Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In vivo administration of cyclosporin A (CyA) was found to determine some variations in nucleotide content of rat lymphocytes. ATP levels were reduced by CyA treatment, and the effect was more evident in peripheral blood than in spleen lymphocytes. In contrast, cAMP values were increased upon pharmacologic treatment with the same major evidence at the blood lymphocyte level. Intralymphocytic phosphodiesterase enzyme activity became detectable during CyA administration, whereas the intracellular redox state (NAD+/NADH ratios) did not vary significantly. These results were amplified by increasing CyA concentration.
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PMID:The effect of cyclosporine on nucleotide content of rat lymphocytes. 300 Sep 62

Nucleotide pyrophosphatase was purified from human placenta to near homogeneity with a specific activity of about 500-fold over the Triton extract of the homogenate. Purification was achieved most effectively by successive chromatographic steps with AMP-agarose and ADP-agarose columns, based on the affinity of the enzyme towards 5'-adenylate and adenosine 3',5'-diphosphate, and a lectin-Sepharose column, based on the glycoprotein nature of the enzyme. The purified enzyme was found to be essentially homogeneous on SDS-polyacrylamide gel electrophoresis with a mobility corresponding to 130K. The purified enzyme was found to hydrolyze a wide variety of nucleotides, i.e. 3'-phosphoadenosine 5'-phosphosulfate (PAPS), adenosine 5'-phosphosulfate (APS), NADH, ATP, nucleotide sugars, oligonucleotides, and p-nitrophenyl-thymidine 5'-phosphate (PNTP). From the oligonucleotides, the enzyme produced 5'-phosphates. Mg2+ was required for full activity. Glycine and sulfhydryl compounds such as 2-mercaptoethanol and 2,3-dimercapto-1-propanol were inhibitory. Most of these properties are common to nucleotide pyrophosphatases [EC 3.6.1.9] and type I (5'-phosphate forming) phosphodiesterases [EC 3.1.4.1] from various sources. The relevance of this enzyme to a unique genetic disease, Lowe's syndrome, is discussed.
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PMID:Purification and properties of nucleotide pyrophosphatase from human placenta. 300 Oct 38

Many reports indicate that anaesthesia affects several immunological functions that decrease the immune response, but the mechanisms involved are still unknown. We investigated the in vitro effect of halothane on human lymphocyte metabolism and plasma membrane function by evaluating the intracellular concentration of 3',5'-cyclic adenosine-monophosphate (cAMP), phosphodiesterase enzyme activity, NAD+/NADH intralymphocytic ratios and the degree of antibody and lectine-induced 'capping' of surface markers. Our results demonstrated an impaired lymphocyte capping of surface immunoglobulins and concanavalin A receptors 60 min after exposure to halothane at the concentration of 1% in oxygen. This phenomenon was reversible after 24 h and it was unrelated to the presence of adherent cells during the culture. Furthermore, halothane was able to induce a persistent increase in cAMP intracellular concentrations, which was reversible within 48 h. This effect was not dependent on adherent cells or on phosphodiesterase enzyme inhibition. Finally, no alteration in NAD+/NADH ratios after halothane exposure was observed.
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PMID:In vitro effects of halothane on lymphocytes. 302 44

In studies designed to reexamine the in vivo occurrence of retinyl phosphate mannose we injected hamsters intraperitoneally with either [2-3H]mannose or [15-3H]retinol and sacrificed the animals 15 min later. The small intestine was removed, the epithelial cells were scraped, and a methanolic extract of the labeled cells was prepared and chromatographed on a Mono Q anion-exchange column. Intraperitoneal administration of either [2-3H]mannose or [15-3H]retinol lead to the formation of a tritium-labeled anionic compound with a retention time on the Mono Q column similar to that of standard retinyl phosphate mannose. However, the biochemical properties of this labeled anionic compound were those expected of an organic acid and not retinyl phosphate mannose. The compound was resistant to both strong acid hydrolysis and mild base hydrolysis, as well as digestion with alpha- or beta-mannosidase, phosphodiesterase I, nucleotide pyrophosphatase, or beta-glucuronidase. When chromatographed on an Aminex HPX-87H organic acid analysis column or a silicic acid column the labeled anionic compound derived from either [2-3H]mannose or [15-3H]retinol comigrated with standard lactic acid. Treatment of the anionic compound derived from [2-3H]mannose with lactate oxidase or L-lactate 2-monooxygenase resulted in the formation of a tritium-labeled product that cochromatographed, respectively, with pyruvate or acetate on the Aminex HPX-87H column. However, treatment of the anionic compound derived from [15-3H]retinol with these same two enzymes resulted in a labeled product that migrated on the Aminex column at the same position as tritiated water. This result demonstrated that the labeled hydrogen was removed during enzymatic digestion and suggested that it was present on the second carbon of lactic acid. During the course of these studies no evidence for the in vivo labeling of a compound with the properties of retinyl phosphate mannose was found. Since [2-3H]mannose leads to labeled lactic acid in vivo the tritium label must not always be lost, as expected, during the entry step into glycolysis in which mannose 6-phosphate is converted to fructose 6-phosphate. The results suggest that an intramolecular hydrogen transfer from the C-2 position of mannose 6-phosphate to the C-1 position of fructose 6-phosphate can occur during the phosphomannose isomerase reaction. The finding that the position of the tritium label on lactic acid derived from [15-3H]retinol is on the second carbon is consistent with it coming from NADH labeled with tritium in the transferable hydrogen which was formed intracellularly during the NAD+-linked oxidation of retinol to retinaldehyde.
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PMID:In vivo formation of tritium-labeled lactic acid from [2-3H]mannose or [15-3H]retinol by hamster intestinal epithelial cells. 357 14

