In Silico Design of Amino Acid-Functionalized Materials for the Capture of Neonicotinoids.

We used a computational methodology to guide the design of bio-inspired materials for the adsorption of neonicotinoids. The study resorts to a multi-stage protocol, previously proposed for imidacloprid, to select key amino acids for incorporation into chitosan to enhance the adsorption of thiacloprid, acetamiprid, clothianidin, and S- and R-dinotefuran enantiomers. Molecular dynamics (MD) simulations of the protein-pesticide complexes were used to identify relevant amino acids of the Aplysia californica acetylcholine-binding protein (Ac-AChBP). Among these amino acids, the final selection was based on the electronic-structure calculations of pesticide-residue interactions. Tryptophan (Trp), tyrosine (Tyr), isoleucine (Ile) and cysteine (Cys) emerged as promising candidates to functionalize chitosan, while phenylalanine (Phe) was also considered for comparison. The efficiency of functionalized chitosan models for adsorbing each pesticide was evaluated against non-functionalized analogues through MD simulations. The functionalization of chitosan with aromatic amino acids, and especially Trp, significantly enhances the adsorption of neonicotinoids in water media.