Results 201 to 210 of about 24,432 (224)
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Connecting Mutant Phenylalanine Hydroxylase With Phenylketonuria
Journal of Clinical Monitoring and Computing, 2008The 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, 1981AbstractPhenylalanine 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, 1964One 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 +3 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.
S W, Bailey, J E, Ayling
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Phenylalanine Hydroxylase Activity-Reply
Archives of Pediatrics & Adolescent Medicine, 1983In Reply .—For most metabolic disorders, a diagnosis based on a single symptom would not be acceptable. Hyperphenylalaninemia is a symptom that in a newborn infant suggests either complete or partial PH deficiency (PKU), dihydropteridine reductase deficiency, or deficiency in biopterin synthesis.
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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 ...
T, Nagatsu +4 more
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Electrostatic Activation of Rat Phenylalanine Hydroxylase
Biochemical and Biophysical Research Communications, 1994The conversion of phenylalanine to tyrosine is accelerated approximately five fold by phosphorylation of the enzyme which catalyzes this step, phenylalanine hydroxylase. To gain a clearer understanding of the mechanism of this activation, we have applied site-directed mutagenesis to specifically modify a clone of the hydroxylase at the phosphorylation ...
B A, Citron, M D, Davis, S, Kaufman
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Phenylalanine hydroxylase activity in mammalian cells
Journal of Cellular Physiology, 1969AbstractSurvey of twelve mouse tissues revealed the presence of appreciable phenylalanine hydroxylase activity in the pancreas and kidney as well as the liver but in no other of the tissues tested. Single cell suspensions of mouse liver were prepared by use of tetraphenylboron.
A, Tourian, J, Goddard, T T, Puck
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Hepatic Phenylalanine Hydroxylase and PKU
1975The conversion of phenylalanine to tyrosine in mammalian tissues is catalyzed by a complex enzyme system composed of several essential enzymes and cofactors. All of these components have been assayed in liver biopsy samples from patients with the classic form of PKU.
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[74] Phenylalanine hydroxylase (Pseudomonas)
1970Publisher Summary This chapter discusses the assay, purification, and properties of phenylalanine hydroxylase from Pseudomonas. The hydroxylation of phenylalanine to tyrosine is catalyzed by an inducible enzyme from Pseudomonas. This conversion requires molecular oxygen and a tetrahydropteridine.
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