A spectroscopic study of the interaction of the antioxidant naringin with bovine serum albumin

The interaction of naringin with bovine serum albumin has been performed using fluorescence, circular dichroism and fourier transform infrared spectroscopy in 20 mM phosphate buffer of pH 7.0 as well as molecular docking studies. The changes in enthalpy (ΔH°) and entropy (ΔS°) of the interaction were found to be +18.73 kJ/mol and +143.64 J mol K respectively, indicating that the interaction of naringin with bovine serum albumin occurred mainly through hydrophobic interactions. Negative values of free energy change (ΔG°) at different temperatures point toward the spontaneity of the interaction. Circular dichroism studies reveal that the helical content of bovine serum albumin decreased after interaction with naringin. According to the Förster non-radiative energy transfer theory the distance between Trp 213 residue and naringin was found to be 3.25 nm. Displacement studies suggest that naringin binds to site 1 (subdomain IIA) of bovine serum albumin (BSA) which was also substantiated by molecular docking studies.