Correction to “Potassium ions enhance guanine radical generation upon absorption of low-energy photons by g-quadruplexes and modify their reactivity"

Behnaz Behmand (1, 2) , Evangelos Balanikas (1, 2) , Lara Martinez-Fernandez (1, 2) , Roberto Improta (1, 3) , A. Banyasz (1, 4) , Gerard Baldacchino (1, 2) , Dimitra Markovitsi (1, 2)

1 DICO - Dynamique et Interactions en phase Condensée
2 LIDYL - Laboratoire Interactions, Dynamiques et Lasers (ex SPAM)
3 CNR - Consiglio Nazionale delle Ricerche [Napoli]
4 LC - Laboratoire de Chimie - UMR5182

G-Quadruplexes are formed by guanine rich DNA/RNA sequences in the presence of metal ions, which occupy the central cavity of these four-stranded structures. We show that these metal ions have a significant effect on the photogeneration and the reactivity of guanine radicals. Transient absorption experiments on G-quadruplexes formed by association of four TGGGGT strands in the presence of K$^+$ reveal that the quantum yield of one-photon ionization at 266 nm (8.1 × 10$^{–3}$) is twice as high as that determined in the presence of Na$^+$. Replacement of Na$^+$ with K$^+$ also suppresses one reaction path involving deprotonated radicals, (G-H2)$^•$ → (G-H1)$^•$ tautomerization. Such behavior shows that the underlying mechanisms are governed by dynamical processes, controlled by the mobility of metal ions, which is higher for Na$^+$ than for K$^+$. These findings may contribute to our understanding of the ultraviolet-induced DNA damage and optimize optoelectronic devices based on four-stranded structures, beyond DNA.

Domaines: Chimie théorique et/ou physique; Chimie-Physique [physics.chem-ph]

Behnaz Behmand, Evangelos Balanikas, Lara Martinez-Fernandez, Roberto Improta, A. Banyasz, et al.. Correction to “Potassium ions enhance guanine radical generation upon absorption of low-energy photons by g-quadruplexes and modify their reactivity". Journal of Physical Chemistry Letters, 2020, 11 (4), pp.1305-1309. ⟨10.1021/acs.jpclett.0c00815⟩. ⟨cea-03053797⟩