Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The levels of prostaglandin F1 (6-keto-PGF1 alpha), thromboxane B2 (11-dehydro-TxB2), and peptidoleukotriene C4 (LTC4) were measured (acetylcholinesterase immunoassay) in the frontal cortex (FC) and the striatum (SA) of the rat brain to study the possible role of eicosanoids in seizures induced by hyperbaric oxygen (HBO). The rats were exposed to (1) hyperbaric oxygen (HBO, 6 ATA O2) up to the first seizure (2) compressed air (6 ATA air, i.e., approximately equal to 1.25 ATA O2) or (3) atmospheric pressure (1 ATA air, i.e., 0.21 ATA O2); there was no seizure in groups 2 and 3. Transition from 6 ATA to atmospheric pressure was obtained in 15 min; the rats were then decapitated and their heads frozen in liquid nitrogen before extraction and analysis of prostanoids. Whatever the conditions, cortical levels of 6-keto-PGF1 alpha and 11-dehydro-Tx B2 are higher than striatal levels; considering the same area, 11-dehydro-Tx B2 and LTC4 concentrations were not significantly different whatever the condition, but there is a trend for lower 6-keto-PGF1 alpha levels in FC after HBO seizure. Biochemical mechanisms are discussed. Eicosanoids do not seem to play a major role in HBO seizures, although some modifications of their metabolism may take place.
Mol Chem Neuropathol 1991 Aug
PMID:The influence of one hyperbaric oxygen-induced seizure on brain eicosanoid content. 177 30

Multiple molecular forms of acetylcholinesterase have been isolated and characterized from the root-knot nematodes Meloidogyne arenaria and Meloidogyne incognita. The forms of enzyme present in these 2 species are similar but not identical to those that occur in the free-living nematode Caenorhabditis elegans. The 5 enzyme forms exhibit differential solubilities and can be classified into 3 classes, A, B, and C, based on substrate affinity, inhibitor and detergent sensitivity, and thermal inactivation profiles. An unusual class of acetylcholinesterase has been isolated from Meloidogyne which has very high affinity for acetylcholine, but is highly resistant to carbamate and organophosphate inhibitors. The potential roles of the molecular forms in nematode behavior and sensitivity to nematicides are discussed.
Mol Biochem Parasitol 1991 Dec
PMID:Characterization of acetylcholinesterase molecular forms of the root-knot nematode, Meloidogyne. 177 64

The epithelial cells of the human intestine exhibit a cholinesterase activity which is restricted to the apex of the villi. This activity displays a maximum in the colon and a minimum in the jejunum. Contrary to most of the studied vertebrates, the human cells present both acetylcholinesterase and butyrylcholinesterase activities, acetylcholinesterase being predominant in all the intestinal segments: duodenum, jejunum, ileum and colon. Like in the other vertebrates, only globular forms are identified by sucrose gradient centrifugation. However, the simultaneous presence, on the one hand of three globular forms (G1, G2 and G4) and, on the other hand of soluble as well as detergent-soluble molecular species seems to be a particular feature of the human cells.
Mol Cell Biochem 1991 Dec 11
PMID:Human intestine epithelial cell acetyl- and butyrylcholinesterase. 177 60

1. Coding sequences for the human acetylcholinesterase (HuAChE; EC 3.1.1.7) hydrophilic subunit were subcloned in an expression plasmid vector under the control of cytomegalovirus IE gene enhancer-promoter. The human embryonic kidney cell line 293, transiently transfected with this vector, expressed catalytically active acetylcholinesterase. 2. The recombinant gene product exhibits biochemical traits similar to native "true" acetylcholinesterase as manifested by characteristic substrate inhibition, a Km of 117 microM toward acetylthiocholine, and a high sensitivity to the specific acetylcholinesterase inhibitor BW284C51. 3. The transiently transfected 293 cells (100 mm dish) produce in 24 hr active enzyme capable of hydrolyzing 1500 nmol acetylthiocholine per min. Eighty percent of the enzymatic activity appears in the cell growth medium as soluble acetylcholinesterase; most of the cell associated activity is confined to the cytosolic fraction requiring neither detergent nor high salt for its solubilization. 4. The active secreted recombinant enzyme appears in the monomeric, dimeric, and tetrameric globular hydrophilic molecular forms. 5. In conclusion, the catalytic subunit expressed from the hydrophilic AChE cDNA species has the inherent potential to be secreted in the soluble globular form and to generate polymorphism through self-association.
Cell Mol Neurobiol 1991 Feb
PMID:Recombinant human acetylcholinesterase is secreted from transiently transfected 293 cells as a soluble globular enzyme. 184 51

