Interaction of diuron to human serum albumin: Insights from spectroscopic and molecular docking studies

ABSTRACT

This investigation was undertaken to determine the interaction of diuron with human serum albumin (HSA) was studied by monitoring the spectral behavior of diuron-HSA system. The fluorescence of HSA at 340 nm excited at 230 nm was obviously quenched by diuron due to dynamic collision and the quenching constant was of the order of 10⁴ L mol⁻¹ at 310 K. However, no fluorescence quenching was observed when excited at 280 nm. Thermodynamic investigations revealed that the combination between diuron and HSA was entropy driven by predominantly hydrophobic interactions. The binding of diuron induced the drastic reduction in α-helix conformation and the significant enhancement in β-turn conformation of HSA. In addition, both sites marker competition study and molecular modeling simulation evidenced the binding of diuron to HSA primarily took place in subdomain IIIA (Sudlow's site II).

KEYWORDS:

• Diuron
• human serum albumin
• molecular docking
• spectroscopy
• toxicity

Funding

This work was supported by grants from the National Natural Science Foundation of China (41473074, 41103058, and 41430106), the Fundamental Research Funds for the Central Universities (FRF-TP-14-081A2), National Outstanding Youth Research Foundation of China (40925010), and International Joint Key Project from Chinese Ministry of Science and Technology (2010DFB23160).