Halogen Anion Formation in 5-Halouracil Films: X Rays Compared to Subionization Electrons

Klyachko, Dimitri; Huels, Michael A.; Sanche, Léon

doi:10.2307/3579768

Cited by 87 publications

(82 citation statements)

References 44 publications

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“…The studies [157][158][159][160][161][162][163][164][165][166][167] confirmed the prediction of Zimbrick and coworkers [168] that the radiosensitizing properties of these compounds arose from DEA of solvated electrons, and further showed that DEA of higher energy (0-7eV) electrons was also involved in radiosensitization. Platinum bromide, aromatic compounds containing nitro group and other halogenated thymidine derivatives were found to play similar roles [58, 70, 71, 163-165, 169, 170].…”

Section: Transient Anions In Halogen Compoundssupporting

confidence: 73%

“…When formed within DNA, such fragments could react with local subunits, and thus lead to lethal clustered damage, further to that already occurring in unsensitized DNA. The most striking evidence of a huge enhancement of LEE damage obtained upon Br substitution in thymine is seen in the early results of Klyachko et al [160], who found that, in the presence of water, DEA to bromouracil could be enhanced by orders of magnitude compared to the dry compound. Differences between wet and dry TMA states of halogenated pyrimidines have recently been investigated by Cheng et al [172].…”

Section: Transient Anions In Halogen Compoundsmentioning

confidence: 93%

“…Platinum bromide, aromatic compounds containing nitro group and other halogenated thymidine derivatives were found to play similar roles [58, 70, 71, 163-165, 169, 170]. Following early investigations with solvated electrons [168], a relatively large number of experiments have been performed both in the gas (see Section 4.4) and condensed phases [160,161,165] to study electron scattering from--and attachment to--halogenated pyrimidines. Several experiments were performed using SAMs of BrdU-containing oligonucleotides [157,158,171].…”

Section: Transient Anions In Halogen Compoundsmentioning

confidence: 99%

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Transient Anions in Radiobiology and Radiotherapy: From Gaseous Biomolecules to Condensed Organic and Biomolecular Solids

Alizadeh¹,

Ptasińska²,

Sanche³

2016

Radiation Effects in Materials

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This chapter focuses on the fundamental processes that govern interactions of lowenergy (1-30 eV) electrons with biological systems. These interactions have been investigated in the gas phase and within complex arrangements in the condensed phase. They often lead to the formation of transient molecular anions (TMAs), and their decay by autoionization or dissociation accompanied by bond dissociation. The damage caused to biomolecules via TMAs is emphasized in all sections. Such damage, which depends on a large number of factors, including electron energy, molecular environment, and type of biomolecule, and its physical and chemical interactions with radiosensitizing agents are extensively discussed. A majority of recent findings resulting from experimental and theoretical endeavors are presented. They encompass broad research areas to elucidate important roles of TMAs in irradiated biological systems, from the molecular level to nanoscale cellular dimensions. Fundamental aspects of TMA formation are stressed in this chapter, but many practical applications in a variety of radiation-related fields such as radiobiology and radiotherapy are addressed.

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Section: Transient Anions In Halogen Compoundssupporting

confidence: 73%

Section: Transient Anions In Halogen Compoundsmentioning

confidence: 93%

Section: Transient Anions In Halogen Compoundsmentioning

confidence: 99%

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Transient Anions in Radiobiology and Radiotherapy: From Gaseous Biomolecules to Condensed Organic and Biomolecular Solids

Alizadeh¹,

Ptasińska²,

Sanche³

2016

Radiation Effects in Materials

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“…To examine the efficiency of the DNA adsorption on the gold substrates, X-ray Photoelectron Spectroscopy (XPS) was performed using our previously described XPS spectrometer [20]. The X-ray source (15kV, 350 W) uses an Al anode.…”

Section: Methodsmentioning

confidence: 99%

Electron stimulated desorption of anions containing Oxygen and Nitrogen from self-assembled monolayers of DNA

