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)

The effects of fixation with various concentrations of glutaraldehyde or formaldehyde, acetone or ethanol, and freeze-drying on 5 phosphatases of Eimeria tenella and chick kidney cell cultures were demonstrated in situ. Gultaraldehyde inactivated the phosphatases more than did the formaldehyde, but the effect of the combination of the 2 (Karnovsky's fixative) was greater than that of either glutaraldehyde or formaldehyde alone. The higher the concentration of aldehyde and the longer the duration of exposure, the greater the inactivation. The order of sensitivity to aldehyde fixation of the enzymes tested was glucose-6-phosphatase greater than thiamine pyrophosphatase greater than 5'-nucleotidase greater than adenosine triphosphatase greater than acid phosphatase. Cytologic detail was preserved more efficiently with glutaraldehyde than with formaldehyde. Optimal preservation of enzyme activity for cytochemistry was with 2% glutaraldehyde for 30 min or 2% formaldehyde for 1 hr for G-6-Pase, TPPase, and 5'-nucleotidase, and with 2% glutaraldehyde or 2% formaldehyde for 2 hr with ATPase and AcPase. Quenching with subsequent fixation in cold acetone or ethanol resulted in complete inactivation of G-6-Pase, TPPase, and 5'-nucleotidase; although cells fixed in this manner yielded large amounts of reaction product for ATPase and AcPase, the distribution was diffuse, and some of it appeared to be artifactual. Quenching with subsequent freeze-drying was unsatisfactory because nearly all of the cell layers rolled off the cover glasses.
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PMID:Effect of fixation on demonstration of phosphatases of Eimeria tenella grown in chick kidney cell cultures. 6 Dec 71

Vesicular fragments of Golgi apparatus, smooth- and rough-surfaced microsomes from rat liver are differently partitioned in aqueous polymer two-phase systems consisting of dextran, polyethylene glycol, and sodium phosphate buffer. At a given polymer concentration, the amount of material partitioned in the top phase increases in the following order: rough microsomes less than smooth microsomes less than Golgi fragments. Counter-current distribution of Golgi fragments in the system consisting of 6.8% (w/w) dextran T500 and 6.8% polyethylene glycol 4,000 results in the separation of the fragments into three fractions; i.e. Fractions I, II, and III. NADH- and NADPH-cytochrome c reductase activities are detected almost exclusively in Fraction I, whereas the activities of galactosyltransferase, acid phosphatase, 5'-nucleotidase, and thiamine pyrophosphatase are maximal in Fraction III and minimal in Fraction I. The distribution of these enzymes suggests that Fraction I is similar to, though not identical with, microsomes, Fraction III resembles plasma membrane and lysosomes, and Fraction II is between the two. It is concluded that NADH- and NADPH-cytochrome c reductases are localized in a restricted region of the Golgi structure and that intra-Golgi differentiation seems to proceed in a discontinuous manner.
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PMID:Biochemical studies on rat liver Golgi apparatus. III. Subfractionation of fragmented Golgi apparatus by counter-current distribution. 9 9

1. The distributions of several enzymes and other marker components were examined after zonal centrifugations of whole homogenates from glucose-repressed Saccharomyces cerevisiae on sucrose and iso-osmotic Ficoll, and the composition and morphology of the fractions were investigated. 2. After high-speed zonal centrifugation most of the protein, acid and alkaline phosphatases, alkaline pyrophosphatase, adenosine monophosphatase, beta-fructofuranosidase, alpha-mannosidase, NADPH-cytochrome c oxidoreductase and an appreciable amount of phospholipid and sterol were non-sedimentable, i.e. were at densities below 1.09 (g/cm3). Most of the RNA was at p=1.06-1.08 in Ficoll and at p=1.09-1.11 in sucrose. 3. The bulk of the Mg2+-dependent adenosine triphosphatase (Mg-ATPase) was coincident with the main peak of phospholipid and sterol, at median density 1.10, which was also rich in smooth-membrane vesicles. In Ficoll, a minor peak of phospholipid and sterol at p-1.12-1.15 contained a smaller part of the oligomycin-insensitive Mg-ATPase and heavy membrane fragments. In sucrose, several minor peaks of Mg-ATPase were in the mitochondrial density range, and a peak of oligomycin-insensitive Mg-ATPase coincident with a minor peak of phospholipid and sterol at around p-1.25 contained heavy membrane fragments of high carbohydrate content, especially mannose. 4. Further purification of the oligomycin-insensitive Mg-ATPase containing membrane preparations was performed on Urografin gradients. 5. It is argued that the oligomycin-insensitive Mg-ATPase containing membranes are fragments of the plasma membrane, but have different densities because they contain different amounts of glycoprotein particles.
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PMID:Distribution of membranes, especially of plasma-membrane fragments, during zonal centrifugations of homogenates from glucose-repressed Saccharomyces Cerevisiae. 13 74

