Spontaneous vs. induced mutations in DNA: a QMMM approach
José Pedro Cerón et Denis Jacquemin
CEISAM, Université de Nantes, Nantes, France.
jose.ceron@univ-nantes.fr
Lundi 6 Mai 2013, 11h00
bibliothèque LCT, tour 12 - 13, 4e étage
The investigation of the tautomeric equilibria in guanine-cytosine base pairs is crucial to understand
DNA's mutations [1]. In these tautomeric equilibria the bases pairs exchange one or more proton(s)
through proton transfer (PT) reactions, which eventually lead to a so-called rate tautomeric forms. In
this talk I will review our work on the study of the PT mechanisms in both undamaged and altered
DNA, with a focus on the influence of π-stacking and solvent effects that have been appraised by
combining ONIOM calculations [2] to a hydrated doubled stranded DNA fragment [3] (Figure 1).
I will discuss how external agents, e.g. metals and ionizing radiation [4], drastically alters these
tautomeric equilibria and consequently the DNA's stability.
![[Picture]](Ceron-image1.jpg)
Figure 1: Side (left) and top (right) views of the three base pairs DNA fragment. The ONIOM layers
are represented with balls-and-sticks (high), tube (medium) and wireframe (low), respectively.
[1] L. Gorb, Y. Podolyan, P. Dziekonski, W. A. Sokalski, and J. Leszczyńki. J. Am. Chem. Soc. 126
10119 (2004)
[2] T. Vreven, K. S. Byun, I. Komáromi, S. Dapprich, J. A. Montgomery-Jr, K. Morokuma, and M.
J. Frisch. J. Chem. Theory Comput. 2 815 (2006)
[3] H.-Y. Chen, C.-L. Kao, and S. C. N. Hsu. J. Am. Chem. Soc. 131 15930 (2009)
[4] a) J. P. Cerón-Carrasco, J. Zúñiga, A. Requena, E. A. Perpete, C. Michaux, and D. Jacquemin.
Phys. Chem. Chem. Phys. 13 14584 (2011); b) J. P. Cerón-Carrasco, A. Requena, and D.
Jacquemin. Theor. Chem. Acc. 131 1188 (2012); c) J. P. Cer´on-Carrasco, A. Requena, C.
Michaux, E. A. Perpete, and D. Jacquemin. J. Phys. Chem. B 114 13439 (2010)