Melting process of twisted DNA in a thermal bath

TL;DR

This study models the melting transition of twisted DNA in a thermal bath, revealing how torsional effects influence melting temperature and DNA stability, with implications for understanding DNA behavior under physical stress.

Contribution

The paper introduces a simulation of DNA melting that incorporates torsional effects via a twist angle, highlighting the impact of twisting on melting temperature and biological relevance.

Findings

Melting temperature increases linearly with twist angle.

High twist angles lead to DNA rigidity and higher melting temperatures.

Biological functionality is compromised at high twist angles before melting occurs.

Abstract

We investigate melting transition of DNA sequences embedded in a Langevin fluctuation-dissipation thermal bath. Torsional effects are considered by a twist angle $\varphi$ between neighboring base pairs stacked along the molecule backbone. Our simulation results show that the increase of twist angle translates linearly the melting temperature with a positive slope. After the so called equilibrium angle $\varphi_\mathrm{eq}$, the DNA chain becomes very rigid against opening and accordingly very high temperatures are required to initiate the melting process. In such cases however, the biofunctionality of DNA is destroyed before so that the observed in our model melting process becomes biologically irrelevant. We believe that the outcome of this survey would deeper understanding of the interplay between DNA twisting and melting transition for precise control of DNA behavior.