Study of in vitro interaction between tetrabromobisphenol A and bovine serum albumin by fluorescence spectroscopy.

The interaction between tetrabromobisphenol A (TBBPA) and bovine serum albumin (BSA) in simulated physiological conditions (pH = 7.4) was investigated by fluorescence spectroscopy. The results revealed that TBBPA caused the fluorescence quenching of BSA through a static quenching procedure. The binding constants (K) of TBBPA with BSA at 277, 298, and 310 K were obtained as 4.75 × 10(5) L/mol, 5.63 × 10(5) L/mol, and 6.66 × 10(5) L/mol, respectively. There may be two binding sites of TBBPA on BSA. The enthalpy change (ΔH), free energy change (ΔG), and entropy change (ΔS) of thermodynamic parameters indicated that the interaction between TBBPA and BSA was driven mainly by hydrophobic and electrostatic forces. Synchronous fluorescence spectra showed TBBPA binding slightly changed the conformation of BSA by decreasing its polarity and increasing its hydrophobicity. The results of the present study may provide valuable information for studying the distribution and toxicity mechanisms of TBBPA in vivo.