Probing the Binding Interaction of Terbinafine with Human Serum Albumin via Multiple Fluorescence Spectroscopy and Molecular Modeling

Human serum albumin (HSA) is the major serum protein affording the transportation of drugs. The investigation on binding interaction between a drug and HSA will be beneficial to understand its pharmacokinetic characters. Terbinafine is a potent antifungal agent in clinic. Herein we report the interaction of terbinafine with HSA and relevant mechanisms by fluorescence spectroscopy and molecular modeling. The results show the affinity of terbinafine to HSA is potent through the formation of terbinafine-HSA complex, which also initializes the static fluorescence quenching of HSA. The binding site for terbinaflne is site I in subdomain HA of HSA. The driving forces for the complex formation include hydrogen bond, van der Waals force, hydrophobic interaction and electrostatic interaction. And the process for the formation is exothermic and spontaneous. The formation of the complex also affects the secondary structure of HSA. Molecular docking has further continued the conclusion derived from experiments.