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)

Fetal lung cyclic AMP phosphodiesterase, cyclic AMP, phosphatidyl choline, and incorporation of precursors into phosphatidyl choline were measured in rabbits after maternal administration of hydrocortisone phosphate and aminophylline. Both agents inhibited lung phosphodiesterase activity and augmented cyclic AMP concentrations (Table 1). Aminophylline administration was associated with a significant increase in lung saturated phosphatidyl choline (Table 2). Incorporation of [14C] choline and [3H] methionine was increased by both aminophylline and hydrocortisone (Table 3).
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PMID:Role of adenosine 3', 5'-monophosphate in maturation of fetal lungs. 17 50

A modification of Aurbach & Houston's enzymic method for measuring cAMP is presented. The procedure is relatively simple and in several respects new. Urinary cAMP is separated from other nucleotides and phosphate by ZnSO4-Ba(OH)2 precipitation and column chromatography. The eluate is concentrated by evaporation. Recovery at this stage is 60-82%. The cAMP from urine and the standards are dissolved in a reaction mixture and converted to 5-AMP with cyclic 3',5'-nucleotide phosphodiesterase (PDE) and further to ATP with adenylate kinase and pyruvate kinase. The ATP formed is labelled with 32P by an exchange reaction catalysed by glyceraldehyde phosphate dehydrogenase and phosphoglycerate kinase. The remaining 32P used to count the [32P]ATP in the aqueous phase. Daily human urinary cAMP excretion is 3380 +/- 836 nmol (S.D.). After an injection of 100 USP units of parathormone intravenously into a patient with idiopathic hypoparathyroidism, urinary cAMP excretion increased 40-fold above the basal concentration within 30 min. Drinking of coffee or water did not affect cAMP excretion. The limit of detection of the method is 170 pmol of cAMP, and the variation coefficient for urine ranges from 7 to 10%. When the enzymic cAMP method was compared with a radioimmunological procedure, the correlation coefficient was found to be 0.98.
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PMID:Determination of cyclic adenosine 3',5'-monophosphate in urine. 17 27

In the isolated perfused rat heart, the dose-related cardiostimulation produced by norepinephrine (NE) or calcium chloride (Ca2+) was followed by a corresponding increase in coronary flow (CF) and in the cardiac level of adenosine 3',5'-cyclic phosphate (cAMP). Prolonged prostaglandin E2 (pge2) infusion did not change the basic force of contraction, CF, or cAMP level but when NE or Ca2+ were administered, only the responses of the CF and the cAMP were diminished. A phosphodiesterase inhibitor, diazoxide (Dx), caused insignificant increase in the basal cAMP, without affecting the force of contraction or CF. With NE or Ca2+, during Dx both the changes in CF and cAMP were augmented compared to the nontreated hearts. The inhibitory effects of NE or Ca2+ remained unchanged. Propranolol abolished the NE but not the Ca2+ effects. It is suggested that PGE2 modulates the cardiac cAMP level and that the latter plays an important role in the adaptive regulation of the CF. It is also postulated that changes in cAMP levels may be brought about by the hyperactivity per se produced by a variety of cardiostimulating agents.
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PMID:Prostaglandin E2 and cyclic AMP in the coronary vasodilatation due to cardiac hyperactivity. 17 82

The acyl carrier protein of citrate lyase contains adenine, phosphate, sugar, cysteamine, beta-alanine and pantoic acid in a molar ratio of 1:2:2:1:1:1. Peptides containing these components in the same stoichiometric relationship were isolated after proteolytic digestion of acyl carrier protein. All components were linked together in a single prosthetic group. This was released from the peptide by mild alkaline hydrolysis. Under these conditions a phosphodiester bond is cleaved which links the prosthetic group to a serine residue of the peptide. Incubation of the prosthetic-group-containing peptide with phosphodiesterase I yielded 4'-phosphopantetheine and adenylic acid. The 5'-AMP was not free but was substituted by presumably an acidic sugar residue, which was released by mild acid hydrolysis yielding free 5'-AMP. It was concluded from these results that the prosthetic group of citrate lyase acyl carrier protein consists of a substituted isomeric dephospho-CoA. This is bound to the protein by the 5'-phosphate group of adenylic acid. The 4'-phosphopantetheine residue is bound by a phosphodiester linkage to the 2' or 3' position of ribose and the remaining hydroxyl group of ribose is substituted with presumably an acidic sugar residue. The structural similarities of this prothetic group and coenzyme A are discussed and related to the catalytic properties of citrate lyase.
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PMID:The prosthetic group of citrate-lyase acyl-carrier protein. 17 9

