Spectroscopic and Molecular Docking Approaches for Investigating theInteraction of Fenvalerate with Human Serum Albumin

Fenvalerate is an insecticide which is widely utilized in agriculture. In this research, the interaction of fenvalerate with HSA, which is a blood carrier of small molecules such as drugs and toxins, is investigated. Four different methods, UV-Vis, FT-IR spectroscopy, Fluorescence spectroscopy, and molecular modeling were used to characterize the binding properties of fenvalerate with HSA at the molecular level under physiological conditions. The binding constant, which was obtained via UV-Vis spectroscopy, was computed to be KHSA/Fen=3.78 × 10+4 M-1, which indicated a relatively strong binding interactions between ligands and receptors. FT-IR results indicated a decrease in α-helixes from 55% to 50.23% and an increase in β-sheet from 13.96% to 16.82%, β-antiparallel from 6% to 8.93%, were observed on first and thirtieth day and a major decrease of α-helix from 42.99% to 38.82% and an increase in β-sheet from 1.9% to 13.9%, β-antiparallel from 2.21% to 2.53% were observed during ligand binding especially at high concentrations of ligand. The fluorescence intensity of HSA decreased regularly with the gradually increasing concentration of fenvalerate. These results also could be an evidence for binding ligands to the receptors and they were in good agreement with UV-Vis results. On the other hand, a potential binding site in the region III-B of HSA protein was determined via docking calculations. In addition, the obtained results indicate a binding site for interaction of fenvalerate with HSA, which is a chance for excreting this toxin by utilizing HSA protein.