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Interaction of Dinuclear Ruthenium(II) Supramolecular Cylinders with DNA: Sequence-Specific Binding, Unwinding, and Photocleavage

✍ Scribed by Jaroslav Malina; Michael J. Hannon; Viktor Brabec


Publisher
John Wiley and Sons
Year
2008
Tongue
English
Weight
497 KB
Volume
14
Category
Article
ISSN
0947-6539

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✦ Synopsis


Abstract

Metallosupramolecular chemistry was used to design a new class of synthetic agents, namely, tetracationic supramolecular cylinders, that bind strongly and noncovalently in the major groove of DNA. To gain additional information on interactions of the cylinders with DNA we explored DNA unwinding and sequence‐specific binding properties, as well as DNA photonuclease activity of ruthenium(II) metallosupramolecular cylinder [Ru~2~L~3~]^4+^, where L is a bis‐pyridylimine ligand. We found that [Ru~2~L~3~]^4+^ unwinds negatively supercoiled plasmid DNA and exhibits binding preference to regular alternating purine–pyrimidine sequences in a similar way to the [Fe~2~L~3~]^4+^ analogue. Photocleavage studies showed that, unlike [Fe~2~L~3~]^4+^, [Ru~2~L~3~]^4+^ induces single‐strand breaks on irradiation by visible and UVA light and cleaves DNA mainly at guanine residues contained preferentially in regularly alternating purine–pyrimidine nucleotides. As [Ru~2~L~3~]^4+^ binds and cleaves DNA in a sequence‐dependent manner, it may provide a useful tool for basic and applied biology, such as for controlled manipulation of the genome.