Biophysical and Computational Investigation of the Interaction between Indole-3-Acetic Acid and DNA.

In this work, the interaction of indole-3-actic acid (IAA) -the plant growth hormone auxin- with salmon sperm DNA was investigated by different method such as UV-Vis absorption and fluorescence emission spectroscopy, viscosity measurement and voltammetric methods. Also, the computational strategy including molecular dynamics simulation and molecular docking study was used to consider the details of IAA-DNA interaction. The experimental results suggested that the interaction of IAA with DNA is predominantly intercalative. The thermodynamic parameters (ΔG, ΔH, and ΔS) suggested that hydrogen bonding and van der Waals interactions contribute to the binding process. Ionic strength studies further suggested that electrostatic interactions contribute to the overall binding process. The binding affinity of IAA toward DNA was further investigated by SWV, yielding a binding constant of 1.19 × 10⁵ M⁻¹.