1. In a recent study, we distinguished two classes of amphiphilic AChE3 dimers in Torpedo tissues: class I corresponds to glycolipid-anchored dimers and class II molecules are characterized by their lack of sensitivity to PI-PLC and PI-PLD, relatively small shift in sedimentation with detergent, and absence of aggregation without detergent. 2. In the present report, we analyze the amphiphlic or nonamphiphilic properties of globular AChE forms in T28 murine neural cells, rabbit muscle, and chicken muscle. The molecular forms were identified by sucrose gradient sedimentation in the presence and absence of detergent and analyzed by nondenaturing charge-shift electrophoresis. Some amphiphilic forms showed an abnormal electrophoretic migration in the absence of detergent, because of the retention of detergent micelles. 3. We show that the amphiphilic monomers (G1a) from these tissues, as well as the amphiphilic dimers (G2a) from chicken muscle, resemble the class II dimers of Torpedo AChE. We cannot exclude that these molecules possess a glycolipidic anchor but suggest that their hydrophobic domain may be of a different nature. We discuss their relationship with other cholinesterase molecular forms.
Cell Mol Neurobiol 1991 Feb
PMID:Amphiphilic, glycophosphatidylinositol-specific phospholipase C (PI-PLC)-insensitive monomers and dimers of acetylcholinesterase. 184 52

1. After a brief survey of the basic affinity electrophoresis concepts, the usual ways for preparing affinity electrophoresis ligands are examined. 2. Then results obtained on cholinesterases are reviewed. This section includes (a) structural and functional investigations on anionic sites, i.e., study of ligand-induced conformational change, organophosphate-induced "aging," genetic variants, and active-site topology; and (b) characterization of cholinesterase conjugates (hybrid proteins) and glycoinositol phospholipid-anchored cholinesterases. 3. The future prospects of affinity electrophoresis, e.g., investigations on the esteratic site and exploration of the carbohydrate moiety, are emphasized in the concluding section.
Cell Mol Neurobiol 1991 Feb
PMID:Structural and functional investigations of cholinesterases by means of affinity electrophoresis. 184 53

1. We analyzed the mode of attachment of 16 S tailed acetylcholinesterase (AChE; EC 3.1.1.7) to rat superior cervical ganglion (SCG) neuronal membranes. Using extractions by high-salt (HS) and nonionic detergent (Triton X-100), we found two pools of 16 S AChE. 2. The detergent-extracted (DE) 16 S AChE was tightly bound to membranes through detergent-sensitive, high-salt insensitive interactions and was distinct from high-salt-soluble 16 S AChE. The detergent-extracted (DE) 16 S AChE constituted a significant proportion of about one-third of the total 16 S AChE. 3. Treatment of the neuronal membranes by a phosphatidylinositol-specific phospholipase C (PIPLC) resulted in the release of some, but not all DE 16 S AChE, indicating that a significant amount of the neuronal DE 16 S AChE, about one-third, is anchored to membranes through a phosphatidylinositol containing residue. Thus, a covalent association of a glycolipid and catalytic or structural AChE polypeptidic chains occurs not only for dimeric AChE but also for the asymmetric species of AChE. 4. The complex polymorphism of AChE is due not only to different globular or asymmetric associations of catalytic and structural subunits but also to the alternative existence of a transmembrane domain or a glycolipid membrane anchor.
Cell Mol Neurobiol 1991 Feb
PMID:Phosphatidylinositol is involved in the attachment of tailed asymmetric acetylcholinesterase to neuronal membranes. 184 54

