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)

Activities of a broad spectrum of enzymes were studied histochemically in renal adenocarcinomas induced in young male F344 rats by chronic dietary administration of the carcinogen N(4'-fluoro-4-biphenylyl)acetamide. Enzymes included were: dehydrogenases of glucose-6-phosphate, lactate, succinate, malate, and alpha-glycerophosphate; peroxidase (catalase); glucose-6-phosphatase; alkaline and acid phosphatase; Mg2+ ATPase; 5'-nucleotidase; and aminopeptidase. Levels of enzyme activity were estimated visually and scored from 0 (not detectable) to a maximum of 5 (intense). Comparison of estimated activity for each enzyme was made between small neoplastic nodules (stage III tumors) and large adenocarcinomas (stage IV tumors) and between tumors and portions of normal proximal tubules in parenchyma of kidneys from untreated control rats. The results, which revealed nearly identical levels of activity for most enzymes in both stages III and IV tumors, suggested similar metabolic and biologic behavior of these lesions. However, when data for tumors were compared with data for normal proximal tubules, striking differences were observed consistent with: 1) a marked shift of energy metabolism from oxidative to glycolytic production of ATP, with a corresponding reduction in mitochondrial respiration; and 2) simplification of plasma membrane specializations that were possibly associated with a reduction or loss of transport function. These findings were compared with other histochemical, biochemical, and ultrastructural studies of renal adenocarcinomas in rats and man.
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PMID:Adenocarcinoma of the kidney. II. Enzyme histochemistry of renal adenocarcinomas induced in rats by N-(4'-fluoro-4-biphenylyl)acetamide. 18 77

To determine the mechanism of the maturation of the brush border membrane in intestinal epithelial cells, purification of the plasma membrane from undifferentiated rat crypt cells and of the basal-lateral membrane from villous cells has been performed. The method is based on density perturbation of the mitochondria to selectively disrupt their association with the membrane. With both cell populations, two membrane subfractions displaying the same respective density on sucrose gradient have been obtained with an overall yield of 15--20% and a 10-fold enrichment of the plasma membrane markers 5'-nucleotidase and (Na+ + K+)-dependent, ouabain-sensitive ATPase chosen to follow their purification. The four fractions were constituted by sheets and apparently closed vesicles of various sizes. Each fraction was characterized by a distinct protein composition and different levels of enzyme activities. The cells, used for the preparation of the membranes, were isolated as a villus to crypt gradient. This separation and that of the membranes, led to the conclusion that the (Na+ + K+)-dependent ATPase is localized principally in the plasma membrane of all cells whatever their state of maturation, while 5'-nucleotidase is predominantly located in the basal-lateral membrane of the villous cells and may serve as a specific marker for the purification of this membrane. Finally it has been shown that aminopeptidase, dissacharidases and alkaline phosphatase do not appear simultaneously in the maturation process of the cells, alkaline phosphatase being absent from the crypt cells and aminopeptidase being the first to be synthesized. This enzyme seems to appear in the crypt cells membrane before being integrated into the mature brush border membrane.
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PMID:Plasma membranes from rat intestinal epithelial cells at different stages of maturation. I. Preparation and characterization of plasma membrane subfractions originating from crypt cells and from villous cells. 21 16

Reports on correlations between the activity of so-called "marker enzymes of cholestasis" in serum and the ultrastructural changes of the liver are rare. Therefore studies of ultrastructural changes were carried out in 40 patients with intrahepatic cholestasis. In the patients' serum activity of alkaline phosphatase, bile duct alkaline phosphatase, leucine-aminopeptidase (LAP), and 5'-nucleotidase (5'-Nu) as well as the concentration of bilirubin were determined. The results showed a significant correlation between the morphometry of the bile canaliculi and the serum activity of LAP and 5'-Nu. In patients with elevated LAP, an enlargement of the bile canaliculi could be proved. An increased serum activity of 5'-Nu correlated with a higher incidence of bile canaliculi in the ultrastructural picture. The results suggest an investigation of the ultrastructure of bile canaliculi and the determination of marker enzymes of cholestasis in the serum may both contribute to the assessment of cholestatic liver disease.
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PMID:[Ultrastructural-morphometric analysis of liver biopsies in patients with intrahepatic cholestasis. I. Correlations between morphometry of bile canaliculi and so-called "marker enzymes of cholestasis" (author's transl)]. 80 5

Basolateral and brush-border membranes were prepared from the intestines and kidneys of spontaneously hypertensive (SHR) and normotensive (WKY) rats fed on a calcium-adequate diet and assayed for their enzyme activities. In intestinal basolateral membranes the activities of Na+ K(+)-ATPase (EC 3.6.1.37) Ca2(+)-ATPase (EC 3.6.1.38) and alkaline phosphatase (EC 3.1.3.1) were lower in SHR rats when compared with WKY rats, whilst 5'-nucleotidase (EC 3.1.3.5) (a marker for basolateral membranes) was unaffected. In kidney basolateral membranes all enzymes were similar in activity in SHR and WKY rats. In intestinal brush-border membranes the activities of Ca2(+)-ATPase and alkaline phosphatase were lower in SHR rats when compared with WKY rats, whilst microvillus aminopeptidase (EC 3.4.11.2) (a marker for brush-border membranes) was unaffected. In kidney brush-border membranes all enzymes were similar in activity in SHR and WKY rats. The blood pressures of the SHR rats were considerably higher than those of the WKY rats. When SHR rats were fed on a Ca-deficient diet the activities of Na+K(+)-ATPase, Ca2(+)-ATPase and alkaline phosphatase in basolateral membranes and Ca2(+)-ATPase and alkaline phosphatase in brush-border membranes were all increased in the intestine when compared with SHR rats fed on a Ca-adequate diet. The equivalent enzymes in the kidneys of SHR rats, and the intestines and kidneys of WKY rats, were not affected by altering the Ca in the diet. The blood pressures of SHR rats fed on a Ca-deficient diet were higher than in those fed on a Ca-adequate diet. Blood pressures of WKY rats were not affected by altering the diet in this way. The results indicate that the absorption of Ca by active mechanisms may be reduced in SHR rats compared with WKY rats. Changing the level of Ca in the diet modified both blood pressure and the activities of enzymes which catalyse active Ca transport. The implications of these results to the aetiology, and possible nutritional treatment, of essential hypertension are discussed.
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PMID:The effect of diets adequate and deficient in calcium on blood pressures and the activities of intestinal and kidney plasma membrane enzymes in normotensive and spontaneously hypertensive rats. 231 78

Membrane vesicles, showing a 21 +/- 2-fold enrichment in the activity of 5'-nucleotidase and a 11 +/- 4-fold enrichment in the activity of angiotensin-converting enzyme relative to homogenate, were prepared from the myenteric plexus-containing longitudinal muscle layer of guinea pig ileum. Incubation of the vesicles with substance P and neurokinin A led to degradation of the peptides, and metabolites were isolated by reverse-phase HPLC and identified by amino acid composition. Cleavages of substance P between Glu6-Phe7, Phe7-Phe8, and Gly9-Leu10 and of neurokinin A between Gly8-Leu9 were observed and could be inhibited in a dose-dependent manner by phosphoramidon, an inhibitor of neutral endopeptidase 24.11. Formation of these metabolites was not completely inhibited by this agent, indicating that a phosphoramidon-insensitive form of endopeptidase 24.11 was present in the gut. Substance P was resistant to degradation by aminopeptidases, but neurokinin A was a substrate for bestatin-sensitive aminopeptidase(s), so that the neurokinin A (3-10) fragment represented the predominant metabolite in the chromatograms. The rate of formation of all the metabolites was not inhibited by enalapril and not enhanced by an increased Cl- concentration, indicating that angiotensin-converting enzyme was unimportant in the degradation process. Degradation of neurokinin A by the vesicles (Km 30 microM; Vmax 7.2 +/- 0.8 nmol min-1 mg of protein-1) was more rapid than degradation of substance P (Km 25 microM; Vmax 4.4 +/- 0.4 nmol min-1 mg of protein-1).
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PMID:Proteolytic inactivation of substance P and neurokinin A in the longitudinal muscle layer of guinea pig small intestine. 242 10

We have undertaken the analytical fractionation of epithelial cells from toad urinary bladder, a tissue extensively used to study epithelial transport of ions and water. In an attempt to establish markers for the main subcellular organelles, a number of enzymes were assayed in cell homogenates. The nearly ubiquitous plasma membrane marker 5'-nucleotidase, and the transferases that donate N-acetylglucosaminyl, galactosyl, and sialyl residues to glycoproteins and glycolipids in the Golgi complex were not detectable. Glucose-6-phosphatase activity was low in relation to that of nonspecific phosphatases and, therefore, not suitable for identifying the endoplasmic reticulum. Like the cytosolic enzyme lactate, dehydrogenase, catalase was essentially found in the high-speed supernatant, with a noteworthy part of aminopeptidase (substrate, leucyl-beta-naphthylamide) and NAD glycohydrolase. Other enzymes, including cytochrome c oxidase, acid phosphatase, acid N-acetyl-beta-glucosaminidase, alkaline phosphatase, alkaline phosphodiesterase I, nucleoside diphosphatase (substrate ADP), oligomycin-resistant Mg++-ATPase, and mannosyltransferase (acceptor, dolichylphosphate) were fairly active and largely sedimentable. After differential centrifugation, cytochrome oxidase, acid phosphatase, and acid N-acetyl-beta-glucosaminidase were typically associated with the large granule fraction, whereas the other sedimentable enzymes exhibited a broad distribution profile overlapping the nuclear, large granule, and microsome fractions. Their behavior in density equilibrium centrifugation is examined in a companion paper.
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PMID:Subcellular fractionation of epithelial cells from toad urinary bladder. 1. Assay of marker enzymes and differential centrifugation. 250 71

The presence and particle association of various hydrolytic enzymes in Naegleria fowleri has been studied in whole cell extracts of trophozoites in an effort to establish authentic markers for surface membrane and lysosomal components. Evidence from the experiments reported here indicates that in N. fowleri a) acid proteinase, N-acetylglucosaminidase, and acid phosphatase are associated with cytoplasmic granules closely resembling lysosomes; b) 5'-nucleotidase is associated with the surface membrane, probably on the external surface; c) aspartate aminotransferase is associated with mitochondria; d) alpha-D-glucosidase and an aminopeptidase have bimodal distributions, activity being associated with both the surface membrane and lysosomal particles.
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PMID:Subcellular distribution of hydrolases in Naegleria fowleri. 299 80

Pinocytosis was induced in rat kidney by exposure to horseradish peroxidase (HRP). Pinocytic vesicle preparations were enriched after homogenization of kidney cortex by differential centrifugation and free-flow electrophoresis with HRP as an exogenous marker. Vesicles were identified by enzymatic analysis and by electron microscopy, including specific staining procedures. Typical brush-border enzymes such as alkaline phosphatase, aminopeptidase, 5'-nucleotidase, lysosomal acid phosphatase, and mitochondrial succinic dehydrogenase were reduced in the vesicular fraction, compared to the kidney cortex homogenate. Glucose-6-phosphatase and Na(+)-K(+)-ATPase were only slightly increased in the fraction. These results indicate that preparations of pinocytic vesicles from rat kidney cortex can be enriched. They have biochemical characteristics that differ from those of the cell organelles and membranes previously purified from renal tissue.
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PMID:Analysis of the pinocytic process in rat kidney. I. Isolation of pinocytic vesicles from rat kidney cortex. 437 80

Plasma membranes (PM) were prepared by discontinuous density gradient centrifugation of crude nuclear fractions from 6 rat livers. These "nuclear" PM (PM-n) were 15-fold enriched in plasma membrane marker enzymes and contained an endopeptidase activity degrading azocasein at pH 7. To get larger amounts of plasma membranes, microsomal fractions obtained in large scale subcellular fractionations were subjected to continuous gradient zonal centrifugation. These "microsomal" PM (PM-m) were 22-fold enriched in 5'-nucleotidase, however, the separation of PM from endocellular membranes was not complete. PM-m showed endopeptidase activity degrading azocasein at pH 5.4 faster than at pH 7.5 and exopeptidases degrading Ala-Pro-pNA and Ala-pNA at pH 7.6. The latter two activities were distributed over the gradient similar to PM marker enzymes and can be solubilized by detergent and proteinase treatment. Therefore, dipeptidyl-aminopeptidase IV and Ala-aminopeptidase are intrinsic plasma membrane enzymes and can be used as additional markers for rat liver plasma membranes. The efficiency and selectivity to solubilize plasma membrane bound endopeptidase, DPP IV and aminopeptidase activities are compared.
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PMID:Proteolytic activities in plasma membrane preparations from rat liver. 1. Preparation of rat liver plasma membranes and solubilization of membrane bound proteases. 636 Jan 63

Microvillus membrane vesicles from pig small intestine, isolated by hypotonic lysis, Mg2+ aggregation of contaminants and differential centrifugation, have been further purified by immunoadsorbent chromatography. The vesicles adhere to an immunoadsorbent prepared by coupling antibodies raised against three of the principal proteins of the brush border membrane (aminopeptidase, sucrase-isomaltase and lactase) to Sepharose 4B. After the contaminants are removed by washing, the adherent vesicles are released from the immunoabsorbent by applying shear forces. The purity of the immunoadsorbed vesicles has been established by electron microscopy and by measuring the activity of marker enzymes. The enrichment factor is 1.17 +/- 0.02 for aminopeptidase and 0.70 +/- 0.05 for 5'-nucleotidase. The contamination of the preparation before immunoadsorption constitutes 10% of the membrane protein and consists mainly of basolateral membrane fragments as judged from marker enzyme determinations and the lipid composition.
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PMID:Purification of microvillus membrane vesicles from pig small intestine by immunoadsorbent chromatography. 710 46


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