DNA capture into the ClyA nanopore: diffusion-limited versus reaction-limited processes

TL;DR

This paper reviews models of DNA capture into ClyA nanopores, comparing theoretical and experimental data, and concludes that the process is reaction-limited, with salt dependence supporting this finding.

Contribution

It provides a comparative analysis of diffusion-limited versus reaction-limited models for DNA capture in ClyA nanopores, supported by experimental validation.

Findings

Capture is reaction-limited for both single- and double-stranded DNA.

Salt dependence of capture rate matches theoretical predictions.

Experimental data supports the reaction-limited model.

Abstract

The capture and translocation of biomolecules through nanometer-scale pores are processes with a potential large number of applications, and hence they have been intensively studied in the recent years. The aim of this paper is to review existing models of the capture process by a nanopore, together with some recent experimental data of short single- and double-stranded DNA captured by Cytolysin A (ClyA) nanopore. ClyA is a transmembrane protein of bacterial origin which has been recently engineered through site-specific mutations, to allow the translocation of double- and single-stranded DNA. A comparison between theoretical estimations and experiments suggests that for both cases the capture is a reaction-limited process. This is corroborated by the observed salt dependence of the capture rate, which we find to be in quantitative agreement with the theoretical predictions.