Immobilisation of trypsin on acrylic copolymers

Twenty-six carriers from three series of acrylic copolymers were evaluated for trypsin immobilisation. The following monomers were used to prepare polymer matrices: ethylene glycol dimethacrylate, trimethylolpropane triacrylate, ethyl acrylate, butyl acrylate, hydroxypropyl methacrylate, acrylonitrile, and divinylbenzene. The carriers with trimethylolpropane triacrylate as the cross-linking agent were selected as the most profitable matrices for expressing enzyme activity. Considering the influence of inert diluents on the carrier's superstructure and trypsin immobilisation it was shown that cyclohexanol as co-diluent produced a good microenvironment for enzyme activity while toluene created an unsuitable carrier structure. The most effective carrier was a copolymer of acrylonitrile/trimethylolpropane triacrylate synthesised in the presence of cyclohexanol and 2-ethylhexanol. A comparison of the properties of the enzyme-carrier preparation and native trypsin demonstrated that the binding of the protein to the carrier caused an increase of the storage and pH-stability of the bound enzyme. (C) 1998 Elsevier Science Ltd. All rights reserved.