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

---

Query: EC:3.1.3.5 (5'-nucleotidase)
3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The objective of this investigation was to find out whether vitamin E deficiency, apart from influencing the lipid component of cellular membranes, also influences the protein component. For that purpose a number of membrane-bound enzymes in the liver of the Pekin duckling were histochemically, cytochemically, and biochemically examined. Furthermore, cells, cellular membranes, and protein particles in membranes were morphometrically investigated. Histochemically five membrane-bound enzymes appeared to be stimulated in vitamin E deficiency: 5'-nucleotidase, glucose-6-phosphatase, isocitrate dehydrogenase (NADP), tetrazolium reductase (NADH), and tetrazolium reductase (NADPH). 5'-Nucleotidase and glucose-6-phosphatase were also investigated cytochemically and biochemically. The cytochemical localization of these enzymes was identical in control and vitamin E-deficient ducklings. Biochemically, a stimulation of these two enzymes also could be demonstrated. The increase per milligram of DNA appeared to be largest whereas the increase per milligram of protein, per milligram of phospholipid, and per milligram of RNA was only half of the increase per milligram of DNA. This can be explained by the 30 per cent increase of the cell volume in vitamin E deficiency leading to an increase of protein, phospholipid, and RNA per cell. The thickness of membranes and the diameter of protein particles in membranes were measured in liver parenchymal cells. In vitamin E deficiency the thickness of the outer mitochondrial membrane and the diameter of protein particles in this membrane were smaller whereas the thickness of the endoplasmic reticular membrane was larger. The increase of the activities of mitochondrial and microsomal enzymes and the decrease of the thickness of the outer mitochondrial membrane and of its protein particles are interpreted to be the result of the influence of free radicals on membranes with electron transport functions. The increase of 5'-nucleotidase activity in the plasma membrane is likely to have a different cause; it may be related to the transport of nucleotides across this membrane.
...
PMID:Cellular membranes and membrane-bound enzymes in vitamin E deficiency. A histochemical, cytochemical, biochemical, and morphologic study of the liver of the Pekin duckling. 16 37

A method is described for the isolation of secondary lysosomes from homogenates of rabbit liver; The uptake of Triton WR-1339 by rabbit-liver lysosomes when administered by intraperitoneal injection was used to decrease the density of secondary lysosomes. Lysosomal fractions prepared by this method contain an NAD nucleosidase (NAD glycohydrolase, EC 3;2.25), an enzyme which has previously been considered to be associated with other subcellular fractions. The enzyme has maximum activity at pH 6 and cleaves both NAD and NADP. It is inhibited by nicotinamide (Ki equals 4.5 mM) and by HgCl2. Both nucleosidase and 2'-nucleotidase show in-vitro latency typical of lysosomal acid hydrolases. Rabbit-liver plasma-membrane fractions were isolated which contained most 5'-nucleotidase but relatively little nucleosidase, whereas rabbit liver lysosomes contain both 5'-nucleotidase and nucleosidase enzymes but little adenyl cyclase.
...
PMID:Evidence for NAD nucleosidase in rabbit-liver lysosomes. 23 77

Dehydroepiandrosterone (DHEA) treatment is effective in preventing or delaying the onset of various genetic and induced disorders of mice and rats. Associated with the beneficial therapeutic effects exerted by action of this steroid is the development of hepatomegaly. To determine whether the changes associated with hepatomegaly also involve alterations in activities of tissue enzymes, we evaluated the effects of DHEA (0.45% in food, w/w) on hepatic protein kinases, phosphatases, and lipogenic enzymes in mice of various strains. The rates of fatty acid and cholesterol syntheses also were evaluated. DHEA administration resulted in profound changes in the sodium dodecylsulfate-polyacrylamide gel electrophoresis patterns of endogenous radiophosphorylated proteins obtained by incubation of liver homogenates with (gamma-32P]ATP. These changes were dependent upon the medium used for homogenization. Thus, when homogenates of liver tissue of DHEA-treated mice were prepared in Tris buffer containing sucrose (0.25 M) there was a marked decrease in phosphorylation of the proteins of relative molecular weight approximately 116,000 (Mr approximately 116,000), approximately 82,000, approximately 80,000, approximately 58,000, approximately 56,000, approximately 48,000, approximately 34,000, and approximately 31,000 compared with controls. With liver homogenates of DHEA-treated mice prepared in Tris buffer alone, there was a marked increase in phosphorylation of the proteins of Mr approximately 70,000, approximately 49,000, approximately 34,000, approximately 31,000, and 28,000 compared with controls. Moreover, the specific activity of kinases for endogenous protein acceptors in liver of control mice was higher than that in liver of DHEA-treated animals. The specific activities of casein kinase, cAMP-dependent protein kinase, and cGMP-dependent protein kinase remained unchanged with DHEA treatment, but the specific activity of histone kinase was increased approximately 30%. Long-term administration of DHEA also was associated with increases in the specific activities of liver AMPase and GTPase (approximately two times), but not of other nucleotidases, alkaline phosphatase, acid phosphatase, glucose-6-phosphatase, or phosphotyrosine phosphatase. The activity of hepatic NADP-linked malic enzyme was increased significantly (two to three times) by DHEA treatment of female mice of three different strains, but was unchanged in male C57BL/6 mice. The specific activities of hepatic glucose-6-phosphate dehydrogenase, NADP-linked isocitrate dehydrogenase, and ATP-citrate lyase were not affected significantly by DHEA treatment of mice. The rate of hepatic lipogenesis, determined by incorporation of tritium from 3H2O into fatty acids, was decreased approximately 70% in DHEA-treated mice, while the rate of cholesterol synthesis was increased approximately 44% compared with controls.
...
PMID:Dehydroepiandrosterone feeding and protein phosphorylation, phosphatases, and lipogenic enzymes in mouse liver. 215 82

