monophenol monooxygenase
Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin. The enzyme is mainly involved in two distinct reactions of melanin synthesis otherwise known as the Raper–Mason pathway. Firstly, the hydroxylation of a monophenol and secondly, the conversion of an o-diphenol to the corresponding o-quinone. o-Quinone undergoes several reactions to eventually form melanin. Tyrosinase is a copper-containing enzyme present in plant and animal tissues that catalyzes the production of melanin and other pigments from tyrosine by oxidation. It is found inside melanos
Key facts
- Enzyme.Name
- monophenol monooxygenase
- Enzyme.EC_number
- 1.14.18.1
- Enzyme.CAS_number
- 9002-10-2
- Enzyme.GO_code
- 0004503
- Enzyme.image
- Catechol-Quinone.svg
- Enzyme.caption
- Catechol-Quinone
- Protein family.Symbol
- Tyrosinase
- Protein family.Name
- Common central domain of tyrosinase
- Protein family.image
- PDB 1js8 EBI.jpg
- Protein family.caption
- Tridimensional structure of a functional unit from octopus hemocyanin
- Protein family.Pfam
- PF00264
- Protein family.Pfam_clan
- CL0205
Article
19 sectionsContents
- Catalyzed reaction
- Active site
- Structure
- Plant
- Mammalian
- Bacterial
- Fungal
- Gene regulation
- Clinical significance
- Inhibitors
- Genetics
- Evolution
- Applications
- In the food industry
- In the cosmetic industry
- In insects
- In mussel-glue inspired polymers
- References
- External links
Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin. The enzyme is mainly involved in two distinct reactions of melanin synthesis otherwise known as the Raper–Mason pathway. Firstly, the hydroxylation of a monophenol and secondly, the conversion of an o-diphenol to the corresponding o-quinone. o-Quinone undergoes several reactions to eventually form melanin. Tyrosinase is a copper-containing enzyme present in plant and animal tissues that catalyzes the production of melanin and other pigments from tyrosine by oxidation. It is found inside melanosomes which are synthesized in the skin melanocytes. In humans, the tyrosinase enzyme is encoded by the TYR gene.
== Catalyzed reaction == Tyrosinase carries out the oxidation of phenols such as tyrosine and dopamine using dioxygen (O2). In the presence of catechol, benzoquinone is formed (see reaction below). Hydrogens removed from catechol combine with oxygen to form water.