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:3.1.1.7 (acetylcholinesterase)
28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Axolemma-enriched fractions were prepared from rat brain by osmotic shock of a purified preparation of myelinated axons and subsequent separation of myelin, two axolemma-enriched fractions and myelin-free axons by density gradient centrifugation. Compared with the starting whole homogenate, the fractions were enriched in specific activity of Na+K+ ATPase, acetylcholinesterase, 5'nucleotidase as well as 2',3'-cyclic nucleotide 3'phosphohydrolase. Compared with myelin, the axolemmal fractions are greatly enriched in high molecular weight proteins. The 1.0/1.2 fraction has a predominant peak of fucose-labeled glycoprotein with a molecular weight between that of the myelin associated glycoprotein and the Wolfgram protein which is absent from the myelin glycoprotein profile. Polyacrylamide gel electrophoresis showed that the protein profile of myelin isolated by this procedure was similar to that of myelin isolated by other procedures and that the myelin specific basic and proteolipid proteins were virtually absent in the axolemma-enriched fractions. Both axolemma fractions were enriched in higher MW proteins, some of which resembled proteins in the myelin protein profile. Both axolemma-enriched fractions specifically bind between 2 and 3 pmoles of [3H]tetrodotoxin per mg protein. The axolemma-enriched fractions incorporated [3H]leucine and [14C]fucose exclusively into high molecular weight proteins and glycoproteins. In contrast myelin concomitantly isolated with the axolemma-enriched fractions had a significant amount of [3H]leucine labeled protein in myelin proteolipid and basic proteins. In addition to the myelin associated g-ycoprotein the [14C]fucose labeled a glycoprotein of slightly larger apparent molecular weight than proteolipid protein was found in the myelin fraction while the comparable labeled glycoprotein was absent in the axolemma-enriched fractions. The possible extent of contamination of these fractions by myelin or myelin subfractions and relationship of these axolemma-enriched fractions to other axolemma preparations are discussed.
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PMID:Isolation and partial characterization of rat CNS axolemma enriched fractions. 20 16

1. The cholinesterase (ChE) of frog brain and retina could be easily solubilized. About 10% of the brain and 20% of the retina ChE were found to be soluble in 0.05 M phosphate buffer. After treatment with 0.5% (v/v) Triton X-100, about 30% of the total ChE activity of the brain and only 10% for retina was left particle bound. NaCl by itself did not solubilize ChE. Use of higher NaCl concentrations in combination with Triton X-100 as well as higher detergent concentrations alone seemed to cause an inhibiting effect of the solubilized ChE from retina. 2. The solubilized ChE from brain as well as retina were electrofocused as one main activity peak, corresponding to isoelectric points of pH 6.1 and 6.0, respectively. A second molecular form at pH 5.9 was distinguishable for the brain, but not for retina ChE. 3. Sucrose gradient centrifugation indicated that the ChE solubilized from the brain and retina consists of two molecular forms exhibiting S values of 5.1 +/- 0.24, 10.9 +/- 0.33 and 6.1 +/- 0.30, 10.9 +/- 0.43, respectively. After solubilization by higher Triton X-100 concentrations the soluble extracts from brain and retina seemed to contain the activity of these forms in different proportions. 4. Polyacrylamide gel electrophoresis separated three molecular forms of the brain ChE. One of these forms was found to have a molecular weight of 394,000 +/- 20,000. The others were found to have an identical molecular weight of 550,000 +/- 10,000. Two molecular forms exhibiting molecular weights of 292,000 +/- 10,000 and 470,000 +/- 10,000, could be separated for retina.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Solubilization of frog brain and retina cholinesterase and studies of different molecular forms. 31 46

Nine bispyridinium oximes containing two pyridinium rings linked by dimethylether were synthesised. Each compound had on one of the pyridinium rings a hydroxyiminomethyl group in position 2 or 4, while the other ring was unsubstituted or had a methyl or a hydroxyiminomethyl group in position 2 or 4. The reactivating potency and therapeutic effect of the oximes were tested on two organophosphates: O,O-dimethyl-2,2-dichlorovinylphosphate (DDVP) and O-ethyl-S-(2-diisopropylaminoethyl)-methylphosphonothioate (VX). The reactivation was measured on human erythrocyte acetylcholinesterase and the therapeutic effect was evaluated on male albino rats. The oximes with a hydroxyiminomethyl group in position 4 in the pyridinium ring were good reactivators of both phosphorylated and phosphonylated acetylcholinesterase. They were also very effective given together with atropine against VX and DDVP poisoning. The compounds are almost as effective as PAM-2, but PAM-2 is less toxic.
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PMID:1,3-Bispyridinium-dimethylether mono- and dioximes: synthesis, reactivating potency and therapeutic effect in experimental poisoning by organophosphorus compounds. 43 80

