Dopamine ^-hydroxylase (EC 126.96.36.199) is a copper-containing enzyme involved in the synthesis of the catecholamines noradrenaline and adrenaline from tyr-osine in the adrenal medulla and central nervous system. The active enzyme contains Cu+, which is oxidized to Cu2+ during the hydroxylation of the substrate; reduction back to Cu+ specifically requires ascorbate, which is oxidized to monodehydroascorbate.
A number of peptide hormones have a terminal amide, and amidation is essential for biological activity. The amide group is derived from a glycine residue in the precursor peptide, by proteolysis to leave a carboxy terminal glycine. This is hydroxy-lated on the a-carbon; the hydroxyglycine decomposes nonenzymically to yield the amidated peptide and glyoxylate. This reaction is catalyzed by pepti-dyl glycine hydroxylase (peptidyl a-amidase, EC 188.8.131.52); like dopamine ^-hydroxylase, it is a copper-containing enzyme, and it requires ascorbate as the electron donor.
Was this article helpful?
Get All The Support And Guidance You Need To Be A Success At The Psychology Of Weight Loss And Management. This Book Is One Of The Most Valuable Resources In The World When It Comes To Exploring How Your Brain Plays A Role In Weight Loss And Management.