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.
Texas Red is a red-fluorescent dye and when bound to Artocarpus integrifolia (Jacalin) Lectin (AIA) can show the binding pattern of this lectin in cellular imaging applications. There is very little overlap between the emission spectra of Texas Red and FITC making this combination ideal for dual-labeling experiments. Rhodamine dyes, such as Texas Red, are more photostable and less sensitive to pH change when compared to other dyes such as fluorescein.