In order to ascertain the pathogenesis of myocardial cell vulnerability in spontaneously hypertensive rats (SHR), several enzyme activities were examined by using subcellular fractions of myocardium and compared to those in Wistar-Kyoto rats (WKY). In the normotensive WKY heart, both 5'-nucleotidase and Na+/K(+)-ATPase, which are plasma membrane associated enzymes, increased with age. But in the SHR heart, both enzymes were lower at 16 weeks than they were at 10 weeks of age. Moreover, at 16 weeks of age they were lower in SHR than in WKY. On the other hand, NADP(+)-isocitrate dehydrogenase activity, a mitochondria associated enzyme, was higher in SHR than in WKY at 6 weeks, but lower at 10 and again at 16 weeks of age. The activities of both acid phosphatase and N-acetyl-beta-glucosaminidase, which are lysosomal enzymes, decreased with age in SHR but not in WKY. These results suggest that an enzymatic alteration in the plasma membrane and mitochondria may be one of important factors behind myocardial vulnerability in the SHR heart.
...
PMID:Some enzyme characteristics of spontaneously hypertensive rats myocardium. 223 22

A simple and reliable procedure for removal of AMP from NADP preparation is described. In this procedure, a mixture of AMP and NADP solution is first incubated with 5'-nucleotidase to hydrolyze AMP to adenosine and inorganic phosphate (Pi). The reaction mixture is then applied to a Dowex 1 (formate) column. Adenosine and 5'-nucleotidase are removed by washing the column with 20 mM HCOOH. NADP is finally eluted with 3.5 M HCOOH followed by precipitation and washing with acetone. The yield of salt-free NADP is about 80%. Although Pi is coeluted with NADP in the acid form (H3PO4), it is removed during the precipitation and repeated washing with acetone. A slight modification of this procedure for simultaneous removal of AMP, ADP, and ATP from NADP preparation has also been discussed.
...
PMID:Simple procedure for removal of AMP from NADP preparation. 299 3

A spectrophotometric method is described for the determination of 5'-nucleotidase. In combination with the enzymes nucleoside phosphorylase and xanthine oxidase, inosine, formed by hydrolysis of 5'-IMP by 5'-nucleotidase, is cleaved phosphorolytically to hypoxanthine, which is oxidized to uric acid. In the presence of ethanol, the hydrogen peroxide formed is reduced by catalase and equivalent amounts of acetaldehyde are produced. The aldehyde is dehydrogenated (NADP-dependent) by aldehyde dehydrogenase and the production rate of NADPH is recorded at 334 nm. The inhibition of the unspecific cleavage of 5'-IMP by phosphatases is examined critically.
...
PMID:A new spectrophotometric method for the determination of 5'-nucleotidase. 625 57

The continuous spectrophotometric assay of 5'-nucleotidase originally described by Heinz et al. ((1980) J. Clin. Chem. Clin. Biochem. 18, 781-788) was modified and fully automated on a Kem-O-Mat transfer analyzer, using inosine 5'-monophosphate as substrate. The reaction product was hydrogen peroxide and the reduction of NADP was observed for 10 minutes at 340 nm and at a reaction temperature of 30 degrees C. The different factors involved in the enzyme reaction were checked, including the substrate concentration, reaction rate, linearity and substrate preservation. Normal values ranged from 1 to 13 U/l. Between-day reproducibility was estimated with two different commercial control sera, and the coefficient of variation was 5% for the upper limit of normal activity (23 U/l). There was good agreement between the present method and a semi-automatic colorimetric technique (for 100 sera tested by both methods, the correlation coefficient was 0.974 and the regression line equation, y = 0.85 x- 1.5). Despite the lengthy reagent mixture preparation procedure, the method permitted assay of 50 samples per hour. The occurrence of high serum blanks in certain pathological states is discussed.
...
PMID:Continuous assay of serum 5-nucleotidase activity with inosine 5'-monophosphate as substrate and total automation using a transfer-analyzer (Kem-O-Mat). 631 43

