title: Contribution of indirect effects to clustered damage in DNA irradiated with protons.
abstract: Protons are the dominant particles both in galactic cosmic rays and in solar particle events and, furthermore, proton irradiation becomes increasingly used in tumour treatment. It is believed that complex DNA damage is the determining factor for the consequent cellular response to radiation. DNA plasmid pBR322 was irradiated at U120-M cyclotron with 30 MeV protons and treated with two Escherichia coli base excision repair enzymes. The yields of SSBs and DSBs were analysed using agarose gel electrophoresis. DNA has been irradiated in the presence of hydroxyl radical scavenger (coumarin-3-carboxylic acid) in order to distinguish between direct and indirect damage of the biological target. Pure scavenger solution was used as a probe for measurement of induced OH· radical yields. Experimental OH· radical yield kinetics was compared with predictions computed by two theoretical models-RADAMOL and Geant4-DNA. Both approaches use Geant4-DNA for description of physical stages of radiation action, and then each of them applies a distinct model for description of the pre-chemical and chemical stage.
authors.affiliation: Department of Applied Physics, Chalmers University of Technology, Fysikgränd 3, Göteborg SE-412 96, Sweden Department of Radiation Dosimetry, Nuclear Physics Institute of the CAS, Na Truhlářce 39/64, Prague 180 00, Czech Republic.
authors.forename: K
authors.initials: K
authors.lastname: Pachnerová Brabcová
authors.affiliation: Université de Bordeaux, CNRS/IN2P3, Centre d'Etudes Nucléaires de Bordeaux-Gradignan, CENBG, Chemin du Solarium, BP 120, 33175 Gradignan, France Department of Radiation Dosimetry, Nuclear Physics Institute of the CAS, Na Truhlářce 39/64, Prague 180 00, Czech Republic.
authors.forename: V
authors.initials: V
authors.lastname: Štěpán
authors.affiliation: Université de Bordeaux, CNRS/IN2P3, Centre d'Etudes Nucléaires de Bordeaux-Gradignan, CENBG, Chemin du Solarium, BP 120, 33175 Gradignan, France.
authors.forename: M
authors.initials: M
authors.lastname: Karamitros
authors.affiliation: Department of Biotechnology, Institute of Chemical Technology Prague, Technická 5, Prague 166 28, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Karabín
authors.affiliation: Department of Biotechnology, Institute of Chemical Technology Prague, Technická 5, Prague 166 28, Czech Republic.
authors.forename: P
authors.initials: P
authors.lastname: Dostálek
authors.affiliation: Université de Bordeaux, CNRS/IN2P3, Centre d'Etudes Nucléaires de Bordeaux-Gradignan, CENBG, Chemin du Solarium, BP 120, 33175 Gradignan, France.
authors.forename: S
authors.initials: S
authors.lastname: Incerti
authors.affiliation: Department of Radiation Dosimetry, Nuclear Physics Institute of the CAS, Na Truhlářce 39/64, Prague 180 00, Czech Republic davidkova@ujf.cas.cz.
authors.forename: M
authors.initials: M
authors.lastname: Davídková
authors.affiliation: Department of Applied Physics, Chalmers University of Technology, Fysikgränd 3, Göteborg SE-412 96, Sweden Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna, Austria.
authors.forename: L
authors.initials: L
authors.lastname: Sihver
mesh_terms: D003374:Coumarins / Q000737:chemistry; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects*; D004249:DNA Damage / Q000528:radiation effects*; D004260:DNA Repair / Q000235:genetics; D004307:Dose-Response Relationship, Radiation; D029968:Escherichia coli Proteins / Q000378:metabolism; D017665:Hydroxyl Radical / Q000737:chemistry; D007700:Kinetics; D010957:Plasmids / Q000737:chemistry / Q000235:genetics*; D011522:Protons
chemical_list: D003374:Coumarins; D029968:Escherichia coli Proteins; D011522:Protons; D017665:Hydroxyl Radical; D004247:DNA; C104227:coumarin-3-carboxylic acid