Investigation of far-infrared vibrational modes in polynucleotides

Nonlinear dynamics of topological solitons in DNA

“…The lowest value of the optical frequency is According to [41] ω o (0) = 35 cm −1 , therefore from (7) we have…”

Terahertz optical measurements of correlated motions with possible allosteric function

“…Similar results have been found for a variety of proteins, thus suggesting the possibility that specific vibrations can be identified using optical spectroscopy. A number of proteins have been measured spectroscopically with Raman and traditional Fourier transform infrared (FTIR) transmission techniques (Lindsay et al 1988;Lisy et al 1997;Powell et al 1987Powell et al , 1991. While extensive Raman spectroscopy studies have been performed, there is some disagreement among various research groups on band identification, possibly due to the application of complex Lorentzian line-fitting procedures for extracting weak contributions to the main elastic scattering peak (Lisy et al 1997;Weidlich et al 1990).…”

Phonon spectra of disordered chains: an application to DNA

“…We begin by investigating a periodic chain, in which the unit cell, with a 0 lattice parameter, comprises four masses, two m p masses and one m 1 and one m 2 mass. In order to model the elastic forces among them we assume the linear regime and use two different constant forces k 1 = 0.090 mdynes/Å and k 2 = 0.075 mdynes/Å [7]. Later on we introduce disorder such that m p masses stay put on their sites, while the masses m 1 (m 2 ) occupy half of the remaining places.…”

“…In particular, if an analysis of the effects of hydrogen bonds is desired, single-chain models are not enough and doble-chain models are in order [6]. As in several models discussed in the literature over the last 20 years [7][8][9], we describe the DNA molecule as a single or a double chain, where the nucleotides are represented by effective sites, connected to each other by means of effective elastic constants. The double chain model allows us to analyze the role of interchain coupling in the vibrational properties.…”