Beyond solvent exclusion: i-Motif detecting capability and an alternative DNA light-switching mechanism in a ruthenium(II) polypyridyl complex

Spence, Philip, Fielden, John ORCID: https://orcid.org/0000-0001-5963-7792 and Waller, Zoë. A. E. (2020) Beyond solvent exclusion: i-Motif detecting capability and an alternative DNA light-switching mechanism in a ruthenium(II) polypyridyl complex. Journal of the American Chemical Society, 142 (32). pp. 13856-13866. ISSN 0002-7863

[thumbnail of JACS Article RuiM-AuthorsAccepted]
Preview
PDF (JACS Article RuiM-AuthorsAccepted) - Accepted Version
Download (870kB) | Preview

Abstract

Cytosine-rich DNA can fold into secondary structures known as i-motifs. Mounting experimental evidence suggests that these non-canonical nucleic acid structures form in vivo and play biological roles. However, to date, there are no optical probes able to identify i-motif in the presence of other types of DNA. Herein, we report for the first time the interactions between the three isomers of [Ru(bqp)2]2+ with i-motif, G-quadruplex, and double-stranded DNA. Each isomer has vastly different light-switching properties: mer is “on”, trans is “off”, and cis switches from “off” to “on” in the presence of all types of DNA. Using emission lifetime measurements, we show the potential of cis to light up and identify i-motif, even when other DNA structures are present using a sequence from the promoter region of the death-associated protein (DAP). Moreover, separated cis enantiomers revealed Λ-cis to have a preference for the i-motif, whereas Δ-cis has a preference for double-helical DNA. Finally, we propose a previously unreported light-switching mechanism that originates from steric compression and electronic effects in a tight binding site, as opposed to solvent exclusion. Our work suggests that many published non-emissive Ru complexes could potentially switch on in the presence biological targets with suitable binding sites, opening up a plethora of opportunity in the detection of biological molecules.

Item Type: Article
Faculty \ School: Faculty of Science > School of Pharmacy
Faculty of Science > School of Chemistry
UEA Research Groups: Faculty of Science > Research Groups > Chemistry of Materials and Catalysis
Faculty of Science > Research Groups > Chemistry of Light and Energy
Faculty of Science > Research Groups > Energy Materials Laboratory
Faculty of Science > Research Groups > Chemical Biology and Medicinal Chemistry (former - to 2021)
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 25 Aug 2020 00:06
Last Modified: 18 Jul 2023 19:30
URI: https://ueaeprints.uea.ac.uk/id/eprint/76570
DOI: 10.1021/jacs.0c04789

Downloads

Downloads per month over past year

Actions (login required)

View Item View Item