Dopamine beta-hydroxylase
Dopamine beta-hydroxylase (DBH), also known as dopamine beta-monooxygenase, is an enzyme (EC 1.14.17.1) that in humans is encoded by the DBH gene. Dopamine beta-hydroxylase catalyzes the conversion of dopamine to norepinephrine.
| dopamine beta-monooxygenase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 1.14.17.1 | ||||||||
| CAS no. | 9013-38-1 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
The three substrates of the enzyme are dopamine, vitamin C (ascorbate), and O2. The products are norepinephrine, dehydroascorbate, and H2O.
DBH is a 290 kDa copper-containing oxygenase consisting of four identical subunits, and its activity requires ascorbate as a cofactor.
It is the only enzyme involved in the synthesis of small-molecule neurotransmitters that is membrane-bound, making norepinephrine the only known transmitter synthesized inside vesicles. It is expressed in noradrenergic neurons of the central nervous system (i.e. locus coeruleus) and peripheral nervous systems (i.e. sympathetic ganglia), as well as in chromaffin cells of the adrenal medulla.