ABSTRACT
Xanthine oxidase from bovine milk was first purified by Ball 1 using a procedure which is now applied to commercial preparations of the enzyme. Ball’s procedure included treatment of cream with “steapsin”, a crude pancreatic extract. Purification procedures subsequently described generally omit the proteolytic treatment. 2 , 3 Carey et al. 4 observed that the enzyme “purified” by a procedure incorporating proteolytic treatment could be further resolved into several components of similar specific activity by elution from hydroxylapatite. Unproteolyzed enzyme, however, eluted principally as a single peak.
