Abstract
The chemistry of the photoactivation of daunomycin-DNA complexes is reported and the mechanism is elucidated. We quantitatively assessed the type of DNA damage, such as strand breaks, oxidized bases, and abasic sites, that arise using a plasmid relaxation assay coupled with DNA repair endonucleases. Photoexcitation of daunomycin leads to oxidative DNA damage in a dose- and irradiation time-dependent manner and guanine-specific oxidized purines are substantially produced under these conditions. Oxidative DNA base damage was also inhibited by argon degassing, indicating that guanine-specific damage arises from an oxygen-dependent mechanism. In addition, photoexcitation of daunomycin-DNA complexes leads to superoxide anion radical formation. From these studies of the actual product formed, we conclude that a charge transfer is a main driving force of the mechanism.
Original language | English (US) |
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Pages (from-to) | 200-204 |
Number of pages | 5 |
Journal | Journal of Photochemistry and Photobiology A: Chemistry |
Volume | 198 |
Issue number | 2-3 |
DOIs | |
State | Published - Aug 15 2008 |
Externally published | Yes |
Keywords
- Charge transfer reactions
- DNA damage
- Daunomycin
- Photochemistry
ASJC Scopus subject areas
- Chemistry(all)
- Chemical Engineering(all)
- Physics and Astronomy(all)