Immobilisation of horseradish peroxidase onto monodisperse poly(glycidyl methacrylate) microspheres

Abstract

The aim of this study was to immobilise horseradish peroxidase (HRP) onto poly(glycidyl methacrylate) (PGMA) microspheres. In this study, PGMA particles were synthesised by dispersion polymerization from the glycidyl methacrylate (GMA) monomer. The monomer conversion value was determined to be 89% by weight. The first step comprised opening of the epoxide rings and formation of amine groups on the particle surfaces. The characterised particles were used as micro-carriers for the immobilisation of HRP. Glutaraldehyde, as bifunctional reactive, has been used as the spacer arm in the second step of the covalent binding method. The optimum immobilisation conditions found are as follows: immobilisation time 10 min, pH 7.2, temperature 25 degrees C, initial enzyme concentration 0.05 mg/ml. Kinetic parameters of native and immobilised enzyme, such as K-m and V-max values, have been calculated 2.33 mmol/l and 0.670 mmol/l per s for the native enzyme and for the immobilised enzyme 69.13 mmol/l and 0.175 mmol/l per s, respectively. The HRP immobilised microparticules were used to purify a textile bleaching solution in which excess H2O2 remains.