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)

This study establishes an in vitro model for examining endochondral cartilage cell metabolism. Chondrocytes derived from the resting cell zone and adjacent growth zone of rat costochondral cartilage were compared for retention of phenotype in culture. At third passage confluence, two cell populations differ morphologically and biochemically. Resting zone cells are fibroblast-like, with smooth cell membranes and little rough endoplasmic reticulum. Growth zone cells are more polygonal, smaller in diameter, with numerous cytoplasmic extensions of the plasma membranes and abundant rough endoplasmic reticulum. Both cell populations produce matrix vesicles that are comparable morphologically to matrix vesicles isolated enzymatically from epiphyseal cartilage. While membrane vesicles are released into the media by cells derived from the resting zone as well as from the growth cartilage, alkaline phosphatase activity is enriched in media vesicles produced by growth cartilage cells. Alkaline phosphatase enriched vesicles appear to be preferentially incorporated into the extracellular matrix. Both the plasma membrane marker enzyme activity and the membrane phospholipid composition are differentially expressed in matrix vesicles and plasma membranes and are cell specific. Matrix vesicles produced by resting zone cells are enriched in alkaline phosphatase, 5'-nucleotidase, ouabain sensitive Na+/K+ ATPase and cardiolipin when compared to the cell membrane. In addition, the plasma membranes of these cells contain more phosphatidylcholine plus sphingomyelin than do growth cartilage plasma membranes. Resting zone cell matrix vesicles have less phosphatidylethanolamine than do vesicles from growth cartilage cultures. Matrix vesicles produced by growth cartilage cells contain one proteolipid at 43,000 Mr which comigrates with plasma membrane proteolipid and an additional proteolipid at approximately 3,000 Mr. These data indicate that both cells retain differential expression of phenotype in culture and that one expression of this phenotype is production of specific extracellular matrix vesicles.
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PMID:Differential expression of phenotype by resting zone and growth region costochondral chondrocytes in vitro. 316 34

1. A method for the preparation of brush border from rabbit kidneys is described. Contamination by other organelles was checked by electron microscopy and by the assay of marker enzymes and was low. 2. Seven enzymes, all hydrolases, were substantially enriched in the brush-border preparation and are considered to be primarily located in this structure. They are: alkaline phosphatase, maltase, trehalase, aminopeptidase A, aminopeptidase M, gamma-glutamyl transpeptidase and a neutral peptidase assayed by its ability to hydrolyse [(125)I]iodoinsulin B chain. 3. Adenosine triphosphatases were also present in the preparation, but showed lower enrichments. 4. Alkaline phosphatase was the most active phosphatase present in the preparation. The weak hydrolysis of AMP may well have been due to this enzyme rather than a specific 5'-nucleotidase. 5. The two disaccharidases in brush border were distinguished by the relative heat-stability of trehalase compared with that of maltase. 6. The individuality of the four peptidases was established by several means. The neutral peptidase and aminopeptidase M, both of which can attack insulin B chain, differed not only in response to inhibitors and activators but also in the inhibitory effect of a guinea-pig antiserum raised to rabbit aminopeptidase M. This antiserum inhibited both the purified and the brush-border activities of aminopeptidase M. The neutral peptidase and gamma-glutamyl transpeptidase were unaffected but aminopeptidase A was weakly inhibited. The characteristic responses to Ca(2+) and serine with borate served to distinguish aminopeptidase A and gamma-glutamyl transpeptidase from other peptidases. 7. No dipeptidases, tripeptidases or carboxypeptidases were identified as brush-border enzymes. 8. Incubation of brush border with papain released almost all the aminopeptidase M activity but only about half the activities of maltase, gamma-glutamyl transpeptidase and aminopeptidase A. No release of alkaline phosphatase, trehalase or the neutral peptidase was observed.
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PMID:Studies on the enzymology of purified preparations of brush border from rabbit kidney. 414 72

