enzymes catalyzing the oxidative deamination of amino acids to the corresponding oxo (keto) acids; two relatively nonspecific varieties exist, l and d, for which l-amino acids and d-amino acids are the respective substrates; the products include NH3 and a reduced hydrogen acceptor (NADH in the l case); amino acid dehydrogenases of greater specificity exist (e.g., glycine dehydrogenase). Cf.: amino acid oxidases