Purification Studies on Urate Oxidase

Abstract

Several steps in a known purification sequence for urate oxidase were examined critically. Standard conditions for optimum yields and purification were given for each procedure. These were the alkaline extraction of the acetone powder, fractionation with ammonium sulphate, and lyophilisation. A new buffer, ethylene diamine acetate, designed to improve lyophilisation, was found similar to ammonia buffers in most properties. The value of dithiothreitol incubation and gel filtration as the major purification step was again demonstrated, and the action of dithiothreitol on proteins briefly examined. Possible artifactual consequences of the acetone powder preparation are examined and alternative procedures discussed.