A full understanding of the molecular basis of oxidative lesionsrequires the combination of experimental and theoretical techniques, which caninvestigate both ground- and excited-state conformations. In this context, classicalMD simulations have been used to study ground-states of DNA photoreactivesequences, in order to get insights into the population of conformers presentat the instant when a molecule absorbs UV photons.
We have studied DNA sequences particularly prone to photodimerization,also including C5-methylated cytosines (5mC): C5-methylation is an importantmodification playing a role in epigenetic regulation of gene expression andbeing correlated to about 40% of melanomas. MD simulations have allowed to findthe
Structural factors that favour photodimerization in DNA sequences ofdifferent lengths, containing TCG, T5mCG, and TT, within different moleculararchitectures (single and double stranded DNA) [3-5]. We have recently extendedour study to the analysis of the structural effects of Guanine radical cationson G-quadruplex structures formed by tracts of the human telomeric sequences.
 Martinez-Fernandez,L., Banyasz, A., Esposito, L., Markovitsi, D., Improta, R. (2017).
UV-induced damage to DNA: effect of cytosine methylation on pyrimidinedimerization. Signal Transduct Target Ther. Jun 9;2:17021.
 Martinez-Fernandez,L., Esposito, L., Improta, R. (2020).
Studyingthe excited electronic states of guanine rich DNA quadruplexes by quantummechanical methods: main achievements and perspectives. Photochem. Photobiol.Sci 19(4):436-444.
 Banyasz, A., Esposito, L., Douki, T., Perron, M., Lepori, C.,Improta, R., Markovitsi, D. (2016) Effect of C5-Methylation of Cytosine on theUV-Induced Reactivity of Duplex DNA: Conformational and Electronic Factors. JPhys Chem B 120, 4232-42.
 Esposito,L., Banyasz, A., Douki, T., Perron, M., Markovitsi, D., Improta, R. (2014).
Effect of C5-Methylation of Cytosine on the Photoreactivity of DNA: AJoint Experimental and Computational Study of TCG Trinucleotides.
J. Am.Chem. Soc. 136, 10838-41.
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|▼ The fine structure of proteins as a new tool for protein structure validation, quality assessment, and prediction|
|▼ Structural characterization of self-assembling systems of biomedical and biotechnological interest|
|▼ Study of the interaction between UV light and nucleic acids: elucidating the molecular mechanisms responsible of the genetic stability and of the oxidative damaging processes by using computational methods|