Polymer Translocation througha Pore in a Membrane

TL;DR

This paper develops a statistical physical model of polymer translocation through a membrane pore, analyzing how factors like chain flexibility, chemical potential, and ratchets influence translocation time.

Contribution

It introduces a new model incorporating entropic barriers and examines the effects of different driving mechanisms on polymer translocation.

Findings

Chemical potential differences significantly affect translocation times.

Brownian ratchets suppress the influence of chemical potential and chain flexibility.

The model provides insights into the roles of entropic barriers and driving forces.

Abstract

We construct a new statistical physical model of polymer translocation through a pore in a membrane treated as the diffusion process across a free energy barrier. We determine the translocation time in terms of chain flexibility yielding an entropic barrier, as well as in terms of the driving mechanisms such as transmembrane chemical potential difference and Brownian ratchets. It turns out that, while the chemical potential differences induce pronounced effects on translocation due to the long-chain nature of the polymer, the ratchets suppress this effect and chain flexibility.