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)

A procedure for cellular fractionation and preparation of plasma membrane from a Burkitt's lymphoma cell line is described. This procedure involves homogenization with a Polytron in buffered isotonic sucrose, and separation of cellular fractions by differential and isopycnic centrifugation in sucrose. The isolated plasma membrane fraction contains 44% of the cellular cholesterol, 50% of the ouabain-sensitive (Na+ + K+)-ATPase activity, 43% of the gamma-glutamyltranspeptidase activities and 16% of the phospholipid. This fraction contains only 3% of cellular protein and is contaminated with less than 4% of the total cellular activities of microsomal, lysosomal, mitochondrial, Golgi and soluble marker enzymes. The cholesterol : phospholipid molar ratio of the crude plasma membrane is 0.56. The membranes in this fraction are in the form of vesicles. Further purification of plasma membrane is achieved by sucrose density gradient centrifugation and results in a 25- to 30-fold enrichment of plasma membrane markers. Plasma membrane markers band in these gradients between 1.10 and 1.15 g/cm3. The distribution patterns in the cell fractions of 18 cellular constituents are quantitatively determined. Most constituents are found to distribute in a fashion consistent with the results obtained in other systems. Thymidine-5'-phosphodiesterase (phosphodiesterase I), esterase, nucleoside diphophatase and glucose-6-phosphatase, however, are shown to be poor markers of membrane fractions in this system. Lactoperoxidase-catalyzed iodination was used to identify several plasma membrane proteins which are exposed at the surface. After separation of labeled polypeptides by sodium dodecyl sulfate gel electrophoresis, the predominant labeled protein was identified as the heavy chain of IgM. Several lesser labeled proteins were observed.
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PMID:Cellular fractionation and isolation of the plasma membrane of Burkitt's lymphoma cells. 740 42

Venoms from two related Australian ants, a jumper ant (Myrmecia pilosula) and a bulldog ant (Myrmecia pyriformis), were quantitatively analysed for the following enzymic activities: phospholipase A2, phospholipase B, phospholipase C, hyaluronidase, esterase, acid phosphatase, alkaline phosphatase and phosphodiesterase. Both venoms contained phospholipase A2, phospholipase B, hyaluronidase, acid phosphatase and alkaline phosphatase activities. Myrmecia pyriformis venom had significantly greater phospholipase B, acid phosphatase and alkaline phosphatase activities than Myrmecia pilosula venom. No detectable quantities of phospholipase C, esterase or phosphodiesterase activities were found in either venom.
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PMID:Some enzymic activities of two Australian ant venoms: a jumper ant Myrmecia pilosula and a bulldog ant Myrmecia pyriformis. 772 23

The influence of paraoxon and bis(4-nitrophenyl)phosphate (BNPP) on carboxylesterases of human skin is assayed. Both organophosphates have frequently been used as inhibitors of carboxylesterases of the B-esterase type. Homogenates from carefully washed skin have no paraoxon-cleaving activity and very little phosphodiesterase activity with BNPP. However, a number of skin enzymes are irreversibly inhibited by these compounds. Three zones of carboxylesterase bands can be detected in the soluble fraction of skin homogenate by isoelectric focusing. One zone containing 5 esterase bands in the pI-range of 6.7-7.0 and another zone at pI 4.9 are insensitive to organophosphate inhibition. The zone with the main esterase activities contains at least 6 bands in the range of pI 5.7-6.2. All of these are quickly and completely inhibited by paraoxon. The complex inhibition kinetics with BNPP and observations with differing substrates point to a functional heterogeneity. The esterases with pI-values in the range of 5.7 to 6.2 and the esterase with pI 4.9 can be enriched using anion exchange chromatography and FPLC. From the data presented here it is concluded that human skin contains at least four different carboxylesterases which act on simple aromatic esters.
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PMID:Organophosphate sensitive and insensitive carboxylesterases in human skin. 834 78

