General information. 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].
Contents
- 1 Where does Tetrahydrobiopterin come from?
- 2 What is BH4 used for?
- 3 What foods increase BH4?
- 4 What does BH4 do in the body?
- 5 What is tetrahydrobiopterin deficiency?
- 6 What enzyme converts dopa to dopamine?
- 7 How is BH4 deficiency treated?
- 8 What is phenylalanine made from?
- 9 Does royal jelly have BH4?
- 10 How do you test for BH4 deficiency?
- 11 What is BH4 chemistry?
- 12 How is BH4 made?
- 13 How does tyrosine work?
- 14 How is BH4 formed?
Where does Tetrahydrobiopterin come from?
Tetrahydrobiopterin is biosynthesized from guanosine triphosphate (GTP) by three chemical reactions mediated by the enzymes GTP cyclohydrolase I (GTPCH), 6-pyruvoyltetrahydropterin synthase (PTPS), and sepiapterin reductase (SR).
What is BH4 used for?
BH4 is a naturally-occurring compound that serves as a cofactor for PAH and other enzymes. Kure et al. (1999) and a number of subsequent studies have found that BH4 supplementation is effective in lowering blood serum phe levels in a subset of individuals with PKU (for review, see Hegge et al., 2009).
What foods increase BH4?
From study period 2 onwards all BH4-sensitive patients increased their consumption of foods with a higher protein content such as bread, pasta, rice and dairy products as well as meat, egg and fish.
What does BH4 do in the body?
BH4 is a natural substance found in the body that helps the PAH enzyme reduce Phe to safe levels in the blood.
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.
What enzyme converts dopa to dopamine?
DOPA is converted to dopamine by aromatic amino acid decarboxylase. Dopamine-β-hydroxylase hydroxylates dopamine to norepinephrine, which is methylated to epinephrine by phenylethanolamine N-methyltransferase. Tyrosine hydroxylase is the rate-limiting enzyme of the pathway.
How is BH4 deficiency treated?
Treatment of BH4 deficiencies consists of BH4 supplementation (2-20 mg/kg per day) or diet to control blood phenylalanine concentration and replacement therapy with neurotransmitters precausers (L-dopa/CarbiDOPA and 5-hydroxytryptophan), and supplements of folinic acid in DHPR deficiency.
What is phenylalanine made from?
Good sources of phenylalanine are eggs, chicken, liver, beef, milk, and soybeans. Another common source of phenylalanine is anything sweetened with the artificial sweetener aspartame, such as diet drinks, diet foods and medication; the metabolism of aspartame produces phenylalanine as one of the compound’s metabolites.
Does royal jelly have BH4?
BH4 plays a critical role in both neurotransmitter and nitric oxide production. This formulation contains Royal Jelly, which has naturally occurring BH4, folinic acid (as calcium folate and 5-MTHF 2:1), 6S-5-MTHF, SAMe and lithium to support production of BH4.
How do you test for BH4 deficiency?
Pterins, neurotransmitter metabolites and folates can be measured in cerebrospinal fluid (CSF). These tests can help to distinguish tetrahydrobiopterin deficiencies from one another and to assess the potential severity of the disease. Molecular genetic testing can confirm a diagnosis of these disorders.
What is BH4 chemistry?
Description. Borohydride is a boron hydride. ChEBI. A class of inorganic or organic compounds that contain the borohydride (BH4-) anion.
How is BH4 made?
BH4 is made from the molecule GTP (guanosine triphosphate). GTP is converted into BH4 in three stages, which are catalysed (in order) by the enzymes GTPCH, PTPS and SR. These enzymes are coded for, respectively, by the GCH1, PTS and SR genes. Interestingly, rare mutations in these genes can lead to deficiency of BH4.
How does tyrosine work?
Supplementing with tyrosine is thought to increase levels of the neurotransmitters dopamine, adrenaline and norepinephrine. By increasing these neurotransmitters, it may help improve memory and performance in stressful situations (4). Summary Tyrosine is an amino acid that the body produces from phenylalanine.
How is BH4 formed?
BH4 is formed de novo from GTP, via a sequence of enzymatic steps carried out by GTP cyclohydrolase I (GTPCH), 6-pyruvoyl tetrahydropterin synthase (PTPS) and sepiapterin reductase (SR) [15].
