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)

Homogenates of HTC cells have been fractionated by differential centrifugation (in four particulate fractions: N, M, L, P, and a supernatant S) or isopycnic banding in linear sucrose gradients. On this basis, the following subcellular organelles may be characterized: (i) Mitochondria, detected by cytochrome oxidase and succinodehydrogenase, are collected in the M and L fractions, and equilibrate, as a narrow band, at a median buoyant density of 1.18 g/cm3. (ii) Lysosomes, detected by the latent hydrolases beta-glycerophosphatase and N-acetyl-beta-glucosaminidase, are largely sedimented in the M and L fractions, and display a broad density distribution pattern with a median value of 1.17 g/cm3. This density is decreased or increased after cultivation of the cells in presence of Triton WR-1339 or Dextran 500, respectively. The behavior of cathepsin D is somewhat at variance with that of the two other hydrolases. (iii) Plasma membrane is tentatively detected by alkaline phosphodiesterase I. Largely recovered in the P fraction, this enzyme equilibrates at a median density close to that of the lysosomal hydrolases; the bulk of cholesterol and about half of the leucyl-2-naphthylamidase are closely associated with alkaline phosphodiesterase I; HTC cells do not contain typical 5'-nucleotidase. (iv) Catalase-bearing particles, of high buoyant density (1.22 g/cm3) are present, but 30-40% of the catalase is also found readily soluble. NADPH- and NADH: cytochrome c reductase, and RNA show more complex distributions. It is suggested that the former enzyme is associated with the endoplasmic reticulum; as in liver, NADH reductase activity is shared between the endoplasmic reticulum and the mitochondria; half of the RNA is associated with free ribosomes of polysomes. True glucose-6-phosphatase could not be detected.
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PMID:Analytical fractionation of cultured hepatoma cells (HTC cells). 56 43

Rat serum 5'-nucleotidase, L-leucyl-beta-naphthylamidase and beta-glycerophosphatase activities are increased whilst alkaline p-nitrophenylphosphatase and alkaline phosphodiesterase activities are unchanged or decreased three days after bile duct ligation. Affinity chromatography on an immobilised antiserum raised against highly purified liver plasma membranes showed that although 5'-nucleotidase in normal serum is unrelated to the 5'-nucleotidase of liver plasma membrane, the 5'-nucleotidase of bile and much of the 5'-nucleotidase in the jaundiced serum are closely related to the plasma membrane enzyme. Since bile is rich in 5'-nucleotidase, the changes in level of this enzyme after bile duct ligation are most simply explained by leakage of bile into the blood; changes in the patterns of the other enzymes are shown to be consistent with this explanation. The jaundiced serum was examined by gel exclusion chromatography and flotation in sucrose gradients for the presence of small fragments of plasma membrane as reported in human jaundiced sera, but no such fragments could be detected three days after bile-duct ligation.
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PMID:Bile 5'-nucleotidase in the serum of jaundiced rats. 89 Sep 46

We have used isopycnic gradient ultracentrifugation to isolate a total lamellar body fraction (total-lb) from rat lung and then further subfractionated this using differential centrifugation to obtain two distinct subpopulations of organelles. When the total-lb was diluted to 0.25 M with sucrose and centrifuged at 8000 X for 30 min we obtained a fraction (lbA) that contained primarily intact classic-appearing lb. When the supernatant was then centrifuged at 80,000 X g for 60 min we obtained a vesicular fraction (lbB). Whereas both fractions had an identical phospholipid composition, their enzyme profiles differed markedly. The lbA had a higher level of beta-glycerophosphatase, while lbB had more 5'-nucleotidase. Moreover, lbB had a phospholipid:protein ratio of 9.2 while lbA had one of 6.3. An examination of the specific activity-time curves revealed that lbA had a curve that was broader and reached a peak earlier than lbB, but the downslopes of both curves were identical; they did not bear a classic precursor-product relationship to one another. The two fractions differed very significantly in their protein profiles. Whereas lbA contained a large amount of a 15-kDa protein with very small amounts of 35-, 37-, 38-, 45-, and 60-kDa proteins, lbB contained predominantly a 35-kDa protein with smaller amounts of 15-, 23-, 26-, 37-, 38-, 45-, and 60-kDa proteins. We suggest that lbB is surfactant taken back up into the alveolar type II cell, or a second release form of tissue surfactant, or a mixture of the two.
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PMID:Surfactant-associated 15- and 35-kDa proteins are concentrated in different organelles in rat lung tissue. 337 Dec 75

