(1) L-amino acid oxidase, which exists in kidney and liver mold, snake venom, bacteria, etc., is an aerobic dehydrogenase that directly oxidizes L-amino acid. EC1.4.3.2. If not present catalase And H2O2 is used to decarboxylate to form keto acid. Its coenzyme is FMN or FAD. It has wide substrate specificity and can well oxidize leucine methionine But does not act on aspartic acid, glutamic acid, glycine, etc. However, the enzyme pair of bird liver Basic amino acid It has specificity. However, due to the low activity, the enzyme pairs of animals Amino acid metabolism It is doubtful whether it is meaningful. However, the oxidation activity of L - α - hydroxy acid is strong, which may be of significance in this regard. The enzyme molecular weight of snake venom is about 130000 and contains 2 molecules of FAD. (2) D-amino acid oxidase. An enzyme that produces ketoacids for the oxidation of D-amino acids. EC1．4．3．3。
D-amino acid+O2 → ketoacid+H2O2+NH3 takes FAD as coenzyme, which is widely found in biology. It is also common in the kidney and liver of animals, but its significance is unclear. It may also be the real substrate because it can act well on D - α - carboxylic acid. yes d-proline It works best, but it also acts on many other amino acids. The molecular weight of crystalline enzyme in pig kidney is 115000 and contains 2 molecules of FAD. 
