Skip to Main content Skip to Navigation
Journal articles

Deprotonation dynamics of guanine radical cations

Evangelos Balanikas 1 Akos Banyasz 1, 2 Gérard Baldacchino 1 Dimitra Markovitsi 1
1 DICO - Biomolécules Excitées
IRAMIS - Institut Rayonnement Matière de Saclay, LIDyl - Laboratoire Interactions, Dynamiques et Lasers (ex SPAM)
Abstract : This review is dedicated to guanine radical cations (G$^+$)$^•$ that are precursors to oxidatively generated damage to DNA. (G$^+$)$^•$ are unstable in neutral aqueous solution and tend to lose a proton. The deprotonation process has been studied by time-resolved absorption experiments in which (G$^+$)$^•$ radicals are produced either by an electron abstraction reaction, using an external oxidant, or by low-energy/low-intensity photoionization of DNA. Both the position of the released proton and the dynamics of the process depend on the secondary DNA structure. While deprotonation in duplex DNA leads to (G-H1)$^•$ radicals, in guanine quadruplexes the (G-H2)$^•$ analogues are observed. Deprotonation in monomeric guanosine proceeds with a time constant of ~60 ns, in genomic DNA is completed within 2 µs and spans from at least 30 ns to over 50 µs in guanine quadruplexes. Such a deprotonation dynamics in four-stranded structures, extended over more than three decades of times, is correlated with the anisotropic structure of DNA and the mobility of its hydration shell. In this case, commonly used second order reaction models are inappropriate for its description.
Document type :
Journal articles
Complete list of metadata

https://hal-cea.archives-ouvertes.fr/cea-03383354
Contributor : Caroline Lebe Connect in order to contact the contributor
Submitted on : Monday, October 18, 2021 - 3:41:29 PM
Last modification on : Saturday, October 30, 2021 - 7:22:41 PM

Files

deprotonation dynamics review ...
Files produced by the author(s)

Licence


Copyright

Identifiers

Citation

Evangelos Balanikas, Akos Banyasz, Gérard Baldacchino, Dimitra Markovitsi. Deprotonation dynamics of guanine radical cations. Photochemistry and Photobiology, Wiley, In press, ⟨10.1111/php.13540⟩. ⟨cea-03383354⟩

Share

Metrics

Record views

35

Files downloads

71