Dihydrobiopterin reductase

Dihydrobiopterin reductase is an enzyme that catalyzes the reversible formation of tetrahydrobiopterin from dihydrobiopterine using NADPH. A deficiency of this enzyme can result in malignant hyperphenylalaninemia.^[1]

Dihydrobiopterin is a compound produced in the synthesis of dopamine, norepinephrine and epinephrine through production of the intermediate 3,4-dihydroxy phenylalanine, also known as dopa. Phenylalanine is converted into dopa using tetrahydrobiopterin releasing dihydrobiopterin and water, which is then converted back into tetrahydrobiopterin using the NADPH-dependent enzyme dihydrobiopterin reductase. This enzyme is sometimes defective in patients with phenylketonuria, and is treated in the same fashion, with tyrosine supplements and a controlled diet which is lacking in phenylalanine.^[2]

References

↑ "Dihydropteridine reductase".
↑ Pawlina, Wojciech; Ross, Michael W. (2006). Histology: a text and atlas: with correlated cell and molecular biology. Philadelphia: Lippincott Wiliams & Wilkins. ISBN 0-7817-5056-3.

Oxidoreductases: NADH or NADPH (EC 1.6)

1.6.1: NAD/NADP	NAD(P)⁺ transhydrogenase (Si-specific) NAD(P)⁺ transhydrogenase (Re/Si-specific)

1.6.2: Heme	Methemoglobin reductase NADPH—hemoprotein reductase/Cytochrome P450 reductase NADPH—cytochrome-c2 reductase Leghemoglobin reductase

1.6.3: Oxygen	NADPH oxidase P91-PHOX Neutrophil cytosolic factor 1 Neutrophil cytosolic factor 2 Neutrophil cytosolic factor 4 dual oxidase Dual oxidase 1 Dual oxidase 2

1.6.5: Quinone or similar	NADH dehydrogenase

1.6.6: Nitrogenous group	Trimethylamine-N-oxide reductase

1.6.99: other	NADH dehydrogenase (quinone)

Proteins: enzymes

Activity	Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Catalytically perfect enzyme Coenzyme Cofactor Enzyme catalysis Enzyme kinetics Lineweaver–Burk plot Michaelis–Menten kinetics

Regulation	Allosteric regulation Cooperativity Enzyme inhibitor

Classification	EC number Enzyme superfamily Enzyme family List of enzymes

Types	EC1 Oxidoreductases(list) EC2 Transferases(list) EC3 Hydrolases(list) EC4 Lyases(list) EC5 Isomerases(list) EC6 Ligases(list)

This article is issued from Wikipedia - version of the Thursday, December 31, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.

Dihydrobiopterin reductase

See also

References