Tetrahydrobiopterin

Tetrahydrobiopterin
Identifiers
CAS number	17528-72-2
PubChem	1125
MeSH	tetrahydrobiopterin
Properties
Molecular formula	C9H15N5O3
Molar mass	241.247
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Tetrahydrobiopterin or BH₄ is a cofactor in the synthesis of nitric oxide. It is also essential in the conversion of phenylalanine to tyrosine by the enzyme phenylalanine-4-hydroxylase; the conversion of tyrosine to L-dopa by the enzyme tyrosine hydroxylase; and conversion of tryptophan to 5-hydroxytryptophan via tryptophan hydroxylase.

Clinical significance

A defect in BH₄ production and/or a defect in the enzyme dihydropteridine reductase (DHPR) causes phenylketonuria type IV, as well as dopa-responsive dystonias.

Synthesis

Tetrahydrobiopterin is synthesized from GTP via two intermediates.

References

Thony B, Auerbach G, Blau N (2000). "Tetrahydrobiopterin biosynthesis, regeneration and functions". Biochem J 347 Pt 1: 1-16. PMID 10727395.

See also

• Tetrahydrobiopterin deficiency This can also cause mental retardation as seen in patients with Phenylketonuria (PKU).

External links

• coenzyme tetrahydrobiopterin (BH4)
• The Tetrahydrobiopterin website

<tr bgcolor="#ccccff"><td colspan="3" align="center">Major families of biochemicals</td></tr><tr><td colspan="3" style="text-align: center;">Peptides | Amino acids | Nucleic acids | Carbohydrates | Nucleotide sugars | Lipids | Terpenes | Carotenoids | Tetrapyrroles | Enzyme cofactors | Steroids | Flavonoids | Alkaloids | Polyketides | Glycosides</td></tr><tr bgcolor="pink"><td style="white-space: nowrap; width: 10%; color: pink;">Analogues of nucleic acids:</td><td align="center">Types of enzyme cofactors</td><td style="white-space: nowrap; width: 10%; color: pink;">Analogues of nucleic acids:</td></tr>