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Cells with DNA incorporating Br-dUMP as a thymidine monophosphate (dTMP) analog are known to be highly sensitive to ionizing radiation. To clarify physicochemical mechanism of the bromine-radiosensitization, the electronic state of the Br-DNA related molecules was investigated applying X-ray photoelectron spectroscopy (XPS). Quantum chemical calculations were also performed for these molecules which were undergone structural optimization using the Hartree-Fock (HF) and Møller-Plesset (MP2) method, and Density Functional Theory (DFT) to investigate whether the bromination affects the highest occupied and lowest unoccupied orbital (HOMO and LUMO) of these molecules. In terms of “radiation effect”, total yield of low-energy electrons generated by inelastic scattering of photo- or Auger electrons were also quantified using the XPS apparatus. The main findings from this study on the bromination of DNA are the following: (i) little effect on the core levels, the LUMO shapes and their spatial distributions for all atoms, (ii) contrarily reducing the binding energy of valence electrons to 0 eV from 1.0-1.8 eV, (iii) a high efficiency in generating the low energy electrons. These results suggest that the presence of Br reduce an energy gap between HOMO and LUMO so that it facilitates transfer of charges, holes, or the low energy electrons. The brominated DNA would possess a half-metal-like electronic property localized (presumably a nucleotide level) around bromine atom leading finally deleterious DNA damage in cells., 日本放射線影響学会第64回大会

この論文は国立情報学研究所の電子図書館事業により電子化されました。, 研究会報告

この論文は国立情報学研究所の電子図書館事業により電子化されました。

この論文は国立情報学研究所の電子図書館事業により電子化されました。, 研究会報告

この論文は国立情報学研究所の電子図書館事業により電子化されました。, ポスターセッション