Stochastic resonance in a model of a periodically driven DNA : Multiple transitions, scaling and sequence dependence

TL;DR

This study investigates stochastic resonance in a model of DNA unzipping under periodic force, revealing multiple resonance peaks, phase diagrams, and the influence of chain heterogeneity and length on the dynamics.

Contribution

It demonstrates the existence of multiple stochastic resonance peaks and their dependence on force, temperature, chain length, and sequence heterogeneity in DNA unzipping models.

Findings

Multiple resonance peaks indicate multiple stable and metastable states.

Phase diagrams show the relationship between force, temperature, and resonance.

Scaling behavior of the output signal varies with DNA length and sequence heterogeneity.

Abstract

We numerically study stochastic resonance in the unzipping of a model double-stranded DNA by a periodic force. We observe multiple peaks in stochastic resonance in the output signal as the driving force frequency is varied for different force amplitudes, temperature, chain length, and chain heterogeneity. Multiple peaks point to the existence of multiple stable and metastable states, which correspond to dynamical states of partially zipped and unzipped conformations and transitions between them. We quantify such transitions by looking at the time evolution of the fraction of bound base pairs. We obtain phase diagrams in the force amplitude-temperature plane both in the resonance frequency of the primary peak and the output signal at the peak value. We further obtain an excellent scaling behavior of the output signal for changing lengths of the DNA. Resonance behavior is also affected by chain heterogeneity as it depends strongly on which base pair the periodic forcing is applied.