X-ray absorption near edge structures of DNA or its components around the oxygen K-shell edge.
(2001)
Journal - Radiation research (United States )
Abstract :
The initial process of radiation damage in DNA was investigated by measuring the X-ray absorption near edge structures (XANES) within the energy region around the oxygen K-shell absorption edge for DNA, cytosine and 2-deoxy-d-ribose. Irradiation and XANES experiments were performed with the BL23SU soft X-ray beamline, using synchrotron radiation from the 8 GeV electron storage ring at SPring-8. Samples were mounted on gold-coated plates in a vacuum chamber. The XANES spectra were obtained by measuring the photoelectron current of the samples. 2-Deoxy-d-ribose was exposed to X rays at the absorption peak corresponding to the oxygen (O) 1s-->sigma* transition energy (538 eV); the XANES spectra were obtained after each irradiation. DNA and cytosine, possessing characteristic XANES spectra, both had two major energy bands corresponding to the O 1s-->pi* and 1s-->sigma* transitions. Two new peaks appeared and gradually increased in the XANES spectra of 2-deoxy-d-ribose during irradiation. These results suggest that C-O bonds in 2-deoxy-d-ribose are transformed to C=O bonds by O 1s-->sigma* transition, suggesting that the molecules undergo chemical changes into carbonyl-containing compounds.
| ISSN : | 0033-7587 |
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| Mesh Heading : | DNA Electron Probe Microanalysis Nucleic Acid Conformation chemistry |
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| Mesh Heading Relevant : | X-Rays radiation effects |
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X-ray absorption near-edge structure (XANES) spectral changes of 2-deoxy-D-ribose by irradiation within the energy region around the oxygen K-shell absorption edge.
(2001)
Journal - Journal of synchrotron radiation (Denmark )
Abstract :
The physicochemical characteristics of 2-deoxy-D-ribose moieties in DNA strands are important to understand biological radiation stress. So, the X-ray absorption near edge structure (XANES) of 2-deoxy-D-ribose within the energy region around the oxygen K-shell absorption edge was measured. 2-deoxy-D-ribose was exposed to 3 energies of X-rays, i.e., 526.3 eV (below O 1s-->pi*), 537.8 eV (at the absorption peak of O 1s-->sigma*) and 552.6 eV (above O 1s-->sigma*) for given periods. Slight differences in spectral changes were seen in the each irradiation energy, suggesting in fact that the chemical state and following rearranged chemical structure of 2-deoxy-D-ribose may be different between the 3 irradiation energies.
| ISSN : | 0909-0495 |
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| Mesh Heading : | DNA DNA Damage Deoxyribose Dose-Response Relationship, Radiation Spectrometry, X-Ray Emission chemistry radiation effects methods |
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| Mesh Heading Relevant : | chemistry radiation effects |
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