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)

A procedure was developed for the isolation of cardiac sarcolemmal vesicles. These vesicles are enriched about ten-fold (with respect to the tissue homogenate) in K+-stimulated p-nitrophenylphosphatase, (Na+ + K+)-ATPase, 5'-nucleotidase activities and sialic acid content, all of which are believed to be components of the sarcolemma. The sarcolemma of tissue culture cardiac cells were radioiodinated and the distribution of this radioiodine paralleled the distribution of the other membrane markers above. There was very little contamination of the sarcolemmal fraction by sarcoplasmic reticulum (as judged by Ca2+-ATPase and glucose-6-phosphatase activities) or inner mitochondrial membranes (as judged by succinate dehydrogenase activity). There may, however, be some contamination by outer mitochondrial membranes (as judged by monoamine oxidase and rotenone-insensitive NADH cytochrome c reductase activities) which have rarely been monitored in cardiac sarcolemmal preparations. The purity of this preparation is good when compared with other cardiac sarcolemmal preparations. This preparation should be very useful in studying the roles of the cardiac sarcolemma (e.g. in excitation contraction coupling and Ca2+ binding).
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PMID:Isolation and characterization of cardiac sarcolemma. 22 23

3T3 and SV3T3 mouse embryo cells and a variety of other monolayer cell lines can be induced to form and shed plasma membrane vesicles by exposure to sulphydryl blocking agents including formaldehyde and N-ethyl malemide. Morphological studies show that multiple vesicles are formed and released from individual cells and that the vesicle membrane is continuous with the plasma membrane of the cell. Vesicles measure from o.1 to 15 micrometer in diameter and are free of detectable contamination with cytoplasmic membranes and organelles. Vesicles also show a 10-fold enrichment in the plasma membrane marker enzyme 5'-nucleotidase and are devoid of detectable NADH-cytochrome C reductase and succinic dehydrogenase activity which are marker enzymes for endoplasmic reticulum and mitochondria, respectively. Vesicles have a high cholesterol: phospholipid ratio and show enrichment in sphingomyelin content. They contain receptors for Con A and WGA, approximately 20 size class polypeptides and intramembranous particles. These results suggest that vesicles are derived from and have the general characteristics of plasma membranes.
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PMID:Plasma membrane vesiculation in 3T3 and SV3T3 cells. I. Morphological and biochemical characterization. 37 Jan 29

A new procedure for the purification of plasma membranes of Dictyostelium discoideum is described. Cells are broken by vigorously stirring in the presence of glass beads, and plasma membranes are isolated by equilibrium sucrose density centrifugation. The purified membranes are considerably enriched in alkaline phosphatase and 5'-nucleotidase and contain very low levels of succinate dehydrogenase and NADPH-cytochrome c reductase. The purified membranes contain relatively high levels of phospholipid, sterol and carbohydrate. They appear as a relatively homogeneous population of membrane vesicles in the electron microscope. This new method of purification is compared to previously published procedures which have been found to be unsuitable for our purposes.
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PMID:The purification and characterization of Dictyostelium discoideum plasma membranes. 40 46

A highly enriched sarcolemma preparation was isolated by differential centrifugation of a canine ventricular homogenate followed by centrifugation of a membrane fraction layered over 22% (w/v) sucrose. Ouabain binding, ouabain-sensitive potassium phosphatase activity and 5'-nucleotidase activity were enriched 19--27 fold over the homogenate whereas Ca2+-ATPase and succinate dehydrogenase activities were 0.75 and 0.36, respectively, of that for the homogenate. The isolation procedure was relatively rapid and yielded about 2.0 mg protein/100 g of ventricular muscle. The highest salt concentration used in the procedure was 0.6 M KCl and no detergents were employed. Initial characterization studies suggested that the sarcolemma-enriched fraction consists predominantly if not totally of freely permeable membrane vesicles and that the sarcolemma does not manifest a Ca2+-ATPase activity, at least within the limits of the assay procedures employed. This preparation was concluded to be about 1.5- to 4-fold more highly enriched with sarcolemmal markers than preparations obtained by previously published procedures. Accordingly, the preparation provides an improved basis for the probe of calcium movements that occur across the sarcolemma in association with the excitation-contraction-relaxation sequence of the mammalian myocardial cell.
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PMID:Isolation of a highly enriched sarcolemma membrane fraction from canine heart. 45 91

