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)

1. Proteolipid was extracted from the electric organ of Narke japonica by using chloroform/methanol (2:1, v/v). This extract was separated into acetylcholine-binding and non-binding substances by column chromatography. However, acetylcholine-binding substances did not show the characteristic properties of protein. 2. The membrane fragments of the electric organ were separated into three main parts by sucrose density gradient centrifugation. From the heaviest, the fractions were acetylcholine receptor rich, ATPase rich, and acetylcholinesterase rich. 3. The membrane fraction having acetylcholine receptor showed the excitability, the increase of Na+ permeability by the application of cholinergic agonists. However, the acetylcholine binding substance extracted by the organic solvent was richer in the lighter fraction. This substance differed from the true acetylcholine receptor.
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PMID:Acetylcholine-binding substance extracted by using organic solvent and acetylcholine receptor of electric organ of Narke japonica. 12 23

Membrane preparations of erythrocytes from normal and P. chabaudi-infected mice and membrane preparations of P. chabaudi-infected and uninfected erythrocytes from infected mice and separated by zonal centrifugation were characterized by the pattern of proteins and extracted glycoproteins obtained by SDS-polyacrylamide gel electrophoresis and by the specific activities of membrane associated enzymes. The protein pattern of the membrane preparation of infected erythrocytes showed similar differences from membrane preparations of normal erythrocytes as those described by Weidekamm et al. for P. berghei. The pattern of glycoproteins extracted by the chloroform-methanol method showed characteristic differences as compared to the controls. A new band (PASi) with a molecular weight of about 165,000 corresponds with the protein band IIa. In membrane preparations of normal erythrocytes and of nonparasitized erythrocytes separated from parasitized erythrocytes by zonal centrifugation was no difference in specific activities of ATPase, adenylate kinase and acetylcholinesterase. Adenylate kinase activity was markedly increased and acetyl-cholinesterase activity was slightly increased in membrane preparations of infected cells. Specific activities of ATPase of membrane preparations of normal and parasitized erythrocytes did not show significant differences. There was a decrease in enzyme activity of ATPase and an increase of acetylcholinesterase in Triton X 100 containing samples. Specific activities of an acid phosphatase were lower in membrane preparations of parasitized cells than in the controls.
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PMID:Plasmodium chabaudi-infection of mice: specific activities of erythrocyte membrane-associated enzymes and patterns of proteins and glycoproteins of erythrocyte membrane preparations. 19 21

The results of a preliminary rangefinding 13-wk oral toxicity study and of two longer term studies on chloroform in toothpaste base are reported. Significant changes in serum enzymes and certain haemotological parameters were seen at the higher dose-levels in the rangefinding study. Intercurrent disease made it necessary to terminate the first long-term experiment prematurely after 1 yr. No evidence of serious toxicity was recorded. In the second long-term experiment, groups of 50 caesarian-derived SPF Sprague-Dawley rats of each sex received either the equivalent of 60 mg CHCl3/kg/d in toothpaste base or the vehicle only, by gavage on 6 d/wk for 80 wk and were then observed for up to a further 15 wk. Chloroform-treated rats of both sexes survived better than the controls, though both groups had a high incidence of non-neoplastic respiratory and renal disease. Female rats gave a consistent finding of decrease in plasma cholinesterase, shown to be related to activity against butyrylcholine but not acetyl-beta-methylcholine. Tumours of various sites were seen in 39 percent of chloroform-treated rats of both sexes examined histologically, compared with 38 percent of vehicle controls. There were no treatment-related effects on the incidence of liver or kidney tumours. Histologically-malignant mammary tumours were reported in more treated than control rats, but the difference in incidence was not statistically significant.
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PMID:Safety evaluation of toothpaste containing chloroform. II. Long term studies in rats. 42 37

Acetylcholinesterase was released from bovine erythrocytes in hypo-osmotic sodium phosphate buffer. Initially, about 30% of the enzyme was released in a soluble lipoprotein form, and further incubation resulted in the progressive release of the enzyme in a particulate form. Solubilization of the acetylcholinesterase in the particulate fraction with Lubrol WX (2 mg/ml) resulted in the loss of all lipids except a non-exchangeable fraction identified as cardiolipin. Addition of a mixture of erythrocyte phospholipids to the soluble forms and to the Lubrol WX-solubilized enzyme resulted in the formation of particulate forms of the enzyme with increased partial specific volume and Stokes radius, and a break in the Arrhenius plot of the enzyme activity around 20 degrees C. The break in the Arrhenius plot was abolished by treatment of a soluble enzyme preparation with 1.8 M salt (NaCl) in phosphate buffer, conditions that allowed the extraction of cardiolipin from the enzyme by chloroform/methanol. Failure of the high-salt treatment to decrease the Stokes radius made it unlikely that the bound cardiolipin formed a boundary layer or annulus around the protein. It is suggested that cardiolipin is bound to the core of the dimeric protein structure, thereby controlling the acetylcholinesterase activity.
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PMID:Characterization of lipid-protein interactions in acetylcholinesterase lipoprotein extracted from bovine erythrocytes. 47 49