Although the preparation of rat liver Golgi apparatus isolated by our method contains appreciable activities of NADH- and NADPH-cytochrome c reductases and glucose-6-phosphatase, these enzymes as well as thiamine pyrophosphatase of the extensively fragmented Golgi fraction are partitioned in aqueous polymer two-phase systems quite differently from those associated with microsomes. Similarly, the partition patterns of acid phosphatase and 5'-nucleotidase of the Golgi fragments differ from those of homogenized lysosomes and plasma membrane, respectively. It is concluded that most, if not all, of these marker enzymes in the Golgi fraction cannot be ascribed to contamination by the non-Golgi organelles. In sucrose density gradient centrifugation the NADH- and NADPH-cytochrome c reductase activities of the Golgi fraction behave identically with galactosyltransferase but differently from the reductase activities of microsomes, again indicating that the reductases are inherently associated with the Golgi apparatus. NADPH-cytochrome c reductase of the Golgi preparation is immunologically identical with that of microsomes. The marker enzymes mentioned above and galactosyltransferase behave differently from one another when the Golgi fragments are subjected to partitioning in aqueous polymer two-phase systems, suggesting that these enzymes are not uniformly distributed in the Golgi apparatus structure.
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PMID:Biochemical studies on rat liver Golgi apparatus. II. Further characterization of isolated Golgi fraction. 20 81

An exocellular pyrophosphatase, active on the nucleotide precursors of peptidoglycans, has been found in the culture medium of Streptomyces mediterranei ME/R 17. This enzyme was separated from the DD-carboxypeptidase by batchwise adsorption on DEAE cellulose. The pyrophosphatase had no strict substrate requirements, it hydrolyzed various UDP-sugar substrates: UDP-GlcNAc, UDP-Mur NAc and UDP-MurNAc peptides, giving rise to the corresponding sugar phosphate and to UMP. The enzyme preparation also contained a 5'-nucleotidase activity and UMP was further split to give uridine. This nucleotidase activity was inhibited by potassium tetraborate. Both cytoplasmic and particulate preparations from cells of S. mediterranei also contained a pyrophosphatase activity while only the particulate fractions showed the DD-carboxypeptidase activity. The pyrophosphatase excretion was tested during the grwoth cycle. The activity of the enzyme showed a constant increase throughout the exponential growth and a stronger increase in the late exponential phase. Such a result could be correlated with a consumption of the nutrients in the culture medium, in fact a relatively poor culture medium had a strong positive effect upon the production of the exocellular pyrophosphatase.
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PMID:[Identification of an extracellular nucleotide pyrophosphatase in the culture media of Streptomyces mediterranei ME/R 17]. 42 55

This study has investigated the effect of prenatal alcohol exposure on the qualitative and quantitative ultrastructure of proliferating and differentiated astrocytes in primary cultures as well as on the cytochemical activity of several subcellular phosphatase markers, including acid phosphatase, uridine diphosphatase, thiamine pyrophosphatase, 5'-nucleotidase and glucose-6-phosphatase. The astrocytes were obtained from 21-day-fetuses of both control and alcohol-fed rats. Our results show that several cell components, such as mitochondria, rough endoplasmic reticulum and lysosomes, exhibit qualitative and/or quantitative ultrastructural changes during the process of astrocyte maturation. In some cases these morphological changes are accompanied by variations in the cytochemical activity of enzymes located in these and other cell components, suggesting that these enzymes, and therefore the functional state of these organelles, are modulated during astrocyte development. When prenatally exposed to ethanol, both proliferating and differentiated astrocytes showed striking ultrastructural alterations compared with controls, including an increment of lysosomes as well as a decrease in the values of stereological parameters relative to mitochondria, rough endoplasmic reticulum and Golgi apparatus. Cytochemical analysis of these cells indicates that prenatal exposure to ethanol decreased the activities of all the enzymes tested, except for acid phosphatase, which was increased in both groups of treated astrocytes. These results suggest that prenatal exposure to ethanol could affect astrocytes during development in two different but probably complementary ways: a) by causing a delay in astrocyte maturation and, b) by inducing a direct toxic effect on these cells.
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PMID:Cytochemical and stereological analysis of rat cortical astrocytes during development in primary culture. Effect of prenatal exposure to ethanol. 132 14

Cytochemical techniques associated with transmission electron microscopy were used for the localization in Tritrichomonas foetus of enzymes used as markers of different cell structures. Reaction product indicating the presence of Mg(2+)-adenosine triphosphatase (Mg(2+)-ATPase) and 5'-nucleotidase was observed in the plasma membrane. Glucose-6-phosphatase was seen in association with the endoplasmic reticulum, revealing its organization as parallel cisternae. Thiamino-pyrophosphatase was located in the cis-most region of the Golgi complex. Acid phosphatase was found within lysosomes as well as in several cisternae of the Golgi complex, in contrast to previous observations in mammalian cells. These observations provide support for the use of enzyme markers in future studies on cell fractionation of T. foetus.
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PMID:Cytochemical localization of enzyme markers in Tritrichomonas foetus. 166 35

