title: Inhibition of DNA-ethidium bromide intercalation due to free radical attack upon DNA. I. Comparison of the effects of various radicals.
abstract: The fluorescent intercalation complex of ethidium bromide (ETB) with DNA was used as a probe to compare the effects of various radicals with respect to impairment of the DNA base-pair region. .OH radicals inhibit up to 0.7 dye intercalations per .OH at low salt concentration, and for various oxidizing species the effect decreases in the order .OH greater than Br.2- greater than N.3 much greater than (SCN).2-. DNA impairment by the .OH product of Met-Gly is comparable to that of N.3, but no effect was found due to the interaction between DNA and Lys-Tyr-Lys phenoxyl radicals. The reducing species e-aq, H., O.2-, and CO.2- hardly affect the DNA-ETB intercalation.
mesh_terms: D001482:Base Composition / Q000528:radiation effects; D055598:Chemical Phenomena; D002621:Chemistry; D004247:DNA / Q000528:radiation effects; D004996:Ethidium; D005453:Fluorescence; D005609:Free Radicals; D005720:Gamma Rays; D010084:Oxidation-Reduction; D013050:Spectrometry, Fluorescence
chemical_list: D005609:Free Radicals; D004247:DNA; D004996:Ethidium