Biopolymers and cell. 2005; 21 (4): 351 - 357

Quantum-chemical modelling radiation damage of DNA components during inelastic interaction with slow electrons. Desoxyribose irradiation

B. F. Minaev, Y. V. Yevtukhov, V. A. Minaeva

The total energies and heat of formation of intermediates of the deoxyribose dissociation during its interaction with a monochromatic electron beam have been calculated by the method of molecular orbitals of self-consistent field (SCF) with AM1 approximation. Dissociative attachment of slow electrons begins at the energy close to zero, although the electron affinity of deoxyribose is negative (near -2 eV), which points to the tunnelling mechanism of the reaction. The calculation of energies for all channels of dissociation of anion halfproducts closely fits the experiment for the effective cross section of the dissociative electron capture.

Key words:  2-deoxy-b-D-ribose, AMI method, dissociation energy, anion products, electron.