Abstract |
The goal of this study was to define the effect of DNA sequence on the reactivity of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) toward oxidation. To this end, we developed a quadrupole/time-of-flight (QTOF) mass spectrometric method to quantify the reactivity of site specifically modified oligodeoxyribonucleotides with two model oxidants: nitrosoperoxycarbonate (ONOOCO(2)(-)), a chemical mediator of inflammation, and photoactivated riboflavin, a classical one-electron oxidant widely studied in mutagenesis and charge transport in DNA. In contrast to previous observations with guanine [ Margolin , Y. , ( 2006 ) Nat. Chem. Biol. 2 , 365 ], sequence context did not affect the reactivity of ONOOCO(2)(-) with 8-oxodG, but photosensitized riboflavin showed a strong sequence preference in its reactivity with the following order (8-oxodG = O): COA ≈ AOG > GOG ≥ COT > TOC > AOC. That the COA context was the most reactive was unexpected and suggests a new sequence context where mutation hotspots might occur. These results point to both sequence- and agent-specific effects on 8-oxodG oxidation.
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Authors | Kok Seong Lim, Koli Taghizadeh, John S Wishnok, I Ramesh Babu, Vladimir Shafirovich, Nicholas E Geacintov, Peter C Dedon |
Journal | Chemical research in toxicology
(Chem Res Toxicol)
Vol. 25
Issue 2
Pg. 366-73
(Feb 20 2012)
ISSN: 1520-5010 [Electronic] United States |
PMID | 22103813
(Publication Type: Journal Article, Research Support, N.I.H., Extramural)
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Chemical References |
- Carbonates
- Nitrates
- Oxidants
- Photosensitizing Agents
- nitrosoperoxycarbonate
- 8-Hydroxy-2'-Deoxyguanosine
- Deoxyguanosine
- Riboflavin
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Topics |
- 8-Hydroxy-2'-Deoxyguanosine
- Base Sequence
- Carbonates
(chemistry)
- Deoxyguanosine
(analogs & derivatives, chemistry, genetics, radiation effects)
- Nitrates
(chemistry)
- Oxidants
(chemistry)
- Oxidation-Reduction
- Photochemical Processes
- Photosensitizing Agents
(chemistry, radiation effects)
- Riboflavin
(chemistry, radiation effects)
- Ultraviolet Rays
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