Plasma membranes were isolated from the ameba Acanthamoeba castellanii by low-speed velocity centrifugation followed by equilibrium centrifugation in a sucrose gradient. The isolated membranes had a high ratio of sterol to phospholipid (0.98 moles/mole) and of phospholipid to protein (0.43 mg/mg). The plasma membranes had very low concentrations of DNA, RNA, lipid inositol, and glycerides. Glycolipids and glycoproteins were enriched in the plasma membranes relative to their concentrations in the whole cell. The plasma membranes were also judged to be of high purity by the absence, or very low level, of enzymatic activities considered to be indicative of other cell membranes, and by electron microscope examination. Alkaline phosphatase and 5'-nucleotidase activities were enriched in the plasma membranes 13-fold relative to the whole homogenate and had higher specific activities in the plasma membranes than in any other cell fractions. A Mg(++) adenosine triphosphatase (ATPase) was enriched sixfold in the plasma membranes relative to the whole homogenate. The phospholipids of the plasma membranes contained more phosphatidylethanolamine and phosphatidylserine and less phosphatidylcholine than did the phospholipids of the whole cells. There were differences in the fatty acid compositions of corresponding phospholipids in the plasma membranes and whole cells but no difference in the ratios of total saturated to unsaturated fatty acids. The membranes of phagosomes isolated from amebae that had ingested polystyrene latex had essentially the same phospholipid, sterol, and enzymatic composition as plasma membranes.
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PMID:Plasma and phagosome membranes of Acanthamoeba castellanii. 432 20

The authors utilized the technic of plastic embedding with enzyme histochemistry for the evaluation of enzymatic expression by epithelium of the lower urinary tract in humans. Alpha-naphthyl acetate esterase and acid phosphatase generally were expressed by normal and neoplastic urothelium. Expression of 5'-nucleotidase and ATPase was more restricted. Alkaline phosphatase, prominent in the transitional cells of lower mammalian species, generally was not present in human urothelium. Enzyme histochemistry has not been applied generally to the study of disease of the lower urinary tract, but this study suggests it may be of value in understanding the biology of this tissue and be of potential use in histopathologic diagnosis of diseases of this region.
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PMID:Enzyme histochemistry of normal and neoplastic transitional epithelium. 609 41

Two-cell embryos were incubated during 44 h in media containing either microtubule or microfilament inhibitors. The lowest doses that inhibit cleavage were found to be 0.5 micrograms/ml for colchicine and colcemid, 5 micrograms/ml for cytochalasin B and 0.5 micrograms/ml for cytochalasin D. After incubation with the minimal doses of these drugs, embryos were either fixed immediately or transferred to fresh media without drugs and cultured for different times before fixation. Then, embryos were processed for scanning electron microscopy. Following incubation with microtubule inhibitors, less than 10% of the embryos were compacted and about 20% became so in fresh medium. Regionalization was revealed by the cytochemical demonstration of alkaline phosphatase or 5'-nucleotidase on the apposing surfaces of blastomeres in 50% of the embryos, including all those that were compacted. By scanning microscopy microvilli were seen evenly distributed on the embryo surface, as they are observed in normal 2-cell embryos. Following incubation with microfilament inhibitors, few embryos were compacted and about 90% compacted within 4 h in fresh medium. Alkaline phosphatase activity was detected between blastomeres in all compacted embryos and in one half of those still uncompacted. Scanning microscopy showed patches of microvilli on the outer surface which had become otherwise smooth. During incubation in fresh medium, microvilli concentrated in two large patches placed at the antipodes of the embryo. From these results we conclude that cytokineses is not required for cell membrane regionalization, that blastomeres regionalize before they compact, that microtubule and microfilament inhibitors affect differently the array of microvilli on the external surface of arrested embryos.
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PMID:Plasma membrane regionalization and compaction of mouse cleaving embryos: effect of microtubule and microfilament inhibitors. 609 95

Alkaline phosphatase, 5'-nucleotidase nucleoside diphosphatase and thiamine pyrophosphatase activities were studied by cytochemical method applied to electron microscopy of brain microvasculature in normal and scrapie infected mice. In control mice, the major location of all phosphatases studied was the luminal plasma membrane of the endothelial cells. In scrapie infected mice, changes in activity and distribution of the above mentioned phosphatases manifested themselves in the appearance of the reaction product on the abluminal side of the vessel wall. Our data presents evidence that following scrapie infection, these enzymes change their specific localization along the endothelial cell membranes. These enzymatic changes may serve as useful indicators of some alterations in the mammalian blood-brain barrier following infection by scrapie agent in the mouse.
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PMID:Ultrastructural cytochemical studies of cerebral microvasculature in scrapie infected mice. 611 87

