What is the biopterin pathway?

Biopterin synthesis occurs through two principal pathways; the de novo pathway involves three enzymatic steps and proceeds from GTP, while the salvage pathway converts sepiapterin to biopterin. BH4 is the principal active cofactor, and a recycling pathway converts BH2 to BH4.

How is Biopterin deficiency treated?

Treatment for individuals with GTPCH deficiency and PTPS deficiency requires oral doses of synthetic tetrahydrobiopterin (BH4; sapropterin dihydrochloride). Individuals with DHPR deficiency may require additional therapy with folinic acid to prevent central nervous system folate deficiency.

What is tetrahydrobiopterin deficiency?

Tetrahydrobiopterin deficiency is a rare disorder characterized by a shortage (deficiency) of a molecule called tetrahydrobiopterin or BH4. This condition alters the levels of several substances in the body, including phenylalanine.

Is Tetrahydrobiopterin a vitamin?

Tetrahydrobiopterin is a naturally occurring nutrient and an essential co-factor of enzymes involved in the biosynthesis of 5-hydroxytryptamine (5HT, serotonin), dopamine, noradrenaline (norepinephrine), adrenaline (epinephrine), melatonin, and nitric oxide [1].

How does the synthesis of biopterin take place?

Biopterin synthesis occurs through two principal pathways; the de novo pathway involves three enzymatic steps and proceeds from GTP, while the salvage pathway converts sepiapterin to biopterin. BH4 is the principal active cofactor, and a recycling pathway converts BH2 to BH4.

How are biopterin derivatives used in amino acid hydroxylases?

Biopterins act as cofactors for aromatic amino acid hydroxylases (AAAH), which are involved in the synthesis of a number of neurotransmitters including dopamine, norepinephrine, epinepherine, and serotonin, along with several trace amines; nitric oxide synthesis also utilizes biopterin derivatives as cofactors.

Which is an enantiomer of D-erythro-biopterin?

D-erythro-biopterin is a biopterin in which the 1,2-dihydroxypropyl group has (1S,2R)-configuration. It is an enantiomer of a L-erythro-biopterin. A natural product that has been considered as a growth factor for some insects. InChI=1S/C9H11N5O3/c1-3 (15)6 (16)4-2-11-7-5 (12-4)8 (17)14-9 (10)13-7/h2-3,6,15-16H,1H3, (H3,10,11,13,14,17)/t3-,6-/m1/s1

What kind of disorders are caused by defects in biopterin?

Biopterin disorders. A number of disorders of biopterin regulation exist. Single-gene defects affecting the gene GCH1 block the first step in biopterin synthesis, and lead to dopamine-responsive dystonia, also known as Segawa’s syndrome.