Results 191 to 200 of about 24,432 (224)

Isozymes of Phenylalanine Hydroxylase

Science, 1972
Three isozymes of phenylalanine hydroxylase exist in adult rat liver. They are chromatographically unique. Partial characterization suggests that they are similar in chemical properties and differ only in charge. Estimation of the Stokes radii indicates that the isozymes have similar molecular weights of about 200,000. Two isozymes exist in human fetal
J A, Barranger, P J, Geiger, A, Huzino, S P, Bessman   +3 more
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Phenylalanine hydroxylase: metabolic aspects

Biochemical Society Transactions, 1985
Phenylalanine 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 ...
C I, Pogson, M A, Santana, M J, Fisher
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Characterization of phenylalanine hydroxylase

Biochemistry, 1986
Iron 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, S J, Benkovic, B J, Gaffney
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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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