A two-state kinetic model for the unfolding of single molecules by mechanical force.
A two-state kinetic model for the unfolding of single molecules by mechanical force.
复制标题
通过机械力展开单分子的二态动力学模型。
DOI：
10.1073/pnas.172525099
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发表时间：
2002
影响因子：
11.1
通讯作者：
TinocoJr,I
中科院分区：
文献类型：
--
作者：
Ritort,F;Bustamante,C;TinocoJr,I
我们使用代表实验数据所需的最简单模型，研究了机械力在单分子不可逆展开过程中所消耗的功。该模型由两个级别（折叠状态和展开状态）组成，由中间屏障隔开。我们计算耗散功的概率分布，并给出分布的平均值和方差的解析表达式。对于一阶而言，耗散功的量与施加力的速率（加载速率）和分子的弛豫时间成正比。该模型得出的表征受力展开动力学参数的估计值与最近实验结果中获得的结果一致。我们使用 Jarzynski 公式从非平衡实验中获得了获得 kBT 内平衡自由能所需的最少重复实验次数的一般方程。不可逆实验的数量随着平均耗散功的比率呈指数增长， \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{方程*}\overline{{\mathit{W}}_{dis}}\end{方程*}\end{文档} tokBT.
We investigate the work dissipated during the irreversible unfolding of single molecules by mechanical force, using the simplest model necessary to represent experimental data. The model consists of two levels (folded and unfolded states) separated by an intermediate barrier. We compute the probability distribution for the dissipated work and give analytical expressions for the average and variance of the distribution. To first order, the amount of dissipated work is directly proportional to the rate of application of force (the loading rate) and to the relaxation time of the molecule. The model yields estimates for parameters that characterize the unfolding kinetics under force in agreement with those obtained in recent experimental results. We obtain a general equation for the minimum number of repeated experiments needed to obtain an equilibrium free energy, to withinkBT, from nonequilibrium experiments by using the Jarzynski formula. The number of irreversible experiments grows exponentially with the ratio of the average dissipated work, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}\overline{{\mathit{W}}_{dis}}\end{equation*}\end{document} tokBT.