Noun
xanthine oxidase (plural xanthine oxidases)
(biochemistry) A crystallizable flavoprotein enzyme containing iron and molybdenum that promotes the oxidation especially of hypoxanthine and xanthine to uric acid and of many aldehydes to carboxylic acids and that is obtained usually from milk or liver.
Xanthine oxidase inhibitors block uric acid production. Source: Internet
Xanthine oxidase loses its function and gains ascorbase function when some of the iron atoms in XO are replaced with copper atoms. Source: Internet