title: Density Functional Study of the Influence of C5 Cytosine Substitution in Base Pairs with Guanine.
abstract: The present study employs density-functional electronic structure methods to investigate the effect of chemical modification at the C5 position of cytosine. A series of experimentally motivated chemical modifications are considered, including alkyl, halogen, aromatic, fused ring, and strong σ and π withdrawing functional groups. The effect of these modifications on cytosine geometry, electronic structure, proton affinities, gas phase basicities, cytosine-guanine base-pair hydrogen bond network and corresponding nucleophilicity at guanine are examined. Ultimately, these results play a part in dissecting the effect of endogenous cytosine methylation on the reactivity of neighboring guanine toward carcinogens and DNA alkylating agents.
authors.affiliation: Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN 55455-0431, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Moser
authors.forename: Rebecca
authors.initials: R
authors.lastname: Guza
authors.forename: Natalia
authors.initials: N
authors.lastname: Tretyakova
authors.forename: Darrin M
authors.initials: DM
authors.lastname: York