Jacalin lectin (AIA) is purified by affinity chromatography and is tetrameric two-chain structure consisting of four identical protomers with an isoelectric point of pH 7.8. The lectin has specificity for blood group types O (+SA) and T. Jacalin is considered a galactose-specific lectin and elutes with galactose or melibiose. A post-translational proteolytic modification of Jacalin gives the lectin a novel carbohydrate-binding site involving the N terminus of the α-chain. The protein’s structure explains it’s carbohydrate-binding specificity of T-antigen disaccharide Galβ1,3GalNAc. Potent inhibitors of jacalin include D-galactose, β-Met-Gal and 2-deoxy-α-D-galactose.
Colloidal gold can be used to visualize localization of specific saccharide moieties and examine the distribution of plasma membrane glycoproteins based on the binding pattern of Artocarpus integrifolia (Jacalin) Lectin (AIA). Colloidal gold labeled lectins can be viewed via electron microscopy.