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:3.1.4.3 (phospholipase C)
18,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

rac-Phosphatidyl carnitine and rac-phosphatidyl beta-methylcholine were synthesized by direct condensation of phosphatidic acid and the appropriate alcohols in the presence of 2,4,6-triiso-propylbenzenesulphonylchloride and pyridine. Tetraphenylborates of the quarternary ammonium compounds beta-methylcholine and carnitine benzyl ester were shown to be particularly convenient for synthesis in homogeneous phase. Physical and chemical properties of the two phosphoglycerolipids and some intermediates were described. Phosphatidyl carnitine and phosphatidyl beta-methylcholine were hydrolyzed by phospholipase A2 (phosphatide acyl-hydrolase, EC 3.1.1.4), pancreatic lipase (triacylglycerol acyl-hydrolase, EC 3.1.1.3), and phospholipase C from Bacillus cereus (phosphatidylcholine cholinephosphohydrolase, EC 3.1.4.3). Neither hydrolysis nor transphosphatidylation of phosphatidyl carnitine and phosphatidyl beta-methylcholine was achieved by phospholipase D (phosphatidylcholine phosphatidohydrolase, EC 3.1.4.4). The occurrence of phosphatidyl carnitine in embryonic chicken tissue was suggested by comparison with the synthesized compound. Phosphatidyl carnitine could not be detected in the tissue of rat embryos.
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PMID:Synthesis and properties of phosphatidyl carnitine and phosphatidyl beta-methylcholine. 80 79

An acidic glycoconjugate could be extracted from a delipidated residue fraction of [3H]galactose, [3H]mannose or [32P]orthophosphate metabolically labeled Entamoeba histolytica with water/ethanol/diethylether/pyridine/NH4OH (15:15:5:1:0.017). The radioactively labeled glycoconjugate comprised 50-55% of the total [3H]galactose label incorporated into macromolecules. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of the radiolabeled glycoconjugate showed two diffuse smears centering around 110 kDa and 45 kDa. Similar profiles were observed for both [3H]galactose- and [32P]orthophosphate-labeled glycoconjugate. No such bands were visible in [35S]methionine-labeled material. The hydrophobic nature of this glycoconjugate was inferred from its chromatographic behavior on phenyl-Sepharose. The molecule was rendered hydrophilic after digestion with phosphatidylinositol-specific phospholipase C. It was also sensitive to deamination by nitrous acid. Mild acid hydrolysis led to its fragmentation into smaller molecules as revealed by Sepharose 4B chromatography. Paper chromatographic analysis of the depolymerized [3H]galactose- and [3H]mannose-labeled fragments revealed that each was sensitive to alkaline phosphatase. The major dephosphorylated fragment migrated as an apparent galactose and mannose containing disaccharide which migrated identically to the Gal beta 1-4Man disaccharide derived from the lipophosphoglycan of Leishmania donovani. The above data support the existence of a major acidic glycoconjugate in E. histolytica bearing striking structural similarities to the lipophosphoglycan of Leishmania.
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PMID:Identification and partial characterization of a lipophosphoglycan from a pathogenic strain of Entamoeba histolytica. 147 94

The method of DNA binding to nitrocellulose filters was applied to DNA isolated from mouse liver and Ehrlich ascite carcinoma (EAC), calf thymus, and lymphocytes from patients with chronic lymphoid leukemia. In those and phage PM2 DNA the increase in the DNA binding to the filters with a rise in NaCl concentration from 0.5 up to 4.5 M was sigmoidal being suggestive of a conformational transition. No such activity was found in the case of phage lambda or single-stranded DNA. The binding decreased dramatically after mild cleavage of DNA with DNAase I or treatment with phospholipase C or Eco RI and Hin PI restrictases. Incubation of DNA with ethidium bromide led to decrease in the amount of bound DNA. This effect was enhanced with a rise in the dye concentration. The isotherms of ethidium bromide binding to eukaryotic DNA obtained in Scatchard plots by optic titration had a component with a positive slope at low values of r. Bivalent ions (Mg2+, Zn2+) shifting the equilibrium towards the Z-form increased the proportion of macromolecules retained on the filters at NaCl concentrations of 1-3 M. Local changes in the helix conformation were studied with the help of chemical probes: diethylpyrocarbonate (guanine Z-DNA) and osmium-pyridine reagent (pyrimidines of boundary B-Z sites). These probes incorporation into samples of liver DNA, EAC, and lymphocytes resulted in chemical modification of all these samples. Modification of DNA by osmium-pyridine reagent led to inhibition of subsequent restriction by Eco RI restrictase. The data obtained are suggestive of the presence of Z-regions in the B-helix of eukaryotic DNA. A topological model of Z-site stabilization in small superhelical loops of DNA fixed by protein or lipoprotein molecules is proposed.
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PMID:[Detection of left-helical segments in eukaryotic DNA]. 148 26

