Exploring the mechanism of interaction between 5-(ethoxycarbonyl)-6-methyl-4-(4-methoxyphenyl)-3,4-dihydropyrimidin-2(1H)-one and human serum albumin: Spectroscopic, calorimetric and molecular modeling studies

In this paper, binding interaction of 5-(ethoxycarbonyl)-6-methyl-4-(4-methoxyphenyl)-3,4-dihydropyrimidin-2(1H)-one (EMMD) with human serum albumin (HSA) under physiological conditions was investigated by using spectroscopy, isothermal titration calorimetry (ITC) and molecular modeling techniques. The results of spectroscopic studies suggested that EMMD have a strong ability to quench the intrinsic fluorescence of HSA through static quenching procedure. ITC investigations indicated that drug-protein complex was stabilized by hydrophobic forces and hydrogen bonds, which was consistent with the results of molecular modeling studies. Competitive experiments indicated the displacement of warfarin by EMMD, which revealed that the binding site of EMMD to HSA was located at subdomain IIA.