Study on the interaction of Olmesartan with human serum albumin (HSA) by spectroscopic and molecular docking techniques

This study aims to investigate the interaction of olmesartan drug with human serum albumin (HSA) using fluorescence, circular dichroism (CD) spectra and molecular docking techniques under physiological conditions. Fluorescence quenching of HSA by olmesartan indicated that a moderate binding affinity (Ka = ۳۳۰۵ M‒۱) and spontaneous reaction between olmesartan and HSA obtained in phosphate buffer (۰.۰۵ M) and pH ۷.۴ at ۲۵° C. The CD results revealed a decrease in the α-helical content of HSA from ۶۱.۱% to ۵۹.۲% with the addition of olmesartan, indicating that olmesartan binding induces changes in the secondary structure of HSA. The study of molecular docking also indicated that the optimal binding site for olmesartan on HSA is located in the IIA and IIB subdomains. Thermodynamic analysis and molecular docking results suggested that the binding of olmesartan to HSA is dominated by hydrophobic interactions and hydrogen bonds. Also, olmesartan formed hydrophobic interactions with Trp۲۱۴, Asp۴۵۱, Tyr۴۵۲, and Asn۲۹۵, and established five hydrogen bonds with Lys۱۹۵, Arg۲۱۸, and Pro۳۳۹. However, theoretical and experimental findings demonstrated excellent agreement.

کلیدواژه ها:

Olmesartan ، Human Serum Albumin ، Molecular docking ، Fluorescence ، Circular dichroism