Estudos estruturais de duas lectinas do gênero Arachis por ferramentas de bioinformática

Abstract

Lectins are proteins capable of interacting with specific carbohydrates in a reversible manner. Because carbohydrates are molecules involved in recognition and addressing processes, some lectins are able to induce cellular reactions when interacting with these sugars. The Arachis genus belongs to the Dalbergieae tribe, a group of plants that has shown promising lectins for studying biological activities and biotechnological applications. This genus has already three purified lectins, the three being isolated from the same species, Arachis hypogaea (peanut). Genomes of two species closely related to commercial peanuts, Arachis duranensis and Arachis ipaensis, were recently sequenced and published. Therefore, based on the information of the genomes of these two species, this study aims to predict the three-dimensional structure of Arachis duranensis (ADL) and Arachis ipaensis (AIL) lectins by homology modeling, to analyze the possibility of interaction of these models with different mannosides through molecular docking and study their molecular behaviors through molecular dynamics (DM). The three-dimensional conformation obtained for the molecular models is in agreement with experimentally obtained data of previously studied leguminous lectins, presenting the conserved jellyroll motif. The two lectins had their metal binding and carbohydrate recognition domains characterized by overlapping crystallographic structures of Dalbergieae lectins and by molecular docking. Lectins obtained different anchorage scores when tested with monosaccharides, disaccharides, and high-mannose N-glycans, suggesting that they may interact with these binders at different intensities. Simulations of DM were performed with the proteins under conditions without binder, interacting with D-mannose and interacting with α- methyl-D-mannoside. DM analysis demonstrated molecular determinants for α-methyl-Dmannosid specificity. During D-mannose simulation, the molecular interactions presented lower stability than those established with α-methyl-D-mannoside. The data presented in this study can thus serve as a guide for new researches aiming α-methyl-D-mannoside specific lectins of the Arachis genus.