Results 121 to 130 of about 6,269 (167)

Prenatal exclusion of purine nucleoside phosphorylase deficiency

European Journal of Pediatrics, 1986
We report on the prenatal exclusion of purine nucleoside phosphorylase (PNP) deficiency in a fetus whose parents were known to be heterozygotes for the enzyme defect. Prenatal investigation was performed in the 16th week of gestation on amniotic fluid and cultured amnion cells using sensitive techniques.
E. Carapella De Luca, STEGAGNO, MICHELE, C. Dionisi Vici, PAESANO, Rosalba, L. D. Fairbanks, G. S. Morris, H. A. Simmonds   +6 more
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LINGCOD MUSCLE PURINE NUCLEOSIDE PHOSPHORYLASE

Canadian Journal of Biochemistry and Physiology, 1958
A purine nucleoside phosphorylase enzyme preparation, which catalyzed the general reaction ribose (deoxyribose) [Formula: see text] nucleoside (deoxynucleoside)+orthophosphate, was isolated from muscles of the lingcod (Ophiodon elongatus). The reaction was found to be about 85% in favor of nucleoside synthesis with 10 μM./ml.
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Purine nucleoside phosphorylase from bovine liver

Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, 1978
1. Purine nucleoside phosphorylase (purine nucleoside:orthophosphate ribosyltransferase, E.C. 2.4.2.1) from liver of cattle, Bos taurus, was purified to homogeneity. Some properties of the enzymes from three different bovine tissues were compared and discussed. 2.
Z, Ikezawa, T, Nishino, K, Murakami, K, Tsushima   +3 more
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A new ultramicrochemical assay for purine nucleoside phosphorylase

Analytical Biochemistry, 1978
Abstract An ultramicrochemical method using radioactive substrates has been developed for the quantitation of purine nucleoside phosphorylase (NP) activity in single cells. NP activity can reproducibly be measured in both directions of the enzyme reaction. A quantitative relationship between the number of cells incubated and the NP activity was found.
M P, Uitendaal, C H, De Bruyn, T L, Oei, P, Hösli, C, Griscelli   +4 more
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Purine Nucleoside Phosphorylase. 2. Catalytic Mechanism

Biochemistry, 1997
X-ray crystallography, molecular modeling, and site-directed mutagenesis were used to delineate the catalytic mechanism of purine nucleoside phosphorylase (PNP). PNP catalyzes the reversible phosphorolysis of purine nucleosides to the corresponding purine base and ribose 1-phosphate using a substrate-assisted catalytic mechanism.
M D, Erion, J D, Stoeckler, W C, Guida, R L, Walter, S E, Ealick   +4 more
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Plasma purine nucleoside phosphorylase in cancer patients

Clinica Chimica Acta, 2004
Purine nucleoside phosphorylase (PNP) is the purine salvage enzyme that converts guanosine to guanine and inosine to hypoxanthine.279 samples from patients with differing cancers were collected during treatment at both pre- and post-dose stages for plasma PNP activity and compared with a normal population.Normal plasma PNP activity was found to be 3.2+/
Russell P Newton
exaly   +3 more sources

Purine Nucleoside Phosphorylase Deficiency: A Mutation Update

Nucleosides, Nucleotides and Nucleic Acids, 2011
Purine nucleoside phosphorylase (PNPase) deficiency is an autosomal recessive disorder affecting purine degradation and salvage pathways. Clinically, patients typically present with severe immunodeficiency, neurological dysfunction, and autoimmunity. Biochemically, PNPase deficiency may be suspected in the presence of hypouricemia.
P L C, Walker, Adele, Corrigan, Monica, Arenas, Emilia, Escuredo, Lynette, Fairbanks, Anthony, Marinaki   +5 more
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Purine nucleoside phosphorylase polymorphism in sheep erythrocytes

Biochemical Genetics, 1977
A polymorphism of purine nucleoside phosphorylase is described in sheep erythrocytes. Two isozymes were distinguished electrophoretically, one with high activity (NP-1) and one with low activity (NP-2). Breeding data suggest that the two isozymes are the product of two codominant alleles, NP1 and NP2.
P G, Board, J E, Smith
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Genetic Variability of Purine Nucleoside Phosphorylase in the Mouse

1984
The inherited human deficiency of purine nucleoside phosphorylase is associated primarily with cellular immune dysfunction1. We have begun to screen for quantitative activity variants of purine nucleoside phosphorylase in Mus musculus in attempts to establish an animal model for the enzyme deficiencies associated with immunodeficiency disease.
F F, Snyder, F G, Biddle, T, Lukey, M J, Sparling   +3 more
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16 Purine Nucleoside Phosphorylase

1972
Publisher Summary This chapter focuses on purine nucleoside phosphorylases (PNPases), which are widely distributed in nature and have been identified and studied in a number of tissues in mammals, chickens, fish, yeast, and in several species of bacteria. In the erythrocytes of dogs, the activity of PNPase is remarkably low when compared with the red
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