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:3.1.4.1 (phosphodiesterase)
18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of this study was to try to differentiate histochemically between the various enzymes which may catalyze the hydrolysis of ATP in developing rat dental tissues. Freeze cut and freeze dried sections of molar and incisor teeth were incubated in lead capture-based media at pH 5.0, 7.2 or 9.4 with one of the following substrates: beta-glycerophosphate, AMP, ADP, ATP, AMP-PNP and tetrasodium pyrophosphate. To establish the enzymatic nature of the hydrolysis parallel sections were incubated after prior fixation in either formaldehyde or glutaraldehyde. By comparing the enzymatic stainings obtained with the various substrates and at the different pH:s, it was concluded that ATP can be visibly hydrolyzed in rat dental tissues by alkaline phosphatase (stratum intermedium, apical part of maturation ameloblasts, basal part of all ameloblasts, odontoblasts and subodontoblastic layer), specific ATPase (apical and basal parts of secretory ameloblasts) and ATP pyrophosphatase and/or adenylate cyclase (stratum intermedium, odontoblasts). Acid phosphatase, specific ADPase, 5'-nucleotidase, inorganic pyrophosphatase, 3':5'-cyclic-AMP-phosphodiesterase and adenylate kinase on the other hand, seem not to be engaged in the ATP hydrolysis to such a degree as to complicate the interpretation of the histochemical staining. The alkaline phosphatase part of the ATP hydrolysis appeared to be rather insensitive to aldehyde fixation, while the hydrolysis effected by specific ATPase and ATP pyrophosphatase and/or adenylate cyclase was extinguished after fixation with formaldehyde for 4 h or glutaraldehyde for 10 min.
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PMID:Adenosine triphosphate hydrolysis in rat dental tissues. A histochemical study to differentiate the enzymes involved. 18 60

This study demonstrates the postsynaptic localization of one of the isozymes of cyclic nucleotide phosphodiesterase (PDE) activity at asymmetrical, axospinous terminals in the rat corpus striatum and neocortex. Characterization of this enzymatic activity demonstrates that the PDE form surviving aldehyde fixation for electron cytochemistry can be considered to preferentially hydrolyze cyclic 3'5'-guanosine monophosphate, and it requires calcium and a heat-stable calcium-dependent regulator protein (CDR) for full hydrolytic activity. Ion exchange chromatographic analysis of extracts of corresponding unfixed brain regions demonstrates that only one enzyme activity peak exhibits similar aldehyde resistance and calcium and regulator protein activatibility.
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PMID:Biochemical characterization of postsynaptically localized cyclic nucleotide phosphodiesterase. 22 34

The effect of salt stress on glycine betaine-binding activity has been investigated in periplasmic fractions released from Rhizobium meliloti 102F34 by cold osmotic shock. Binding activity was monitored by three techniques: equilibrium dialysis, filter procedure, and detection of 14C ligand-protein binding by direct non-denaturing polyacrylamide gel electrophoresis (PAGE) followed by autoradiography. The three methods demonstrated the existence of a strong glycine betaine-binding activity, but only in periplasmic fractions from cells grown at high osmolarity. The non-denaturing PAGE of such periplasmic shock fluids mixed with [methyl-14C]glycine betaine showed only one radioactive band, indicating the involvement of one glycine betaine-binding protein. To determine the possible implication of this binding protein in glycine betaine uptake, transport activity was measured with cells submitted to cold osmotic shock. No significant decrease of transport activity was noticed. This lack of effect could be explained by the small quantity of periplasmic proteins released as judged by the low activity of phosphodiesterase, a periplasmic marker enzyme, observed in the shock fluid. The specificity of binding was analysed with different potential competitors: other betaines such as gamma-butyrobetaine, proline betaine, pipecolate betaine, trigonelline and homarine, or amino acids like glycine and proline, did not bind to the glycine betaine-binding protein, whereas glycine betaine aldehyde and choline were weak competitors. Optimum pH for binding was around 7.0, but approx. 90% of the glycine betaine-binding activity remained at pH 6.0 or 8.0. The calculated binding affinity (KD) was 2.5 microM. Both glycine betaine-binding activity and affinity were not significantly modified whether or not the binding assays were done at high osmolarity. A 32 kDa osmotically inducible periplasmic protein, identified by SDS-PAGE, apparently corresponds to the glycine betaine-binding protein.
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PMID:Identification of an osmotically induced periplasmic glycine betaine-binding protein from Rhizobium meliloti. 184 27