In view of the ability of several phosphoesterases to hydrolyze organophosphates to toxic phenols, the bioactivation of bis[p-nitrophenyl]phosphate (BNPP) by the earthworm Lumbricus terrestris was investigated. In a contact toxicity test, BNPP was was less toxic than the metabolite p-nitrophenol (PNP), but more toxic than the metabolite p-nitrophenylphosphate (PNPP). Results from an artificial soil test (soil containing BNPP) revealed that the phosphomonoesterase and phosphodiesterase activities from the enteric tissue of the annelid could be selectively depressed without significant reduction of these activities in other tissues. Since these esterase activities are 5 to 7 fold higher in the enteric tissue, these results suggest that the phosphoesterases in the annelid participate in the activation of BNPP to the more toxic metabolite, p-nitrophenol.
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PMID:Bioactivation of bis[p-nitrophenyl]phosphate by phosphoesterases of the earthworm, Lumbricus terrestris. 838 50

1. During in vitro culture in 10% human AB serum, human peripheral blood monocytes acquire a macrophage-like phenotype. The underlying differentiation was characterized by increased activities of the macrophage marker enzymes unspecific esterase (NaF-insensitive form) and acid phosphatase, as well as by a down-regulation in surface CD14 expression. 2. In parallel, a dramatic change in the phosphodiesterase (PDE) profile became evident within a few days that strongly resembled that previously described for human alveolar macrophages. Whereas PDE1 and PDE3 activities were augmented, PDE4 activity, which represented the major cyclic AMP-hydrolysing activity of peripheral blood monocytes, rapidly declined. 3. Monocytes and monocyte-derived macrophages responded to lipopolysaccharide (LPS) with the release of tumour necrosis factor-alpha (TNF). In line with the change in CD14 expression, the EC50 value of LPS for induction of TNF release increased from approximately 0.1 ng ml-1 in peripheral blood monocytes to about 2 ng ml-1 in macrophages. 4. Both populations of cells were equally susceptible towards inhibition of TNF release by cyclic AMP elevating agents such as dibutyryl cyclic AMP, prostaglandin E2 (PGE2) or forskolin, which all led to a complete abrogation of TNF production in a concentration-dependent manner and which were more efficient than the glucocorticoid dexamethasone. 5. In monocytes, PDE4 selective inhibitors (rolipram, RP73401) suppressed TNF formation by 80%, whereas motapizone, a PDE3 selective compound, exerted a comparatively weak effect (10-15% inhibition). Combined use of PDE3 plus PDE4 inhibitors resulted in an additive effect and fully abrogated LPS-induced TNF release as did the mixed PDE3/4 inhibitor tolafentrine. 6. In monocyte-derived macrophages, neither PDE3- nor PDE4-selective drugs markedly affected TNF generation when used alone (< 15% inhibition), whereas in combination, they led to a maximal inhibition of TNF formation by about 40-50%. However, in the presence of PGE2 (10 nM), motapizone and rolipram or RP73401 were equally effective and blocked TNF release by 40%. Tolafentrine or motapizone in the presence of either PDE4 inhibitor, completely abrogated TNF formation in the presence of PGE2. Thus, an additional cyclic AMP trigger is necessary for PDE inhibitors to become effective in macrophages. 7. Finally, the putative regulatory role for PDE1 in the regulation of TNF production in macrophages was investigated. Zaprinast, at a concentration showing 80% inhibition of PDE1 activity (100 micromol l-1), did not influence TNF release. At higher concentrations (1 mmol l-1), zaprinast became effective, but this inhibition of TNF release can be attributed to a significant inhibitory action of this drug on PDE3 and PDE4 isoenzymes. 8. In summary, the in vitro differentiation of human peripheral blood monocytes to macrophages is characterized by a profound change in the PDE isoenzyme pattern. The change in the PDE4 to PDE3 ratio is functionally reflected by an altered susceptibility towards selective PDE inhibitors under appropriate stimulating conditions.
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PMID:In vitro differentiation of human monocytes to macrophages: change of PDE profile and its relationship to suppression of tumour necrosis factor-alpha release by PDE inhibitors. 915 31