We studied the ultrastructure and cytochemistry of mitotic parotid acinar cells in vivo after induction of mitosis by isoproterenol injection. With entrance of the cells into the division cycle, the Golgi apparatus lost its characteristic stacked structure and internal polarity among the cisternae, appearing as fragments distributed throughout the cytoplasm. These fragments consisted of electron-lucent vesiculotubular structures and electron-dense 70-nm vesicles; neither component showed thiamine pyrophosphatase activity, a marker for trans cisternae of the Golgi apparatus, but the 70-nm vesicles showed a positive reaction for osmium impregnation, indicating retention of the cis nature. The rough endoplasmic reticulum was dilated and fragmented. Recovery of the structure of Golgi apparatus and rearrangement of rough endoplasmic reticulum occurred in daughter cells during telophase. These changes were the same as those observed after drug-induced inhibition of protein transport. The secretory granules were not dispersed but were divided into two groups with which centrioles were closely associated. Both groups migrated with the centrioles as far as the next interphase. The distribution of 5'-nucleotidase on the luminal plasma membrane showed no change during the process of division, thus demonstrating that surface polarity was maintained during mitosis. These changes in organelle structure and distribution may be due to the conversion of cell function from a secretory to a mitotic action.
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PMID:Changes in cell polarity during mitosis in rat parotid acinar cells. 185 56

Horseradish peroxidase (HRP, 10 mg/100 g body weight) was intravenously injected into rats in order to investigate the nature of the compartments involved in the transcellular transport of the protein through hepatocytes into bile. Double cytochemistry for HRP and the marker enzymes for cytoplasmic organelles was used. HRP was shown to be taken up by hepatocytes via vesicles at the sinusoidal surface, some of which were positive for 5'-nucleotidase activity. HRP was then found in the smooth-surfaced vesicles and tubules which were negative in 5'-nucleotidase, glucose 6-phosphatase, thiamine pyrophosphatase and acid phosphatase activity, suggesting that the tubular structures are neither the endoplasmic reticulum, the Golgi apparatus nor lysosomes. Biochemical studies revealed that the lead procedures used for the double cytochemistry did not inhibit the peroxidatic activity of HRP, and conversely that HRP did not interfere with the marker enzyme activity. Such cytochemical observations seemed to be supported by the observation that administration of monensin (3.5 mg/100 g) and chloroquine (5 mg/100 g), which markedly altered the structure of the Golgi apparatus and lysosomes, respectively, slightly altered the biliary excretion of HRP but not to a significant extent.
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PMID:Cytochemical examination of the compartments involved in the transcellular transport of horseradish peroxidase in rat hepatocytes. 208 41

An enzyme with FAD pyrophosphatase activity was extracted from human placental syncytiotrophoblast microvilli and purified to near-homogeneity. The enzyme has been identified as 5'-nucleotidase by several criteria. Throughout purification, parallel increases in the specific activities of FAD pyrophosphatase and AMP phosphatase were observed. The enzyme was a glycoprotein with a subunit molecular weight of 74,000. EDTA treatment resulted in a marked decline in both activities, and restoration of FAD pyrophosphatase activity but not 5'-nucleotidase activity was accomplished by the addition of Co2+ or, to a lesser extent, Mn2+. The substrate specificity of the 5'-nucleotidase activity that we observed agreed closely with the results of others. The pyrophosphatase activity was relatively specific for FAD. ADP, ATP, NAD(H), and FMN were not hydrolyzed, and ADP strongly inhibited both activities. For FAD pyrophosphatase activity, a Km of 1.2 x 10(-5) M and a Vmax of 1.1 mumol/min/mg protein were determined in assays performed in the presence of Co2+. In the absence of added Co2+, the Vmax declined but the Km was unchanged. For 5'-nucleotidase (AMP as substrate) the Km was 4.1 x 10(-5) M and the Vmax 109 mumol/min/mg protein. Hydrolysis of FMN to riboflavin was observed in partially purified detergent extracts of microvilli that contained alkaline phosphatase activity and lacked FAD pyrophosphatase and 5'-nucleotidase activity. The presence of both FAD pyrophosphatase and FMN phosphatase activities in syncytiotrophoblast microvilli supports the view that the placental uptake of vitamin B2 involves the hydrolysis of FAD and FMN to riboflavin which is then absorbed, a sequence postulated for intestinal absorption and liver uptake.
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PMID:5'-Nucleotidase of human placental trophoblastic microvilli possesses cobalt-stimulated FAD pyrophosphatase activity. 284 89


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