Buyukdagli Sahin, Sarabadani Jalal, Ala-Nissila Tapio
Department of Physics, Bilkent University, Ankara 06800, Turkey.
School of Nano Science, Institute for Research in Fundamental Sciences (IPM), Tehran 19395-5531, Iran.
Polymers (Basel). 2019 Jan 11;11(1):118. doi: 10.3390/polym11010118.
The theoretical formulation of driven polymer translocation through nanopores is complicated by the combination of the pore electrohydrodynamics and the nonequilibrium polymer dynamics originating from the conformational polymer fluctuations. In this review, we discuss the modeling of polymer translocation in the distinct regimes of short and long polymers where these two effects decouple. For the case of short polymers where polymer fluctuations are negligible, we present a stiff polymer model including the details of the electrohydrodynamic forces on the translocating molecule. We first show that the electrohydrodynamic theory can accurately characterize the hydrostatic pressure dependence of the polymer translocation velocity and time in pressure-voltage-driven polymer trapping experiments. Then, we discuss the electrostatic correlation mechanisms responsible for the experimentally observed DNA mobility inversion by added multivalent cations in solid-state pores, and the rapid growth of polymer capture rates by added monovalent salt in α -Hemolysin pores. In the opposite regime of long polymers where polymer fluctuations prevail, we review the iso-flux tension propagation (IFTP) theory, which can characterize the translocation dynamics at the level of single segments. The IFTP theory is valid for a variety of polymer translocation and pulling scenarios. We discuss the predictions of the theory for fully flexible and rodlike pore-driven and end-pulled translocation scenarios, where exact analytic results can be derived for the scaling of the translocation time with chain length and driving force.
由孔的电流体动力学与源于聚合物构象涨落的非平衡聚合物动力学相结合，使得驱动聚合物通过纳米孔的理论公式变得复杂。在本综述中，我们讨论了聚合物在短聚合物和长聚合物不同区域内转位的建模，在这些区域中这两种效应相互解耦。对于聚合物涨落可忽略不计的短聚合物情况，我们提出了一个刚性聚合物模型，其中包括了对转位分子的电流体动力的详细描述。我们首先表明，电流体动力学理论能够准确地描述在压力 - 电压驱动的聚合物捕获实验中聚合物转位速度和时间对静水压力的依赖性。然后，我们讨论了在固态孔中通过添加多价阳离子导致实验观察到的DNA迁移率反转以及在α - 溶血素孔中通过添加单价盐使聚合物捕获率快速增长的静电相关机制。在聚合物涨落占主导的长聚合物的相反区域中，我们回顾了等通量张力传播（IFTP）理论，该理论能够在单个链段层面上描述转位动力学。IFTP理论适用于各种聚合物转位和拉伸情况。我们讨论了该理论对完全柔性和棒状的孔驱动和末端拉伸转位情况的预测，在这些情况下，可以得出转位时间随链长和驱动力缩放的精确解析结果。