The mechanism by which tripeptide aldehyde proteinase inhibitors decrease prolactin (PRL) and growth hormone (GH) secretion was studied. Agents known to modify the intracellular levels of cyclic adenosine monophosphate (cAMP) or cytosolic free calcium were used in monolayer cultures of the rat anterior pituitary gland. The phosphodiesterase inhibitor isobutyl-methylxanthine (IBMX), 8-bromo-cAMP and forskolin all stimulated PRL release. Boc-D-Phe-Pro-arginal (Boc-DPPA) at 1 mmol/l concentration was a potent inhibitor of basal PRL release and significantly decreased the effect of 8-Br-cAMP, forskolin or IBMX (0.5 mmol/l). Forskolin (1 mumol/l) stimulated ACTH, PRL and GH release and all these effects were decreased by 100 mumol/l of Boc-D-Phe-Phe-lysinal (Boc-DPPL). Neither tripeptide aldehyde affected the forskolin-induced rise in intracellular cAMP. Growth hormone releasing factor (hpGRF, 1 nmol/l) stimulated both GH release and intracellular cAMP generation; Boc-DPPL (100 mumol/l) significantly decreased stimulated GH release without affecting cAMP accumulation. Increasing medium K+ to 10 times normal level stimulated PRL release presumably by enhancing Ca2+ entry into the cells and 1 mmol/l Boc-DPPA decreased high potassium-stimulated PRL release. The ionophore A-23187 stimulated PRL release at 10 mumol/l but not at 1 mumol/l. At 1 mumol/l A-23187 prevented the Boc-DPPA-induced inhibition of PRL release. These findings suggest that the tripeptide aldehyde proteinase inhibitors inhibit PRL and GH release at a site beyond cAMP formation.
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PMID:Is calcium or cyclic AMP involved in the inhibitory effect on pituitary hormone secretion of the tripeptide aldehyde proteinase inhibitors? 244 48

Condensation products (CP) of the ethanol metabolite, acetaldehyde, and endogenous amines, such as dopamine and serotonin, have been proposed to be effectors of some symptoms of chronic ethanol use. Since hemostatic defects are known to occur in chronic ethanol use, the effects of CP on in vitro human platelet aggregation responses induced by several agents were determined. Both isoquinoline and beta carboline type CP significantly inhibited aggregation responses induced by epinephrine, with the concentrations to produce 50% inhibition ranging from 8-347 uM. The beta-carbolines significantly inhibited ADP-induced aggregation and also inhibited aggregation induced by collagen or arachidonic acid, but at high concentrations. Effects on epinephrine aggregation and ADP aggregation were reversible. Potential mechanisms of the inhibitory effects were briefly examined. Concomitant use of the phosphodiesterase inhibitor theophylline potentiated the effect of some but not other CP, possibly indicating an involvement of cyclic AMP. Concomitant use of the non-specific beta-adrenergic inhibitor propranolol had no effect on CP inhibition, indicating that CP probably do not stimulate platelet adenylyl cyclase-coupled beta 2-adrenoceptors. Thus, general inhibition by CP of platelet responses in the circulation is unlikely, except, possibly, for epinephrine-induced aggregation, because of the high concentrations of CP required. However, local regulation of platelet responses by release of stored CP during aggregation is possible since CP are stored in platelet dense granules.
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PMID:Effects of acetaldehyde condensation products on human platelet aggregation. 362 6

The effects of volatile oils of 22 plants from 11 different families and of some of their constituents on tracheal and ileal smooth muscles were investigated. The results were compared with the relaxant effects of catecholamines and phosphodiesterase inhibitors. All of the oils had relaxant effects on the tracheal smooth muscle, the most potent were angelica root, clove, elecampane root, basil and balm leaves oil. 16 oils inhibited the phasic contractions of the ileal myenteric plexus-longitudinal muscle preparation, the most potent were elecampane root, clove, thyme, balm leaves and angelica root oil. 2 oils (anise and fennel) increased the phasic contractions, and 4 oils (bitter orange, caraway, mace, pepper) produced a marked increase in resting force (i.e. contracture). In regard to the relaxant effects, most of the 16 oils were more potent on the ileal than on the tracheal muscle. However, a small group of 4 oils (angelica root, clove, basil, black caraway) had a higher relaxant effect on the tracheal than on the ileal muscle. This was also found to be the case with eugenol, eugenol acetate and cinnamic aldehyde as well as with isoprenaline and phosphodiesterase inhibitors.
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PMID:Relaxant effects on tracheal and ileal smooth muscles of the guinea pig. 403 78

