Dynamical model for the full stretching curve of DNA

TL;DR

This paper introduces a phenomenological dynamical model that accurately describes the stretching behavior of DNA across different force regimes, capturing the transition to overstretching with good agreement to experimental data.

Contribution

It develops a novel dynamical model based on a modified wormlike chain and double-well potential to explain DNA stretching features, including overstretching transition.

Findings

Model accurately reproduces DNA stretching curves

Captures the overstretching transition at high forces

Shows good agreement between simulation and experimental data

Abstract

We present a phenomenological dynamical model able to describe the stretching features of the curve of DNA length vs applied force. As concerns the chain, the model is based on the discrete wormlike chain model with elastic modifications, which properly describes the elongation features at low and intermediate forces. The dynamics is developed under a double-well potential with a linear term, which, at high forces, accounts for the narrow transition present in the DNA elongation (overstretching). A quite good agreement between simulation and experiment is obtained.