Structural basis of ConM binding with resveratrol, an anti-inflammatory and antioxidant polyphenol

Resveratrol can also inhibit the activation of proinflammatory mediators and cytokines at the early gene expression stage. It is well known that lectins are sugar-binding proteins that act as both pro- and anti-inflammatory molecules. Thus, the objective of this work was to verify the binding of a polyphenol compound with a lectin of Canavalia maritima (ConM) based on their ability to inhibit pro-inflammatory processes. To accomplish this. ConM was purified and crystallized, and resveratrol was soaked at 5 mM for 2 h of incubation. The crystal belongs to the monoclinic space group C2, the final refinement resulted in an R-factor of 16.0% and an R-free of 25.5%. Resveratrol binds in the rigid beta-sheet through H-bonds and hydrophobic interaction with amino acids that compose the fifth and sixth beta-strands of the rigid beta-sheet of ConM. The ConM and resveratrol inhibited DPPH oxidation, showing synergic activity with the most effective ratio of 2:3 and carbohydrate binding site is not directly related to antioxidant activity. It is the interaction between ConM and resveratrol that indicates the synergism of these two molecules in acting as free radicals scavengers and in reducing the inflammatory process through the inhibition of many pro-inflammatory events. (C) 2014 Elsevier B.V. All rights reserved.