A procedure was devised for the preparation of enriched populations of subcellular organelles from homogenized bovine spleen. The fractions obtained were characterized for arylsulfatase, succinate dehydrogenase, UDPgalactosyltransferase and 5'-nucleotidase activities. The distribution of sialidase (acylneuraminyl hydrolase, EC 3.2.1.18) activity directed towards either endogenous substrate or exogenous ganglioside substrate suggests that it is enriched in the plasma membrane/microsomal fractions. Sialidase activity towards exogenous sialoglycoproteins, isolated from erythrocyte membrane, was enriched in the least dense of the plasma membrane/microsomal-containing fractions. The endogenous sialidase substrates were primarily the sialoglycolipids, hematoside and disialogangliosides. At the pH optimum, 3.8, and 37 degrees C, release of endogenous sialic acid was linear with time for 3 h. At the end of this time, 85% or more of the available endogenous substrate was hydrolyzed.
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PMID:Distribution in spleen subcellular organelles of sialidase active towards natural sialogylcolipid and sialoglycoprotein substrates. 48 91

An analysis of starvation and starvation followed by refeeding was undertaken to characterize some organismic, organ, and mitochondrial responses to these two circumstances. Body weight, organismic respiration as well as weight protein and succinic dehydrogenase activity for liver, kidney, and heart were determined over the course of 6 days of starvation and 5 days refeeding for adult male rats. Assays of marker enzyme activities for mitochondria (cytochrome oxidase), lysosomes (acid phosphatase), endoplasmic reticulum (glucose-6-phosphatase), and plasma membranes (5'-nucleotidase) were conducted for liver in addition to quantitations of mitochondrial protein. All enzyme determinations were done on whole tissue homogenates and reported as total organ activity. Liver mitochondria were harvested quantitatively directly from whole liver homogenates by zonal centrifugation for determination of mitochondrial protein. Starvation resulted in a major loss of body weight, organ weight, and organ protein; liver greater than kidney greater than heart. These changes were accompanied by a major reduction in organ succinic dehydrogenase activity; liver greater than kidney. In heart, succinic dehydrogenase was doubled in activity at day 2 of starvation and subsequently diminished to values not significantly lower than controls. In liver, mitochondrial mass (protein) was severely diminished. From analysis of marker enzyme activities, it appeared that lysosomes, endoplasmic reticulum, and plasma membrane were also decreased. Refeeding restored the greatest part of these losses within 5 days.
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PMID:Starvation and refeeding in rats: effect on organismic respiration, cytoplasmic constituents of liver, and succinic dehydrogenase activity in liver, kidney, and heart. 70 2

A method for the isolation of plasma membranes from an experimental murine ependymoblastoma is described. In this procedure, 5'-nucleotidase was used as the plasma membrane marker, since cytochemical methods demonstrated that the enzyme was present on this subcellular structure only. The final plasma membrane preparation showed a 15-fold enrichment in 5'-nucleotidase activity and a 17-fold enrichment in the activity of phosphodiesterase I, another plasma membrane marker. The specific activity of beta-glucuronidase (lysosomal enzyme) was twice that of the whole homogenate, the specific activity of arylesterase (microsomal enzyme) was similar to that of the whole homogenate and succinate dehydrogenase (mitochondrial marker) was not detected. Electron microscopy of this fraction showed vesicles on which 5'-nucleotidase activity could be demonstrated. The subcellular distribution of [3H]amphotericin B per mg of protein was similar in the plasma membrane preparation and in the whole homogenate. It is concluded that, in ependymoblastoma, amphotericin B shows no selective affinity for the plasma membrane.
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PMID:Isolation of plasma membranes from murine ependymoblastoma and subcellular distribution of amphotericin B in this tumor. 85 31

