Copper Containing Hydroxylases

Dopamine ^-hydroxylase (EC 1.14.17.1) 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 1.14.17.3); like dopamine ^-hydroxylase, it is a copper-containing enzyme, and it requires ascorbate as the electron donor.

Food Allergies

Food Allergies

Peanuts can leave you breathless. Cat dander can lead to itchy eyes, a stuffy nose, coughing and sneezing. And most of us have suffered through those seasonal allergies with horrible pollen counts. Learn more...

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