Investigation of the interaction between endocrine disruptor bisphenol A and human serum albumin

In this study, the interaction of the endocrine disruptor bisphenol A (BPA) and human serum albumin (HSA) was investigated by molecular modelling, fluorescence, ultraviolet–visible spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FT-IR) and circular dichroism spectroscopy (CD). The association constants between BPA and HSA were determined using the Scatchard equation. The thermodynamic parameters of the binding reaction (ΔG0, ΔH0 and ΔS0) were measured, and they indicated the presence of hydrophobic forces in the BPA–HSA interaction, which agreed well with the results from molecular modelling. The alterations of protein secondary structure in the presence of BPA were confirmed by UV–vis, FT-IR and CD spectroscopy. Lastly, the average binding distance, r, between BPA and HSA was evaluated and found to be 1.82 nm according to Förster’s theory of non-radiation energy transfer.