The authors tested the hypothesis that ethanol or its metabolite acetaldehyde might interfere in cyclic guanosine monophosphate (GMP) metabolism in coronary smooth muscle cells. Ethanol at the physiologically relevant concentration of 4.0 mg/mL or more significantly decreased basal guanylate cyclase activity and inhibited activation of the enzyme by sodium nitroprusside (SNP) in cultured porcine coronary smooth muscle cells. Two isoforms of phosphodiesterase (PDE), cyclic GMP-specific form and calmodulin-stimulated form, were both inhibited by 12.0 mg/mL or more ethanol. Intact cell study revealed that although 12.0 mg/mL or more ethanol was needed to significantly decrease cyclic GMP accumulation in control cells, 4.0 mg/mL or more ethanol significantly inhibited the increase of cyclic GMP accumulation induced by 1 microns SNP. Acetaldehyde showed similar effects, but the concentrations involved were more than physiological. Thus, ethanol may decrease cellular cyclic GMP levels and attenuate cyclic GMP accumulation in response to SNP in coronary smooth muscle cells by inhibiting soluble guanylate cyclase activity at physiologically relevant concentrations.
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PMID:Ethanol modulates cyclic GMP metabolism in cultured coronary smooth muscle cells. 809 30

The breakdown of sodium O,O-diethyl dithiophosphate (O,O-diethyl phosphorodithioate) by four bacterial strains (tentatively identified as strains of Aeromonas, Pseudomonas, Flavobacterium and Bacillus) isolated from contaminated metalworking fluids was shown to involve the successive formation of ethanol, aldehyde and orthophosphate. An acid phosphodiesterase was identified in cell-free extracts that was five- to sevenfold enhanced in specific activity in bacteria grown on O,O-diethyl dithiophosphate as sole phosphorus source, compared with bacteria grown on orthophosphate. This is thought to initiate the breakdown process.
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PMID:The degradation of sodium O,O-diethyl dithiophosphate by bacteria from metalworking fluids. 1003 34

Schizosaccharomyces pombe Nthpl, an ortholog of the endonuclease III family, is the sole bifunctional DNA glycosylase encoded in its genome. The enzyme removes oxidative pyrimidine and incises 3' to the apurinic/apyrimidinic (AP) site, leaving 3'-alpha,beta-unsaturated aldehyde. Analysis of nth1 cDNA revealed an intronless structure including 5'- and 3'-untranslated regions. An Nth1p-green fluorescent fusion protein was predominantly localized in the nuclei of yeast cells, indicating a nuclear function. Deletion of nth1 confirmed that Nth1p is responsible for the majority of activity for thymine glycol and AP site incision in the absence of metal ions, while nth1 mutants exhibit hypersensitivity to methylmethanesulfonate (MMS). Complementation of sensitivity by heterologous expression of various DNA glycosylases showed that the methyl-formamidopyrimidine (me-fapy) and/or AP sites are plausible substrates for Nth1p in repairing MMS damage. Apn2p, the major AP endonuclease in S. pombe, also greatly contributes to the repair of MMS damage. Deletion of nth1 from an apn2 mutant resulted in tolerance to MMS damage, indicating that Nth1p-induced 3'-blocks are responsible for MMS sensitivity in apn2 mutants. Overexpression of Apn2p in nth1 mutants failed to suppress MMS sensitivity. These results indicate that Nth1p, not Apn2p, primarily incises AP sites and that the resultant 3'-blocks are removed by the 3'-phosphodiesterase activity of Apn2p. Nth1p is dispensable for cell survival against low levels of oxidative stress, but wild-type yeast became more sensitive than the nth1 mutant at high levels. Overexpression of Nth1p in heavily damaged cells probably induced cell death via the formation of 3'-blocked single-strand breaks.
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PMID:Roles of base excision repair enzymes Nth1p and Apn2p from Schizosaccharomyces pombe in processing alkylation and oxidative DNA damage. 1607 63

The C4'-oxidized abasic site (C4-AP) is produced by a variety of DNA damaging agents. This alkali labile lesion can exist in up to four diastereomeric cyclic forms, in addition to the acyclic keto-aldehyde. Synthetic oligonucleotides containing the lesion were prepared from a stable photochemical precursor. Chemical integrity of the lesion containing oligonucleotides was probed using phosphodiesterase lability. Analysis of the 3',5'-phosphate diester of the monomeric lesion released from single diastereomers of photolabile precursors by 1H NMR indicates that isomerization of the hemiacetal and/or hemiketal is rapid. The syntheses and characterization of oligonucleotides containing configurationally stable analogues of C4-AP, which serve as mechanistic probes for deciphering the structural basis of the biochemical and biological effects of the C4'-oxidized abasic lesion, are also described.
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PMID:Preparation and analysis of oligonucleotides containing the c4'-oxidized abasic site and related mechanistic probes. 1627 38


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