Perturbed soliton-like molecular excitations in a deformed DNA chain

TL;DR

This paper investigates how periodic deformations in DNA influence soliton-like excitations, revealing that such deformations alter soliton velocity without affecting their width, through a perturbation analysis of a coupled sine-Gordon model.

Contribution

It introduces a coupled sine-Gordon and wave equation model for deformed DNA and analyzes how periodic deformation affects soliton dynamics, a novel approach in DNA nonlinear dynamics.

Findings

Periodic deformation changes soliton velocity.

Soliton width remains unaffected by deformation.

Perturbed kink and antikink solitons represent open DNA states.

Abstract

We study the nonlinear dynamics of a deformed Deoxyribonucleic acid (DNA) molecular chain which is governed by a perturbed sine-Gordon equation coupled with a linear wave equation representing the lattice deformation. The DNA chain considered here is assumed to be deformed periodically which is the energetically favourable configuration, and the periodic deformation is due to the repulsive force between base pairs, stress in the helical backbones and due to the elastic strain force in both the strands. A multiple scale soliton perturbation analysis is carried out to solve the perturbed sine-Gordon equation and the resultant perturbed kink and antikink solitons represent open state configuration with small fluctuation. The perturbation due to periodic deformation of the lattice changes the velocity of the soliton. However, the width of the soliton remains unchanged.