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)

Human neutrophils which are pretreated with subtoxic concentrations of a variety of lysophosphatides (lysophosphatidylcholine, lysophosphatidylcholine oleoyl, lysophosphatidylcholine myrioyl, lysophosphatidylcholine stearoyl, lysophosphatidylcholine gamma-O-hexadecyl, lysophosphatidylinositol, and lysophosphatidylglycerol) act synergistically with neutrophil agonists phorbol myristate acetate, immune complexes, poly-L-histidine, phytohemagglutinin, and N-formyl-methionyl-leucyl-phenyalanine to cause enhanced generation of superoxide (O2-). None of the lyso compounds by themselves caused generation of O2-. The lyso compounds strongly bound to the neutrophils and could not be washed away. All of the lyso compounds that collaborated with agonists to stimulate O2- generation were hemolytic for human red blood cells. On the other hand, lyso compounds that were nonhemolytic for red blood cells (lysophosphatidylcholine caproate, lysophosphatidylcholine decanoyl, lysophosphatidylethanolamine, lysophosphatidylserine) failed to collaborate with agonists to generate synergistic amounts of O2-. However, in the presence of cytochalasin B, both lysophosphatidylethanolamine and lysophosphatidylserine also markedly enhanced O2- generation induced by immune complexes. O2- generation was also very markedly enhanced when substimulatory amounts of arachidonic acid or eicosapentanoic acid were added to PMNs in the presence of a variety of agonists. On the other hand, neither phospholipase C, streptolysin S (highly hemolytic), phospholipase A2, phosphatidylcholine, nor phosphatidylcholine dipalmitoyl (all nonhemolytic) had the capacity to synergize with any of the agonists tested to generate enhanced amounts of O2-. The data suggest that in addition to long-chain fatty acids, only those lyso compounds that possess fatty acids with more than 10 carbons and that are also highly hemolytic can cause enhanced generation of O2- in stimulated PMNs.
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PMID:Lysophosphatides enhance superoxide responses of stimulated human neutrophils. 254 11

A vasodepressor phospholipid fraction named Depressor-IA from a bovine brain lipid extract was analyzed by capillary gas-liquid chromatography-mass spectrometry as tert-butyldimethylsilyl derivatives after hydrolysis with phospholipase C. Results show that Depressor-IA is a mixture of 3 platelet-activating factors and 17 1-acyl analogues. Three platelet-activating factors having sn-1-O-hexadecyl, octadecyl, and octadecenyl groups were suggested to account for the hypotensive activity of Depressor-IA, although the total amount of 1-acyl analogues of platelet-activating factor was much more than that of platelet-activating factor in the purified Depressor-IA. 1-Long-chain acyl-2-short-chain acyl-glycero-3-phosphocholines identified in Depressor-IA included novel molecular analogues having sn-2-propionyl, acryloyl, butyryl, valeryl, caproyl, and hepatonoyl groups.
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PMID:Novel molecular analogues of phosphatidylcholines in a lipid extract from bovine brain: 1-long-chain acyl-2-short-chain acyl-sn-glycero-3-phosphocholines. 271 26

Fast atom bombardment-tandem mass spectrometry was used to identify molecular species of paf-acether (paf) produced by human polymorphonuclear neutrophils. Using this biological material, normal phase high performance liquid chromatography was necessary prior to the fast atom bombardment-tandem mass spectrometry step. Gas liquid chromatography/electron capture detection after hydrolysis with phospholipase C and conversion to heptafluorobutyrate derivatives was used to confirm the results. The results indicated the presence of mainly 1-O-hexadecyl/octadecyl-2-acetyl-sn-glycero-3-phosphocholine, acyl analogs of paf and only trace amounts of other alkyl analogs of paf. We did not detect the 2-propionyl analog of paf. Moreover, supplementation of human polymorphonuclear neutrophils with sodium propionate did not result in formation of the 2-propionyl analog of paf.
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PMID:Capillary gas chromatography and tandem mass spectrometry of paf-acether and analogs: absence of 1-O-alkyl-2-propionyl-sn-glycero-3-phosphocholine in human polymorphonuclear neutrophils. 275

