Results 191 to 200 of about 38,679 (221)

Activation of phenylalanine hydroxylase by phenylalanine

Biochimica et Biophysica Acta (BBA) - Enzymology, 1971
Abstract 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 from Human Kidney

Enzyme, 1975
In this report the presence, and level, of phenylalanine hydroxylase in the cortex of human kidney is established. The average activity found in 15 surgically removed kidneys was 47.2 plus or minus 11.2 mU/g wet weight of tissue. The average value, determined under the same experimental conditions, for two human liver biopsies was 217 mU/g tissue.
J E, Ayling, G D, Helfand, W D, Pirson
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PHENYLALANINE-HYDROXYLASE ACTIVITY IN HYPERPHENYLALANINÆMIA

The Lancet, 1967
Abstract 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.
P, Justice, M E, O'Flynn, D Y, Hsia
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Phenylalanine hydroxylase in melanoma cells

Journal of Cellular Physiology, 1978
AbstractA 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.
X O, Breakefield, C M, Castiglione, R, Halaban, J, Pawelek, R, Shiman   +4 more
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Tetrahydrobiopterin-responsive phenylalanine hydroxylase deficiency

The Journal of Pediatrics, 1999
Serum phenylalanine concentrations decreased in 4 patients with hyperphenylalaninemia after loading with tetrahydrobiopterin. There were no abnormalities in urinary pteridine excretion or in dihydropteridine reductase activity. However, mutations were detected in the phenylalanine hydroxylase gene, suggesting a novel subtype of phenylalanine ...
S, Kure, D C, Hou, T, Ohura, H, Iwamoto, S, Suzuki, N, Sugiyama, O, Sakamoto, K, Fujii, Y, Matsubara, K, Narisawa   +9 more
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Molecular Biology of Phenylalanine Hydroxylase

Journal of Inherited Metabolic Disease, 1986
Phenylalanine hydroxylase (PH; EC 1.14.16.1) is a complex enzyme with three substrates and three activators. Little is known about the structural features which are necessary for the function of this enzyme; only the phosphorylation site is known (Wretburn et al., 1980).
R. G. F. Cotton, H. H. M. Dahl, J. F. B. Mercer, I. Jennings, E. A. Haan, C. W. Chow, D. M. Danks, F. J. Morgan   +7 more
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Treatment of phenylalanine hydroxylase deficiency

Acta Paediatrica, 1994
In phenylalanine hydroxylase deficiency detected by screening treatment in early life, both age at start of treatment and phenylalanine control during treatment are the major determinants of eventual psychological status. The influence of phenylalanine control declines with age but executive performance is influenced by hyperphenylalaninaemia at all ...
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Connecting Mutant Phenylalanine Hydroxylase With Phenylketonuria

Journal of Clinical Monitoring and Computing, 2008
The building of a quantitative relationship between genotype and phenotype would be great helpful for better clinical monitoring, diagnosis, prognosis and treatment. As the phenylketonuria is an autosomal recessive disorder caused by mutations in the phenylalanine hydroxylase, in this study we build a descriptively quantitative relationship between ...
Shaomin, Yan, Guang, Wu
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Hepatic phenylalanine hydroxylase activity in hyperphenylalaninaemia

Journal of Inherited Metabolic Disease, 1981
AbstractPhenylalanine tolerancein vivo has been compared with the phenylalanine hydroxylase activity of liver biopsy specimens in 14 newly detected cases of hyperphenylalaninaemia. Hepatic phenylalanine hydroxylase activity does not predict the degree of dietary restriction that will be required.
J L, Dhondt, J P, Farriaux
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PHENYLALANINE HYDROXYLASE ACTIVITY IN NEWBORN INFANTS

Pediatrics, 1964
One of the techniques that may be employed to expedite the diagnosis of phenylketonuria in the newborn infant is the phenylalanine load test. However, this is probably an impractical method for a routine examination but in the suspected sibling may permit rapid differentiation of an affected infant from one entirely normal.
R J, ALLEN, J C, HEFFELFINGER, R E, MASOTTI, M U, TSAU   +3 more
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