Tyrosine N-monooxygenase
Class of enzymes
From Wikipedia, the free encyclopedia
Tyrosine N-monooxygenase (EC 1.14.14.36, tyrosine N-hydroxylase, CYP79A1) is an enzyme with systematic name L-tyrosine,NADPH:oxygen oxidoreductase (N-hydroxylating).[1][2] This enzyme catalyses a sequence of chemical reactions starting from the amino acid L-tyrosine.[3]
| Tyrosine N-monooxygenase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 1.14.14.36 | ||||||||
| CAS no. | 159447-19-5 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
The first is an oxidation using molecular oxygen as oxidant and gives N-hydroxytyrosine:
The enzyme is a cytochrome P450 type of hemoprotein which contains reduced nicotinamide adenine dinucleotide phosphate (NADPH) as a cofactor.[4]
Another similar oxidation step leads to N,N-dihydroxy-L-tyrosine, which loses carbon dioxide and water to give (E)-(4-hydroxyphenyl)acetaldehyde oxime as the final product of the enzyme.[5][6]
N-hydroxytyrosine
O2 + H+
H2O
N,N-dihydroxy-L-tyrosine
CO2 + H2O
-(4-hydroxyphenyl)acetaldehyde_oxime.svg)
(E)-(4-hydroxyphenyl)acetaldehyde oxime
In plants such as sorghum, the product goes on to form the cyanogenic glycoside, dhurrin after the (E) isomer of the oxime is converted to its (Z) form and further transformed.[6][7][8]
