Combined molecular docking and multi-spectroscopic investigation on the interaction between Eosin B and human serum albumin

The binding of Eosin B to human serum albumin (HSA) was studied using molecular docking, fluorescence, UV-vis, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy. The mechanism of interaction between Eosin B and HSA in terms of the binding parameters, the thermodynamic functions and the effect of Eosin B on the conformation of HSA were investigated. Protein-ligand docking study indicated that Eosin B bound to residues located in the subdomain IIA of HSA and Eosin B-HSA complex was stabilized by hydrophobic force and hydrogen bonding. In addition, fluorescence data revealed that Eosin B strongly quenched the intrinsic fluorescence of HSA through a static quenching procedure. Furthermore, alteration of the secondary structure of HSA in the presence of the dye was conformed by UV-vis, FT-IR and CD spectroscopy.