Investigation of the molecular interactions of triclocarban with human serum albumin using multispectroscopies and molecular modeling

Abstract

Triclocarban (TCC), as a broad spectrum antibacterial agent widely used in personal care products, has recently been recognized as environmental pollutant with the potential of adversely affecting wildlife and human health. However, the behavior of TCC in blood circulatory system and the potential toxicity of TCC at the molecular level have been poorly investigated. In this study, the effect of TCC on human serum albumin (HSA) and the binding mechanism of TCC to HSA were examined using spectroscopic techniques and molecular modeling methods. The fluorescence results suggested that the fluorescence of HSA was quenched by TCC through a static quenching mechanism and nonradiation energy transfer, and TCC was bound to HSA with moderately strong binding affinity via hydrophobic interaction based on the analysis of the thermodynamic parameters. The site marker competitive experiments revealed that TCC bound into subdomain IIA (site I) of HSA. In addition, the results obtained from the circular dichroism, Fourier transform infrared (FT-IR), 8-anilino-1-naphthalenesulfonic acid fluorescence, synchronous fluorescence, three-dimensional fluorescence spectra and dynamic light scattering suggested the change in the microenvironment and conformation of HSA during the binding reaction. Finally, the best binding mode of TCC and specific interaction of TCC with amino acid residues were determined using molecular docking and molecular dynamics simulations. In a word, the present studies can provide a way to help us well understand the transport, distribution and toxicity effect of TCC when it diffused in the human body.

Communicated by Ramaswamy H. Sarma

Keywords:

• triclocarban
• human serum albumin
• interaction
• spectroscopic analyses
• molecular modeling

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The data that support the plots within this article and other findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China [21506152]; The Natural Science Foundation of Tianjin [15JCQNJC06200]; The Beiyang Young Scholar of Tianjin University (2016); The grant of China Scholarship Council.