On the effect of force on DNA in the Peyrard-Bishop-Dauxois model

TL;DR

This study uses the Peyrard-Bishop-Dauxois model to numerically analyze how external forces cause DNA breakage, revealing stepwise denaturation, critical force dependence, and hysteresis effects relevant to DNA mechanics.

Contribution

It provides new insights into force-induced DNA denaturation dynamics and hysteresis behavior using a nonlinear oscillator model.

Findings

Denaturation occurs stepwise with characteristic force peaks.

Critical force varies with the point of force application.

Hysteresis effects are observed under periodic forces.

Abstract

This paper presents a numerical study of the dynamics of DNA double helix breakage under the influence of external forces using the Peyrard-Bishop-Dauxois (PBD) model. The PBD model represents DNA as a chain of nonlinearly coupled oscillators, which makes it possible to analyze the processes of melting and mechanical denaturation. The main focus is on cases where an external force is applied to the terminal or central site of a DNA molecule, simulating stretching at a constant rate. The critical force required to break hydrogen bonds, which depends on the point of application of the force, is calculated. It is found that the denaturation process occurs stepwise, with characteristic peaks in the force-time graphs. The phenomenon of hysteresis under periodic exposure to external forces is also studied, which is important for understanding energy losses and heating of the system.