Graft copolymers with immobilized peroxidase for organic synthesis

The graft copolymer poly(propylene)-graft-poly(acrylic acid) (PP-G-AA) was prepared by radiation-induced graft copolymerization of acrylic acid onto polypropylene spheres and characterized by thermal analysis and scanning electron microscopy (SEM). Maximum percentage of grafting (70%) was obtained at a total dose of 12 kGy using 30% (w/w) of acrylic acid. The Michaelis constant, K-M, and the maximum reaction velocity, V-Max, were determined for the free horseradish peroxidase and for the immobilized horseradish peroxidase. The enzyme affinity for the substrate (K-M/V-max) remains quite good after immobilization. The sulfoxidation reaction of a ketosulfide was investigated with the immobilized peroxidase. (C) 1999 Elsevier Science Ltd. All rights reserved.