- L-tyrosine + O(2) <=> dopaquinone + H(2)O
- 2 L-dopa + O(2) <=> 2 dopaquinone + 2 H(2)O
- Found in a broad variety of bacteria, fungi, plants, insects,
crustaceans, and mammals, which is involved in the synthesis of
betalains and melanin.
- The enzyme, which is activated upon binding molecular oxygen,
can catalyze both a monophenolase reaction cycle or a diphenolase
- During the monophenolase cycle, one of the bound oxygen atoms is
transferred to a monophenol (such as L-tyrosine), generating an
O-diphenol intermediate, which is subsequently oxidized to an
o-quinone and released, along with a water molecule.
- The enzyme remains in an inactive deoxy state, and is restored to the
active oxy state by the binding of a new oxygen molecule.
- During the diphenolase cycle the enzyme binds an external diphenol
molecule (such as L-dopa) and oxidizes it to an O-quinone that is
released along with a water molecule, leaving the enzyme in the
intermediate met state.
- The enzyme then binds a second diphenol molecule and repeats the
process, ending in a deoxy state.
- The second reaction is identical to that catalyzed by the related
enzyme catechol oxidase (EC 126.96.36.199).
- However, the latter can not catalyze the hydroxylation or
monooxygenation of monophenols.
- Formerly EC 188.8.131.52.
|PRIAM enzyme-specific profiles||184.108.40.206|
|KEGG Ligand Database for Enzyme Nomenclature||220.127.116.11|
|IUBMB Enzyme Nomenclature||18.104.22.168|
|MEDLINE||Find literature relating to 22.214.171.124|
|Q00024, PPO1_AGABI; ||O42713, PPO2_AGABI; ||Q9V521, PPO2_DROME; |
|C7FF04, PPO3_AGABI; ||Q8I1F6, PPO3_DROER; ||Q9W1V6, PPO3_DROME; |
|C0HJM0, PPO3_SARAR; ||C7FF05, PPO4_AGABI; ||Q27451, PRP1_BOMMO; |
|O44249, PRP1_MANSE; ||P85046, PRP1_SIMDA; ||Q27452, PRP2_BOMMO; |
|Q25519, PRP2_MANSE; ||Q8J130, TYRO_ASPFU; ||Q00234, TYRO_ASPOR; |
|Q8MIU0, TYRO_BOVIN; ||P54834, TYRO_CANLF; ||P55024, TYRO_CHICK; |
|Q08410, TYRO_COTJA; ||P55033, TYRO_FELCA; ||Q9BDE0, TYRO_GORGO; |
|P14679, TYRO_HUMAN; ||P11344, TYRO_MOUSE; ||P00440, TYRO_NEUCR; |
|P55025, TYRO_ORYLA; ||Q0MVP0, TYRO_PELES; ||Q04604, TYRO_PELNI; |
|P55026, TYRO_PELSI; ||A7BHQ9, TYRO_PHONA; ||Q92396, TYRO_PODAS; |
|P33180, TYRO_RHIML; ||P07524, TYRO_STRAT; ||P06845, TYRO_STRGA; |
|P55022, TYRO_STRGB; ||P55023, TYRO_STRLN; ||B8NM74, USTQ_ASPFN; |