title: Direct Oxidative Damage of Naked DNA Generated upon Absorption of UV Radiation by Nucleobases.
abstract: It has been shown that in addition to formation of pyrimidine dimers, UV irradiation of DNA in the absence of photosensitizer also induces formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine, but the mechanism of formation of that oxidized base has not been clearly established. In the present study, we provide an unambiguous demonstration that absorption of UVC and UVB radiation by the nucleobases induces DNA oxidation via a direct process (one-electron oxidation) and not singlet oxygen. Evidence arose from the fact that polyamine-guanine adducts that are specifically produced through the transient formation of guanine radical cation are generated following UV irradiation of DNA in the presence of a polyamine even in the absence of any photosensitizer.
authors.affiliation: Université Grenoble Alpes, INAC-SCIB , F-38000 Grenoble, France.|CEA, INAC-SyMMES Laboratoire des Lésions des Acides Nucléiques , F-38000 Grenoble, France.
authors.forename: Miguel
authors.initials: M
authors.lastname: Gomez-Mendoza
authors.affiliation: LIDYL, CEA, CNRS, Université Paris Saclay , F-91191 Gif-sur-Yvette, France.
authors.forename: Akos
authors.initials: A
authors.lastname: Banyasz
authors.affiliation: Université Grenoble Alpes, INAC-SCIB , F-38000 Grenoble, France.|CEA, INAC-SyMMES Laboratoire des Lésions des Acides Nucléiques , F-38000 Grenoble, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Douki
authors.affiliation: LIDYL, CEA, CNRS, Université Paris Saclay , F-91191 Gif-sur-Yvette, France.
authors.forename: Dimitra
authors.initials: D
authors.lastname: Markovitsi
authors.affiliation: Université Grenoble Alpes, INAC-SCIB , F-38000 Grenoble, France.|CEA, INAC-SyMMES Laboratoire des Lésions des Acides Nucléiques , F-38000 Grenoble, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Ravanat
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004249:DNA Damage / Q000528:radiation effects*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism; D006147:Guanine / Q000737:chemistry*; D010084:Oxidation-Reduction; D012395:Rose Bengal / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D012395:Rose Bengal; D006147:Guanine; D000080242:8-Hydroxy-2'-Deoxyguanosine; D004247:DNA; D003849:Deoxyguanosine