Bian Yukun, Wang Zilin, Chen Anpu, Zhao Nanrong
Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.
College of Chemistry, Sichuan University, Chengdu 610064, China.
J Chem Phys. 2015 Nov 14;143(18):184908. doi: 10.1063/1.4935118.
We have proposed a fluctuation bottleneck (FB) model to investigate the non-exponential kinetics of DNA escape from nanometer-scale pores. The basic idea is that the escape rate is proportional to the fluctuating cross-sectional area of DNA escape channel, the radius r of which undergoes a subdiffusion dynamics subjected to fractional Gaussian noise with power-law memory kernel. Such a FB model facilitates us to obtain the analytical result of the averaged survival probability as a function of time, which can be directly compared to experimental results. Particularly, we have applied our theory to address the escape kinetics of DNA through α-hemolysin nanopores. We find that our theoretical framework can reproduce the experimental results very well in the whole time range with quite reasonable estimation for the intrinsic parameters of the kinetics processes. We believe that FB model has caught some key features regarding the long time kinetics of DNA escape through a nanopore and it might provide a sound starting point to study much wider problems involving anomalous dynamics in confined fluctuating channels.
我们提出了一种涨落瓶颈（FB）模型，以研究DNA从纳米级孔中逸出的非指数动力学。其基本思想是，逸出速率与DNA逸出通道的涨落横截面积成正比，该通道半径r经历受幂律记忆核的分数高斯噪声影响的亚扩散动力学。这样的FB模型有助于我们获得平均生存概率作为时间函数的解析结果，该结果可直接与实验结果进行比较。特别地，我们已将我们的理论应用于研究DNA通过α-溶血素纳米孔的逸出动力学。我们发现，我们的理论框架能够在整个时间范围内很好地重现实验结果，并且对动力学过程的内在参数进行了相当合理的估计。我们相信，FB模型抓住了DNA通过纳米孔的长时间动力学的一些关键特征，它可能为研究涉及受限涨落通道中反常动力学的更广泛问题提供一个良好的起点。
