Mechanism of interaction between Chrysin and different configurations of human serum albumin

Abstract

The mechanism of the interaction between Chrysin (CHR) and human serum albumin (HSA) was investigated using various spectroscopic techniques. It was found that CHR can induce HSA fluorescence emission quenching by static process. Additionally, HSA caused a significant red shift in the ultraviolet absorption of CHR. This indicated that binding with a protein can result in dissociation of the phenolic hydroxyl in CHR. HSA can also cause CHR fluorescence emission. The binding constants of CHR and HAS were calculated based on the fluorescence quenching and emission modes. The results obtained using these two methods were consistent. The binding constant (KA) values at pH 7.4 were (9.97±0.24)×104 and (9.75±0.11)×104 L{bullet operator}mol-1, respectively; and the ratio of combination was 1:1. The binding constants decreased gradually with decreasing the pH value. This is related to conformational changes in the protein. The protein is partly denatured at pH 3.5, with the site II in the HSA opening chain. It was found that CHR was located at site I, which is in subdomain IIA of HAS. Based on molecular modeling, the mechanism of the interaction between CHR and HAS was investigated. © Editorial office of Acta Physico-Chimica Sinica.