A naproxen complex of dysprosium intercalates into calf thymus DNA base pairs

•Binding mode to ctDNA was studied by various methods.•Intercalation is the most possible binding mode.•Dynamic and static quenching occurred simultaneously.•Hydrophobic force played a major role.•Binding characteristic of rare earth complexes to DNA are dependent on the element.

The binding mode and mechanism of dysprosium-naproxen complex (Dy-NAP) with calf thymus deoxyribonucleic acid (ctDNA) were studied using UV-vis and fluorescence spectra in physiological buffer (pH 7.4). The results showed that more than one type of quenching process occurred and the binding mode between Dy-NAP with ctDNA might be intercalation. In addition, ionic strength, iodide quenching and fluorescence polarization experiments corroborated the intercalation binding mode between Dy-NAP and ctDNA. The calculated thermodynamic parameters ΔG, ΔH and ΔS at different temperature demonstrated that hydrophobic interaction force played a major role in the binding process.

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