Homo-oligomeric forms of lectins: their structural insights for glycan binding from the genus Canavalia.

Lectins are made with identical polypeptide subunits as homo-oligomers in various species of Canavalia. Their interaction with the structures of specific glycans is influenced greatly when many identical polypeptides are cooperatively involved in a homo-oligomeric state than when they interact as individual polypeptide subunits. In the present study, lectins characterised from various species of Canavalia available in the literature were identified, and their sequences were retrieved to conduct in-silico bioinformatic analyses to offer a structural insight into their interaction with specific glycans such as D-mannose and. D-glucose. Our results disclosed that one of the critical parameters on the characteristic feature of lectins, i.e. the number of amino acids contributing to carbohydrate recognition domains (CRD) by lectin homo-oligomers in their tertiary and quaternary conformations through. in-silico docking, was less than in reported experimental studies conducted using XRD. Further, the docking results revealed that the kind of amino acids involved in recognising the structures of glycans was significantly different among homo-oligomeric polypeptide chains of various lectins, indicating the unique nature of each protein in their functions. The nature of glycan binding by these lectins was observed with higher affinity scores, with their quaternary structures containing four homo-oligomeric polypeptide chains. It is thus recognised that the unique nature of homo-oligomers of lectins from various species of Canavalia that possess analogous structural features relies profoundly on the kind of amino acid residues for their interaction with glycans in accomplishing their diverse functions.