Mirsaleh-Kohan

Bass

Cloutier

et al. 2010

J. Phys.: Conf. Ser.

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Abstract. The electron stimulated desorption of anions from self-assembled monolayers of double stranded DNA is reported. Desorption of the oxygen and nitrogen containing anions O¯, OH¯, CN¯, OCN¯, and OCNH¯ is induced by the impact of 0.1-20 eV electrons. The anion desorption yields, measured as a function of incident electron energy exhibit pronounced maxima that can be attributed to dissociative electron attachment (DEA) to basic DNA units. Above 15 eV, desorption is attributed to dipolar dissociation (DD). This study further indicates that electrons with energy as low as 2.5 ± 0.3 eV can not only cause damage to DNA but also produce fragments with considerable kinetic energy. IntroductionAlthough the vast majority of investigations have focused on interactions of high energy radiation with living cells and DNA molecules, it is well established that the genotoxic effects of high energy particles are effectuated by the secondary species generated by the primary particles. These secondary species can cause mutagenic, recombinogenic, and other potentially lethal DNA lesions such as single and double strand breaks [1]. The most abundant of these species are secondary electrons with typical energies below 30 eV [2]. Therefore, understanding the mechanisms of low-energy electron (LEE) induced damage in DNA is highly relevant to radiobiology. Boudaïfa et al.[3] investigated strand break formation in plasmid DNA by 3-20eV electrons. Single and double strand breaks were observed even at electron energies well below ionization thresholds (7.5 eV to 10 eV) [4]. Thresholds for these breaks were measured to be near 3-5 eV with a maximum at about 10 eV. The authors concluded that these breaks occur as a result of electron attachment to DNA subunits to form a transient negative ion (TNI), and subsequent bond dissociation. The threshold for strand-breaks in their work differs from that for damage induced by photons, where the onset lies at about 7 eV [5].To better understand the mechanisms underlying DNA damage through electron attachment, studies have examined interactions of LEE with various components of DNA such as the bases [6-10], deoxyribose analogues [ 11,12], and the phosphate group [13] of the backbone in gas and solid phases. For all of the DNA components [6][7][8][9][10][11][12][13], the formation of resonances (i.e., TNI) that dissociate into a stable anionic and radical fragments was observed. One of the remaining challenges is to identify, in a long DNA chain, which TNI state of the different basic constituents ( the bases, sugar and phosphate

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“…10 Briefly, the X-ray source ͑15 kV, 400 W͒ is composed of a magnesium anode and an Al window was used to characterize the surface of nucleobases. The X-ray beam was incident at 72°relative to the sample surface, and the hemispherical electron energy analyzer was positioned normal to the surface.…”

Section: B Xps Measurementsmentioning

confidence: 99%

X-ray induced damage in DNA monitored by X-ray photoelectron spectroscopy

Ptasińska¹,

Stypczyńska²,

Nixon³

et al. 2008

The Journal of Chemical Physics

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In this work, the chemical changes in calf thymus DNA samples were analyzed by X-ray photoelectron spectroscopy ͑XPS͒. The DNA samples were irradiated for over 5 h and spectra were taken repeatedly every 30 min. In this approach the X-ray beam both damages and probes the samples. In most cases, XPS spectra have complex shapes due to contributions of C, N, and O atoms bonded at several different sites. We show that from a comparative analysis of the modification in XPS line shapes of the C 1s, O 1s, N 1s, and P 2p peaks, one can gain insight into a number of reaction pathways leading to radiation damage to DNA.

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Halogen Anion Formation in 5-Halouracil Films: X Rays Compared to Subionization Electrons

Cited by 87 publications

References 44 publications

Transient Anions in Radiobiology and Radiotherapy: From Gaseous Biomolecules to Condensed Organic and Biomolecular Solids

Transient Anions in Radiobiology and Radiotherapy: From Gaseous Biomolecules to Condensed Organic and Biomolecular Solids

Electron stimulated desorption of anions containing Oxygen and Nitrogen from self-assembled monolayers of DNA

X-ray induced damage in DNA monitored by X-ray photoelectron spectroscopy

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