Binding mechanism of triclocarban with human serum albumin: Effect on the conformation and activity of the model transport protein

Triclocarban (TCC) is an antibacterial agent in antibacterial personal care products. Human serum albumin (HSA) is the transport protein with the ligand binding properties. The current study was undertaken to identify the binding mechanism of TCC with HSA by using biophysical methods. The fluorescence and IJV-vis spectral results showed that the fluorescence quenching of HSA by TCC was static quenching by the formation of HSA-TCC complex. The binding constants were obtained by molecular modeling and fluorescence quenching, and the results indicated the existence of strong interaction between HSA and TCC with binding constant K-b similar to 10(5) L/mol. TCC can enter into the binding pocket of domain II of HSA by mainly hydrophobic and hydrogen bonds forces. The conformations of TCC and HSA are all changed during the binding interaction of them. We hope that this work will provide some useful information for understanding the activity and mechanism of antibacterial agent with the transport protein. (C) 2017 Elsevier B.V. All rights reserved.