Probably oxidoreductase that, when reduced, rapidly reacts with molecular oxygen, a hallmark of flavoprotein oxidases. A large panel of alcohols, including carbohydrates, steroids and secondary alcohols were tested as potential substrates, but none has been identified so far. Binds 1 FAD per subunit in a bicovalent manner. The FAD cofactor is bound via a bicovalent 6-S-cysteinyl, 8alpha-N1-histidyl FAD linkage. Belongs to the oxygen-dependent FAD-linked oxidoreductase family.