1. Incubation of Schistosoma mansoni for 5 min in a phosphate-buffered medium, pH 7.4, released tegumental material containing the following phosphohydrolase activities: alkaline phosphatase, 5'-nucleotidase, glycerol-2-phosphatase, glucose 6-phosphatase, phosphodiesterase and ATPase. 2. Maximum activity of these enzymes was measured at pH 9.5; however, the phosphodiesterase and ATPase activities were also appreciable at pH 7.0. 3. Solubilization of the released tegumental material in 1% Triton X-100 followed by gel filtration distinguished three peaks of enzyme activity: an ATPase (mol.wt. greater than 1000 000), a phosphodiesterase (mol.wt. 1 000 000) and an alkaline phosphomonoesterase with broad specificity (mol.wt. 232 000). 4. The ATPase activity was highly activated by 10 mM-Mg2+ or 1 mM-Ca2+ and was inhibited by chelating agents. Ouabain, Na+ and K+ had little effect on enzyme activity, whereas activity was increased by 50% in the presence of calmodulin. The phosphodiesterase activity was highest in the presence of 100 mM-Na+ or -K+, and 10 mM-Mg2+ or -Ca2+. Alkaline phosphatase activity was also stimulated by 100 mM-Na+ or -K+, and 10 mM-Mg2+; however Ca2+ inhibited at greater than 1 mM. 5. Surface iodination of parasites followed by detergent solubilization and gel filtration of the released tegumental membranes indicated that these enzymes were not accessible. A major surface component, apparent mol.wt. 80 000, was iodinated. 6. Rabbit anti-(mouse liver 5'-nucleotidase) antibodies did not inhibit the phosphohydrolase activities. However, an immunoglobulin G fraction from sera of mice chronically infected with S. mansoni partially inhibited alkaline phosphatase activity, but was without effect on the phosphodiesterase and ATPase activities. 7. The location of the enzymes in the double membrane of the tegument and their significance in host-parasite interactions is discussed.
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PMID:Properties of a series of tegumental membrane-bound phosphohydrolase activities of Schistosoma mansoni. 627 49

Enzymatic activities of thymocytes isolated from Swiss albino mice were studied at various ages from immediately post weaning until 100 weeks of age, approaching the life expectancy of these animals. Between 5 and 10 weeks of age, the activities of lactate dehydrogenase and alkaline phosphatase decreased to a level that was maintained throughout the remainder of the aging profile. Neutral beta-glycerophosphatase (pH 7.5) activity in a thymus membrane preparation was similar in all age groups. The activity of membrane-bound 5'-nucleotidase, that is, AMP-hydrolyzing activity inhibited by 100 microM alpha, beta-methyleneadenosine 5'-diphosphate, progressively increased as a function of age, indicating thymocyte population changes occurring very late in life. In thymocytes of the oldest mice examined (100 weeks of age), 5'-nucleotidase specific activity was approximately ten-fold greater than the activity found in 5-week-old mice. Thus, membrane-bound 5'-nucleotidase activity in thymocytes increased markedly as a function of age in Swiss albino mice; yet several other enzymatic activities, including alkaline phosphatase, remained relatively unchanged in mature mice.
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PMID:Age-related changes in 5'-nucleotidase and alkaline phosphatase activities in mouse thymocytes. 629 8

Plasma membranes have been isolated from chicken liver and from Mc-29 virus induced transplantable hepatoma. The purity of membrane preparations has been checked by electron microscopy and by determination of the activity of some enzymes: 5'-nucleotidase, Na+, K+-ATP-ase, Mg2+-ATP-ase, alkaline beta-glycerophosphatase and glucose-6-phosphatase. In hepatoma membranes the activity of 5'-nucleotidase, Na+, K+-ATP-ase and Mg2+-ATP-ase was lower, that of alkaline phosphatase higher, than in liver membrane preparation. The incorporation rate of glucosamine-14C into UDP-N-acetylglucosamine and into plasma membrane glucosamine have been studied as well. The rate of synthesis of UDP-N-acetylglucosamine was faster in liver than in tumor cells. The labeling of hepatoma plasma membranes with glucosamine-14C occurred more slowly than that of liver ones. The rate of transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to membrane-bound glucosamine is lower in hepatoma, than in liver cells.
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PMID:Isolation and partial characterization of plasma membranes from chicken liver and from Mc-29 virus induced transplantable hepatoma. 745 56