Electron induced single strand break and cyclization: A DFT study on the radiosensitization mechanism of the nucleotide of 8-bromoguanine

Lidia Chomicz, Al'Ona Furmanchuk, Jerzy Leszczynski, Janusz Rak*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

Cleavage of the O-P bond in 8-bromo-2′-deoxyguanosine-3′, 5′-diphosphate (BrdGDP), considered as a model of single strand break (SSB) in labelled double-stranded DNA (ds DNA), is investigated at the B3LYP/6-31++G(d,p) level. The thermodynamic and kinetic characteristics of the formation of SSB are compared to those related to the 5′,8-cycloguanosine lesion. The first reaction step, common to both damage types, which is the formation of the reactive guanyl radical, proceeds with a barrier-free or low-barrier release of the bromide anion. The guanyl radical is then stabilized by hydrogen atom transfer from the C3′ or C5′ sites of the 2′-deoxyribose moiety to its C8 center. The C3′ path, via the O-P bond cleavage, leads to a ketone derivative (the SSB model), while the C5′ path is more likely to yield 5′,8-cycloguanosine.

Original languageEnglish (US)
Pages (from-to)6568-6574
Number of pages7
JournalPhysical Chemistry Chemical Physics
Volume16
Issue number14
DOIs
StatePublished - Apr 14 2014

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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