Metal-ion-mediated tuning of duplex DNA binding by bis(2-(2-pyridyl)-1H-benzimidazole)

Bhattacharya, Santanu and Chaudhuri, Padmaparna (2007) Metal-ion-mediated tuning of duplex DNA binding by bis(2-(2-pyridyl)-1H-benzimidazole). In: Chemistry - An Asian Journal, 2 (5). pp. 648-655.

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Abstract

Studies of double-stranded-DNA binding have been performed with three isomeric bis)2-(n-pyridyl)-1H-benzimidazole)s (n = 2, 3, 4). Like the well-known Hoechst 33258, which is a bisbenzimidazole compound, these three isomers bind to the minor groove of duplex DNA. DNA binding by the three isomers was investigated in the presence of the divalent metal ions Mg2+, Co2+, Ni2+, Cu2+, and Zn2+. Ligand-DNA interactions were probed with fluorscence and circular dichroism spectroscopy. These studies revealed that the binding of the 2-pyridyl derivative to DNA is dramatically reduced in the presence of Co2+, Ni2+, and Cu2+ ions and is abolished completely at a ligand/metal-cation ratio of 1:1. Control experiments done with the isomeric 3- and 4-pyridyl derivatives showed that their binding to DNA is unaffected by the aforementioned transition-metal ions. The ability of 2-(2-pyridyl)benzimidazole changes of the ligand associated with ion chelation probably ledto such unusual binding results for the ortho isomer. The addition of ethylenediaminetetraacetic acid (EDTA) reversed the effects completely.

Item Type:	Journal Article
Publication:	Chemistry - An Asian Journal
Publisher:	John Wiley and Sons
Additional Information:	Copy right of this article belongs to John Wiley and Sons.
Department/Centre:	Division of Chemical Sciences > Organic Chemistry
Date Deposited:	07 Jun 2010 09:12
Last Modified:	19 Sep 2010 05:59
URI:	http://eprints.iisc.ac.in/id/eprint/27088

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