a molybdenum cofactor ( mo-co ) from xanthine oxidase ( xanthine : oxygen oxidoreductase , ec 1.2.3.2 ) can be isolated from the enzyme by a technique that has been used to isolate an iron-molybdenum cofactor ( femo-co ) from component i of nitrogenase .
C0030016
oxidoreductase
C0028174
nitrogenase