Amastigotes of Leishmania major were isolated from infected mice and radiolabeled for 2 h with [3H]galactose. An acidic [3H]glycoconjugate was extracted from a dilipidated residue fraction with the solvent water/ethanol/diethylether/pyridine/NH4OH (15:15:5:1:0.017). The radioactivity labeled glycoconjugate was found to possess the following characteristics that were similar to the lipophosphoglycan extractable from promastigotes: (i) migrated as a broad band upon electrophoresis on SDS polyacrylamide gels; (ii) deaminated with nitrous acid; and (iii) hydrolyzed with phosphatidylinositol-specific phospholipase C. Furthermore, analysis of the aqueous soluble material released by the latter enzyme revealed a negatively-charged [3H]polysaccharide intermediate in size compared to the analogous portions of LPG isolated from non-infective and metacyclic promastigotes. Most importantly, the [3H]polysaccharide was found to contain phosphate and was susceptible to mild acid hydrolysis, establishing that the intact molecule is a lipophosphoglycan. A structural difference, however, was found in the major, mild acid-generated fragment of the amastigote phosphoglycan, which was larger in size and not as anionic as the analogous fragment from the promastigote phosphoglycans. These results indicate that the amastigotes do express a lipophosphoglycan, but that it is structurally distinct from its promastigote counterparts.
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PMID:Expression of a stage-specific lipophosphoglycan in Leishmania major amastigotes. 164 60

In pancreatic islets the bulk of phosphoinositide-specific phospholipase C (PI-PLC) activity was cytosolic. The soluble enzyme was activated by submicromolar concentrations of Ca2+, independent of calmodulin. It was unaffected by glucose and a series of glycolytic intermediates, including glyceraldehyde 3-phosphate. These observations lend support to the hypothesis that glucose-stimulated inositol triphosphate production in islets may be secondary to and provoked by glucose-mediated Ca2+ influx. All four pyridine nucleotides stimulated PI-PLC. Phosphatidylinositol hydrolysis was also stimulated by dioleine and arachidonic acid, and by the polyamines, putrescine and spermine. Phosphatidylinositol hydrolysis was inhibited by chlorpromazine, tetracaine, ATP, 5'-AMP, inorganic pyrophosphate and by phosphatidylinositol 4,5-bisphosphate, phosphatidylcholine and phosphatidylserine--but not affected by phosphatidylethanolamine. The cyclic nucleotides, cAMP and cGMP had no effect on the enzyme, and GTP-gamma-S did not activate the enzyme event at very low Ca2+ concentrations. The diglyceride lipase inhibitor, RHC 80267, and the cyclooxygenase inhibitor, indomethacin, had no effect on PI-PLC activity.
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PMID:Characteristics of phosphoinositide-specific phospholipase C activity from mouse pancreatic islets. 166 77

This article describes the preparation of sn-1,2-[11C]diacylglycerols and sn-1,3-[11C]diacylglycerols by a no-carrier-added reaction based on a labeling method using [1-11C]propyl ketene, which is one of the most potent acylating agents. [1-11C]Propyl ketene was produced by pyrolytic decomposition of [1-11C]butyric acid and was trapped in pyridine containing L-alpha-palmitoyl-lysophosphatidylcholine, producing L-alpha-palmitoyl-2-[1-11C]butyryl-sn-glycero-3-phosphorylcholine. We adopted an enzymatic reaction to remove the phosphorylcholine, in which L-alpha-palmitoyl-2-[1-11C]butyryl-sn-glycero-3-phosphorylcholine was incubated with phospholipase C, hydrolyzing to produce 1-palmitoyl-sn-2-[1-11C]butyrylglycerol. Total synthesis time was about 50 minutes and the specific activity was estimated at 93 GBq/mumol (2.5 Ci/mumol) at end of synthesis. Radiochemical yield was 3.8% based on the trapped 11CO2. sn-1,3-[11C]Diacylglycerol was also synthesized by [1-11C]propyl ketene reaction with 1-palmitoyl-sn-glycerol in a single procedure. The regional brain tissue radioactivities obtained in sn-1,2-[11C]diacylglycerol were higher than those of sn-1,3-[11C]diacylglycerol, and the regional values varied widely. In autoradiography of brain slices from conscious rats, sn-1,2-[11C]diacylglycerol incorporation sites were discretely localized, especially in the amygdala, cerebral cortex, and hippocampus, suggesting that intensive neuronal processing occurred in these areas on the basis of phosphatidylinositol turnover.
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PMID:No-carrier-added carbon-11-labeled sn-1,2- and sn-1,3-diacylglycerols by [11C]propyl ketene method. 174 Jul 22

1. The effects of a novel anti-asthmatic drug, 3-isobutyryl-2-isopropylpyrazolo [1,5-a]pyridine (ibudilast, KC-404) on leukotriene D4 (LTD4)-induced formation of inositol phosphates were studied in slices of guinea-pig lung and hippocampus. 2. In guinea-pig lung, ibudilast inhibited LTD4 (0.01-1 microM)-induced formation of inositol monophosphate (IP1) in a concentration-dependent manner (IC50 = 10 microM) without affecting LTD4 receptor binding. 3. Ibudilast (10 microM) inhibited histamine (0.1-1 mM)-induced formation of IP1 in guinea-pig lung slices but not in hippocampal slices. 4. Inhibition of agonist-induced formation of IP1 by ibudilast was non-competitive. 5. Ibudilast had no effect on either GTP- or calcium-stimulated phosphatidylinositol specific-phospholipase C activity of lung membranes. 6. These results suggest that ibudilast has no direct effect on LTD4 receptors, GTP binding proteins (G proteins) or phospholipase C, but inhibits inositol phosphate formation, possibly by interfering with the coupling between receptors and G proteins.
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PMID:Inhibition by ibudilast of leukotriene D4-induced formation of inositol phosphates in guinea-pig lung. 211 81

