Fluorescence decays recorded at 330 nm for 5m-dC (filled circles) and dC (squares) fitted by bi-exponential functions.
Cytosine methylation, which determines the hot spots for DNA photo-damage, is shown to induce a red-shift of the nucleoside absorption spectrum, making the chromophore more vulnerable to solar radiation, and a tenfold increase of the fluorescence lifetime, making excited state reactions more probable. A femtosecond investigation of the excited state deactivation reveals a quite complex mechanism.
• Physics and chemistry for life sciences and the environment › Physics and life
• Service des Photons Atomes et Molécules • Service des Photons Atomes et Molécules