无规线团物种存活时间不够长，无法通过核磁共振光谱测量，因此t大于或等于10^(-1)s的值并不反映螺旋-线团转变的弛豫时间。
