Diocleinae lectins present high degree of similarity in their amino acid sequence and three-dimensional structures, but significant differences in biological activities. This study aimed to evaluate the relationship between the structures and stimulatory effects of four seed lectins isolated from the genus Canavalia with respect to leukocyte migration and the involvement of nitric oxide (NO) in rats. The lectins of Canavalia brasiliensis (ConBr), Canavalia maritima (ConM), Canavalia gladiata (CGL) and Canavalia ensiformis (ConA) were purified by affinity chromatography and analyzed for their inflammatory effects (leukocyte migration and nitric oxide production) in the rat peritonitis model. With regard to the structural analysis, the lectin-carbohydrate binding was evaluated by molecular docking and the carbohydrate-recognition domain (CRD) properties such as surface area and volume, were compared. CRD analysis showed site volumes of 298.02, 239.84, 227.23 and 201.65 Å3, and surface areas of 152.13, 120.83, 124.84 and 115.90 Å2 for ConM, CGL, ConBr and Con A, respectively. Molecular docking of lectins revealed favorable interaction with representative high-mannose N-glycans. In vivo, CGL increased the leukocyte migration into the peritoneal cavity of rats by 3.2 times (2.73 ± 0.19x103 cells), ConBr by 2.9 times (2.48 ± 0.10x103 cells), ConM by 2.3 times (1.99 ± 0.16x103 cells) and ConA by 2.1 times (1.81 ± 0.20x103 cells). In vitro, ConBr increased the NO2 concentration (mM/mL) in the animal peritoneal fluid by 25.6 times (1.22 ± 0.22), ConM by 24.7 times (1.16 ± 0.28), CGL by 5.4 times (0.25 ± 0.08) and ConA by 3.9 times (0.18 ± 0.06). In conclusion, it was possible to correlate the carbohydrate-binding and structural features with the leukocyte migration and NO2 production elicited by Canavalia lectins.
Buy this Article