Preparation and kinetic properties of gel entrapped urate oxidase

Publisher Website
Google Scholar
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 μm. A threefold increase in Km (app) was observed for the 128 μm 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.