Mapping between the order of thermal denaturation and the shape of the critical line of mechanical unzipping in 1-dimensional DNA models

TL;DR

This paper explores the relationship between thermal denaturation and mechanical unzipping in 1D DNA models, revealing a power-law connection and proportional critical exponents linking thermal and mechanical transitions.

Contribution

It establishes a quantitative link between thermal and mechanical denaturation in DNA models, showing the critical line follows a power-law and relates critical exponents.

Findings

Critical line is a power-law in temperature-force plane.

Critical exponent for unzipping is proportional to thermal specific heat exponent.

Provides theoretical insight into DNA denaturation mechanisms.

Abstract

In this Letter, we investigate the link between thermal denaturation and mechanical unzipping for two models of DNA, namely the Dauxois-Peyrard-Bishop model and a variant thereof we proposed recently. We show that the critical line that separates zipped from unzipped DNA sequences in mechanical unzipping experiments is a power-law in the temperature-force plane. We also prove that for the investigated models the corresponding critical exponent is proportional to the critical exponent alpha, which characterizes the behaviour of the specific heat in the neighbourhood of the critical temperature for thermal denaturation.