Two enzyme activities involved in the biosynthesis of peptidoglycan in Micrococcus luteus (sodonensis), a transglycosidase and a phosphodiesterase, have been demonstrated in isolated membrane preparations. The transglycosidase activity promotes the in vitro synthesis of an uncross-bridged peptidoglycan that is completely susceptible to lysozyme. This in vitro-synthesized peptidoglycan consists of 76% "soluble" and 24% "insoluble" material. The soluble peptidoglycan is primarily a single low-molecular-weight species of approximately 20 disaccharide peptide units. "Insoluble" peptidoglycan, which likely represents newly synthesized material incorporated into an existing cell wall, was solubilized by butanol extraction, and the two were compared. The phosphodiesterase activity demonstrated in this system cleaves uridine diphosphate-N-acetylmuramyl-L-alanyl-D-isoglutamyl-L-lysyl-D-alanyl-D-alanine to yield N-acetylmuramyl-L-alanyl-D-isoglutamyl-L-lysyl-D-alanyl-D-alanine plus uridine 5'-monophosphate plus inorganic phosphate. This phosphodiesterase activity, not detected under normal transglycosidase assay conditions, is a recycling mechanism and acts indirectly through formation and subsequent cleavage of a lipid-linked intermediate.
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PMID:Peptidoglycan biosynthesis in Micrococcus luteus (sodonensis): transglycosidase and phosphodiesterase activities in membrane preparations. 17 77

The effects of sodium alpha-tocopherol phosphate (TPNa), a new vitamin E derivative, on cyclic nucleotide phosphodiesterases from a soluble supernatant fraction of rat liver were investigated. TPNa produced a dose-dependent increase in cyclic AMP hydrolysis at a low substrate concentration (1 muM cyclic AMP), whereas the compound inhibited the hydrolytic activity at a high substrate level (100 muM cyclic AMP). Cyclic GMP phosphodiesterase activity was suppressed by TPNa regardless of the substrate concentration. The addition of TPNa did not change the apparent Km value (50 muM) of cyclic AMP phosphodiesterase at low substrate level (less than 5 muM). In contrast, at higher substrate concentration, the concave downward curve observed in a Lineweaver-Burk plot became straight in the presence of TPNa. Low concentrations of cyclic GMP, which are known to activate cyclic AMP hydrolysis, showed an additive effect on cyclic AMP phosphodiesterase only when a submaximal concentration of cyclic GMP was present in addition to TPNa. These and other data suggest that TPNa modifies cyclic AMP phosphodiesterase in all allosteric fashion.
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PMID:Activation of cyclic AMP phosphodiesterase by a new vitamin E derivative. 18 65

Several cyclic nucleotide derivatives with aminoalkyl side chains attached to the purine ring were synthesized and their interactions with adenosine 3',5'-monophosphate (cAMP) dependent protein kinase were studied before and after immobilization to CNBr-activated Sepharose 4B. The soluble N6-substituted derivatives were as effective as cAMP itself in activating protein kinase and were more effective than 8-substituted cAMP derivatives, whereas the 2-substituted cAMP derivatives and the cGMP derivatives were the least effective. All of the synthetic derivatives tested were poor substrates for beef heart phosphodiesterase being hydrolyzed at rates less than 2% for that of cAMP itself. Utilizing methodology developed to evaluate the affinity of protein kinase for immogilized cyclic nucleotides it was found that all of the immobilized cyclic nucleotides interacted with protein kinase in a biospecific manner as judged by the following criteria: (1) the immobilized cyclic nucleotides competed with cAMP for the binding sites on protein kinase; (2) the analogous spacer-arm did not compete; and (3) the effects of enzyme concentration, MgATP, and cleavage of the cyclic phosphate ring on the interactions of protein kinase with the immobilized cyclic nucleotides were the same as previously shown for free cAMP. In addition, the immobilized ligands were bound with the same order of effectiveness as the analogous soluble ligand. The observed Ka for the activation of 0.005 muM protein kinase by N6-H2N(CH2)2-cAMP was increased from 0.23 to 3 muM by the process of immobilization. This increase was unaffected by the coupling density and spacer-arm length. The observed Kb for 0.10 muM protein kinase binding to immobilized N6-H2N(CH2)2-cAMP was increased as the molecular sieving exclusion limit of the matrix used was decreased indicating that at least part of this decrease in apparent affinity upon immobilization is due to exclusion of the enzyme from a portion of the matrix and therefore of the immobilized ligand molecules.
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PMID:Binding of adenosine 3',5'-monophosphate dependent protein kinase regulatory subunit to immobilized cyclic nucleotide derivatives. 18 16

