论文标题
DNA纳米孔的非平衡热力学解动
Nonequilibrium thermodynamics of DNA nanopore unzipping
论文作者
论文摘要
使用理论和仿真，我们通过纳米孔易位对DNA解压缩进行了第一个系统表征。从部分未拉链的状态开始，我们发现了三个动态状态，具体取决于施加力F：（i）异质DNA缩回和重新拉链（F <17pn），（ii）正常（17pn <f <60pn）和（iii）异常（iii）异常（f> 60pn）的漂移 - - 延伸 - 延伸 - 延伸性行为。我们表明，在倾斜的周期性潜力中，可以有效地将正常的漂移扩散状态有效地建模为一维随机过程。我们使用随机过程的理论来从非平衡的解压缩轨迹中恢复电势，并表明它与单基对的自由能景观相对应。将这种通用方法应用于具有周期性电势的其他单分子系统，应从平衡轨迹中产生详细的自由化景观。
Using theory and simulations, we carried out a first systematic characterization of DNA unzipping via nanopore translocation. Starting from partially unzipped states, we found three dynamical regimes depending on the applied force, f: (i) heterogeneous DNA retraction and rezipping (f < 17pN), (ii) normal (17pN < f < 60pN) and (iii) anomalous (f > 60pN) drift-diffusive behavior. We show that the normal drift-diffusion regime can be effectively modelled as a one-dimensional stochastic process in a tilted periodic potential. We use the theory of stochastic processes to recover the potential from nonequilibrium unzipping trajectories and show that it corresponds to the free-energy landscape for single base-pairs unzipping. Applying this general approach to other single-molecule systems with periodic potentials ought to yield detailed free-energy landscapes from out-of-equilibrium trajectories.
