Delocalization of longitudinal acoustic-like excitations in DNA due to structural effects
V. E. Zakhvataev+*, L. A. Kompaniets×
+Federal Research Center "Krasnoyarsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences",
660036 Krasnoyarsk, Russia
*Siberian Federal University, 660041 Krasnoyarsk, Russia
×Institute of Computational Modelling of the Siberian Branch of the Russian Academy of Sciences, 660036 Krasnoyarsk, Russia
Abstract
Terahertz-frequency phonon-like modes in DNA have been widely studied both
experimentally and theoretically in recent years. However, current theoretical models turn
out to fail to reproduce some basic properties of these modes. Using a generalized
hydrodynamics approach and the results of inelastic X-ray scattering measurements, we
propose a model to describe structural effects due to wave number-dependence of the static
structure factor in the dynamics of longitudinal acoustic-like excitations in DNA. Our
analysis qualitatively suggests that on a length scale corresponding to a wave number
region between the positions of the maximum and the minimum of the dispersion relation
for the excitation frequency, structural effects may induce a tendency of delocalization of
the dynamics. This proposal is consistent with the recent experimental observations of
delocalized terahertz-frequency DNA phonon-like modes that seem to be relevant to
biological function.