One Way Traffic: Base-to-Backbone Hole Transfer in Nucleoside Phosphorodithioate.

ABSTRACT: The directionality of the hole-transfer processes between DNA backbone and base was investigated by using phosphorodithioate [P(S^- )=S] components. ESR spectroscopy in homogeneous frozen aqueous solutions and pulse radiolysis in aqueous solution at ambient temperature confirmed initial formation of G^.+ -P(S^- )=S. The ionization potential of G-P(S^- )=S was calculated to be slightly lower than that of guanine in 5'-dGMP. Subsequent thermally activated hole transfer from G^.+ to P(S^- )=S led to dithiyl radical (P-2S^. ) formation on the μs timescale. In parallel, ESR spectroscopy, pulse radiolysis, and density functional theory (DFT) calculations confirmed P-2S^. formation in an abasic phosphorodithioate mode

SUBMITTER: Kaczmarek R 

PROVIDER: S-EPMC7416487 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature