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)

The lateral heterogeneity of rat liver plasma membranes was examined by fragmentation and fractionation by counter-current distribution in an aqueous two-phase polymer system. The distribution pattern was analysed by plotting the relative specific activities of marker components against each other. By this analysis asialo-orosomucoid receptors were found in a domain separated from domains containing 5'-nucleotidase and leucine aminopeptidase by another domain devoid of these markers. 5'Nucleotidase and leucine aminopeptidase resided in adjacent but separate domains. The experimental data were compared with corresponding plots of markers in model membranes. The model membranes yielded plots of different shapes depending on marker distribution and fragment size. This method of analysis should be useful for examining the lateral heterogeneity also of other membranes.
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PMID:Lateral heterogeneity of rat liver plasma membranes analysed by counter-current distribution. 282 55

Fractionation of rat liver by homogenization and differential centrifugation revealed that only about 83% of the transglutaminase activity in the tissue is in a soluble form, and that the remainder is associated with the particulate fraction. This latter activity remained with the membranes even after they were extensively washed to remove 99% of such soluble enzymes as lactate dehydrogenase and aldolase. Subsequent fractionation of the membranes by isopycnic density gradient centrifugation in sucrose resulted in a single band of transglutaminase activity at a density of 1.194 g/cm3. This activity was coincident with the major band of plasma membranes, which was identified by its content of 5'-nucleotidase, alkaline phosphodiesterase I, alkaline phosphatase and leucine aminopeptidase activities. After treatment with digitonin and fractionation on sucrose gradients, the transglutaminase activity and the plasma membrane marker enzyme activities were found at a new density of 1.210 g/cm3, while the enzyme markers for the other membrane fractions remained unchanged. From these data, we conclude that approximately 17% of the transglutaminase activity in rat liver is specifically associated with the plasma membranes.
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PMID:Subcellular localization of a membrane-associated transglutaminase activity in rat liver. 286 17

Two-micrometer sections of methacrylate-embedded kidney were used to investigate the enzymatic activities of mouse kidney where the proximal tubule and Bowman's capsule from the same corpuscle were viewed in the same section. Alkaline phosphatase, acid phosphatase, 5'-nucleotidase, gamma-glutamyl transpeptidase, N-acetyl-beta-glucosaminidase, leucine aminopeptidase, alpha-naphthyl butyrate esterase, and adenosine triphosphatase activities were observed in the proximal tubule, but only 5'-nucleotidase, alpha-naphthyl butyrate esterase, and alkaline phosphatase were observed in the squamous portion of the parietal epithelium of Bowman's capsule. The use of methacrylate-embedded tissue allowed more precise localization of enzymatic activity than is possible with most frozen sections. This may provide interesting applications not only for characterization of kidney diseases but also for characterization of other normal and abnormal tissues.
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PMID:Enzymatic histochemistry of mouse kidney in plastic. 288 Aug 90

The purpose of this investigation was to determine which enzyme activities are true canine neutrophil plasma membrane markers. Three enzymes thought to be present on plasma membranes were chosen for study: 5'-nucleotidase, magnesium-dependent adenosine triphosphatase (Mg2+-ATPase), and leucine aminopeptidase. Both 5'-nucleotidase and Mg2+-ATPase were found to be ectoenzymes in the canine neutrophil but additional Mg2+-ATPase activity was located intracellularly. An endogenous inhibitor of 5'-nucleotidase was found in the cytosol of canine neutrophils. The specific 5'-nucleotidase inhibitor, adenosine 5'-[alpha, beta-methylene] diphosphate also inhibited the canine enzyme in intact cells. Leucine aminopeptidase was located solely in the myeloperoxidase-containing granules of the canine neutrophil. Plasma membrane, as identified by the presence of Mg2+-ATPase and 5'-nucleotidase activities, was separated from other cell organelles by Percoll-density gradient centrifugation of a 10 000 X g supernatant of nitrogen cavitated neutrophils.
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PMID:Canine neutrophil plasma membrane markers. 298 65

Mechanisms of alcoholic liver disease are still ill defined. We evaluated in two outbred lines of mice whether chronic ingestion of ethanol alters the lipid composition and/or enzyme activity of liver plasma membranes. Two mouse lines with different sensitivities towards the hypnotic effect of ethanol, designated long sleep and short sleep, were fed a liquid diet containing ethanol for 30 days. Ethanol intake reached 30 gm per kg per day in both lines, and serum ethanol levels were similar. In addition, hepatic triglyceride levels were similarly increased 2-fold with ethanol feeding. The following effects of ethanol treatment were observed in liver plasma membrane fractions: (i) Na+,K+-ATPase was significantly increased to 26% above control in long sleep only; (ii) alkaline phosphatase activity was 2-fold increased in both lines; (iii) 5'-nucleotidase, leucine aminopeptidase and Mg2+-ATPase activities remained unchanged in both lines; (iv) unesterified cholesterol and total phospholipid contents were unaltered in both lines, and (v) cholesteryl esters were increased in both lines, but to a greater extent in short sleep (1.5 vs. 4-fold). Thus, chronic ethanol ingestion induces specific alterations in liver plasma membrane structure and function, suggesting that adaptive responses to ethanol may be determined in part by inherited factors.
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PMID:Effect of chronic ethanol administration on enzyme and lipid properties of liver plasma membranes in long and short sleep mice. 299 Nov 3

Circulating monocytes in 30 patients with progressive systemic sclerosis (PSS, scleroderma) and 28 age and sex matched normal controls were studied. Binding of the lectin peanut agglutinin (PA) was significantly reduced in PSS monocytes (p less than 0.001) together with a reduction in the density of nonspecific esterase staining (p less than 0.001) suggesting advanced maturation. Using monoclonal antibodies to identify cell surface markers, we demonstrated a significant reduction in PSS monocytes bearing the Leu M2 antigen (Mac 120, antigen presenting cells) over controls (p less than 0.05), but were unable to show any differences in the monocyte subpopulations using antisera against Leu M3 and HLA-DR surface antigens. The ectoenzymes 5'-nucleotidase (5'N) and alkaline phosphodiesterase 1 (APD1) were lower and leucine aminopeptidase (LAP) levels were higher in patients with PSS, compatible with immune activation. Interferon-gamma levels in serum did not appear to account for these changes, whereas the levels of Clq binding complexes correlated inversely with the levels of LAP (p less than 0.05). There was a strong correlation between the number of Leu M3 positive cells and the level of the ectoenzyme LAP (p less than 0.001). With increasing disease duration, higher levels of Clq binding complexes were detected (p less than 0.05). These results indicate that monocytes in PSS differ from those in normals and appear to have undergone advanced differentiation and activation changes.
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PMID:Changes in circulating monocytes in patients with progressive systemic sclerosis. 350 71

Rat liver plasma membranes, enriched in blood-sinusoidal or bile-canalicular regions by differential and sucrose-gradient centrifugation, were further purified by partitioning in an aqueous polymer two-phase system. This method separates membranes according to differences in surface properties rather than size and density. A several-fold increase in the ratio of leucine aminopeptidase (a bile-canalicular marker) and 5'-nucleotidase to asialo-orosomucoid binding (a blood-sinusoidal marker) was obtained in one fraction, whereas another fraction gave a 2-3-fold increase in ratio of blood-sinusoidal to bile-canalicular markers. Furthermore, the markers for both regions of the plasma membrane, as well as markers for Golgi membranes and lysosomes, showed a heterogeneous behaviour on counter-current distribution.
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PMID:Fractionation of rat liver plasma-membrane regions by two-phase partitioning. 375 37

The isolation of plasma membrane from human peripheral blood monocytes is described. Monocytes were isolated by centrifugal elutriation, to eliminate an adherence step, thus minimizing functional and surface antigenic alterations to the cells. Monocytes were surface-labelled with a radiolabelled monoclonal antibody, 125I-WVH-1, and then disrupted by nitrogen cavitation. Membranes were separated according to equilibrium buoyant density by isopycnic centrifugation on a sucrose gradient. The subcellular membranes were localized using marker enzymes for the plasma membrane, 5'-nucleotidase and leucine 2-naphthylamidase (leucine aminopeptidase), and for intracellular membranes: galactosyltransferase (Golgi), arylsulfatase C (endoplasmic reticulum), monoamine oxidase (mitochondria), catalase (peroxisomes), beta-hexosaminidase and beta-glucuronidase (lysosomal vesicles) and lactate dehydrogenase (cytosol). The monoclonal antibody 125I-WVH-1 was shown to label the plasma membrane, as judged by known markers, and represents a highly specific trace label, applicable to the use of plasma membrane as an immunogen for monoclonal antibody production. The NAD-splitting enzyme, NAD+ nucleosidase, was detected and its presence on the plasma membrane was demonstrated. The subcellular localization of non-specific esterase in human mononuclear phagocytes is controversial. No evidence was found for alpha-naphthyl acetate esterase activity on the plasma membrane or in lysosomal vesicles. However, a membrane-bound esterase in fractions with properties similar to the smooth endoplasmic reticulum was detected.
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PMID:Isolation of plasma membrane from human blood monocytes. Subcellular fractionation and marker distribution. 397 89

The "biliary tract" enzymes (leucine aminopeptidase, gamma-glutamyltranspeptidase and 5'-nucleotidase) in serum reflect to varying degrees, obstruction, proliferation, inflammation and neoplasia involving the hepatobiliary duct system. Their use is directed towards two purposes: (1) as non-electrophoretic assays to evaluate the source of an elevated non-specific alkaline phosphatase and (2) to offer greater sensitivity and specificity for space-occuping lesions in the liver. In appropriate clinical states, any of the three enzymes offer these advantages and there is little to chose among them. Selection of the assay to use in the clinical laboratory then becomes based on non-clinical factors, i.e., technical ease, apparent substrate specifities, etc. With these additional factors and despite some shortcomings, our selection is leucine aminopeptidase.
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PMID:The enzymes of the hepatobiliary tract: a biochemical and clinical comparison. 415 29

1. A collagenase digest of rat kidney cortex was separated into four bands by zonal centrifugation. 2. Two of these bands were shown by light-microscopy to contain glomeruli and tubular fragments, which were free from each other and well separated from other renal material. 3. Protein, N-acetyl-beta-glucosaminidase, 5'-nucleotidase, l-leucine beta-naphthylamidase, leucine aminopeptidase, acid phosphatase and alkaline phosphatase were assayed across the gradient. 4. The greater proportion of these enzyme activities was recovered in the tubular fragments and acid phosphatase was the only enzyme detected in significant amounts in the glomeruli. 5. Tubular fragments and glomeruli were sedimented and multiple forms of beta-naphthylamidase, N-acetyl-beta-glucosaminidase, acid phosphatase and alkaline phosphatase were investigated by starch-gel electrophoresis.
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PMID:The distribution of some hydrolases in glomeruli and tubular fragments prepared from rat kidney by zonal centrifugation. 433 86


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