Multi-spectroscopic and molecular docking studies for binding interaction between fluvoxamine and human serum albumin

In the present study, different spectroscopic techniques have been used to study the binding interaction between the antidepressant drug fluvoxamine and human serum albumin under simulated physiological conditions (pH 7.4). The utilized spectroscopic techniques include fluorescence emission spectroscopy, synchronous fluorescence spectroscopy, UV-Vis absorption spectroscopy, Fourier Transform Infrared spectroscopy (FT-IR), and molecular modeling methods. The obtained results revealed that the formation of a complex between human serum albumin and fluvoxamine was responsible for quenching the native fluorescence of human serum albumin. The results indicated that the quenching mechanism between human serum albumin and fluvoxamine was static. Besides, the binding constant (K), number of binding sites (n), thermodynamic parameters (ΔH, ΔS, and ΔG), and binding forces were calculated at three different temperatures (298, 310, and 318 K). These data proposed that hydrophobic forces were the principal intermolecular forces stabilizing the complex. From the molecular docking results, it could be deduced that fluvoxamine was inserted into sub-domain II A (site I) of human serum albumin and led to a slight change in human serum albumin conformation.