Copper-catalyzed DNA damage by ascorbate and hydrogen peroxide: kinetics and yield.
Time profiles for degradation of DNA via reaction of H2O2 with the DNA-Cu+ complex were analyzed over a wide range of concentrations of the components. The yield of DNA damage per H2O2 molecule is 10 times lower than that obtained with gamma-radiolytically generated .OH radicals. The observations can be explained by a model in which H2O2 reacts, slowly on the one hand with DNA-Cu+ by formation of toxic .OH radicals immediately at the DNA and faster on the other hand with Cu+ in the bulk solution by formation of less toxic Cu(III) intermediates.
Stoewe
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Universität Freiburg, Institut für Biophysik und Strahlenbiologie, Federal Republic of Germany.
Prütz
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WA
D001205:Ascorbic Acid / Q000494:pharmacology*; D003300:Copper / Q000494:pharmacology*; D004249:DNA Damage; D005609:Free Radicals; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D006878:Hydroxides / Q000494:pharmacology; D017665:Hydroxyl Radical; D007700:Kinetics
D005609:Free Radicals; D006878:Hydroxides; D017665:Hydroxyl Radical; D003300:Copper; D006861:Hydrogen Peroxide; D001205:Ascorbic Acid