Copper in Urate Oxidase

Abstract

The use of gel filtration as a step in the purification of ox kidney urate oxidase has again been demonstrated. Using this technique an enzyme has been obtained that has a higher specific activity than that obtained by Tate and Stannard. This improved purification was largely due to the preparation of the enzyme extract before it was put on the column. This preparation involved the use of 0.1 M en as an extracting solvent and concentration of the extract by freeze-drying. Most of the enzyme came out of solution during freeze-drying of the activity peak from the gel filtrate. Extraction of this enzyme with 0.1 M en yielded an enzyme solution of very high specific activity. Copper determinations on enzyme samples from various purification stages could not be correlated with activity or protein concentration. The copper concentration of the purest samples was too low to record an ESR signal.