Escherichia coli was grown in chemostat culture under glycerol-limited and ammonium-limited conditions at growth rates between 0.1 and 0.5 h-1. At steady state, the concentrations of cyclic AMP and cyclic GMP and the activities of four constitutive enzymes (glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, NADH oxidase and cyclic phosphodiesterase) were determined in the organism. Addition of exogenous cyclic AMP, cyclic GMP or phencyclidine perturbed the steady state and caused inhibition or stimulation of synthesis of phosphodiesterase and isocitrate dehydrogenase. A novel hypothesis is proposed to account for the ability of bacteria to regulate the synthesis of constitutive enzymes with cyclic nucleotides and possibly other small molecules.
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PMID:Cyclic AMP and cyclic GMP control of synthesis of constitutive enzymes in Escherichia coli. 628 44

Distribution of specific binding sites for [3H]nitrendipine was studied in subcellular fractions isolated from rat gastric fundus smooth muscle and from rat myometrium. There was an excellent correlation between the distribution of [3H]nitrendipine binding determined at the nitrendipine concentrations of 0.138 and 1.38 nM, and the distribution of the plasma membrane markers K+-activated ouabain-sensitive p-nitrophenylphosphatase, 5'-nucleotidase, phosphodiesterase I, and Mg-ATPase, but not between the mitochondrial markers cytochrome c, oxidase, succinate-dependent cytochrome c reductase, or rotenone-insensitive NADH-dependent cytochrome c reductase or the putative endoplasmic reticulum marker NADPH-dependent cytochrome c reductase. The binding occurred with high affinity and with a similar (0.097-0.146 nM) equilibrium dissociation constant to all the fractions, even though the density of binding sites varied and was highest in the plasma membrane marker-enriched fractions. The maximal binding in the plasma membrane-enriched fraction from the rat gastric fundus smooth muscle was 0.43 +/- 0.04 pmol/mg, and in that from rat myometrium was 0.72 +/- 0.09 pmol/mg. Thus in the two smooth muscles studied the plasma membrane is the locus of the high affinity nitrendipine binding.
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PMID:Subcellular distribution of [3H]nitrendipine binding in smooth muscle. 632 63

Lymph node cell homogenates were fractionated by differential or isopycnic centrifugation and the fractions analyzed for biochemical markers with particular focus on plasma membrane constituents. Markers for the nucleus (DNA), mitochondria (cytochrome oxidase), and lysosomes (acid hydrolases) showed the expected distributions which were different from those of membrane-bound enzymes. 5'-Nucleotidase, alkaline phosphodiesterase, gamma-glutamyltranspeptidase, and cholesterol were membrane-bound and distributed identically after isopycnic centrifugation with peaks at 1.15. The distributions of the enzymes were all shifted to higher densities by digitonin treatment, confirming their association with plasma membrane-derived elements. The distribution of galactosyltransferase (ovalbumin acceptor), largely overlapped those of plasma membrane markers but it was only slightly shifted by digitonin, suggesting its localization in Golgi apparatus. The distribution of mannosyltransferase (dolichyl phosphate acceptor) also overlapped those of plasma membrane and Golgi markers but it was centered at higher density (1.18) and was unaffected by digitonin. It is a useful marker for endoplasmic reticulum. 50% of the activity was in low speed "nuclear" sediments where it was associated with the nuclear membrane. A number of other putative and previously used markers for the endoplasmic reticulum of lymphocytes were shown not to be localized in these membranes. In particular, NADH-cytochrome c reductase was only partly associated with the endoplasmic reticulum (56%) and the remainder of the activity was in mitochondria (44%). The results show the heterogeneity in equilibrium density of plasma membrane vesicles and the considerable overlap of their distribution with those of other cellular membranes; they should provide a basis for the more rational design of preparative procedures for the lymphocyte plasma membrane.
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PMID:Characterization of rat lymphocyte cell membranes by analytical isopycnic centrifugation. 660 29

