Results 231 to 240 of about 32,654 (265)
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Acta Paediatrica, 2002
The aim of this study was to determine whether any relationship exists between the severity of mutation of the phenylalanine hydroxylase (PAH) gene and the plasma concentrations of phenylalanine (Phe) and tyrosine (Tyr) under fasting and semifasting conditions among heterozygotes in a matched case-control study.
E. Verduci +7 more
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The aim of this study was to determine whether any relationship exists between the severity of mutation of the phenylalanine hydroxylase (PAH) gene and the plasma concentrations of phenylalanine (Phe) and tyrosine (Tyr) under fasting and semifasting conditions among heterozygotes in a matched case-control study.
E. Verduci +7 more
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Phenylalanine Hydroxylase Activity
Archives of Pediatrics & Adolescent Medicine, 1983Sir .—In the article, "Diagnosis of Phenylalanine Hydroxylase Deficiency (Phenylketonuria)" (Journal1982;136:111-114), we are concerned by the recommendation of Berry and collegues that centers treating patients with phenylketonuria (PKU) should " . . .
David M. Danks, Richard G.H. Cotton
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Characterization of phenylalanine hydroxylase
Biochemistry, 1986Iron can be bound to phenylalanine hydroxylase (PAH) in two environments. The assignment of the electron paramagnetic resonance spectrum of PAH to two, overlapping high-spin ferric signals is confirmed by computer simulation. Both environments are shown to be populated in the crude enzyme.
L. M. Bloom +2 more
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Phenylalanine hydroxylase deficiency
Genetics in Medicine, 2011Phenylalanine hydroxylase deficiency is an autosomal recessive disorder that results in intolerance to the dietary intake of the essential amino acid phenylalanine. It occurs in approximately 1:15,000 individuals. Deficiency of this enzyme produces a spectrum of disorders including classic phenylketonuria, mild phenylketonuria, and mild ...
Yannis Trakadis +2 more
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PHENYLALANINE-HYDROXYLASE ACTIVITY IN HYPERPHENYLALANINÆMIA
The Lancet, 1967Abstract Phenylalanine-hydroxylase activities have been determined in two cases of " classic " phenylketonuria and in two cases of hyperphenylalaninaemia without phenylketonuria. The patients with phenylketonuria showed no phenylalanine-hydroxylase activity; and this was confirmed as being due to deficiency of enzyme, not cofactor.
Parvin Justice +2 more
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Pyrimidines as cofactors for phenylalanine hydroxylase
Biochemical and Biophysical Research Communications, 1978Abstract It has been generally assumed that a tetrahydropterin (2-amino-5,6,7,8-tetrahydro-4-pteridinone) is essential for activity of the three aromatic amino acid hydroxylases. In this report it is shown that appropriately substituted pyrimidines can assume the role of cofactor for phenylalanine hydroxylase.
J.E. Ayling, S.W. Bailey
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Activation of phenylalanine hydroxylase by phenylalanine
Biochimica et Biophysica Acta (BBA) - Enzymology, 1971Abstract 1. 1. Phenylalanine activates phenylalanine hydroxylase ( l -phenylalanine, tetrahydropteridine:oxygen oxidoreductase (4-hydroxylating), EC 1.14.3.1), when dithiothreitol is used to regenerate 2-amino-4-hydroxy-6,7-dimethyltetrahydropteridine. 2. 2.
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Phenylalanine hydroxylase in melanoma cells
Journal of Cellular Physiology, 1978AbstractA pigmented subclone of Cloudman S91 melanoma cells, PS1‐wild type, can grow in medium lacking tyrosine. This ability is conferred by phenylalanine hydroxylase activity, and not by tryptophan hydroxylase, tyrosine hydroxylase or tyrosinase activities, although the latter activity is also present in these cells.
John M. Pawelek +4 more
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Phenylalanine hydroxylase: metabolic aspects
Biochemical Society Transactions, 1985Phenylalanine hydroxylase [L-phenylalanine,tetrahydropteridine :oxygen oxidoreductase (4-hydroxylating); EC 1.14.16.11 catalyses the first reaction in the irreversible catabolism of the essential amino acid phenylalanine. Studies of the isolated enzyme and of phenylalanine metabolism in viuo and in oitro support the view that the hydroxylase plays the ...
M. Angelica Santana +2 more
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Effects of melanin on tyrosine hydroxylase and phenylalanine hydroxylase
Biochimica et Biophysica Acta (BBA) - Enzymology, 1978Melanin inhibited rat liver phenylalanine hydroxylase, but activated tyrosine hydroxylase from rat brain (caudate nucleus), rat adrenal glands, and bovine adrenal medulla. Activation of tyrosine hydroxylase by melanin was demonstrated with the extensively dialyzed enzyme and in suboptimal concentrations of the substrate (tyrosine) and the cofactor (6 ...
Kenji Sugiyama +4 more
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