Molecular layer, granular layer and white matter are dissected from bovine cerebellum under optical microscope and without freezing under conditions which preserve their main anatomical features. Polyacrylamide gel electrophoresis in sodium dodecyl sulphate of the isolated layers reveal that the P400 protein characteristic of the Purkinje cells is found in the isolated molecular layer and in the molecular layer free from Purkinje cell soma, but not in the granular layer or white matter. The histones (F1, F2A1,2, F2B, F3) are abundant in the granular layer and myelin proteins in the white matter. The DNA content per wet weight is 10 times greater in the isolated granular layer than in the other layers and the RNA content twice as great in the granular layer than in any other layer. The specific activity of acetylcholinesterase is 4 times greater in the granular layer than in the other layers. Homogenates of the isolated layers take up labeled amino-acids and the velocity of glutamate incorporation is 9 times greater in the molecular layer than in the granular layer, while GABA incorporation is about twice as great in the granular layer than in the molecular layer. Homogenates of isolated molecular layer are centrifuged on discontinuous Ficoll gradient after incubation with L[3H]glutamate and [14C]GABA. The analysis of the distribution of glutamate and GABA after centrifugation reveals that the particles which incorporate glutamate can be separated from those which take up GABA.
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PMID:Morphological and biochemical studies on isolated molecular and granular layers from bovine cerebellum. 63 47

The distribution of acetylcholinesterase (ACHe) in the twitch fibers of the extraocular muscles of the mouse was examined by light and electron microscope autoradiography after labeling with radioactive diisopropyl fluorophosphate (DFP) with, and without, 2-pyridine aldoxime methiodide (2-PAM) reactivation. The values obtained were compared with those previously reported for the diaphragm and sternomastoid muscles. The extraocular muscles were studied because they differ from the other two muscles in that they are among the fastest of the mammalian muscles, yet their endplates have sparse junctional folds. They could thus provide information on the extent to which ACHe concentration is an invariant feature of endplate morphology and what, if any aspects may be related to their fast speed of response. We found, using light microscope autoradiography, that in the twitch fibers of the extraocular muscle, there is n average of 6.4 +/- 2.1 X 10(7) DFP-binding sites per endplate, of which 29% (1.8 X 10(7)) are reactivated by 2-PAM and are thus AChe. The morphology of the extraocular endplates allowed us to conclude, on statistical grounds, that the AChe site are probably localized not only along the surface area of the postjunctional membrane (PJM) but also along the surface of the presynaptic axonal membrane. Based on this localization, we calculate 7,800 DFP sites and 2,500 2-PAM-reactivated sites/micron 2 of surface area of pre-and postjunctional membrane. This stacking density of DFP-binding sites per surface area of membrane ( probably in the overlying sheets of basal lamina) is very similar to that in the diaphragm and sternomastoid muscles.
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PMID:Acetylcholinesterase in the fast extraocular muscle of the mouse by light and electron microscope autoradiography. 67 Feb 95

