One-electron oxidation of the guanine moiety of 2'-deoxyguanosine: influence of 8-oxo-7,8-dihydro-2'-deoxyguanosine.
The influence of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) on riboflavin and UVA-mediated one-electron oxidation of an aqueous aerated solution of 2'-deoxyguanosine (dGuo) has been studied. Using labeled experiments, we have demonstrated that, despite not being able to detect significant amounts of 8-oxodGuo upon one-electron oxidation of dGuo, 8-oxodGuo is indeed produced but is further rapidly degraded to oxidized nucleosides. Evidence is provided showing that an efficient electron transfer reaction from 8-oxodGuo to the guanine radical cation or rather its deprotonated form occurs, giving rise to the specific decomposition of 8-oxodGuo together with the restitution of dGuo. It could be concluded that 8-oxodGuo efficiently protects dGuo from decomposition by the one-electron oxidation reaction.
Ravanat
Jean-Luc
JL
Laboratoire "Lésions des Acides Nucléiques", Service de Chimie Inorganique et Biologique, UMR 5046, DRFMC, CEA Grenoble, F-38054 Grenoble Cedex 9, France. jravanat@cea.fr
Saint-Pierre
Christine
C
Cadet
Jean
J
D000080242:8-Hydroxy-2'-Deoxyguanosine; D002851:Chromatography, High Pressure Liquid; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000737:chemistry*; D006147:Guanine / Q000737:chemistry*; D007700:Kinetics; D013058:Mass Spectrometry; D010084:Oxidation-Reduction
D006147:Guanine; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine