Plant Lectins

Plant lectins are a heterogeneous group of proteins or glycoproteins that share in common their ability to recognize and bind specific sugar residues. At present hundreds of plant lectins have been isolated and characterized with respect to their molecular structures and carbohydrate-binding specificities. Since the unique biological properties of lectins can be exploited in the investigation of numerous biochemical and cellular phenomena, intense efforts are being made in many labs to isolate lectins with unique and unusual sugar-binding specificities. The study deals with the purification and partial characterization of a lectin from Crotalaria pallida belonging to Leguminoseae. Conformational changes and changes in biological properties by chemical modification of the lectin are also a part of the study. The lectin is a monomeric galactose and blood group A specific glycoprotein with about 4% carbohydrate and a molecular weight of 43 kDa. The activity yield of the lectin was about 4.6% with nearly three fold purification. Conformational changes were investigated by gel filtration, viscometery and UV absorption spectroscopy.