The enzymes from the venom of Heterometrus scaber, the indole compounds present and the toxic protein of the venom have been studied. The venom contains acid phosphatase, ribonuclease, 5'-nucleotidase, hyaluronidase, acetylcholine esterase and phospholipase. A. The indole compounds present in the venom have been identified as 5-hydroxytryptophan, tryptophan, serotonin and tryptamine, along with two unidentified indole compounds. The venom produces hyperglycaemia in sublethal doses and this has been found to be due to increased adrenaline secretion. The toxic protein of the venom has been obtained in a pure form by (NH4)2SO4 fractionation, followed by fractional precipitation with acetone and chromatography over DEAE-Sephadex. The toxic fraction has been found to be homogeneous on acrylamide gel electrophoresis. It is a glycoprotein (molecular weight 15 000) containing 1.74% glucosamine, 0.87% galactosamine, 0.313% sialic acid, 3.25% fucose and 0.45% of an unidentified neutral sugar. It did not show any enzyme activities, haemolytic activity or inhibition of succinate dehydrogenase activity but it produced hyperglycaemia in sublethal doses. The toxic level (intravenous administration in rats) was found to be 0.72 mg/kg body weight.
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PMID:Investigations on the venom of the South Indian scorpion Heterometrus scaber. 111 82

The protein content and activity of enzymatic markers of cell organelles: succinate dehydrogenase, glucose-6-phosphatase, uricase, acid phosphatase, 5'-nucleotidase and alkaline phosphatase were assayed in the homogenate and the supernatant (after two-hour centrifugation at 140,000 X g) of the liver and intestinal epithelium in rabbits irradiated with a single dose of 550 rads of gamma rays. The determinations were carried out on 1,3,6,9,15 and 30 days after irradiation for experimental and control animals. After gamma irradiation the following alterations were found: 1) increase in protein content (marked between 3-6 days), 2) remarkable rise of alkaline phosphatase activity (during the entire period of study), 3) elevation of 5'-nucleotidase activity (only in the intestinal epithelium), 4) marked reduction of succinate dehydrogenase and uricase activity (on the first day of study), 5) moderate decrease of glucose-6-phosphatase activity (mainly on the third day). Apart from a slight decline in the activity of acid phosphatase in the homogenate of intestinal epithelium, on the third day there practically were no changes in the activity of this enzyme either in the supernatant of intestinal epithelium or in the liver tissue.
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PMID:Effect of gamma radiation on the enzymatic activity of cell organelles of liver and epithelium of small intestine in rabbits. 123 88

D-Galactosamine (800 mg/kg, intraperitoneally) caused significant decrease in the activities of 5'-nucleotidase, glucose-6-phosphatase and cytochrome P450 and increase in activities of gamma-glutamyl transpeptidase, succinate dehydrogenase, acid phosphatase and acid ribonuclease in liver after 24 hr. The levels of RNA, protein and glycogen decreased while total lipids, phospholipids, cholesterol and lipid peroxides increased. It also increased the serum levels of transaminases, alkaline phosphatase and bilirubin while protein concentration decreased significantly. Oral administration of Picroliv (12 mg/kg/day for 7 days), a standardised iridoid glycoside fraction of Picrorhiza kurroa, significantly prevented the biochemical changes in liver and serum of galactosamine-toxicated rats. Kutkoside (12 mg/kg/day for 7 days) also protected against changes in most of the hepatic and serum constituents studied. Another iridoid glycoside from Picroliv, Picroside I, at the same dose level could only prevent toxicant-induced changes in acid phosphatase, phospholipids and lipid peroxides in liver and alkaline phosphatase in serum. Mixture of Picroside I and Kutkoside in the ratio of 1:1.5 at 12 mg/kg dose elicited lesser response than Picroliv.
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PMID:Picroliv and its components kutkoside and picroside I protect liver against galactosamine-induced damage in rats. 133 78


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