Background: Human serum albumin (HSA) was chosen as the model for the study because it is the most abundantplasma protein component. In addition, HSA has a high affinity for many drugs and is considered a carrier transmitterdrug.Methods: The spectroscopic methods, including ultraviolet-visible (UV) spectroscopy, circular dichroism (CD), andequilibrium dialysis, were utilized better to understand the binding interaction between buspirone hydrochlorideand HSA.Results: UV-Vis analysis of buspirone hydrochloride with HSA showed that adding the addition of the drug changedthe protein structure. There are two absorption peaks for free HSA. The small peak in the 280 nm region is mainlyascribed to the Phe, Tyr, and Trp residues. CD analysis show that the binding of the drug to the protein changes theamount of alpha helix, indicating a change in the second structure of the protein. The equilibrium dialysis methodshows the affinity of the drug to the protein. From the Hill diagram, by determining n and then calculating the valuesof Ln(r/n-r) and Ln (Cf), the Hill diagram for the buspirone hydrochloride is defined. This diagram is a straight lineand the Hill coefficient indicates the slope of this diagram, which is determined for nH=2.44 HSA. It concluded thatthe binding procedure of the buspirone hydrochloride to HSA is positively cooperative.Conclusion: From the conclusions of analysis results, we deduced that the data obtained from equilibrium dialysisshowed a positive slope, suggesting a cooperative binding pattern for buspirone hydrochloride to HSA. CDspectroscopy findings showed that buspirone hydrochloride was able to induce slight structural changes in HSA. Thefindings of this study might be useful for better understanding the effects of buspirone hydrochloride on thestructure and mechanism of HSA in the body as well as for designing more suitable and optimal drugs.
