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Resonant Formation of Strand Breaks in Sensitized Oligonucleotides Induced by Low‐Energy Electrons (0.5–9 eV)
Author(s) -
Schürmann Robin,
Tsering Thupten,
Tanzer Katrin,
Denifl Stephan,
Kumar S. V. K.,
Bald Ilko
Publication year - 2017
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201705504
Subject(s) - electron , oligonucleotide , low energy , atomic physics , materials science , energy (signal processing) , chemistry , molecular physics , physics , nuclear physics , dna , quantum mechanics , biochemistry
Halogenated nucleobases are used as radiosensitizers in cancer radiation therapy, enhancing the reactivity of DNA to secondary low‐energy electrons (LEEs). LEEs induce DNA strand breaks at specific energies (resonances) by dissociative electron attachment (DEA). Although halogenated nucleobases show intense DEA resonances at various electron energies in the gas phase, it is inherently difficult to investigate the influence of halogenated nucleobases on the actual DNA strand breakage over the broad range of electron energies at which DEA can take place (<12 eV). By using DNA origami nanostructures, we determined the energy dependence of the strand break cross‐section for oligonucleotides modified with 8‐bromoadenine ( 8Br A). These results were evaluated against DEA measurements with isolated 8Br A in the gas phase. Contrary to expectations, the major contribution to strand breaks is from resonances at around 7 eV while resonances at very low energy (<2 eV) have little influence on strand breaks.