Insights into the interaction of azinphos-methyl with bovine serum albumin: experimental and molecular docking studies

Abstract

In the present study, combining spectroscopic and molecular modeling techniques has been used to analyze azinphos-methyl binding properties, as an organophosphorus pesticide, to bovine serum albumin. The quenching interaction of azinphos-methyl with bovine serum albumin was investigated in an appropriate physiological state (pH = 7.4). Fluorescence spectroscopy, UV–visible spectroscopy, circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR). Findings showed differences in the secondary protein structure microenvironment following interaction with azinphos-methyl. The results from spectroscopic experiments suggest that azinphos-methyl binds to bovine serum albumin residues with a binding constant in the range of 0.099 × 10⁵−0.209 × 10⁵ M⁻¹ in one binding site (Tyr 160). The experimental results are supported by computational techniques such as docking using a bovine serum albumin crystal model. The results show that azinphos-methyl is linked to the site I of bovine serum albumin (in subdomain IB), and the result was in accordance with the experimental result. Based on the negative ΔG°, ΔH° and ΔS° values, the binding between azinphos-methyl and bovine serum albumin was spontaneous, and docking studies confirmed hydrogen bonding and van der Waals forces between them.

Communicated by Ramaswamy H. Sarma

Keywords:

• Bovine serum albumin
• azinphos-methyl
• organophosphorus pesticide
• ligand-protein interactions
• fluorescence spectroscopy
• molecular modeling

Acknowledgements

We would like to express our very great appreciation to Dr. Majid Amiri and Dr. Ali Heydari for their valuable and constructive suggestions during the planning and development of this research work. Their willingness to give his time so generously has been very much appreciated.

Disclosure statement

The authors did not report any conflict of interest.