The pattern of gammaglutamyl transpeptidase levels was studied in the sera of 25 subjects with hyperthyroidism and 11 subjects with hypothyroidism, before and after treatment, and in 14 age- and sex-matched control subjects. Gammaglutamyl transpeptidase levels were significantly increased in hyperthyroidism (65 +/- 59 U/l) (p less than 0.01) and significantly decreased under treatment (40 +/- 27 U/l) (p less than 0.001). Before treatment, gammaglutamyl transpeptidase levels correlated with alkaline phosphatase levels and 5'-nucleotidase levels, the correlation persisting after treatment with 5'-nucleotidase. Alkaline phosphatase levels significantly increased under treatment (p less than 0.01). The percentages of gammaglutamyl transpeptidase variation correlated with thyroxine (r = 0.44, p less than 0.03), triiodothyronine (r = 0.47, p less than 0.02) and latent fixation capacity (r = 0.44, p less than 0.03) variations. Subjects with hypothyroidism had significantly decreased gammaglutamyl transpeptidase levels before treatment (18 +/- 9 U/l, p less than 0.01). Alkaline phosphatase levels were significantly decreased before treatment, and significantly increased after treatment. For all subjects with hyperthyroidism of hypothyroidism, the percentages of gammaglutamyl transpeptidase variations correlated with thyroxine (r = 0.48, p less than 0.003) and triiodothyronine (r = 0.39, p less than 0.016) variations. These results suggest that variations in gammaglutamyl transpeptidase levels in hyperthyroidism and hypothyroidism are, at least in part, in relation with variations in thyroid hormone levels.
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PMID:[Evolution of serum gammaglutamyl transpeptidase activity in treated hyperthyroid and hypothyroid patients]. 614 51

A profile of biochemical tests was performed on 72 patients attending a lymphoma clinic. Urinary hydroxyproline excretion was increased in 24 cases at the outset; of these ten had positive clinical or radiological evidence of bone disease at that time, and in a further ten such evidence became available over the next two years. Hepatic involvement was detected among 9 patients at the initial examination. All of these, and a further five who developed liver involvement over the next two-year period had raised activity of serum 5'-nucleotidase. Total serum alkaline phosphatase was raised in 8 of the 9 patients with initial involvement, but only 1 of the 11 patients who subsequently developed hepatic disease; the heat stability test indicated the presence of the hepatic isoenzyme in these cases. Alkaline phosphatase was raised in 10 of the 20 cases with initial or subsequent evidence of bone disease, heat stability indicating the bone isoenzyme to be predominant. Serum ornithine transcarbamoylase was raised in only 7 patients with initial hepatic involvement, and the aminotransferases were not helpful in identifying lymphomatous involvement of the liver.
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PMID:Assessment of biochemical tests for bone and liver involvement in malignant lymphoma patients. 624 83

Research on quantitative determination of activity of alkaline phosphatase (EC) 3.1.3.1) and 5'-nucleotidase (EC 3.1.3.5) of Pacinian corpuscles was performed. Two enzymes are shown to be different, which are distinguished by the pH optimum and substrate concentration. Alkaline phosphatase is found to be more active in splitting glycerophosphates. The alkaline phosphatase activity towards beta-glycerophosphate and alpha-naphthylphosphate is caused by various enzyme molecular forms with different electrophoretic mobility. The phosphatase and 5'-nucleotidase are shown to be activated by Mg2+ and Ca2+.
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PMID:[Alkaline phosphomonohydrolases of Pacinian corpuscles]. 627 Aug 57

Highly purified plasma membrane fractions have been prepared from GH3 pituitary cells grown in suspension cultures. These membrane fractions have been obtained by differential and sucrose gradient centrifugation and were characterized in terms of their lipid content, marker enzyme analysis and the binding of 3H-labelled thyrotropin-releasing hormone (TRH) to its receptor. Alkaline phosphatase and 5'-nucleotidase activities were enriched 12-to 15-fold in the plasma membrane fraction with somewhat greater enrichment (28-fold) of the specific binding component for [3H]TRH, with a specific activity of 2286 fmol [3H]TRH bound per mg protein. A single class of binding sites for TRH was observed with an apparent dissociation constant of 18 nM, a value similar to that observed for intact cells. No detectable TRH binding to the nuclear fraction was observed that could not be ascribed to residual plasma membrane contamination. By electron microscopy, these fragments appeared to be sealed vesicles with an average diameter of approximately 1800 A. The binding of 125I-labelled wheat germ agglutinin was used as a marker for plasma membrane purification. In addition to specific binding to this membrane fraction, specific binding was also observed in the nuclear fraction. Studies with fluorescein-labelled wheat germ agglutinin revealed that, in fixed cells, fluorescence was restricted to the plasma membrane. However, if the cells were treated with Triton before labelling, most of the fluorescence was then associated with the cell nucleus. Hence, the use of wheat germ agglutinin binding as a specific membrane marker must be reevaluated.
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PMID:Purification and characterization of plasma membrane fractions from cultured pituitary glands. 627 5


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