[Computer analysis of anisotropic ESR spectra and the structure of radical H and OH adducts of nucleic acid components in frozen aqueous solutions]

Abstract

Computer analysis of ESR spectra recorded under gamma-irradiation of polycrystal and glass-like solutions of nucleotides and nitrous bases was carried out to determine the localization sites of free valency (damage) in DNA macromolecule when interacting with water radiolysis products (OH and H). The analysis was performed on a mini-computer with the program of reconstruction of ESR anisotropic spectra in the variation search regime. When calculating the theoretical spectra anisotropic width of the lines, g-factors and HHS constants on X and Z axes were taken into account. Good reproduction of the experimental spectra on the computer was achieved, as a result the ESR spectra were obtained. Relative contribution of each of OH- and H-adducts of nitrous bases to the total ESR spectrum of gamma-irradiated DNA will be determined in future.