Ruthenium(II) Polypyridyl Complexes as FRET donors: structure- and sequence-selective DNA-binding and anticancer properties

Ruthenium(II) polypyridyl complexes (RPCs) that emit from metal-to-ligand charge transfer (MLCT) states have been developed as DNA probes and are being examined as potential anticancer agents. Here, we report that MLCT-emissive RPCs that bind DNA undergo Förster resonance energy transfer (FRET) with...

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Bibliographic Details
Main Authors: Elgar, Christopher E., Yusoh, Nur Aininie, Tiley, Paul R., Kolozsvári, Natália, Bennett, Laura G., Gamble, Amelia, Péan, Emmanuel V., Davies, Matthew L., Staples, Christopher J., Ahmad, Haslina, Gill, Martin R.
Format: Article
Language:English
Published: American Chemical Society 2023
Online Access:http://psasir.upm.edu.my/id/eprint/103125/
http://psasir.upm.edu.my/id/eprint/103125/1/103125.pdf
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Summary:Ruthenium(II) polypyridyl complexes (RPCs) that emit from metal-to-ligand charge transfer (MLCT) states have been developed as DNA probes and are being examined as potential anticancer agents. Here, we report that MLCT-emissive RPCs that bind DNA undergo Förster resonance energy transfer (FRET) with Cy5.5-labeled DNA, forming mega-Stokes shift FRET pairs. Based on this discovery, we developed a simple and rapid FRET binding assay to examine DNA-binding interactions of RPCs with diverse photophysical properties, including non-“light switch” complexes [Ru(dppz)2(5,5′dmb)]2+ and [Ru(PIP)2(5,5′dmb)]2+ (dppz = dipyridophenazine, 5,5′dmb = 5,5′-dimethyl-2,2′-bipyridine, PIP = 2-phenyl-imidazo[4,5-f][1,10]phenanthroline). Binding affinities toward duplex, G-quadruplex, three-way junction, and mismatch DNA were determined, and derived FRET donor-acceptor proximities provide information on potential binding sites. Molecules characterized by this method demonstrate encouraging anticancer properties, including synergy with the PARP inhibitor Olaparib, and mechanistic studies indicate that [Ru(PIP)2(5,5′dmb)]2+ acts to block DNA replication fork progression.