Stizolobinate synthase
From Wikipedia, the free encyclopedia
Stizolobinate synthase (EC 1.13.11.30) is an enzyme that catalyzes the chemical reaction
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| Stizolobinate synthase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 1.13.11.30 | ||||||||
| CAS no. | 65979-38-6 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
The two substrates of this enzyme are L-DOPA and oxygen. Its initial product is 5-(L-alanin-3-yl)-2-hydroxy-cis,cis-muconate 6-semialdehyde.[1]
The intermediate readily cyclises and further oxidises, forming a 2-pyrone ring; this is stizolobinic acid, which is the product that is isolated and after which this enzyme is named.[2][3]
The oxidation step uses oxidised nicotinamide adenine dinucleotide as a cofactor and the enzyme also requires zinc. It belongs to the family of oxidoreductases, specifically those acting on single donors with O2 as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O2. The systematic name of this enzyme class is 3,4-dihydroxy-L-phenylalanine:oxygen 4,5-oxidoreductase (recyclizing). It participates in tyrosine metabolism.[1]
A separate enzyme, stizolobate synthase also present in higher plants cleaves L-DOPA in a way which produces the isomeric compound, stizolobic acid.[3]
