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Damage to Isolated DNA Mediated by Singlet Oxygen
Author(s) -
Ravanat JeanLuc,
SaintPierre Christine,
Di Mascio Paolo,
Martinez Glaucia R.,
Medeiros Marisa H. G.,
Cadet Jean
Publication year - 2001
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/1522-2675(20011219)84:12<3702::aid-hlca3702>3.0.co;2-y
Subject(s) - chemistry , singlet oxygen , dna , deoxyguanosine , pyrimidine , dna damage , pyrimidine dimer , deoxyadenosine , cyclobutane , dna oxidation , photochemistry , stereochemistry , biochemistry , oxygen , organic chemistry , ring (chemistry)
In the present work, we study the reaction of singlet oxygen ( 1 O 2 ) with isolated DNA. Emphasis is placed on the identification and quantitative measurement of the DNA modifications that are produced by the reaction of 1 O 2 with DNA. For this purpose, calf‐thymus DNA was incubated with the endoperoxide of N,N ′‐di(2,3‐dihydroxypropyl)‐1,4‐naphthalenedipropanamide, a chemical generator of 1 O 2 . Thereafter, DNA was digested, and the resulting oxidized nucleosides were measured by means of a recently optimized high‐performance‐liquid‐chromatography tandem‐mass‐spectrometry assay. It was found that, among the different DNA lesions observed, 7,8‐dihydro‐8‐oxo‐2′‐deoxyguanosine is the major 1 O 2 ‐mediated DNA‐damage product. Interestingly, cyclobutane pyrimidine dimers, oxidized pyrimidine bases, 7,8‐dihydro‐8‐oxo‐2′‐deoxyadenosine, and 2,6‐diamino‐5‐formamido‐4‐hydroxypyrimidine are not formed, at least not in detectable amounts, following treatment of DNA with the 1 O 2 generator. The reported results strongly suggest that the decomposition of the endoperoxide provides a pure source of 1 O 2 , and that reaction of 1 O 2 with isolated DNA induces the specific formation of 7,8‐dihydro‐8‐oxo‐2′‐deoxyguanosine.