Radiation Research · 2000 · 42 citations · 11 references
Natural SciencesBiophysicsMolecular BiologyDna RepairNucleic Acid ChemistrySpectroscopyDna DamageDna Double-strand Break RepairDna Strand BreaksDouble-strand Break RepairPhotochemistrySpectroscopy Of BiomoleculesDna Damage InductionDna Double-strand BreaksDna Strand Break RepairDouble-strand Dna BreaksIonizing Radiation-induced Dna BreaksPhotoabsorption SpectraPlatinum CompoundsReaction Quantum Yields
Le Sech, C., Takakura, K., Saint-Marc, C., Frohlich, H., Charlier, M., Usami, N. and Kobayashi, K. Strand Break Induction by Photoabsorption in DNA-Bound Molecules.Dried samples of a DNA–chloroterpyridine platinum complex were irradiated with monochromatic X rays tuned to the photoabsorption resonance of the LIII inner shell of the platinum atom. The number of single- and double-strand breaks (SSBs and DSBs) triggered by the Auger effect in supercoiled DNA plasmids was measured by the production of circular nicked and linear forms. To probe the specific contribution of the LIII inner-shell excitation of the platinum atom, photon wavelengths were tuned on the resonance energy (on peak) and below (off peak). The quantum yields of the resonance radiation were typically found to be 11 for the SSBs and 1 for the DSBs. The DSB-to-SSB ratio increased by 20% when switching from off-resonance to on-resonance irradiation.
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K. W. Jennette, Stephen J. Lippard, G. A. Vassiliades et al. · Proceedings of the National Academy of Sciences · 1974 · 341 citations · Full text