Investigation on the interaction between triclosan and bovine serum albumin by spectroscopic methods

Multi-spectroscopic and molecular docking methods were used to study the interaction between triclosan (TCS) and bovine serum albumin (BSA). The results indicated that the fluorescence quenching of BSA by TCS was due to the formation of TCS-BSA complex through static quenching. This result was also demonstrated by time-resolved fluorescence experiment. The binding constants and number of binding sites between TCS and BSA were 1.30 × 10⁵ M^-1 and 1.17 at 298 K, respectively. The thermodynamic parameters were studied in detail which suggested that hydrophobic forces and hydrogen bond played major roles in the TCS-BSA interaction. Moreover, the site marker competitive experiments and docking studies revealed that TCS could bind BSA into site I in subdomain IIA. All the results of UV-vis spectrophotometry, circular dichroism spectroscopy and synchronous fluorescence spectroscopy showed that interaction between TCS and BSA induced conformation changes of BSA.