Stretching vibration influence of the hydrogen bond on a localized excitation and thermodynamic properties of DNA double helices

The propagation of a localized excitation and the thermodynamic properties in DNA double helices due to stretching vibration of hydrogen bond are disc ussed. The stretch of the hydrogen bonds is considered as a nonlinear chain with cubic and quartic potential. The analytic solution of the solitary wa ve is obtained by using the continuum approximation and its stability has b een discussed. With the help of the thermodynamic Green function technique, the temperature and anharmonicity effects on the thermodynamic properties of DNA are investigated. The theoretical calculation of the specific heat i n DNA at low temperature is consistent with the experimental result. The nu merical simulation of the differential-difference equation shows that the s olitary wave is pinned by the lattice. It is also pointed out that the conf ormational transitions from B-DNA to A-DNA can occur in the case of asymmet ry potential with quartic term. (C) 1999 Published by Elsevier Science B.V. All rights reserved.