5',8-Cyclo-2'-deoxyadenosine (cdA) formation by gamma-radiation. Theoretical quantum mechanics study.

  • Boleslaw T Karwowski Laboratoire des Lésions des Acides Nucléiques, INAC/SCIB-UMR-E n degrees 3 CEA-UJF, CEA/Grenoble, Grenoble Cedex 9, France. Bolek.Karwowski@wp.pl;
  • Andre Grand
  • Jean Cadet

Abstract

Reactions of reactive oxygen species and more specifically - of hydroxyl radical ((*)OH) - with nucleosides may lead to the generation of radicals in the base and 2-deoxyribose moieties. In the present study emphasis was put on the possible reaction modes of 2'-deoxyadenosine (dA) radicals, leading to the formation of related 5',8-cyclonucleosides. It appears that the prerequisite for the formation of 5',8-cyclo-2'-deoxyadenosine (cdA) is the adoption of O4'-exo conformation by 2-deoxyribose; however, this is the least energetically favored conformer among the different puckered forms adopted by the furanose ring. The O4'-exo conformation was found to be present in each of the discussed mechanisms.
Published
2009-10-15
Section
Articles