Background: Human serum albumin (HSA) is a synthetic protein in the liver that makes up the bulk of plasma protein.Buspirone hydrochloride is a monoamine oxidase inhibitor family drug that increases the neurotransmittersserotonin, adrenaline, and dopamine levels.Methods: The interaction between buspirone hydrochloride (BSH) and HSA was studied by, fluorescence, FT-IRspectroscopy, and molecular docking. The spectroscopic technique is suitable for studying the drug and HSAinteraction owing to its sensitivity, reproducibility, and convenience.Results: UV-Vis analysis of BSH in conjunction with HSA revealed that the drug modifies the protein's structure. Thisis evidenced by shifts in the position and shape of the amide I peak, indicating that BSH interacts with the carbonylgroup of HSA. Fluorescence spectroscopy revealed that the quenching mechanism of protein with BSH was mixedquenching. Fluorescence studies were also performed to verify and determine the binding constant and the numberof binding sites. The molecular docking results revealed that BSH was incorporated and inserted into thehydrophobic groove in the ⅠB and IIB subdomains of HSA. The current research investigated the interactionbetween the anti-anxiety drug BSH and HSA using spectroscopic techniques, and molecular docking. Theexperimental results demonstrate that BSH can quench the endogenous fluorescence of HSA. The quenchingmechanism is mixed with dynamic and static quenching, and the binding procedure is spontaneous. The bindingconstant (Kb) was determined to be 104M-1, indicating a robust binding interaction of BSH with HSA.Conclusion: From the conclusions of thermodynamic parameter analysis and molecular docking results, we deducedthat the main interaction force between BSH and HSA involves hydrophobic interactions. After the binding of BSH,there is a slight change in the secondary structure of HSA. This study provides important insights into the uniquebinding sites and the characteristics of interactions between BSH and HSA in physiological conditions.
