Enzymes immobilized by graft copolymerization to different polysaccharides

A method for grafting enzymes on polysaccharides using a redox system as a radical initiator is reported (Fe2+-H2O2). Glycidylmethacrylate was used as a vinylating reagent and the reaction product with enzymes (HRP, GOD, Am, ChT) was copolymerized with different matrices (cellulose, Sepharose, Sephadex, starch). During the enzyme vinylation reaction, no appreciable denaturation was observed, and various products were obtained using chromatography. Various factors affect the final activity of the copolymers; these include the redox system, the type of support, and the quantity and type of vinyl monomer added. Using a fixed quantity of enzyme, recovery of activity varied 2–50%. Graft copolymers thus obtained appear to be stable in storage and present higher thermal stability than that of the free enzyme. The kinetics of these copolymers indicate that diffusion is not appreciably limited, and that the immobilization reaction does not alter the enzymatic activity.