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Complexation of norfloxacin with DNA in the presence of caffeine

Evstigneev, M.P. and Rybakova, K.A. and Davies, David B. (2006) Complexation of norfloxacin with DNA in the presence of caffeine. Biophysical Chemistry 121 (2), pp. 84-95. ISSN 0301-4622.

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Official URL: http://dx.doi.org/10.1016/j.bpc.2005.12.003

Abstract

1H NMR spectroscopy (500 MHz) has been used to quantify the complexation of the antibacterial antibiotic Norfloxacin (NOR) with DNA in the presence of Caffeine (CAF). Separate studies have been made for the self-association of NOR, its hetero-association with CAF and complexation with a model self-complementary DNA tetramer, 5′-d(TpGpCpA), in order to determine the equilibrium parameters (induced chemical shifts, association constants, enthalpy and entropy) of the two-component mixtures to aid the analysis of the three-component systems. Investigations of the self-association of NOR and its hetero-association with CAF show that the aggregation of NOR molecules and association with CAF in solution are driven by the stacking of aromatic chromophores. The complexation of NOR with d(TGCA) has been analysed in terms of intercalation with the double-stranded form and non-intercalative binding with the single-stranded form of DNA. Investigations of the competitive binding of NOR and CAF with DNA show that at physiological concentrations of NOR (μM) and CAF (mM) the dominant mechanism influencing the affinity of NOR with DNA is the displacement of bound NOR molecules from DNA due to CAF–DNA complexation (i.e. the protector action of Caffeine).

Item Type: Article
Keyword(s) / Subject(s): norfloxacin, caffeine, self-association, hetero-association, DNA complexation, competitive binding
School or Research Centre: Birkbeck Schools and Research Centres > School of Science > Biological Sciences
Depositing User: Sandra Plummer
Date Deposited: 19 Jun 2006
Last Modified: 17 Apr 2013 12:32
URI: http://eprints.bbk.ac.uk/id/eprint/378

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