title: Oscillating formation of 8-oxoguanine during DNA oxidation.
abstract: Oxidation of free guanine and guanine in salmon testes ds-DNA by hydroxyl radicals generated with Fenton reagent resulted in oscillating 8-oxoguanine concentrations. These oscillations were superimposed on a general trend of decreasing ratio of [8-oxoguanine]/{[8-oxoguanine] + [guanine]} with time, suggesting that a steady state 8-oxoguanine concentration would not be achieved. Mass spectrometry detected 8-oxoguanine and 5-guanidinohydantoin as products, suggesting that the latter was the product of oxidation of 8-oxoguanine. Guanidinohydantoin and other possible intermediates and products may be involved in a complex mechanism leading to the observed behavior. Oscillatory fluctuations in 8-oxoguanine may need to be considered in assessing its clinical significance as a biomarker for oxidative DNA damage.
authors.affiliation: Department of Chemistry, University of Connecticut, U-60, 55 North Eagleville Road, Storrs, CT 06269-3060, USA.
authors.forename: Blánaid
authors.initials: B
authors.lastname: White
authors.forename: Malcolm R
authors.initials: MR
authors.lastname: Smyth
authors.forename: James D
authors.initials: JD
authors.lastname: Stuart
authors.forename: James F
authors.initials: JF
authors.lastname: Rusling
mesh_terms: D000818:Animals; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D006147:Guanine / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D008297:Male; D010084:Oxidation-Reduction; D012474:Salmon
chemical_list: C045076:Fenton's reagent; C024829:8-hydroxyguanine; D006147:Guanine; D004247:DNA; D006861:Hydrogen Peroxide; D007501:Iron