Platelet-activating factors, 1-O-hexadecyl- and 1-O-octadecyl-2-acetyl-sn-glycero-3-phosphocholine (C16-AGEPC and C18AGEPC), were measured by reverse-phase high-performance liquid chromatography with fluorescent detection. C16AGEPC, C18AGEPC, and 1-O-hexadecyl-2-propionyl-sn-glycero-3-phosphocholine, which was suitable for use as an internal standard, were hydrolyzed with phospholipase C, and then the resulting hydrolyzed products were derivatized with 7-methoxycoumarin-3-carbonyl chloride or 7-methoxy-coumarin-4-acetic acid to form 7-methoxycoumarin ester derivatives which permit a fluorometric detection. The lower limit of detection of the derivatives was about 100 pg at a signal-to-noise ratio of 5:1. A commercial platelet-activating factor was demonstrated to contain C16AGEPC (70%) and C18AGEPC (12.8%) by the present method. The present method was also applicable to the measurement of acetyl-CoA:1-alkyl-2-lyso-sn-glycero-3-phosphocholine acetyltransferase activity in a lysate of human polymorphonuclear leukocytes.
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PMID:Quantitation of platelet-activating factor by high-performance liquid chromatography with fluorescent detection. 281 35

Two physicochemical methods have been developed for the quantitative analysis of lyso-platelet activating factor (lyso-PAF) based on gas-liquid chromatography-mass spectrometry (GLC/MS) and fast atom bombardment-mass spectrometry (FAB/MS) using stable isotope dilution. After addition of deuterated internal standards, lyso-PAF produced from neutrophils was purified by silicic acid chromatography and thin-layer chromatography (TLC). The GLC/MS assay employed phospholipase C or hydrofluoric acid for hydrolysis of the phosphocholine moiety to yield ether monoglycerides. Condensation of monoglycerides with acetone yielded the 1-O-alkyl-2,3-isopropylidene glycerol which could be analyzed by GLC/MS. The ions corresponding to M-15 fragments for both the labeled and unlabeled derivatives were monitored in a selected ion recording mode. Standard curves were found to be linear over the range tested (10-2000 ng) with a limit of detection found to be below 200 pg injected on column. For the FAB/MS assay, the unmodified lyso-PAF was well suited for direct analysis; however, the limit of detection (S/N greater than 3) using a glycerol matrix was found to be 5 ng placed on the probe tip. It was found that human neutrophils contain approximately 300 pg/10(6) cells which increased 2-3-fold during the 5-min period following challenge with 1.9 microM calcium ionophore, A23187. Two molecular species of lyso-PAF were identified as hexadecyl and octadecyl ethers at sn-1 with the octadecyl molecular species of lyso-PAF predominating in abundance after stimulation.
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PMID:Quantitation of lyso-platelet activating factor molecular species from human neutrophils by mass spectrometry. 310 21

