DNA Photosensitization by an "Insider": Photophysics and Triplet Energy Transfer of 5-Methyl-2-pyrimidone Deoxyribonucleoside

Emmanuelle Bignon (1, 2) , Hugo Gattuso (3) , Christophe Morell (1) , Elise Dumont (2) , Antonio Monari (3)

1 Chemometrics and theoretical chemistry. - Chimiométrie et chimie théorique
2 LC - Laboratoire de Chimie - UMR5182
3 SRSMC - Structure et Réactivité des Systèmes Moléculaires Complexes

The main chromophore of (6-4) photoproducts, namely, 5-methyl-2-pyrimidone (Pyo), is an artificial noncanonical nucleobase. This chromophore has recently been reported as a potential photosensitizer that induces triplet damage in thymine DNA. In this study, we investigate the spectroscopic properties of the Pyo unit embedded in DNA by means of explicit solvent molecular-dynamics simulations coupled to time-dependent DFT and quantum-mechanics/molecular-mechanics techniques. Triplet-state transfer from the Pyo to the thymine unit was monitored in B-DNA by probing the propensity of this photoactive pyrimidine analogue to induce a Dexter-type triplet photosensitization and subsequent DNA damage.

Mots clés: DNA; energy transfer; molecular dynamics; nucleobases; photophysics; CONSISTENT-FIELD METHOD; AMBER FORCE-FIELD; EXCITED-STATES; DENSITY FUNCTIONALS; NUCLEIC-ACIDS; DAMAGE; BENZOPHENONE; MECHANISM; WATER; OLIGODEOXYNUCLEOTIDES

Domaines: Chimie analytique; Biochimie [q-bio.BM]

Emmanuelle Bignon, Hugo Gattuso, Christophe Morell, Elise Dumont, Antonio Monari. DNA Photosensitization by an "Insider": Photophysics and Triplet Energy Transfer of 5-Methyl-2-pyrimidone Deoxyribonucleoside. Chemistry - A European Journal, 2015, 21 (32), pp.11509-11516. ⟨10.1002/chem.201501212⟩. ⟨hal-01186698⟩