Accession Number : ADA193128

Title :   Calculation of Far Infrared Absorption in B Poly(dA).poly)(dT).

Descriptive Note : Technical rept. Apr 81-Mar 88,

Corporate Author : PURDUE UNIV LAFAYETTE IND DEPT OF PHYSICS

Personal Author(s) : Young, L ; Prohofsky, Earl W

PDF Url : ADA193128

Report Date : 10 Mar 1988

Pagination or Media Count : 28

Abstract : We calculate the far infrared absorption of B conformation poly(dA) poly(dT), using eigenvectors from a lattice dynamical model refined with the latest inelastic neutron scattering data. Our various calculations include the isolated helix, the addition of counterions, and the addition of a 'spine of hydration' in the minor groove. We find agreement with experimental infrared data except for one mode. We then attempt to model a coupling between two helices and show some evidence that this mode is interhelical. Since our initial prediction of vibrational modes in deoxyribonucleic acid DNA in the 1-100 reciprocal centimeters frequency range, several experimental groups have used Brillouin, low frequency Raman, and infrared absorption measurements to study this region of the spectrum. Resonant rather than dissipative modes have been observed and in one case the lifetime of such a mode has been determined. In addition to this new Raman and infrared data, inelastic neutron scattering data is also now available. This neutron data is of particular interest to us as it has allowed refinement of our model of he long range nonbonded interactions in DNA.

Descriptors :   *DEOXYRIBONUCLEIC ACIDS, *HYDRATION, *NEUTRON SCATTERING, *MOLECULAR VIBRATION, BRILLOUIN ZONES, COMPUTATIONS, DISSIPATION, EIGENVECTORS, EXPERIMENTAL DATA, FAR INFRARED RADIATION, FREQUENCY, INELASTIC SCATTERING, INFRARED DETECTION, INFRARED RADIATION, LOW FREQUENCY, MEASUREMENT, NEUTRONS, OPTICAL DATA, PREDICTIONS, RAMAN SPECTRA, REGIONS, SPECTRA, RADIATION ABSORPTION

Subject Categories : Genetic Engineering and Molecular Biology
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE