Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.5 (5'-nucleotidase)
3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

New light microscopic visualization methods were developed for the histochemical detection of non-specific alkaline and acid phosphatase, Mg-, Ca- and Na, K-dependent adenosine triphosphatase, myosin adenosine triphosphatase, glucose-6-phosphatase, 5'-nucleotidase and thiamine pyrophosphatase with cerium ions as trapping agents in cryostat and plastic sections. The techniques are based on the conversion of cerium phosphate into cerium perhydroxide by H2O2 which decomposes at 55 degrees-60 degrees C into cerium hydroxide and oxygen radicals. These radicals are able to oxidize diaminobenzidine (DAB) to DAB brown. Addition of nickel ions to the DAB-H2O2 mixture generates bluish-black stained nickel-DAB complexes. Compared with the classical metal precipitation, azo, azoindoxyl and tetrazolium procedures the H2O2-DAB and especially the H2O2-DAB-nickel methods provided identical or superior results in catalytic phosphatase histochemistry and immunohistochemistry when using non-specific alkaline phosphatase as the enzyme label.
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PMID:The cerium perhydroxide-diaminobenzidine (Ce-H2O2-DAB) procedure. New methods for light microscopic phosphatase histochemistry and immunohistochemistry. 285 63

We have characterized ATP-dependent Ca2+ transport into highly purified plasma membrane fraction isolated from guinea pig ileum smooth muscle. The membrane fraction contained inside-out sealed vesicles and was enriched 30-40-fold in 5'-nucleotidase and phosphodiesterase I activity as compared to post nuclear supernatant. Plasma membrane vesicles showed high rate (76 nmol/mg/min) and high capacity for ATP dependent Ca2+ transport which was inhibited by addition of Ca2+ ionophore A23187. The inhibitors of mitochondrial Ca2+ transport, i.e., sodium azide, oligomycin and ruthenium red did not inhibit ATP-dependent Ca2+ uptake into plasma membrane vesicles. The energy dependent Ca2+ uptake into plasma membranes showed very high specificity for ATP as energy source and other nucleotide triphosphates were ineffective in supporting Ca2+ transport. Phosphate was significantly better as Ca2+ trapping anion to potentiate ATP-dependent Ca2+ uptake into plasma membrane fraction as compared to oxalate. Orthovanadate, an inhibitor of cell membrane (Ca2+-Mg2+)-ATPase activity, completely inhibited ATP-dependent Ca2+ transport and the Ki was approximately 0.6 microM. ATP-dependent Ca2+ transport and formation of alkali labile phosphorylated intermediate of (Ca2+-Mg2+)-ATPase increased with increasing concentrations of free Ca2+ in the incubation mixture and the Km value for Ca2+ was approximately 0.6-0.7 microM for both the reactions.
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PMID:Characterization of Ca2+ uptake in plasma membrane vesicles isolated from guinea pig ileum smooth muscle. 295 Oct 13

Earlier reports suggested that the adenosine monophosphate (AMP)- and the p-nitrophenyl phosphate (pNPP)-hydrolyzing activities of Dictyostelium discoideum membrane preparations are due to different proteins. These results have been apparently contradicted by the recent purification to homogeneity of the two activities from culmination phase cells as a single protein [D. R. Armant and C. L. Rutherford (1981) J. Biol. Chem. 256, 12710-12718]. Results presented here from studies on the activities of vegetative cells support the concept of a single protein. Nondenaturing sodium dodecyl sulfate-polyacrylamide gel electrophoresis of Triton X-100 extracts of cell membrane preparations of D. discoideum showed identical migration of pNPPase and AMPase activities. Furthermore, the previously reported different pH optima of the two activities was due to the fact that pH optima are dependent upon the substrate concentration, and the selective solubilization of AMPase from membrane preparations by phospholipase C can probably be accounted for by the finding that phospholipase C preparations from the same commercial source contain 5'-nucleotidase activity. Moreover, there are alterations in the Km and the stability of both AMPase and pNPPase in a strain with a mutationally altered alkaline phosphatase, further supporting the concept that the two activities are due to a single protein. Both substrates serve as transphosphorylation donors demonstrating that the enzyme activity is mechanistically an alkaline phosphatase.
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PMID:The membrane-bound alkaline phosphatase and 5'-nucleotidase activities of vegetative cells of Dictyostelium discoideum. 298 13

Retinal pigment epithelium plasma membranes have been isolated by differential and density gradient centrifugation of glass-bead-bound, collagenase-treated cells. Electron microscopic evidence indicates that the glass-bead-bound cells were devoid of red blood cells, rod outer segments and other ocular cell contaminants. The plasma membranes were recovered in 4-6 micrograms/eye yields and purified 10-fold by 5'-nucleotidase and alkaline phosphodiesterase I, and 6.5-fold by (Na+ + K+)-ATPase. Plasma membrane purity as measured by covalent labeling of the epithelial cell plasma membrane proteins with p-(diazonium) benzene[32S]sulfonic acid was 8-19-fold. In purified plasma membranes contamination by mitochondria was undetectable and lysosomal contamination reduced 100-fold, while endoplasmic reticulum was 2-fold enriched. SDS-polyacrylamide gel electrophoresis of the plasma membrane proteins revealed 23-26 major bands by Coomassie blue staining and 12-16 major bands by radioactive labeling. The plasma membranes exhibited a 3-fold lower concentration of docosahexaenoic acid, a 3-fold higher cholesterol/phosphate ratio, and were 10-fold enriched in cholesterol per micrograms protein when compared to the whole cell fraction. Retinal epithelial plasma membranes contain an average of 1 mol cholesterol per mol of lipid phosphorus, a high palmitic acid concentration (39 mol%) and a low concentration of docosahexaenoic acid (2 mol%). The lipid profile of the retinal pigment epithelial plasma membranes indicates that they are typical of plasma membranes from many other cell types and that they appear to be less fluid than total rod outer segment membranes.
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PMID:Isolation of plasma membranes from the bovine retinal pigment epithelium. 298 2

The enzymatic activities and in vitro calcification properties of matrix vesicle fractions isolated from normal and osteoarthritic (OA) human articular cartilage were compared to determine the essential conditions for calcification in these tissues. Four groups of human cartilage were examined, I, normal articular cartilage from aged, nonOA joints; II, discolored or fibrillated cartilage from OA joints; III, osteophytic cartilage from OA joints; IV, loose body cartilage from OA joints. Fetal bovine growth plate cartilage was also studied. Both ATP- and 5'-AMP-dependent in vitro matrix vesicle calcification occurs in all cartilage groups examined and, for human articular cartilage, these activities increase progressively from Groups I to II to III. Calcification does not occur in the absence of either phosphate or pyrophosphate. Alkaline phosphatase, 5'-AMPase, and ATP:pyrophosphohydrolase activities are increased in Groups III and IV cartilage compared with Group I and are detected at high levels in fetal bovine growth plate cartilage. Pyrophosphatase activity occurs in only those cartilage groups juxtaposed to areas of new bone formation (osteophytic, loose body, and bovine growth plate). These results suggest that OA, growth plate, and even normal articular cartilage all have the potential to undergo calcification as long as both phosphate and pyrophosphate ions can be generated at sufficiently high levels. However, the capacity for cartilage to deposit hydroxyapatite, as it does during bone formation, may depend on the presence of pyrophosphatase activity.
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PMID:Matrix vesicle enzymes in human osteoarthritis. 298 64

Ultrastructural localization of nucleozidphosphatases (5'-nucleotidase, adenosin triphosphatase (ATPase) and beta-glicerophosphatase) in antral follicles of the guinea-pig ovary has been studied. Certain heterogeneity has been found in distribution of the enzymes: the cells in the follicular tunic possess the greatest 5'-nucleotidase and ATPase activity. When 5'-adenosin monophosphate (5'-AMP) is used as a substrate, the lead phosphate residue is mainly revealed in the external surface of plasmolemma and as "caps" in the margical zone of nucleoplasm. ATPase activity is chiefly observed in nucleoli of granular cells and in those of the external follicular tunic cells. Histochemical reaction with 5'-AMP proceeds most intensively in the lucid tunic and in processes of the granular cells contacting with the oocyte. A possibility is discussed on participation of the metabolic enzymes, that localize in these structures, in the mechanisms controlling the oocyte maturation.
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PMID:[Localization of nucleoside phosphatases in the antral follicle of the guinea pig ovary]. 298 84

The human erythrocyte generates high-energy adenosine triphosphate by anaerobic glycolysis and cycles oxidized and reduced nicotinamide adenine dinucleotide phosphate by the aerobic pentose phosphate shunt pathway. Certain enzymopathies of the pentose phosphate shunt are associated with hemolysis resulting from oxidative denaturation of hemoglobin. Glucose-6-phosphate dehydrogenase deficiency, an X-chromosome-linked disorder, is the prototype of these diseases and is genetically and clinically polymorphic. Six enzymopathies of anaerobic glycolysis cause hemolytic anemia; lactate dehydrogenase deficiency does not. In 2,3-diphosphoglycerate mutase deficiency, 2,3-diphosphoglycerate is greatly reduced and asymptomatic polycythemia is noted. Pyrimidine-5'-nucleotidase deficiency, an enzymopathy of nucleotide metabolism, is characterized by intracellular accumulations of pyrimidine-containing nucleotides, marked basophilic stippling on the stained blood film, splenomegaly, and hemolysis. Lead inhibits the nucleotidase and an identical syndrome occurs during severe lead poisoning. Hemolysis also accompanies an unusual enzymopathy characterized by a 40- to 70-fold increase (not decrease) in adenosine deaminase activity.
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PMID:Hemolytic anemias and erythrocyte enzymopathies. 299 Feb 76

A cytoplasmic 5'-nucleotidase (EC 3.1.3.5) can catalyze the phosphorylation of inosine (Worku, Y., and Newby, A.C. (1982) Biochem. J. 205, 503-510). This enzyme was purified to determine whether it could catalyze the formation of trace levels of phosphorylated acyclovir (ACV), a nucleoside analog with antiherpes activity. Acyclovir phosphorylating activity from rat liver co-chromatographed with the enzyme throughout the 1200-fold purification and through size exclusion chromatography or polyacrylamide-gel electrophoresis. In addition, the pH optimum, ATP stimulation, and phosphate inhibition of the ACV phosphorylating activity paralleled those of the 5'-nucleotidase. Finally, ACV phosphorylation was competitively inhibited by inosine (Kis = 6.5 mM; K'm (inosine) = 5.0 mM). This was consistent with phosphorylation at a common catalytic site. In addition to inosine and ACV, the guanine derivatives Guo, dGuo, 9-beta-D-arabinofuranosylguanine, and 9-(1,3-dihydroxy-2-propoxymethyl)guanine were substrates for the enzyme. The relative phosphorylation rates were, respectively, 100, 0.7, 19, 4, 0.3, and 0.7, at 0.1 mM phosphate acceptor. Approximate K'm values were, respectively, 5, 90, 10, 10, greater than 100, and greater than 100 mM. Although the substrate activity of ACV with the 5'-nucleotidase was inefficient, it appeared to be sufficient to account for the small amounts of ACV phosphates formed in uninfected cells.
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PMID:Cytoplasmic 5'-nucleotidase catalyzes acyclovir phosphorylation. 299 Dec 14

In an attempt to determine the metabolic defect causing severe combined immunodeficiency (SCID) in horses in which altered purine metabolism has been observed, various parameters of purine and pyrimidine metabolism were evaluated. The activities of nine purine enzymes (adenosine kinase, purine nucleoside phosphorylase, deoxyadenosine kinase, deoxycytidine kinase, 5'-nucleotidase, AMP deaminase, hypoxanthine-guanine phosphoribosyl transferase, and adenine phosphoribosyl transferase were measured in fibroblasts. All activities determined for SCID horses were normal. Uptake of 10 microM adenosine or 2'-deoxyadenosine (a growth inhibitory concentration for SCID fibroblasts) by SCID fibroblasts was identical to that found for normal fibroblasts in the presence of both 1 and 50 microM phosphate. The Km determined for the transport of both adenosine and 2'-deoxyadenosine was 35 microM. In the presence of p-nitrobenzylthioguanosine (a nucleoside transport inhibitor), 2'-deoxyadenosine uptake was inhibited to the same extent in all fibroblast lines tested. To determine if the last step in pyrimidine biosynthesis might be altered in SCID fibroblasts, UMP synthase activities were evaluated but found to be normal (0.5 nmol UMP formed/min/mg protein).
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PMID:Metabolic investigations of fibroblasts from horses, Equus caballus, with hereditary severe combined immunodeficiency. 299 78

The presence of 5'-nucleotidase was demonstrated in Onchocerca volvulus and Dirofilaria immitis; the bulk of activity was found in the particulate fraction. The enzyme of filarial worms exhibited a broad pH-optimum between 6.4 and 8.0 and substrate specificity for nucleotides compared to glucose-6-phosphate and p-nitrophenyl phosphate. The apparent Km-values for AMP were found to be 0.15 mM and 0.22 mM for the enzyme from O. volvulus and D. immitis, respectively. The activity of 5'-nucleotidase from both filarial worms was effectively inhibited by the filaricidal compound CGP 8065, a dithiocarbamate-derivative of amoscanate, whereas the 5'-nucleotidase from rat liver was not affected. The parasite-specific inhibition by CGP 8065 was found to be reversible and to be competitive with respect to the substrate AMP. The inhibition constants were calculated to be 24 microM and 8 microM for the enzyme from O. volvulus and D. immitis, respectively.
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PMID:Parasite-specific inhibition of 5'-nucleotidase from Onchocerca volvulus and Dirofilaria immitis by the amoscanate-derivative CGP 8065. 299 82


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