Tyrosinase immobilization on $Cu^{2+}$ chelated poly(ethylene glycol dimethacrylate-N-vinyl imidazole) beads

Abstract

Poly(ethylene glycol dimethacrylate-n-vinyl imidazole) [poly(EGDMA-VIM)] hydrogel beads (average diameter 150– 200 $mu m$) was prepared by copolymerizing of ethylene glycol dimethacrylate (EGDMA) with n-vinyl imidazole (VIM). Poly(EGDMA-VIM) beads had a specific surface area of 59.8 m2/g. Poly-(EGDMA-VIM) beads were characterized by swelling studies, elemental and SEM. $Cu^{2+}$ ions were chelated on the poly(EGDMA-VIM) beads, then these beads were used in the reversible adsorption of mushroom tyrosinase. The maximum tyrosinase adsorption capacity of the poly(EGDMA-VIM)–$Cu^{2+}$ beads was observed as 14.04 mg/g at pH 6.5. Storage stability was found to increase with immobilization. It was observed that enzyme could be repeatedly adsorbed and desorbed without significant loss in adsorption capacity or enzyme activity.