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.