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Photoinduced electron transfer and strand cleavage in pyrenyl–DNA complexes and adducts
Author(s) -
Geacintov Nicholas E.,
Solntsev Kyril,
Johnson Lawrence W.,
Chen Junxin,
Kolbanovskiy Alexander D.,
Liu Tongming,
Shafirovich Vladimir Ya.
Publication year - 1998
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/(sici)1099-1395(199808/09)11:8/9<561::aid-poc61>3.0.co;2-a
Subject(s) - chemistry , photoinduced electron transfer , oligonucleotide , adduct , electron transfer , photochemistry , covalent bond , dna , fluorescence , cleavage (geology) , quantum yield , nucleic acid , residue (chemistry) , stereochemistry , organic chemistry , biochemistry , geotechnical engineering , fracture (geology) , engineering , physics , quantum mechanics
The fluorescence of pyrenyl residues in complexes with the nucleic acid bases G, C and T, but not A, is strongly quenched by photoinduced electron transfer mechanisms. Site‐specifically modified 11‐mer oligonucleotide duplexes containing a single modified guanosyl base G* bearing a covalently attached pyrenyl residue were prepared in order to probe for photochemical damage associated with these photoinduced electron transfer reactions. When the pyrenyl residue positioned at G* is photoexcited with 355 nm light, direct strand cleavage is observed at that site with low quantum yield. Frank strand breaks are also observed up to five base pairs away from G*, suggesting that intrastrand migration of a reactive intermediate from base to base is occurring. © 1998 John Wiley & Sons, Ltd.