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)

Twelve acid hydrolases, 4 near-neutral hydrolases, and alkaline phosphatase were demonstrated in 0.34 M sucrose homogenates of Trypanosoma cruzi strain Y: p-nitrophenylphosphatase and alpha-naphthylphosphatase, with optimum pH at approximately 6.0; alpha=ga;actpsodase. beta=ga;actpsodase. beta=g;icpsodase, N-acetyl-beta-glucosaminidase, cathepsin A and peptidase I and III, with optimum pH between 5.0 and 6.0; and arylsulfatase, cathepsin D, alpha-arabinase and alpha-mannosidase with optimum pH at approximately 4.0. alpha-Glucosidase, glucose-6-phosphatase and peptidase II had optimum pH at approximately 7.0. beta-Glycerophosphatase had a broad pH-activity curve from 4,0 to 7.4, with maximum activity at pH 7.0. The main kinetic characteristics of these enzymes and their quantitative assay methods were studied. No activity was detected for alpha-fucosidase, beta-xylosidase, beta-glucuronidase, elaidate esterase, acid lipase, and alkaline phosphodiesterase.
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PMID:Acid and neutral hydrolases in Trypanosoma cruzi. Characterization and assay. 4 19

Adenine requiring mutants of Serratia marcescens SM-6-F'lac+ have been found to grow well in minimal-glucose medium solely supplemented with cAMP. From one of these ade strains double mutants (called ade cpd) were isolated which could no longer utilize cAMP but which still grew on 5'AMP. Dialyzed cell extracts (soluble fraction) of the double mutants, assayed for cAMP phosphodiesterase, were unable to hydrolyze cAMP whereas cell extracts of the parental strains yielded 5'AMP at a rate of 1.6-2.0 mumoles min-1 mg-1 protein. The loss of the phosphodiesterase activity in S. marcescens cpd W 1181 did not cause an accumulation of large amounts of cAMP as was found for the diesterase-negative mutant AB257pc-1 of Escherichia coli. The induced synthesis of beta-galactosidase in mutant cpd W 1181 showed about the same sensitivity to transient and permanent catabolite (glucose) repression as the corresponding cpd+ strain. Starting from S. marcescens cpd W 1182 three independent double mutants (called cpd cya) were isolated which required exogenous cAMP for utilizing various carbohydrates as carbon source, for motility and for the formation of extracellular lipase and the red pigment prodigiosine. The intracellular concentration of cAMP in these mutants, grown in nutrient broth, was 40-60% of that of the parental strain which is about 4 x 10(-4) M. However, the adenylate cyclase in cell extracts of the mutants W 1237 and W 1270 was like that of the corresponding cya+ strain (about 2 x 10(-2) mumoles min-1 mg-1 protein).
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PMID:Mutants of Serratia marcescens lacking cyclic nucleotide phosphodiesterase activity and requiring cyclic 3',5'-AMP for the utilization of various carbohydrates. 16 32

Halothane has dual effects on lipolysis of human adipose tissue: at low tissue concentrations a stimulatory effect is found, while at higher tissue concentrations lipolysis is inhibited. The lipolytic resonse of human adipose tissue was studied in vitro with or without halothane, the phosphodiesterase inhibitor theophylline, the lipase activator dibutyryl cAMP(dbcAMP), the alpha-receptor antagonist phentolamine, the nonselective beta-receptor antagonist propranolol, and the selective beta1-receptor antagonist practolol. In the absence of beta-receptor antagonists low concentrations of halothane stimulated lipolysis, This effect was blunted by beta-receptor antagonists, indicating that halothane at low tissue concentrations may directly stimulate the beta-receptors. The inhibitory effect of higher tissue concentrations of halothane was not the result of increased alpha-receptor activity since addition of phentolamine did not inhibit this effect. High concentrations of theophylline or dbcAMP increased lipolysis in specimens exposed to halothane, but the lipolytic rate was still less than that found in specimens not exposed to halothane. The data thus indicate that the inhibitory effect of halothane is exerted at a step beyond the formation and degradation of cAMP.
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PMID:Studies of the dual effects of halothane on the lipolysis of human fat cells. 18 21

The role of some agonists of the adrenergic system and inhibitors of phosphodiesterase activity in the modulation of the degree of lipase release from pancreatic granular fraction (zymogen and lysosomes) of control and X-ray irradiated rats was investigated. It was shown the decrease of the release of enzymatic activity under the influence of cyclic adenosine monophosphate (cAMP) and noradrenaline (NA) in the fractions from both investigated groups. Effects were dependent on the concentration used. Isoprenaline evoked opposite changes in control and irradiated specimens. In controls it facilitated the enzyme release when applied in smaller (10(-8)M) concentration. In granules from irradiated animals the decrease of enzyme release was noted under the influence of greater concentration (10(-6)M) of the drug. The action of papaverine was nearly similar in control and irradiated groups. The drug evoked the decrease or increase of enzyme release when applied in greater (10(-6)M) or smaller (10(-8)M) concentration respectively. Lipase release was markedly enhanced in controls by theophylline (both concentrations); in specimens from irradiated pancreas, however, no significant alterations were observed.
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PMID:Investigations on the modification of postirradiation pancreatic lipase activity by some endo- or exogenic factors. Part I. The influence of some agonists of adrenergic system. 20 75

