Étude in silico de la fluoroacétate déhalogénase d’Actinoalloteichus hoggarensis

Abstract

Per- and polyfluoroalkyl substances (PFAS) are persistent and widespread fluorinated organic pollutants that require the development of advanced remediation methods. The fluoroacetate dehalogenase from Actinoalloteichus hoggarensis is a promising microbial enzyme for the defluorination of these compounds. It is involved in the dehalogenation of fluoroacetate by breaking the strong carbon–fluorine (C–F) covalent bond via an SN2-type reaction mechanism, leading to the formation of glycolate. This enzyme was the subject of an in silico study aimed at characterizing its structural and functional properties. Analysis of the physicochemical properties of the protein sequence indicates that it is an acidic, thermostable, and hydrophobic protein. Furthermore, subcellular localization analysis suggests a cytoplasmic protein. The prediction of the secondary structure, performed using the SOPMA and PSIPRED tools, reveals a predominance of α-helices over β-sheets, with an estimated proportion of 43.49%. The three-dimensional structure of the enzyme, predicted by homology modeling using the SWISS-MODEL server, exhibits the highest structural quality compared to other servers. It was subsequently validated using the PROCHECK, ERRAT, and Verify3D tools. Furthermore, analysis performed with MOTIF Finder identified three domains characteristic of the α/β hydrolase superfamily. Molecular docking also allowed us to estimate the interaction energy with perfluorooctanesulfonic acid (PFOS) at −7.2 kcal/mol (Vina score), thereby predicting the enzyme’s potential to interact with the selected ligands. These results provide an important theoretical basis for elucidating the reaction mechanism of fluoroacetate dehalogenase as well as for engineering improved enzyme variants.