Quantum molecular simulation of the H abstraction at C4′ of DNA sugar moiety by the free radical OH

A. Hamza (1, 2) , H. Broch (2) , D. Vasilescu (2)

1 Institut Pasteur de Tunis
2 GRECFO - Laboratoire de Biophysique, Université de Nice Sophia Antipolis

The simulation of the H abstraction at the C4 site of the DNA deoxyribose by the hydroxyl radical was conducted using a supermolecular model composed of a sodium compensated-5 pdCp3 molecule in interaction with OH. The mechanism of the H abstraction is discussed on the basis of various ab initio quantum molecular computations and the obtained Molecular Electrostatic Potentials, frontier orbitals and total spin density. Analysis of the results shows that the hydrogen abstraction by OH at C4 position on the deoxyribose and H2O formation is a bimolecular transfer reaction in agreement with a diffusion controlled process.

Mots clés: DNA; Molecular electrostatic potentials; Free radical OH; 5 -phosphate deotoxycytidine 3-phosphate

Domaines: Biochimie, Biologie Moléculaire

A. Hamza, H. Broch, D. Vasilescu. Quantum molecular simulation of the H abstraction at C4′ of DNA sugar moiety by the free radical OH. Journal of Molecular Structure: THEOCHEM, 1999, 491 (1-3), pp.237-247. ⟨10.1016/S0166-1280(99)00126-8⟩. ⟨pasteur-02052160⟩