1. Polyacrylamide gel electrophoresis in Tris/glycine buffer (pH 8.3) revealed five forms of acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) in the 100 000 X g, 1-h supernatants of aqueous fly-head extracts from the DDT/S strain. Five other housefly strains (CSMA, Bayer 21/199, Cradson/P, Malathion/R and DDT/R)were shown qualitatively to have the same soluble forms of the enzyme. 2. Plots of the electrophoretic mobility versus polyacrylamide concentration indicated that the multiple forms constituted a size isomer family. From the retardation coefficients derived from these plots, molecular weight estimates were obtained; these suggested that the smallest active component was a form of approx. 80 000 daltons. The higher aggregates, however, did not appear as simple oligomers of this component. 3. Density gradient sedimentation supported the electrophoretic findings. The smallest active component, with a sedimentation coefficient of 5.3 S, was confirmed as a molecular species of acetylcholinesterase that has not previously been obtained from house-flies; higher aggregates gave sedimentation coefficients of 7.4, 7.8. 8.1, and 11.8 S. 4. Gel-filtration on calibrated Sephadex G-150 columns provided further evidence that the smallest active component was a form of about 80 000 daltons. 5. Autolysis converted much of the particulate enzyme and all of the soluble forms into a species of approx. 160 000 daltons indistinguishable from the native 7.4-S form. Both the autolysed enzyme and the native 7.4-S form were susceptible to cleavage by disulphide reducing agents, and released catalytically active subunits that corresponded to the 5.3-S form of 80 000 daltons. The data were compatible with a monomer-dimer relationship between the 5.3-S and 7.4-S forms. 6. The possibility is suggested that a form of molecular weight approx. 80 000 constitutes the "fundamental unit" of insect cholinesterase.
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PMID:Acetylcholinesterase from the house-fly head. Molecular properties of soluble forms. 95 30

1. Acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) of house-fly head tissue was solubilized as a 7.4-S form by autolysis for 80-100 h at 25 degrees C and pH 8.0. 2. The autolysed enzyme was purified by affinity chromatography, firstly on Con-A-Sepharose and subsequently on m-trimethylammoniumaniline-Affi-Gel 202. This sequence permitted overall purification yields of approx. 50% of the solubilized enzyme. 3. The 7.4-S purified enzyme was essentially homogeneous on polyacrylamide gel electrophoresis, and its specific activity coincided with the highest previously reported for fly-head acetylcholinesterase. 4. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate and beta-mercaptoethanol revealed two major polypeptide components of molecular weight 82 000 and 59 000. Each of these polypeptides contained diisopropylphosphofluoridate-binding sites, as shown with [3H] diisopropylphosphofluoridate. 5. The results suggest a strong structural similarity between fly-head acetylcholinesterase and the purified electric eel enzyme.
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PMID:Acetylcholinesterase of the house-fly head. Affinity purification and subunit composition. 95 31

Application of Wittig reaction to 4-pyridinecarboxaldehyde leads to 4-beta-formylvinylpyridine (62%). The corresponding oxime (4-(2)) can be quaternized with alpha,alpha'-bis-(chloromegonin), and with methyliodide one to 4-PAM (4-(3)). In this case the formal insertion of an ethylenic double bond between the pyridinium ring and the aldoxime group decreases the ability to reactivate phosphorylated acetylcholinesterase (AChE).
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PMID:[Reactivation of phosphorylated acetylcholinesterase (AChE): quaternary salts of vinylogous pyridinaldoxims (author's transl)]. 103 47

PAM, a cholinesterase reactivator, was administered orally and parenterally to 37 patients with multiple sclerosis and a control group of 24 patients with other neurological diseases and pain syndromes. The effects of the administration of this compound in these patients with and without electrical stimulation of the spinal cord were studied. The clinical response to the drug follows a known time course and is dose related. Administration of large doses orally or intravenously aggravates existing neurological dysfunction. With a dose of 1,000 mg intravenously, a characteristic response is the temporary appearance of new ophthalmological abnormalities, followed by significant improvement in motor control and behavior, which gradually subsides. Parenteral administration is superior to oral. Tolerance to the drug is observed. The presence of electrical stimulation of the spinal cord complements the action of the drug. When electrical stimulation is withdrawn, the effect of the drug reproduces the effect of the electrical stimulation. It is suggested there is a defect in cholinesterase in multiple sclerosis patients, and its reactivation may have a significant relationship to signs and symptoms.
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PMID:Improvement of motor function in multiple sclerosis by use of protopam chloride. 135 24

The efficacy of oxime (HI-6, toxogonin or PAM Cl) therapy against GF (cyclohexyl methylphosphonofluoridate) poisoning was assessed in mice. It was found that the combinations of atropine and either toxogonin or HI-6 were effective therapies against GF poisoning. PAM therapy was ineffective. HI-6 was the only oxime which reactivated GF inhibited acetylcholinesterase. This might explain the reason why the HI-6 treated mice appeared to recover more quickly from the incapacitating effects following GF poisoning.
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PMID:Efficacy of various oximes against GF (cyclohexyl methylphosphonofluoridate) poisoning in mice. 160 30


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