Mannose-specific lectin isolation from Canavalia ensiformis seeds by PHEMA-based cryogel

Mannose-specific lectin Concanavalin A (Con A) was purified from Canavalia ensiformis seeds. For this purpose, mannose attached poly(hydroxyethyl methacrylate) (PHEMA) cryogel was prepared by cryopolymerization. Mannose was used as the affinity ligand and was covalently attached onto the PHEMA cryogel via carbodiimide activation. The PHEMA cryogel containing 23.3 mmol mannose/g polymer were used in the binding studies. Con A binding with the mannose attached PHEMA cryogel from Con A aqueous solution was 5.2 mg/g at pH 7. Maximum binding capacity for Con A from C. ensiformis seed extract was 39 mg/g. Con A was eluted with 0.3 M galactose, and the purity of Con A was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. It was observed that the mannose attached PHEMA cryogel can be used without significant decrease in Con A binding capacity after six binding-elution cycles.