Phenylketonuria (PKU) is an inborn error in the metabolism of the amino acid phenylalanine (Phe) due to the deficiency of an enzyme phenylalanine hydroxylase (PAH). Current therapy consists of a Phe – restricted diet for life to ensure the healthiest development. It is particularly important for PKU women in the reproductive age group to comply with the diet, since elevated maternal blood Phe l...

Incubation of bovine chromaffin cells with L-[14C]phenylalanine resulted in label accumulation in catecholamines at about 30% of the rate seen with L-tyrosine as precursor. Studies with purified tyrosine hydroxylase (EC 1.14.16.2) showed that the enzyme catalysed the hydroxylation of L-phenylalanine first to L-p-tyrosine and then to 3,4-dihydroxyphenylalanine (DOPA). No evidence for a significa...

Source and Description of Clone: phPAH247, a 2.4 kb EcoSl fragment subcloned into pBR322 from a human liver cDNA library (1).

Solutions with as little as 1% enantiomeric excess (ee) of D- or L-phenylalanine are amplified to 90% ee (a 95/5 ratio) by two successive evaporations to precipitate the racemate. Such a process on the prebiotic earth could lead to a mechanism by which meteoritic chiral alpha-alkyl amino acids could form solutions with high ee values that were needed for the beginning of biology.

In the present study we report on the identification of ten novel mutations in the phenylalanine hydroxylase (PAH) gene of Brazilian patients with phenylketonuria (PKU): IVS5-54A>G, IVS6+17G>T, E205A, F240S, K274E, I318T, L321L, C357G, IVS11+17G>A and S411X. These mutations were detected during the characterization of the PAH genotypes of 115 patients with PKU from the southeast region of Brazi...

We report on the long-term follow-up of the first Italian patient with the tetrahydrobiopterin (BH4)-responsive type of phenylalanine hydroxylase deficiency (R243X/Y414C genotype). The patient was diagnosed by the newborn screening for phenylketonuria (PKU) and with a positive BH4 loading test. Introduction of BH4 (initially 10 and later 20 mg/kg/day) in addition to reduced low-phenylalanine di...

Shoot and callus cultures of banana ( Musa sp.) were analyzed for the accumulation of L-DOPA. Treatment of cultures with L-tyrosine and L-phenylalanine yielded higher levels of DOPA compared to those in control cultures without any treatment. Among the two amino acids, phenylalanine induced higher accumulation of DOPA. The study suggests that banana may become an useful system for the productio...

Mammalian phenylalanine hydroxylase (PAH) is a key enzyme in l-phenylalanine (l-Phe) metabolism and is active as a homotetramer. Biochemical and biophysical work has demonstrated that it cycles between two states with a variably low and a high activity, and that the substrate l-Phe is the key player in this transition. X-ray structures of the catalytic domain have shown mobility of a partially ...