Adsorption and elution of lectins by affinity membranes

Affinity membranes suitable for the purification of lectins were prepared by chemical modifications of a cellulose matrix. As a model protein a lectin obtained by chromatographic techniques from Momordica charantia seeds was mainly used; Peanut agglutinin and Ricinus communis agglutinin were also considered. Different ligands were tested according to the different affinity towards the lectins used. Among the various ligands tested arabinogalactan and N-acetyl-D-galactosamine gave the best performances. The ligand binding reaction onto the epoxy groups of the activated matrices has been optimized with respect to concentration of ligand, temperature and reaction time. The ligand immobilized on the membrane surface is quantified indirectly by measuring the amount of protein bound to the membrane. The kinetics of adsorption and desorption of the purification process has been studied in detail for the different supports. Modified membranes have been used in separation process of lectins with good binding capacity towards the protein of interest