In the framework of the international project aimed at the sequencing of the Bacillus subtilis genome, a 40.6 kb chromosome segment, which contains the tre locus, has been cloned and sequenced. This region (40 601 bp; 73 degrees-76 degrees on the genetic map) contains 38 complete ORFs and one partial one. Three ORFs, the closest to the hsdC locus, correspond to the treP, treA and treR genes encoding enzyme IITre, trehalose-6-phosphate hydrolase and the repressor of the tre operon, respectively. A homology search for the products deduced from the 39 ORFs revealed that 23 exhibit significant similarity to known proteins, e.g. proteins involved in acetoin utilization, deoxyribonuclease, methyladenine glycosidase, hydroxyisobutyrate dehydrogenase, multidrug resistance proteins, protein phosphatase, cyclic-nucleotide phosphodiesterase, 5'-nucleotidase and NADP(H)-flavin oxidoreductase. Based on the gene organization and the results of the homology search, it is predicted that YfjG, YfjH, YfjI, YfjJ and YfjK form an acetoin dehydrogenase system (acetoin regulatory protein, and acetoin dehydrogenase components/subunits E3, E2, E1 beta and E1 alpha respectively). yfkN, an extremely large ORF comprising 4386 nucleotides, seems to correspond to the fusion of the genes for 2',3'-cyclic-nucleotide 2'-phosphodiesterase and 5'-nucleotidase precursor.
...
PMID:Cloning and sequencing of a 40.6 kb segment in the 73 degrees-76 degrees region of the Bacillus subtilis chromosome containing genes for trehalose metabolism and acetoin utilization. 896 3

Exogenous NAD utilization or pyridine nucleotide cycle metabolism is used by many bacteria to maintain NAD turnover and to limit energy-dependent de novo NAD synthesis. The genus Haemophilus includes several important pathogenic bacterial species that require NAD as an essential growth factor. The molecular mechanisms of NAD uptake and processing are understood only in part for Haemophilus. In this report, we present data showing that the outer membrane lipoprotein e(P4), encoded by the hel gene, and an exported 5'-nucleotidase (HI0206), assigned as nadN, are necessary for NAD and NADP utilization. Lipoprotein e(P4) is characterized as an acid phosphatase that uses NADP as substrate. Its phosphatase activity is inhibited by compounds such as adenosine or NMN. The nadN gene product was characterized as an NAD-nucleotidase, responsible for the hydrolysis of NAD. H. influenzae hel and nadN mutants had defined growth deficiencies. For growth, the uptake and processing of the essential cofactors NADP and NAD required e(P4) and 5'-nucleotidase. In addition, adenosine was identified as a potent growth inhibitor of wild-type H. influenzae strains, when NADP was used as the sole source of nicotinamide-ribosyl.
...
PMID:NADP and NAD utilization in Haemophilus influenzae. 1076 Jan 56

The present study was undertaken to identify potentially immunoreactive proteins of the muscle larvae (ML) and adult stage (Ad) of the nematode Trichinella spiralis Owen, 1835. To identify immunoreactive proteins that are specifically recognised by anti-Trichinella antibodies, ML and Ad crude extracts and their excretory-secretory (E-S) products were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot with serum samples from pigs experimentally infected with T. spiralis. A total of 18 bands were selected for final identification by liquid chromatography-tandem mass spectrometry. To further understand the functions of the proteins identified in this study, gene ontology terms were applied. Results showed that the specific antibodies against T. spiralis reacted with protein bands matching heat shock proteins, aminopeptidase, enolase, isocitrate dehydrogenase NADP-dependent, tropomyosin, P49 antigen, serine proteinase, secreted 5'-nucleotidase, antigen targeted by protective antibodies, 53 kDa E-S antigen, putative trypsin and paramyosin. Three proteins common for both adult stage and muscle larvae, including heat shock proteins, enolase and 5'-nucleotidase, might play important role during T. spiralis infection. These proteins are presumably presented to the host immune system and may induce humoral immune response. Thus, these proteins may be potential antigens for early diagnosis and the development of a vaccine against the parasite.
...
PMID:Proteomic analysis of potential immunoreactive proteins from muscle larvae and adult worms of Trichinella spiralis in experimentally infected pigs. 2596 May 66


1 2 Next >>

---