Polymorphonuclear leucocytes were isolated from pig blood relatively free from other cells and were characterised biochemically and morphologically and compared with human PMNLs. The activities of 16 enzymes of porcine and human PMNLs were measured and compared. Alkaline phosphatase, acid phosphatase, phosphodiesterase, gamma-glutamyl transpeptidase, NADH-cytochrome c oxidoreductase, malate dehydrogenase and acetylcholinesterase had higher specific activities in procine than in human cells. Alkaline phosphatase has an 87-fold higher specific activity in porcine than in human cells. beta-glucuronidase, lysozyme, beta-galactosidase, N-acetyl-glucosaminidase, beta-glucosidase, myeloperoxidase and catalase had higher specific activities in human than in porcine cells. beta-glucuronidase and myeloperoxidase showed over a 1000- and a 13-fold higher specific activity, respectively, in human than in porcine cells. Porcine PMNLs are readily available in large numbers and are recommended for studies of phagocytosis, chemotaxis and membrane biochemistry.
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PMID:Biochemical characterisation of porcine polymorphonuclear leucocytes: comparison with human polymorphonuclear leucocytes. 687 22

Homogenates of the posterior latissimus dorsi muscle, a phasic muscle, were fractionated by a one-step zonal centrifugation technique into four major organelle populations and cytoplasmic constituents. These were: (1) Plasma membrane fragments with a modal equilibrium density of 1.10 and containing 5'-nucleotidase, alkaline phosphodiesterase, p-nitrophenylphosphatase and acid phosphatase (beta-glycerophosphate was used as the substrate). (2) Sarcoplasmic reticular fragments which could be further subdivided into calcium transport vesicles, with a model equilibrium density of 1.16, that exhibited calcium uptake; K+-ATPase; leucyl-bet-naphthylamidase; acid phosphodiesterase; acid phosphatase (using cytidine monophosphate as the substrate); and sarcoplasmic reticular lysosomes, with a model equilibrium density of 1.18, possessing dipeptidyl-aminopeptidase II, cathepsin D, alpha-glucosidase, N-acetyl-beta-glucosaminidase, and NADH oxidase activity. (3) Mitochondria with a modal equilibrium density of 1.21. (4) Catalase-containing vesicles with a modal equilibrium density of 1.22; and cytoplasmic constituents (modal density of 1.25) with phosphorylase, pyruvate kinase, myosin-ATPase, aldolase, and protein and RNA content. The purity of these organelles was equal to or better than previous efforts, with a 30-fold purification achieved for 5'-nucleotidase and alkaline phosphodiesterase. These results lend support to the hypothesis that the sarcoplasmic reticulum of phasic muscle, in addition to its specialized role in excitation-contraction coupling, represents a multifunctional membrane system, and that, similar to the smooth endoplasmic reticulum of other cells, it includes some membrane-bound lysosomal enzymes and NADH oxidase.
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PMID:Isopycnic-zonal centrifugation of plasma membrane, sarcoplasmic reticular fragments, lysosomes, and cytoplasmic proteins from phasic skeletal muscle. 721 87

A plasma membrane fraction from Malpighian cells has been isolated by differential and density gradient centrifugation of a pig epidermal homogenate. It was enriched in the marker enzymes 2-naphthylamidase, 5'-nucleotidase, phosphodiesterase I and acid phosphatase and depleted of NADH-ferricyanide reductase and cytochrome c oxidase. It had a protein to lipid ratio of 3:2 by weight. The protein composition was complex with compounds ranging from a molecular weight of 150,000 down to 13,000. Major components with molecular weights 120,000 to 90,000 were glycoproteins. Two other components had molecular weights of 39,000 (actin ?) and 24,000. There were minor components with molecular weights from 63,000 to 46,000. About 76% of the total lipid was present as phospholipid, which was enriched in sphingomyelin. Most of the neutral lipids were accounted for by cholesterol, triacylglycerols and fatty acids: very little glycosphingolipid was present. The preparation was probably derived from non-desmosomal areas of the plasma membrane of Malpighian cells, as desmosomes were not seen in the preparation.
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PMID:The plasma membrane of Malpighian cells from pig epidermis: isolation and lipid and protein composition. 743 17


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