Delta chirality ruthenium ‘light-switch’ complexes can bind in the minor groove of DNA with five different binding modes

Hall, J. P. ORCID: https://orcid.org/0000-0003-3716-4378, Keane, P. M., Beer, H., Buchner, K., Winter, G., Sorensen, T. L., Cardin, D. J., Brazier, J. A. ORCID: https://orcid.org/0000-0002-4952-584X and Cardin, C. J. ORCID: https://orcid.org/0000-0002-2556-9995 (2016) Delta chirality ruthenium ‘light-switch’ complexes can bind in the minor groove of DNA with five different binding modes. Nucleic Acids Research, 44 (19). pp. 9472-9482. ISSN 1362-4962 doi: 10.1093/nar/gkw753

Abstract/Summary

[Ru(phen)2(dppz)]2+ has been studied since the 1990s due to its “light-switch” properties. It can be used as a luminescent DNA probe, with emission switched on through DNA binding. The luminescence observed is dependent on the solvent accessibility of the pyrazine nitrogen atoms, and therefore is sensitive to changes in both binding site of the cation and chromophore orientation. The compound is also chiral, and there are distinct differences between the enantiomers in terms of the emission behaviour when bound to a variety of DNA sequences. Whilst a number of binary DNA-complex X-ray crystal structures is available, most include the Λ enantiomer, and there is very little structural information about binding of the Δ enantiomer. Here we present the first X-ray crystal structure of a Δ enantiomer bound to well-matched DNA, in the absence of the other, Λ, enantiomer. We show how the binding site observed here can be related to a more general pattern of motifs in the crystallographic literature and propose that the Δ enantiomer can bind with five different binding modes, offering a new hypothesis for the interpretation of solution data.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/66682
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry Life Sciences > School of Chemistry, Food and Pharmacy > School of Pharmacy > Medicinal Chemistry Research Group
Publisher	Oxford University Press
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