title: Effect of C5-methylation of cytosine on the photoreactivity of DNA: a joint experimental and computational study of TCG trinucleotides.
abstract: DNA methylation, occurring at the 5 position of cytosine, is a natural process associated with mutational hotspots in skin tumors. By combining experimental techniques (optical spectroscopy, HPLC coupled to mass spectrometry) with theoretical methods (molecular dynamics, DFT/TD-DFT calculations in solution), we study trinucleotides with key sequences (TCG/T5mCG) in the UV-induced DNA damage. We show how the extra methyl, affecting the conformational equilibria and, hence, the electronic excited states, increases the quantum yield for the formation of cyclobutane dimers while reducing that of (6-4) adducts.
authors: Istituto di Biostrutture e Bioimmagini-CNR , Via Mezzocannone 16, I-80134 Napoli, Italy.
authors: Luciana
authors: L
authors: Esposito
authors: Akos
authors: A
authors: Banyasz
authors: Thierry
authors: T
authors: Douki
authors: Marion
authors: M
authors: Perron
authors: Dimitra
authors: D
authors: Markovitsi
authors: Roberto
authors: R
authors: Improta
mesh_terms: D003596:Cytosine / Q000737:chemistry* / Q000378:metabolism; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D004249:DNA Damage; D019175:DNA Methylation; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D011789:Quantum Theory; D018911:Trinucleotide Repeats; D014466:Ultraviolet Rays
chemical_list: D003596:Cytosine; D004247:DNA