Estruturas cristalográficas da lectina de canavalia brasiliensis complexadas com adenina e ribose: analise estrutural e perspectivas

Abstract

Legume lectins (e.g ConA) are the most studied plant lectin family. The physiological and biological activities attribute to them, such as plant defense and antidepressant function, take into account their interactions with mono- and oligosaccharides in a specific and reversible manner. However, several studies show that these proteins can bind other biomolecules, such as hydrophobic compounds (e.g. adenine and indole acetic acid) and non protein amino acids (e.g. α-aminobutyric acid, AABA), although the structure-function relationship of these interactions remained poorly understood. In this study, we described two crystallographic structures of ConBr lectin isolated from the seeds of C. brasiliensis, complexed with two different ligands: a complex of the lectin with β-D-ribofuranose and another with adenine, both compounds found in the Carbohydrate-Recognition Domain (CRD). Based on the location of these binders, it is suggested by the docking ConBr can bind to adenosine. In addition, this study shows that AABA can take different provisions in its binding site. Taken together, these results reveal new insights into the physiological and biological activities legume lectins.