DeCicco, B. T. (Rutgers, The State University, New Brunswick, N.J.), and W. W. Umbreit. Utilization of aromatic amino acids by Hydrogenomonas facilis. J. Bacteriol. 88:1590-1594. 1964.-An auxotrophic mutant of Hydrogenomonas facilis was isolated which requires tryptophan, phenylalanine, and p-aminobenzoic acid (PABA) for growth. With glucose as the main carbon and energy source, the quantitativ...

Effects of phenylalanine and diand tetrahydropterins on presteady-state and steady-state catalytic behavior of rat liver phenylalanine hydroxylase are analyzed. From this and previous work (Shiman, R, Xia, T., Hill, M., and Gray, D. (1994) J. BioZ. Chem. 269, 2464724656), which analyzed binding of the same compounds to the enzyme in the absence of catalysis, a model of phenylalanine hydroxylase...

BACKGROUND Phenylalanine and tyrosine are precursor amino acids required for the synthesis of dopamine, the main neurotransmitter implicated in the neurobiology of schizophrenia. Inflammation, increasingly implicated in schizophrenia, can impair the function of the enzyme Phenylalanine hydroxylase (PAH; which catalyzes the conversion of phenylalanine to tyrosine) and thus lead to elevated pheny...

Phenylalanine hydroxylase was prepared from human foetal liver and purified 800-fold; it appeared to be essentially pure. The phenylalanine hydroxylase activity of the liver was confined to a single protein of mol.wt. approx. 108000, but omission of a preliminary filtration step resulted in partial conversion into a second enzymically active protein of mol.wt. approx. 250000. Human adult and fu...

Phenylalanine hydroxylation is necessary for the conversion of phenylalanine to tyrosine and disposal of excess phenylalanine. Studies of in vivo regulation of phenylalanine hydroxylation suffer from the lack of a method to determine intrahepatocyte enrichment of phenylalanine and tyrosine. apoB-100, a hepatic export protein, is synthesized from intrahepatocyte amino acids. We designed an in vi...

It has recently been demonstrated that variability in blood phenylalanine levels is inversely correlated with IQ and is a better predictor of IQ in early and continuously treated patients with phenylketonuria (PKU) than mean blood phenylalanine levels. This suggests that stability of blood phenylalanine should be a therapeutic goal in patients with PKU. The purpose of this study was to determin...

Biogenic amines play an important role in brain metabolism and functioning, participation synaptic transmission as neurotransmitters neuromodulators (dopamine, serotonin, histamine others). Catecholamines are formed from the essential amino acid phenylalanine by hydroxylating it to tyrosine with enzyme phenylalanine-4-hydroxylase, which is subsequently converted dioxyphenylalanine (DOPA) tyrosi...

McKean, C. M. (1971). Archives of Disease in Childhood, 46, 608. Effects of totally synthetic, low phenylalanine diet on adolescent phenylketonuric patients. The long-term responses of 5 adolescent phenylketonuric patients to chemically-defined, synthetic diets with normal and low phenylalanine content were determined. The synthetic preparations were found capable of sustaining good health and ...

We have investigated the p-chlorophenylalanine-dependent loss of phenylalanine hydroxylase activity in cultured hepatoma cells. The similarity of the effect of p-chlorophenylalanine on phenylalanine hydroxylase in the hepatoma cells and that reported from studies in uiuo indicates that the loss of phenylalanine hydroxylase activity is due to a direct interaction of the amino acid analog-ue with...