Galactonolactone dehydrogenase

L-galactonolactone dehydrogenase (, galactonolactone dehydrogenase, L-galactono-gamma-lactone dehydrogenase, L-galactono-gamma-lactone:ferricytochrome-c oxidoreductase, GLDHase, GLDase) is an enzyme with systematic name L-galactono-1,4-lactone:ferricytochrome-c oxidoreductase. This enzyme catalyses the following chemical reaction


 * (1) L-galactono-1,4-lactone + 2 ferricytochrome c $$\rightleftharpoons$$ L-ascorbate + 2 ferrocytochrome c + 2 H+
 * (2) L-ascorbate + 2 ferricytochrome c $$\rightleftharpoons$$ L-dehydroascorbate + 2 ferrocytochrome c + 2 H+ (spontaneous)

This enzyme catalyses the final step in the biosynthesis of L-ascorbic acid in plants and other photosynthetic eukaryotes.