Lipophosphoglycan-like glycoconjugates were isolated, purified and partially characterized from Tritrichomonas foetus and Trichomonas vaginalis. Cell surface radiolabeling of both trichomonads by the galactose oxidase/NaB[3H]4 technique indicated that the glycoconjugate was located on the cell surface of the parasites. The glycoconjugates were extracted from the delipidated residue fraction with the solvent, water/ethanol/diethylether/pyridine/NH4OH (15:15:5:1:0.017) and were purified to homogeneity by Sepharose CL-4B followed by octyl-Sepharose chromatography and methanol precipitation. The glycoconjugates migrated as broad bands upon SDS-PAGE. The T. foetus glycoconjugate contained large amounts of fucose along with some mannose, galactose, glucosamine and glucose and trace amounts of galactosamine and inositol. The T. vaginalis glycoconjugate appeared to contain large amounts of glucosamine and galactose along with some glucose, mannose and traces of galactosamine and inositol. The surface-labeled glycoconjugates from both parasites was found to be deaminated with nitrous acid and susceptible to phosphatidylinositol-specific phospholipase C, indicating the presence of a phospholipid anchor. Furthermore, these glycoconjugate were found to contain phosphate and were labile to hydrolysis by mild acid, strongly suggesting that the intact molecule is related to Leishmania lipophosphoglycans (LPG). The most striking and the unique features of these glycoconjugate molecules are the presence of large amounts of fucose in T. foetus and glucosamine in T. vaginalis along with the presence of galactosamine in both parasites. These results indicate that these glycoconjugates are new types of LPG-like molecules expressed on the trichomonad cell surface and are structurally distinct from Leishmania LPG.
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PMID:Lipophosphoglycan-like glycoconjugate of Tritrichomonas foetus and Trichomonas vaginalis. 843 19

A simple chemical method for the synthesis of 1,2-diacyl-sn-glycerophosphatidylserine (PS), with the same fatty acid composition in the sn-1 and sn-2 glycerol positions as egg phosphatidylcholine (PC), is described. PS synthesis was carried out by a phosphite-triester approach, using 2-cyanoethyl-N,N,N',N'-tetraisopropylphosphorodiamidite (phosphoramiditate) as the phosphorylating agent, for the formation of phosphate linkage between serine and diacylglycerol. 1,2-Diacylglycerol, obtained from PC hydrolysis by phospholipase C, was coupled with N-t-BOC-L-serinebenzhydryl ester phosphoramidite with tetrazole as catalyst. Phosphite-triester was oxidized to the corresponding phosphate-triester with 30% H2O2 in CH2Cl2. The cyanoethyl group was removed by addition of an Et3N/CH3 CN/pyridine mixture, and trifluoroacetic acid was used to eliminate the protecting groups of O-(1,2-diacylglycero-3-phospho)-N-t-BOC-serinebenzhydryl ester. Purified PS was identified by thin-layer chromatography, infrared, and 1H nuclear magnetic resonance.
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PMID:Synthesis of 1,2-diacyl-sn-glycerophosphatidylserine from egg phosphatidylcholine by phosphoramidite methodology. 872 48

Leishmania donovani donovani amastigotes, isolated from spleens of infected hamsters or axenically cultured, and promastigotes were comparatively examined for the expression of lipophosphoglycans (LPG). Parasites were metabolically labeled with [32p]-phosphate, [3H]galactose, or [3H]mannose. Radiolabeled material was extracted with water/ethanol/diethylether/pyridine/NH40H and purified further by gel filtration and hydrophobic column chromatographies. These radiolabeled compounds were identified as phosphorylated lipid-containing glycoconjugates. Mild acid treatment resulted in degradation of the glycolipids into low-molecular-weight fragments. All glycolipids isolated were susceptible to nitrous acid and phosphatidylinositol-specific phospholipase C treatments, as has been reported for the L. donovani promastigote LPG. Moreover, glycoconjugates purified from the three Leishmania stocks were not susceptible to trypsin treatment. Acid hydrolysis of promastigote LPG resulted in a predominant [P04-6galactose(beta1,4)mannose(alpha)1] fragment. In contrast, the main radiolabeled anionic fragments isolated from splenic and axenic amastigotes differed from that of promastigotes, as evidenced by the elution profiles obtained by HPLC anion-exchange chromatography. These cumulative results indicate that lipophosphoglycan molecules, structurally distinct from the previously characterized LPG of the promastigote stage, are being expressed by L. donovani splenic and axenic amastigotes.
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PMID:Isolation of lipophosphoglycans from Leishmania donovani amastigotes. 883 32


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