1. 3'-Guanylyl-ethanol, 3'-guanylyl-propanol, and 3'-guanylyl-alpha-glycerol were synthesized by ribonuclease N1 [EC 3.1.4.8] using guanosine 2',3'-cyclic phosphate as a phosphate donor and various alcohols as phosphate acceptors. The yields of these phosphodiesters were 15%, 13.5%, 38.2%, respectively, with respect to phosphate donor under the optimum conditions. No phosphodiester was synthesized when 2-propanol was used as a phosphate acceptor. Thus, primary alcoholic hydroxyl groups may be regarded as the preferred phosphate acceptor. 2. 3'-Guanylyl-glucose and 3'-guanylyl-ribose were synthesized using glucose and ribose as phosphate acceptors. Under the optimum conditions, the yields of guanylyl-glucose amounted to 52.0%, while that of guanylyl-ribose was much lower. The guanylyl-glucose can be regarded as 3'-guanylyl-6-glucopyranose, based on the results of periodate oxidation. 3. Neither hydroxyamino acids (serine and threonine) nor N-acetylserinamide could be phosphorylated under the conditions used for the above phosphorylations. 4. 3'-Guanylyl-glycerol obtained as above was hydrolyzed by snake venon phosphodiesterase to produce glycerol 3-phosphate. The latter consisted of L-glycerol 3-phosphate (ca 17%) and the D-isomer (ca. 83%). Ribonuclease N1 thus catalyzes an asymmetric synthesis.
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PMID:Synthesis of various phosphodiesters and phosphomonoesters with ribonuclease N. 18 80

1. The role of adenosine 3':5'-phosphate (cyclic AMP) and guanosine 3':5'-phosphate (cyclic GMP) as second messengers for the enzyme secretory response evoked by the autonomic neurotransmitters, noradrenaline and acetylcholine, is examined in this in vitro study on the guinea-pig submandibular gland. 2. Noradrenaline increased enzyme (kallikrein) secretion. The initial stimulation of enzyme release appeared to be dose-dependent. The time course of cumulative kallikrein secretion revealed a complex pattern. Isoprenaline and phenylephrine were almost as potent as noradrenaline in releasing kallikrein. Both propranolol and phentolamine were required to fully inhibit the noradrenaline-stimulated enzyme secretion. 3. The cumulative secretion of kallikrein evoked by acetylcholine was dose-dependent. The onset of secretion showed a significantly greater time-lag than that observed with noradrenaline. Atropine effectively blocked the release of kallikrein by acetylcholine. 4. Dibutyryl cyclic AMP stimulated enzyme secretion. Dibutyryl cyclic GMP caused an initial increase which was not maintained. 5. The cyclic nucleotide phosphodiesterase inhibitors, theophylline and papaverine, increased basal kallikrein secretion. The action of the cyclic phosphodiesterase inhibitors on the secretory response to noradrenaline, acetylcholine, dibutyryl cyclic AMP and dibutyryl cyclic GMP was complex. In general, the increase in enzyme release produced by the secretagogues was additively enhanced by both inhibitors. 6. Omission of calcium inhibited both acetylcholine and dibutyryl cyclic GMP stimulated kallikrein release, but to a lesser degree than that of noradrenaline and dibutyryl cyclic AMP. High concentrations of extracellular calcium (10 mM) appeared to enhance the action of acetylcholine. 7. Noradrenaline produced a rise in the intracellular level of cyclic AMP. The increase preceded the stimulated secretion of kallikrein. Of the various adrenergic agonists, noradrenaline and isoprenaline were the most potent, whereas phenylephrine was significantly less effective in raising basal cyclic AMP values. Acetylcholine was without effect, even in the presence of a cyclic phosphodiesterase inhibitor. 8. Acetylcholine and noradrenaline raised intracellular levels of cyclic GMP only when the tissue incubations were performed in the presence of a cyclic phosphodiesterase inhibitor. The increase in cyclic GMP produced by acetylcholine preceded enzyme secretion. 9. Morphological data substantiated the finding that the in vitro release of kallikrein evoked by the secretagogues was associated with the depletion of secretory granules and vacuolations in acinar cells of the gland slices. 10. The molecular mechanisms which control enzyme secretion in the exocrine submandibular gland are discussed. Models are presented for the role of transmitter-specific cyclic nucleotides and calcium in stimulus-secretion coupling.
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PMID:Stimulus-secretion coupling: role of cyclic AMP, cyclic GMP and calcium in mediating enzyme (kallikrein) secretion in the submandibular gland. 18 62

A practical synthesis of 3'-phosphoadenosine 5'-phosphosulfate (IV) in yields of 68-72% from adenosine 2',3'-cyclic phosphate 5'-phosphate (II) is described. Reaction of II with triethylamine-N-sulfonic acid affords adenosine 2',3'-cyclic phosphate 5'-phosphosulfate (III) which, on treatment with ribonuclease-T2, provides IV. Spleen phosphodiesterase, on the other hand, converts III to 2'-phosphoadenosine 5'-phosphosulfate (V). The biological activity of IV, measured by sulfate transfer to [6,7-3H2]estrone as mediated by bovine adrenal estrone sulfotransferase (3'-phosphoadenylyl-sulfate:estrone 3-sulfotransferase, EC 2.8.2.4), is identical with that obtained with a sample of IV prepared by an established biochemical procedure. By contrast, V exhibits approximately one-third the activity of the natural isomer.
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PMID:Studies on bovine adrenal estrogen sulfotransferase. III. Facile synthesis of 3'-phospho- and 2'-phosphoadenosine 5'-phosphosulfate. 18 16


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