DNA Breathing Dynamics in the Presence of a Terahertz Field

Abstract

We consider the influence of a terahertz field on the breathing dynamics of double-stranded DNA. We model the spontaneous formation of spatially localized openings of a damped and driven DNA chain, and find that linear instabilities lead to dynamic dimerization, while true local strand separations require a threshold amplitude mechanism. Based on our results we argue that a specific terahertz radiation exposure may significantly affect the natural dynamics of DNA, and thereby influence intricate molecular processes involved in gene expression and DNA replication.

Fig. 1

Spontaneous formation of a localized permanent opening in dsDNA in the presence of a THz field with amplitude A = 144 pN, and Ω = 2 and a spatial fluctuation with high amplitude (see text).

Fig. 2

A) Bifurcation diagram for a poly(A) molecule in an external THz field with amplitude A = 144 pN. B) The instability curves for wave vector k = 0 (solid curve) and k = π (dashed curve) are plotted. On the vertical axis is the amplitude of the external field, and on the horizontal axis is the frequency Ω of the THz field.

Fig. 3

The k = π spatial pattern, at Ω = 2.52 THz, is presented. The upper panel shows evolution of the system. The lower panel shows the power spectrum of the breather motion.

Fig. 4

Breather formation at Ω = 2.00 THz. The upper panel shows the evolution of the breather. The lower panel shows the power spectrum of the breather motion.