1. We describe two simple procedures for the rapid identification of certain structural features of glycolipid anchors in acetylcholinesterases (AChEs). 2. Treatment with alkaline hydroxylamine (that cleaves ester-linked acyl chains but not ether-linked alkyl chains) converts molecules possessing a diacylglycerol, but not those with an alkylacylglycerol, into hydrophilic derivatives. AChEs in human and bovine erythrocytes possess an alkylacylglycerol (Roberts et al., J. Biol. Chem. 263:18766-18775, 1988; Biochem. Biophys. Res. Commun. 150:271-277, 1988) and are not converted to hydrophilic dimers by alkaline hydroxylamine. Amphiphilic dimers of AChE from Drosophila, from mouse erythrocytes, and from the human erythroleukaemia cell line K562 also resist the treatment with hydroxylamine and likely possess a terminal alkylacylglycerol. This indicates that the cellular pool of free glycolipids used as precursors of protein anchors is distinct from the pool of membrane phosphatidylinositols (which contain diacylglycerols). 3. Pretreatment with alkaline hydroxylamine is required to render the amphiphilic AChE from human erythrocytes susceptible to digestion by Bacillus thuringiensis phosphatidylinositol-specific phospholipase C (PI-PLC) (Toutant et al., Eur. J. Biochem. 180:503-508, 1989). We show here that this is also the case for the AChE from mouse erythrocytes, which therefore likely possesses an additional acyl chain in the anchor that prevents the action of PI-PLC. 4. In two sublines of K562 cells (48 and 243), we observed that AChE either was directly susceptible to PI-PLC (243) or required a prior deacylation by alkaline hydroxylamine (48). This suggests that glycolipid anchors in AChE of K562-48 cells, but not those in AChE of K562-243 cells, contain the additional acylation demonstrated in AChE from human erythrocytes. These observations illustrate the cell specificity (and the lack of species-specificity) of the structure of glycolipid anchors.
Cell Mol Neurobiol 1991 Feb
PMID:Rapid analysis of glycolipid anchors in amphiphilic dimers of acetylcholinesterases. 184 55

1. The acetylcholinesterase (AChE) gene from the important malaria vector Anopheles stephensi has been isolated by homology to the Drosophila acetylcholinesterase gene. 2. The complete sequence and intron-exon organization has been determined. The encoded protein has 69% identity to Drosophila AChE and 38 and 36% identity to Torpedo AChE and human butyrylcholinesterase, respectively.
Cell Mol Neurobiol 1991 Feb
PMID:The acetylcholinesterase gene of Anopheles stephensi. 190 15

Previous investigations have suggested that immune-sensitization increases airway smooth muscle responsiveness to cholinomimetic stimulation by reducing the rate of degradation of acetylcholine. To examine the hypothesis that increased cholinomimetic responsiveness of tracheal smooth muscle (TSM) caused by immune-sensitization results from inhibition of acetylcholinesterase (AChase) activity, we developed a method for direct measurement of AChase activity in homogenates of TSM obtained from mongrel dogs actively sensitized in vivo to ragweed pollen extract (n = 7) and sham-sensitized littermate controls (n = 7). For both sensitized and control specimens, saturation of AChase was obtained at approximately 3.12 mM substrate (acetylthiocholine); however, maximal enzyme activity in homogenates of ragweed-sensitized tissues was significantly less (0.862 +/- 0.088 absorbance units/min/mg protein [AU/min/mg]) compared to control homogenates (1.590 +/- 0.129 AU/min/mg; P less than 0.001). Kinetic analysis (Eadie-Hofstee plot) indicated similar Michaelis constants (Km) for AChase from ragweed-sensitized (0.360 +/- 0.063) and control (0.336 +/- 0.062) homogenates (P = NS). The concentration of physostigmine eliciting half-maximal inhibition (Ki) of AChase activity also was similar for tissues from sensitized (-7.92 +/- 0.032 log M) and control animals (-7.86 +/- 0.012 log M; P = NS). Pretreatment with selected mediators of anaphylaxis (10(-4) M histamine, 10(-6) M serotonin, 10(-5) M prostaglandin E2, 10(-6) M prostaglandin F2 alpha, and 10(-7) M leukotriene D4) did not affect AChase activity. Our data demonstrate reduced AChase activity in homogenates of canine TSM after active immune-sensitization in vivo. This corresponds to functional augmentation of cholinomimetic contraction in actively sensitized tissues.
Am J Respir Cell Mol Biol 1991 Jul
PMID:Reduced activity of acetylcholinesterase in canine tracheal smooth muscle homogenates after active immune-sensitization. 190 87


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