This enzyme catalyses the final step in the biosynthesis of L-ascorbic acid in higher plants and in nearly all higher animals with the exception of primates and some birds . The enzyme is very specific for its substrate L-galactono-1,4-lactone as D-galactono-gamma-lactone, D-gulono-gamma-lactone, L-gulono-gamma-lactone, D-erythronic-gamma-lactone, D-xylonic-gamma-lactone, L-mannono-gamma-lactone, D-galactonate, D-glucuronate and D-gluconate are not substrates . FAD, NAD+, NADP+ and O2 (cf. EC 22.214.171.124, L-galactonolactone oxidase) cannot act as electron acceptor .
Ostergaard J, Persiau G, Davey MW, Bauw G, Van Montagu M
Isolation of a cDNA coding for L-galactono-gamma-lactone dehydrogenase, an enzyme involved in the biosynthesis of ascorbic acid in plants. Purification, characterization, cDNA cloning, and expression in yeast.