Concentration-dependent mode of binding of drug oxatomide with DNA: multi-spectroscopic, voltammetric and metadynamics simulation analysis
Autor: | G. Mahalakshmi, Sundararajan Ponkarpagam, Kuppanagounder P. Elango, K.N. Vennila |
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Rok vydání: | 2021 |
Předmět: |
Drug
Chemistry Circular Dichroism media_common.quotation_subject Metadynamics DNA General Medicine Fluorescence Piperazines Molecular Docking Simulation Concentration dependent chemistry.chemical_compound Spectrometry Fluorescence Structural Biology Proton NMR medicine Thermodynamics Physical chemistry Spectrophotometry Ultraviolet Oxatomide Spectroscopy Molecular Biology media_common medicine.drug |
Zdroj: | Journal of Biomolecular Structure and Dynamics. 40:8394-8404 |
ISSN: | 1538-0254 0739-1102 |
DOI: | 10.1080/07391102.2021.1911860 |
Popis: | The interaction between antihistaminic drug oxatomide (OXT) and calf-thymus DNA (CT-DNA) has been investigated in a physiological buffer (pH 7.4) using UV–Vis, fluorescence, 1H NMR and circular dichroism spectral techniques coupled with viscosity measurements, KI quenching, voltammetry and in silico molecular modeling studies. OXT binds with CT-DNA in a concentration-dependent manner. At a lower [Drug]/[CT-DNA] molar ratio (0.6–0.1), OXT intercalates into the base pairs of CT-DNA, while at a higher [Drug]/[CT-DNA] molar ratio (13–6), the drug binds in the minor grooves of CT-DNA. The binding constants for the interaction are found to be in the order of 103–105 M−1, and the groove binding mode of interaction exhibits a slightly higher binding constant than that of intercalative mode. Thermodynamic analysis of binding constants at three different temperatures suggests that both these modes of binding are mainly driven by hydrophobic interactions (ΔHo > 0 and ΔSo > 0). Voltammetric investigations indicate that the electro-reduction of OXT is an adsorption controlled process and shifts in reduction peak potentials reiterate the concentration-dependent mode of binding of the drug with CT-DNA. The free energy landscape obtained at the all-atom level, using metadynamics simulation studies, revealed two major binding forces: partial intercalation and minor groove binding, which corroborate well with the experimental results. Communicated by Ramaswamy H. Sarma |
Databáze: | OpenAIRE |
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