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The Reaction of Water with Guanosine Radical Cation in DNA
Author(s) -
Onyemauwa Frank O.,
Schuster Gary B.
Publication year - 2006
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/2005-09-07-ra-677
Subject(s) - guanosine , chemistry , dna , oligonucleotide , molecule , photochemistry , dna damage , radical ion , hydroxyl radical , bond cleavage , stereochemistry , radical , ion , biochemistry , organic chemistry , catalysis
ABSTRACT Structural analyses of DNA oligonucleotides indicate the presence of strongly bound water molecules in the major and minor grooves. These water molecules may react with guanosine radical cation to form 8‐oxo‐7,8‐dihydroguanine and other oxidation products, which can result in strand scission or other DNA damage. We probed the reaction of guanosine radical cation with water by incorporating alkyl‐substituted cytidines and thymidines into anthraquinonelinked DNA duplexes and irradiating them with UV light at 350 nm. The incorporation of these hydrophobic substituents disrupts the DNA spine of hydration and we have observed that these modifications do not affect the trapping or longdistance hopping of radical cations in DNA.