A mouse spleen-derived mast cell line (PT-18) was employed to examine the mechanisms of adenosine 3':5'-monophosphate (cAMP)-mediated inhibition of antigen-induced lipid mediator biosynthesis. Specifically, we tested the hypothesis that increasing cAMP in mast cells inhibits lipid mediator biosynthesis by a mechanism independent of effects on histamine release (degranulation) or changes in cytosolic calcium concentration. Forskolin inhibited antigen-induced prostaglandin D2 (PGD2), leukotriene C4 (LTC4), and leukotriene B4 (LTB4) production by 30-50%. In contrast, forskolin had no inhibitory effect on antigen-induced increases in cytosolic calcium concentration, as monitored by the calcium indicator fura-2, or histamine release from the cells. The combination of the phosphodiesterase inhibitor isobutylmethylxanthine with forskolin inhibited the antigen-induced production of PGD2 and LTC4 by 90-100% and histamine release by about 60%. These responses were accompanied by a virtual abolition of the antigen-induced increase in cytosolic calcium. To test further the hypothesis that increasing cAMP can lead to inhibition of lipid mediator biosynthesis in the absence of effects on cytosolic calcium, we employed the calcium ionophores A23187 and ionomycin. Forskolin alone or in combination with isobutylmethylxanthine had no effect on ionophore-induced increases in cytosolic calcium but effectively inhibited leukotriene biosynthesis. In addition, increasing cyclic AMP led to an inhibition of ionophore-induced production of platelet-activating factor and liberation of arachidonic acid. These data suggest that a relatively modest increase in cAMP-dependent protein kinase activity in mast cells leads to inhibition of the lipase-catalyzed cleavage of arachidonic acid from membrane phospholipids in the absence of measurable effects on either histamine release or changes in cytosolic calcium concentration. This effect results in a selective inhibition of the biosynthesis of lipid mediators including LTC4, LTB4, PGD2, and platelet-activating factor.
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PMID:Inhibition by adenosine 3':5'-monophosphate of eicosanoid and platelet-activating factor biosynthesis in the mouse PT-18 mast cell. 169 Nov 75

The adrenergic regulation of lipolysis was studied, before and after 30 min of submaximal exercise, in isolated adipocytes removed from the abdominal and gluteal regions of healthy non-obese men and women. Noradrenaline-induced lipolysis was significantly enhanced in gluteal adipocytes from men but not in women after exercise. However, the pure beta-adrenergic responsiveness was equally increased in gluteal adipocytes of both sexes after exercise, as judged by the effect of isoprenaline. Furthermore, the alpha 2-adrenergic anti-lipolytic responsiveness was more apparent after exercise in females than in males thereby counter-balancing the increase in the beta-adrenergic effect in the gluteal region in the former. The increased beta-adrenergic responsiveness induced by exercise in gluteal adipocytes of males could be mimicked by agents acting at the levels of adenylate cyclase, coupling proteins, phosphodiesterase, and protein kinase and seems to be due to an adaptive enhancement at the hormone-sensitive-lipase level. There was no change in the stoichiometric properties of beta-adrenoceptors of gluteal adipocytes after exercise. Abdominal adipocytes of both sexes were four to five times more responsive to noradrenaline than gluteal ones. However, exercise induced no further enhancement of the catecholamine-stimulated lipolysis rate in fat cells from this site. Thus, the influence of exercise on catecholamine-stimulated lipolysis is regional and sex dependent. Men, but not women, have a greater ability to adapt lipolysis to increasing energy demands during exercise that are due to an acute increase in the effectiveness of the hormone-sensitive lipase complex.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Adrenergic regulation of lipolysis in human fat cells during exercise. 175 92

Of 120 laboratory-maintained strains of Listeria monocytogenes and two of L. ivanovii examined for haemolytic and lipolytic activity, 62 exhibited haemolytic activity alone, 20 of these showed haemolytic and lipolytic activity and 40 had neither activity. The L. ivanovii strains showed both activities. The results indicated a relationship between haemolysin production and lipolytic activity which was not explained by the serotype of the organism. In addition, the following hydrolytic activities were detected in the cell-free growth media of strains L. monocytogenes Boldy and L. ivanovii (formerly L. monocytogenes) Type 5 (substrates acted upon are given in parentheses): acid phosphate (4-nitrophenylphosphate, naphthyl phosphate, glycerophosphate, phosphorylcholine and GTP); neutral phosphatase (4-nitrophenylphosphate, naphthyl phosphate, phosphorylcholine, NADP and UDPG); phosphodiesterase (bis-4-nitrophenylphosphate, ATP and NADP); NADase (NAD); phospholipase C (4-nitrophenylphosphoryl-choline, phosphatidyl choline and ethanolamine, and sphingomyelin); and lipase and esterase (triacetin, tributyrin, triolein, naphthyl-laurate,-myristate,-caprylate,-palmitate and -oleate, 4-nitrophenyl-acetate-laurate and Tween 80). The preparations also showed weak catalase activity. No evidence was found for the presence of RNAase, DNAase, peptidase/amidase, phosphoamidase, alpha-amylase, glucosidase, galactosidase, pyranosidase or glucose aminidase.
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PMID:Haemolysins and extracellular enzymes of Listeria monocytogenes and L. ivanovii. 250 86

