Translocation of stiff polymers through a nanopore driven by binding particles

TL;DR

This study uses simulations to explore how binding particles influence the translocation of stiff polymers through nanopores, revealing optimal conditions and effects on translocation time distribution.

Contribution

It demonstrates the non-monotonic relationship between translocation time and binding energy or particle concentration, highlighting the impact of binding strength on translocation dynamics.

Findings

Mean translocation time has a minimum at specific binding energy and concentration.

Strong binding increases friction, reducing translocation velocity.

Distribution of translocation times shifts from broad to narrow and Gaussian with stronger binding.

Abstract

We investigate the translocation of stiff polymers in the presence of binding particles through a nanopore by two-dimensional Langevin dynamics simulations. We find that the mean translocation time shows a minimum as a function of the binding energy $\epsilon$ and the particle concentration $\phi$, due to the interplay of the force from binding and the frictional force. Particularly, for the strong binding the translocation proceeds with a decreasing translocation velocity induced by a significant increase of the frictional force. In addition, both $\epsilon$ and $\phi$ have an notable impact on the distribution of the translocation time. With increasing $\epsilon$ and $\phi$, it undergoes a transition from an asymmetric and broad distribution under the weak binding to a nearly Gaussian one under the strong binding, and its width becomes gradually narrower.