This study identifies and partially characterizes an insulin-sensitive glycophospholipid in H35 hepatoma cells. The incorporation of [3H]glucosamine into cell lipids was investigated. A major labeled lipid was purified by sequential thin layer chromatography using first an acid followed by a basic solvent system. After hydrochloric acid hydrolysis and sugar analysis by thin layer chromatography, 80% of the radioactivity in the purified lipid was found to comigrate with glucosamine. H35 cells were prelabeled with [3H]glucosamine for either 4 or 24 h and treated with insulin causing a dose-dependent stimulation of turnover of the glycophospholipid which was detected within 1 min. The purified glycolipid was cleaved by nitrous acid deamination indicating that the glucosamine C-1 was linked to the lipid moiety through a glycosidic bond. [14C]Ethanolamine, [3H]inositol, and [3H]sorbitol were not incorporated into the purified glycolipid. The incorporation of various fatty acids into this glycolipid was also studied. [3H]Palmitate was found to be preferentially incorporated while myristic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and arachidonic acid were either not incorporated or incorporated less than 10% of palmitate. The purified glycolipid labeled with [3H]palmitate was cleaved by treatment with phospholipase A2 but was resistant to mild alkali hydrolysis suggesting the presence of a 1-hexadecyl,2-palmitoyl-glyceryl moiety in the purified lipid. Treatment of labeled glycophospholipid with phosphatidylinositol-specific phospholipase C from Staphylococcus aureus generated a compound migrating as 1-alkyl,2-acyl-glycerol and a polar head group with a size in the range from 800 to 3500. These findings coupled with the nitrous acid deamination demonstrate that glucosamine was covalently linked through a phosphodiester bond to the glyceryl moiety of the purified glycolipid. These findings suggest that insulin acts on this glycophospholipid by stimulating an insulin-sensitive phospholipase C. This unique glycophospholipid may play an important role in insulin action by serving as precursor of insulin-generated mediators.
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PMID:Identification of a novel insulin-sensitive glycophospholipid from H35 hepatoma cells. 354 86

Platelet activating factor was isolated from scales of psoriatic patients by the procedure of Bligh and Dyer and purified by silica gel thin layer chromatography. The purified PAF was digested with phospholipase C and the resulting diglyceride was derivatized into PFB ethers. The PAF-PFB ethers were analyzed using fused silica capillary chromatography-negative ion chemical ionization mass spectrometry. Different molecular species of PAF were identified by their negative ion mass spectra and by their elution time from the capillary column. All the molecular species had high abdundance (greater than 90%) of the molecular anion. 1-0-Hexadecyl-2-acetyl-GPC (16:0) was the major PAF species representing 51% of the total PAF. 17:0 and 18:1 were the next abundant species representing 15 and 16%, respectively. Several minor PAF molecular species were also present. The amount of each PAF molecular species was quantitated from 1-0-hexadecyl-2-2H3 acetyl-GPC used as the internal standard. Nanogram quantities of PAF were recovered from 100 mg of psoriatic scales. Significant amounts of lysoPAF were also present in these scales. The alkyl chain of the lysoPAF was compared with that of PAF.
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PMID:Identification and quantitation of PAF from psoriatic scales. 368 90

Platelet-activating factor (PAF) was found in normal rat uterus and identified as 1-0-hexadecyl/octadecenyl-2-acetyl-sn-glycero-3-phosphocholine. PAF was purified by several successive chromatographic procedures. It showed platelet aggregating activity, which was inhibited by CV 3988, and had no effect on platelets desensitized with 1-0-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine. The tert-butyldimethyl-silylderivative of 1-0-alkyl-2-acetyl-sn-glycerol, which was obtained by hydrolysis of uterine PAF with phospholipase C, was analyzed by gas chromatography-mass spectrometry. One rat uterus contained approximately 21.3 ng of 1-0-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine. This is the first report of the occurrence of a significant amount of PAF in a normal animal tissue.
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PMID:Platelet-activating factor in normal rat uterus. 375 95

Chicken egg yolk phospholipids were subjected to mild alkaline hydrolysis. The resulting alkali-stable phospholipids were characterized by chemical chromatographic, and enzymatic methods. Two major phospholipids, 1 - O - alkyl - sn - glycero - 3 - pohosphoethanolamine and sphingomyelin; and two minor phospholipids, 1-O-alkenyl-sn-glycero-3-phosphoethanolamine and 1-O-alkyl-sn-glycero-3-phosphocholine; were identified. The sphingomyelins were converted into ceramides by enzymatic hydrolysis with phospholipase C. Ceramides derived from sphingomyelins with non-hydroxy fatty acids (99% of total ceramides) consisted predominantly of the N-palmitoyl, N-stearoyl, and N-nervonyl species. Ceramides derived from sphingomyelins with hydroxy fatty acids (1% of total ceramides) consisted almost exclusively of the N-alpha-hydroxyeicosanoyl species. The long chain bases of ceramides derived from both species of sphingomyelins (hydroxy and non-hydroxy fatty acids) consisted of 97% D-erythro-sphing-4-enine and 3% D-erythro-sphinganine, 1-O-alkyl-sn-glycero-3-phosphoethanolamine and 1-O-alkyl-sn-glycero-3-phosphocholine were converted to corresponding 1-O-alkyldiacetylglycerols. The 1-O-alkyldiacetylglycerols derived from both ether phospholipids consisted largely of the hexadecyl and octadecyl species. Smaller quantities of the heptadecyl, cis-9-octadecenyl and eicosanyl derivatives were also present.
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PMID:Mild alkali-stable phospholipids in chicken egg yolks: characterization of 1-alkenyl and 1-alkyl-sn-glycero-3-phosphoethanolamine, sphingomyelin, and 1-alkyl-sn-glycero-3-phosphocholine. 719 4

