dopamine beta-hydroxylase (DBH)

Function

• conversion of dopamine to noradrenaline
• catecholamine biosynthesis

3,4-dihydroxyphenethylamine + ascorbate + O2
              <-->
noradrenaline + dehydroascorbate + H2O

Cofactor:

• binds 1 PQQ per subunit
• binds 2 copper ions per subunit

Structure

• homotetramer composed of two non-covalently bound disulfide-linked dimers
• belongs to the copper type 2 ascorbate-dependent monooxygenase family
• contains 1 DOMON domain

Compartment

• soluble dopamine beta-hydroxylase: cytoplasmic vesicle, secretory vesicle lumen, chromaffin granule lumen
• secretory vesicle membrane
• chromaffin granule membrane

Expression

• activity is enhanced by nerve growth factor (in superior cervical ganglia & adrenal medulla)
• trans-synaptic stimulation with reserpine, acetylcholine & glucocorticoids

Pathology

• defects in DBH are the cause of dopamine-beta hydroxylase deficiency

Polymorphism

• 2 main alleles of DBH:
  • DBH-A with Ala- 318
  • DBH-B with Ser-318

More general terms

• hydroxylase; monooxygenase
• glycoprotein
• membrane protein

Database

• UniProt: http://www.uniprot.org/uniprot/P09172.html
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:1621
• OMIM: https://mirror.omim.org/entry/223360