title: Preparation and kinetic properties of gel entrapped urate oxidase.
abstract: Urate oxidase from hog liver (urate: oxygen oxidoreductase, EC 1.7.33) has been entrapped in a crosslinked 2-hydroxyethyl methacrylate gel with a 47% retention of activity. The kinetic behavior of the gel entrapped enzyme has been studied in a slurried tank reactor using uric acid as substrate. Internal diffusion effects were found to be negligible for particle sizes below 128 mum. A threefold increase in Km (app) was observed for the 128 mum particles and attributed to diffusional effects. The pH activity profile of the gel entrapped enzyme was bell-shaped at high substrate concentration and could be fitted to a titration curve of two ionizable groups, a basic group having a pK of 7.9 and an acidic group with a pK of 11.0. The gel entrapped enzyme showed excellent stability between pH 6.5 and 10.5.
mesh_terms: D000327:Adsorption; D005782:Gels; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008689:Methacrylates / Q000138:chemical synthesis; D010316:Particle Size; D014503:Urate Oxidase / Q000378:metabolism*; D014527:Uric Acid / Q000378:metabolism
chemical_list: D005782:Gels; D008689:Methacrylates; D014527:Uric Acid; D014503:Urate Oxidase