Smooth muscle cells isolated from the circular muscle layer of cat esophagus and lower esophageal sphincter (LES) exhibit distinct contractile intracellular signal transduction pathways in response to acetylcholine. To determine whether these contractile pathways are muscle type dependent, the authors examined the signal transduction pathways utilized by substance P and bombesin, which in other tissues, use different signal transduction pathways, and by the GTP analog, guanosine 5'-O-3-thiotriphosphate (GTP gamma S), which activates all available G proteins. Western blot analysis of esophageal and LES circular muscle revealed the presence of Gq-G11 (42 kD), Gi1-Gi2 (40 kD) and Go-Gi3 (40 kD) types of G proteins. The responses of esophageal cells to bombesin and substance P were blocked by 1) a Gi3 protein antibody, 2) the inhibitor of specific phosphatidylcholine-phospholipase C (PLC) D609 potassium tricyclo-[5.2.1.0(2.6)]-decyl-(9[8])-xanthogenate, 3) inhibition of phosphatidic acid phosphohydrolase by propranolol, 4) the protein kinase C inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H7) and 5) incubation in Ca(++)-free medium. Conversely, the responses of LES muscle cells to bombesin and substance P were blocked by 1) a Gq-G11 antibody, 2) a phosphatidylinositol-specific PLC antagonist U-73122 (1-[6-[[17 beta-3-methoxyestra-1,3,5(10)-trien-17- yl]amino]hexyl]-1H-pyrrole-2,5-dione), 3) the calmodulin inhibitor CGS9343B (1,3-Dihydro-1-[1-((4-methyl-4H,6H-pyrrolo[1,2-a]-[4,1]benzoxazepin++ +-4 - yl)methyl-4-piperindinyl]-2H-benzimidazol-2-one maleate) and 4) incubation in Sr++. After permeabilization by saponin, inositol 1,4,5-trisphosphate contracted LES but not esophageal cells. The inositol 1,4,5-trisphosphate receptor antagonist heparin and depletion of intracellular Ca++ stores by thapsigargin or A23187 4-Benzoxazolecarboxylic acid, 5-(methylamino)-2-[[3,9,11-trimethyl-8-[1-methyl-2-oxo-2-(1H-pyrrol- 2-yl)ethyl]-1,7-dioxaspiro[5.5]undec-2-yl]methyl]-, [6s-[6.alpha. (2S*,3S*),8.beta. (R*), 9.beta., 11. alpha.]]-(9Cl), blocked bombesin- and substance P-induced contraction of LES but not of esophageal muscle. In addition, contraction in response to GTP gamma S, which activates all G proteins, was blocked in esophageal cells by a Gi3-protein antibody, propranolol, D609 and H7. In LES muscle cells, the response to GTP gamma S was blocked by a Gq protein antibody, U-73122 and CGS934B. These data demonstrate that, in esophageal muscle, different agonists activate the same Gi3 protein, phosphatidylcholine-specific phospholipases and protein kinase C-dependent pathway.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Agonist-independent, muscle-type-specific signal transduction pathways in cat esophageal and lower esophageal sphincter circular smooth muscle. 753 46


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