论文标题
从关键力分布中可靠提取能量景观特性
Reliable extraction of energy landscape properties from critical force distributions
论文作者
论文摘要
生物聚合物的结构动力学由通过其构象能量景观扩散的过程控制。在使用光学镊子进行拉动实验时，可以从聚合物展开的临界力的概率分布中提取能量景观的特征。该分析通常基于具有Bell-Evans形式的速率方程，尽管据了解，这种建模是不足的，并且在许多常见情况下导致了不可靠的景观参数。 Dudko和同事[物理学。莱特牧师。 96，108101（2006）]强调了这一批评，并提出了一种替代形式，其中包括附加的形状参数（并以特殊情况为例，它减少到贝尔埃文斯（Bell-Evans））。但是，它们的拟合功能是拉力分布的尾端的病理学，这会出现其自身的问题。我们提出了一个修改的闭合形式表达，以分布临界力，该表达正确地纳入了拉动力中的下一个校正，并且行为良好。我们的说法是，这种新表达式提供了出色的参数提取，即使在中间拉的速率上也有效。我们根据模拟数据确认其实用性，提出结果。
The structural dynamics of a biopolymer is governed by a process of diffusion through its conformational energy landscape. In pulling experiments using optical tweezers, features of the energy landscape can be extracted from the probability distribution of the critical force at which the polymer unfolds. The analysis is often based on rate equations having Bell-Evans form, although it is understood that this modeling is inadequate and leads to unreliable landscape parameters in many common situations. Dudko and co-workers [Phys. Rev. Lett. 96, 108101 (2006)] have emphasized this critique and proposed an alternative form that includes an additional shape parameter (and that reduces to Bell-Evans as a special case). Their fitting function, however, is pathological in the tail end of the pulling force distribution, which presents problems of its own. We propose a modified closed-form expression for the distribution of critical forces that correctly incorporates the next-order correction in pulling force and is everywhere well behaved. Our claim is that this new expression provides superior parameter extraction and is valid even up to intermediate pulling rates. We present results based on simulated data that confirm its utility.