The effect of in ovo administration of ovine growth hormone (oGH) on growth and adipose tissue development of chickens was investigated. Unlike mammalian species, exogenous growth hormone has not been previously shown to increase growth of aves. In trial 1, fertilized eggs were injected with vehicle (.03 M NaHCO3 in .15 M NaCl, pH 8.3), 0.25, 2.5, 25 or 250 micrograms oGH on day 11 of embryogenesis. In trial 2, fertile eggs were injected with vehicle or 250 micrograms oGH. In contrast to previous studies in which GH was administered to growing birds, oGH injected in ovo in the present study increased body weights, skeletal growth and feed efficiencies of male broilers. Growth rate was not altered in females. Adipose cellularity data from both trials indicated that in ovo oGH also altered adipose tissue development of broilers. Seven-week-old male and female broilers treated with oGH during embryogenesis exhibited larger adipocytes with correspondingly less cell per gram of tissue. Additionally, adipocytes from oGH-treated broilers exhibited decreased sensitivity to glucagon, cholera toxin or theophylline-induced lipolysis responsiveness to dcAMP in ovo. Cholera toxin plus theophylline improved the lipolytic response of oGH-treated birds; thus, in broilers injected with oGH cAMP-mediated lipase activation may be reduced by a mechanism of increased phosphodiesterase activity. The results of this study indicate that growth and tissue development of chickens have been altered by mammalian GH in ovo.
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PMID:In ovo growth hormone alters growth and adipose tissue development of chickens. 259 45

The plasma membranes of bovine adrenal chromaffin cells were isolated and the activities of enzymes involved in arachidonic acid liberation were investigated. Only a minute activity of phospholipase A2 (phosphatide 2-acylhydrolase, EC 3.1.1.4) could be detected using externally added phosphatidylcholine (PC) and phosphatidylethanolamine (PE) as substrate. When membranes were treated with exogenous phospholipase C (orthophosphoric acid diester phosphohydrolase, EC 3.1.4.1) there was a liberation of free fatty acids from the sn-2 position of PC. The enzyme responsible for this effect could be demonstrated to be a diacylglycerol lipase (glycerol ester hydrolase, EC 3.1.1.3) localized in the plasma membrane. Using phosphatidylinositol (PI) as a substrate, it was found that an endogenous phospholipase C exists which co-purifies with the membrane preparation. The produced diacylglycerol is subsequently hydrolyzed by diacylglycerol lipase liberating arachidonic acid. The two enzymes, phospholipase C and diacylglycerol lipase were characterized. Phospholipase C was found to be calcium dependent and PI specific, showing an activity of 60 pmol/micrograms protein per h (1.2 mM Ca2+), whereas the diacylglycerol lipase was calcium independent hydrolyzing diacylglycerol at a rate of 7.2 pmol/micrograms protein per h. The lipase but not the phospholipase C was inhibited 50% by 1.7 mM para-bromophenacylbromide.
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PMID:Phospholipase C and diacylglycerol lipase activities associated with plasma membranes of chromaffin cells isolated from bovine adrenal medulla. 308 88

Capsaicin, reported to elevate hormone sensitive lipase (HSL), is also found to inhibit the Ca++ and calmodulin-dependent cAMP phosphodiesterase (PDE) activity in adipose tissue of rats, fed high fat diet. The dependence of the enzyme activity on Ca++ and calmodulin in vitro, in control rats, is shown by its substantial lowering in the presence of EGTA and inhibition by trifluoperazine (TFP) (IC50 between 10-20 microM). This enzyme activity is also inhibited by both red pepper extract (80% inhibition with 50 microliter) and capsaicin (IC50 between 0.3-1 microM) in a dose dependent manner. Capsaicin has been found to inhibit Ca++-dependent PDE activity by 60% in the test rats. Enzyme inhibition in vivo, due to capsaicin, was overcome by addition of calmodulin to the assay system. Inclusion of fluphenazine or capsaicin in assay inhibited not only the calmodulin-restored enzyme activity from test rats but also that of control rats. These results suggest a possible mechanism for the stimulation of lipolytic activity by capsaicin in vivo.
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PMID:Inhibition of calcium and calmodulin-dependent phosphodiesterase activity in rats by capsaicin. 311 70


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