Wong Chiu Tai Andrew, Muthukumar M
Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA 01003, USA.
J Chem Phys. 2008 Apr 21;128(15):154903. doi: 10.1063/1.2897932.
A formalism of polymer translocation through a cylindrical channel of finite diameter and length between two spherical compartments is developed. Unlike previous simplified systems, the finite diameter of the channel allows the number of polymer segments inside the channel to be adjusted during translocation according to the free energy of possible conformations. The translocation process of a Gaussian chain without excluded volume and hydrodynamic interactions is studied using exact formulas of confinement free energy under this formalism. The free energy landscape for the translocation process, the distribution of the translocation time, and the average translocation time are presented. The complex dependencies of the average translocation time on the length and diameter of the channel, the sizes of the donor and receptor compartments, and the chain length are illustrated.
建立了一种聚合物通过两个球形隔室之间有限直径和长度的圆柱形通道进行转位的形式体系。与先前的简化系统不同,通道的有限直径允许通道内聚合物链段的数量在转位过程中根据可能构象的自由能进行调整。在此形式体系下,利用限制自由能的精确公式研究了无排斥体积和流体动力学相互作用的高斯链的转位过程。给出了转位过程的自由能景观、转位时间分布和平均转位时间。阐述了平均转位时间对通道长度和直径、供体和受体隔室大小以及链长的复杂依赖性。