Thermally Stable Schiff Base and its Metal Complexes: Molecular Docking and Protein Binding Studies

In this paper, interaction of Schiff base and its metal complexes carrying naphthalene ring in the structure with bovine serum albumin (BSA) were investigated using UV-vis absorption, fluorescence spectroscopies and molecular docking methods. The effect on the binding mechanism and properties of these compounds containing metal-free, iron and copper ions were also investigated. The fluorescence spectroscopy results showed that fluorescence intensity of BSA in the presence of different concentration of ligands was decreased through a static quenching mechanism. Binding constants (KSV, Kbin and Ka) and thermodynamic parameters (ΔG, ΔH and ΔS) for the ligand-protein interactions were also determined. ΔG values of ligand-protein interaction were calculated in the range - 6.3 to -5.5 kcal/mol. These negative values showed that binding process is spontaneous and, hydrogen bonding and van der Waals force were main interaction of the protein and ligands. ΔH and ΔS value were also calculated in the range of 1.10 to 1.26 kJ/mol and 0.133 to 0.135 kJ/mol. K, respectively. These positive values indicated that the binding process between ligands and BSA are endothermic and electrostatic interaction, respectively.