Beyond solvent exclusion: i-Motif detecting capability and an alternative DNA light-switching mechanism in a ruthenium(II) polypyridyl complex
| Autor: | John Fielden, Zoë A. E. Waller, Philip Spence |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Steric effects
Stereochemistry 010402 general chemistry G-quadruplex Crystallography X-Ray 01 natural sciences Biochemistry Catalysis Ruthenium chemistry.chemical_compound Colloid and Surface Chemistry Coordination Complexes Electronic effect Molecule Binding site Nucleotide Motifs Density Functional Theory chemistry.chemical_classification Molecular Structure Biomolecule General Chemistry DNA 0104 chemical sciences Molecular Docking Simulation chemistry Nucleic acid Solvents |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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