Venoms from the scorpaeniformes Synanceja trachynis and Gymnapistes marmoratus were quantitatively analyzed for enzymic activity. S. trachynis venom displayed significantly higher hyaluronidase activity than G. marmoratus venom, and G. marmoratus venom displayed significantly higher levels of esterase, acid phosphatase, alkaline phosphatase and phosphodiesterase activity. No detectable quantities of phospholipase A2 activity were found in G. marmoratus venom. SDS-polyacrylamide gel electrophoresis of S. trachynis venom indicated the presence of 6 protein bands (20 kDa-295 kDa). G. marmoratus venom displayed 8 protein bands (11 kDa-109 kDa).
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PMID:Enzyme and biochemical studies of stonefish (Synanceja trachynis) and soldierfish (Gymnapistes marmoratus) venoms. 965 39

Four new zwitterionic butanesulfonic acid buffers that are structurally related to four families of Good buffers were evaluated for use in biological systems. These buffers, with pKa values from 7.6 to 10.7, were compared with a variety of other buffers from the same family and with unrelated buffers to determine their effect on enzyme activity and on microbial growth. The activity of four enzymes with optimum pH values in the alkaline range were tested: beta-galactosidase, esterase, phosphodiesterase and alkaline phosphatase. In general, all the Good buffers, including the new butanesulfonic acid buffers, gave good activity; however, there was variation in activity of certain enzymes with certain buffers. Tris, glycine, and phosphate buffers typically showed variation in activity compared to the family of Good buffers. beta-Galactosidase, in particular, showed greater activity with Good buffers than with phosphate or Tris buffers. Similarly, growth of seven bacterial strains was consistent, with a few exceptions, for all the Good family of buffers with Tris often inhibiting growth. Quantitation of alkaline phosphatase conjugated to antibodies is an important tool in many applications in molecular biology. Several Good buffers gave good signals when compared with Tris at pH 9.5 for detection of proteins using alkaline phosphatase-conjugated antibodies.
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PMID:New zwitterionic butanesulfonic acids that extend the alkaline range of four families of Good buffers: evaluation for use in biological systems. 987 Jan 86

MonoSATE aryl phosphotriesters of AZT are able to deliver intracellularly the corresponding 5'-mononucleotide. This process requires activation by an esterase followed by a phosphodiesterase. This finding opens the way to the design of new pronucleotide series.
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PMID:Rational design of a new series of mixed anti-HIV pronucleotides. 987 64

A previously developed Russell's viper venom toxoid in Myanmar is in a liquid form that shows reversion in the form of a reduced number of formaldehyde linkages and toxicity during storage at 37 degrees C and at room temperature. In order to have a safe, potent and stable toxoid, a lyophilized form was prepared in the present study from the liquid toxoid through the use of a freeze dryer. Both the liquid and lyophilized forms were then stored at 4 degrees C and at room temperature, and in addition to safety and immunogenicity tests, biochemical parameters such as the protein content, the activity of venom enzymes (proteinase, phospholipase A, phosphodiesterase, and arginine esterase), and the released free formalin amounts were assessed at 3-month intervals over a period of 1 year. The results indicate that under both conditions, the lyophilized toxoid shows minimum changes in enzyme activity, a reduced tendency toward formaldehyde linkage, no toxicity, and more immunogenicity in comparison with the respective liquid toxoids. It could therefore be hypothesized that Russell's viper venom toxoid in a lyophilized form is more promising in terms of efficacy and stability for prophylactic use in human immunization than the conventional toxoid in a liquid form.
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PMID:Stability of Russell's viper venom toxoid (lyophilized form) on storage. 1073 60

The synthesis and biological activities of phosphotriester derivatives of 3'-azido-2',3'-dideoxythymidine (AZT) bearing a phenyl group or L-tyrosinyl residues are reported. The target compounds were obtained via either P(V) or P(III) chemistry from the appropriate aryl precursors. All the derivatives were evaluated for their in vitro anti-HIV activity, and they appeared to be potent inhibitors of HIV-1 replication in various cell culture experiments, with EC(50) values between the micro- and nanomolar range. Furthermore, compounds incorporating an amino- and/or acid-substituted tyrosinyl residue demonstrated significant anti-HIV effects in thymidine kinase-deficient (TK(-)) cells showing their ability to act as mononucleotide prodrugs. The proposed decomposition process of these mixed mononucleoside aryl phosphotriesters may involve esterase activation followed by phosphodiesterase hydrolysis.
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PMID:S-Acyl-2-thioethyl aryl phosphotriester derivatives as mononucleotide prodrugs. 1108 82


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