Electron attachment-induced DNA single-strand breaks at the pyrimidine sites.

ABSTRACT: To elucidate the contribution of pyrimidine in DNA strand breaks caused by low-energy electrons (LEEs), theoretical investigations of the LEE attachment-induced C(3')-O(3'), and C(5')-O(5') σ bond as well as N-glycosidic bond breaking of 2'-deoxycytidine-3',5'-diphosphate and 2'-deoxythymidine-3',5'-diphosphate were performed using the B3LYP/DZP++ approach. The base-centered radical anions are electronically stable enough to assure that either the C-O or glycosidic bond breaking processes might compete with the electron detachment and yield corresponding radical fragments and anions. In the gas phase, the computed glycosidic bond breaking activation energy (24.1 kcal/mol) excludes the base release pathway. The low-energy barrier for the C(3')-O(3') σ bond cleavage process (∼6.0 kcal/mol fo

SUBMITTER: Gu J 

PROVIDER: S-EPMC2938206 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature