The sequence dependence of photoinduced single strand break in 5-Bromo-2'-deoxyuridine labeled DNA supports that electron transfer is responsible for the damage
Kinga Westphal , Samanta Makurat , Janusz Rak
AbstractThe UVB irradiation of DNA labeled with 5-bromo-2′-deoxyuridine (BrdU) leads to single-strand breaks (SSBs) as a major photochemical damage. Some time ago, we demonstrated that SSB is a secondary damage forming due to thermal dissociation of 2′-deoxyribonolactone generated photochemically in DNA labeled with BrdU. For the first time, we study here the variation of the yield of UVB generated SSBs with the alteration of 3′-neighbor nucleobase of electron donor (2′-deoxyguanine (dG)) and acceptor (excited BrdU) in double-stranded DNA. We showed that the experimental damage yields can be explained by the calculated ionization potentials of dG and electron affinities of excited BrdU via a kinetic scheme based on the Marcus model of electron transfer (ET). Hence, our studies on the sequence dependence of photochemical damage in DNA labeled with BrdU constitute a further argument that photochemically generated SSBs occur as a result of long-range ET.
|Other language title versions|
|Journal series||Journal of Physical Chemistry B, ISSN 1520-6106|
|Publication size in sheets||0.5|
|Score|| = 30.0, 20-12-2017, ArticleFromJournal|
= 30.0, 20-12-2017, ArticleFromJournal
|Publication indicators||: 2016 = 3.177 (2) - 2016=3.177 (5)|
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