The graft copolymer poly(propylene)-graft-poly(acrylic acid) (PP-G-AA) was
prepared by radiation-induced graft copolymerization of acrylic acid onto p
olypropylene spheres and characterized by thermal analysis and scanning ele
ctron microscopy (SEM). Maximum percentage of grafting (70%) was obtained a
t a total dose of 12 kGy using 30% (w/w) of acrylic acid. The Michaelis con
stant, K-M, and the maximum reaction velocity, V-Max, were determined for t
he free horseradish peroxidase and for the immobilized horseradish peroxida
se. The enzyme affinity for the substrate (K-M/V-max) remains quite good af
ter immobilization. The sulfoxidation reaction of a ketosulfide was investi
gated with the immobilized peroxidase. (C) 1999 Elsevier Science Ltd. All r
ights reserved.