Hydrogen Abstraction from Deoxyribose by a Neighboring 3 '-Uracil Peroxyl Radical
2009 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, Vol. 113, no 18, 6574-6578 p.Article in journal (Refereed) Published
Theoretical examination of the reactivity of the uracil-5-peroxyl radical when abstracting a hydrogen atom from a neighboring 5'-deoxyribose in 5'-ApU-5-peroxyl-3' has been performed using density functional theory with the MPWB1K functional. Halogenated uracils are often used as radiosensitizers in DNA since the reactive uracil-5-yl radical is formed upon radiation and is known to create strand break and alkali-labile sites. Under aerobic conditions, such as in the cell, it has been proposed that the uracil-5-peroxyl radical is formed and would be the damaging agent. Our results show low reactivity for the uracil-5-peroxyl radical, determined by calculating the activation and reaction energies for the plausible hydrogen abstraction sites C1', C2' and C3' of the neighboring 5'-deoxyribose. These findings support the hypothesis that hydrogen abstraction primarily occurs by the uracil-5-yl radical, also under aerobic conditions, prior to formation of the peroxyl radical.
Place, publisher, year, edition, pages
2009. Vol. 113, no 18, 6574-6578 p.
DENSITY-FUNCTIONAL THERMOCHEMISTRY; SEQUENCE-SELECTIVE PHOTOREACTION; UV-IRRADIATION; EXACT-EXCHANGE; DUPLEX DNA; MODELS; OLIGONUCLEOTIDES; 5-HALOURACILS; DAMAGE
IdentifiersURN: urn:nbn:se:su:diva-35595DOI: 10.1021/jp9007569ISI: 000265687500047OAI: oai:DiVA.org:su-35595DiVA: diva2:288964