In enzymology, a L-galactonolactone oxidase (EC 126.96.36.199) is an enzyme that catalyzes the chemical reaction
L-galactono-1,4-lactone + O2
L-ascorbate + H2
Thus, the two substrates of this enzyme are L-galactono-1,4-lactone and O2, whereas its two products are L-ascorbic acid and H2O2.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with oxygen as acceptor. The systematic name of this enzyme class is L-galactono-1,4-lactone:oxygen 3-oxidoreductase. This enzyme is also called L-galactono-1,4-lactone oxidase. This enzyme participates in ascorbic acid and aldaric acid metabolism. It employs one cofactor, FAD.