Lipoprotein forms of acetylcholinesterase from bovine erythrocytes gave non-linear Arrhenius plots with a break at 20 degrees C and contained cardiolipin. The break in the Arrhenius plot was abolished by incubation of the enzyme in high salt (I = 1.8), but only in Ca2+ -chelating conditions. At I = 1.8 neither NaCl alone, CaCl2 nor sodium phosphate at acidic pH abolished the break. However, at this ionic strength either NaCl in 2 mM sodium phosphate (pH 7.4) or sodium phosphate, pH 8, or 1.0 M Na2CO3/NaHCO3 (pH 8.5--10, were able to remove the break. The Arrhenius plot break was regenerated by the addition of Ca2+ to the high salt-treated enzyme with mild homogenization, but could not be regenerated in the presence of EDTA unless CaCl2 was added in excess of the EDTA. Conditions which abolished the break enabled endogenous cardiolipin to be removed from the enzyme by chloroform/methanol extraction Cardiolipin from acetylcholinesterase incubated in high salt in Ca2+ -chelating conditions was not accessible to digestion by phospholipase A2, and was not separated from the enzyme by flotation in a sucrose density gradient or by Sephadex G-200 chromatography. Thus both Ca2+ and cardiolipin appear to be inaccessible, possibly by being tightly associated in the hydrophobic core of the enzyme by ionic and hydrophobic forces. Ca2+ may modulate the temperature dependence of acetylcholinesterase activity through a functionally linked ionic interaction with the enzyme-cardiolipin complex.
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PMID:Involvement of calcium ions in the properties of cardiolipin-associated erythrocyte acetylcholinesterase. 54 28

Organic anions of particular importance to biochemistry such as Krebs cycle intermediates, glycolysis intermediates, simple fatty acids, adenine nucleotides and CoA derivatives can be quantitatively extracted from a buffered solution by high-molecular-weight ammonium salts in an organic solvent. Phosphate salts of tertiary amines in chloroform were the most efficient extractants. The isolation procedure was found to be an example of amine neutralization. The effect of pH, different inorganic anions, volume ratios between the two phases, concentration of the isolated anions and concentration of the ammonium salts have been investigated. The extraction technique has been applied to rapid and sensitive radiochemical methods for the determination of acetylcholinesterase and 4-aminobutyrate aminotransferase activities.
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PMID:Isolation of organic anions by extraction with liquid anion exchangers and its application to micromethods for acetylcholinesterase and 4-aminobutyrate aminotransferase. 72 Mar 40

Content of organophosphorous inhibitors (with the structure RO/CH3/P/O/SC2H4SC2H5) of cholinesterase as well as their hydrophobic properties (distribution coefficient in hexan/water system) were studied in subcellular fractions of rat brain. Relative content of organophosphorous inhibitors was distinctly decreased in supermicrosomal fraction with increase of hydrophobic properties of the fraction. Nuclear and mitochondrial fractions contained the more hydrophobic substances in relatively higher amount. When homogenate of supermicrosomal fraction was incubated at 37 degrees, own brain cholinesterase was not depressed by organophosphorous inhibitors, containing in the fraction at low concentration. The phenomenon exhibits that content of free organophosphorous inhibitors is distinctly lower in the subcellular fractions studied than amount of the inhibitors, extracted with chloroform.
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PMID:[Intracellular distribution of phosphoorganic cholinesterase inhibitors in rat brain]. 73 75

Hydrophobity (coefficient in distribution in the hexane water system) and the content of cholinesterase organophosphorous inhibitors (OPI) of the structure Ro (CH3) P (O) SC2H4 SC2H5 were studied in the rat brain. When the O-alkyl radical is increased hydrophobity rises and the relative content of free OPI in the brain extracted by chloroform decreases. With an increase in R from the ethyl to butyl one the ability to the additional inhibition of the brain own cholinesterase lowers due to incubation of homogenate at 37 degrees C, that evidences for an essential drop in the studied series of the free OPI fraction relative to the free OPI extracted by chloroform.
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PMID:[Binding of phosphoorganic cholinesterase inhibitors in rat brain tissue]. 98 15

The article deals with the hydrophobic character (distribution coefficient in the systems hexane - water and chloroform - water) and certain peculiarities of distributing three cation-containing phosphoroganic inhibitors of cholinesterase and their uncharged analogues in the organisms. The distribution coefficients in the charged and uncharged compounds in the system hexane - water differ inconsiderably, whereas in the system chloroform-water by the thousands and millions times. In rabbits with intravenous administration the content of all inhibitors in blood decreases rapidly, the uncharged compounds accumulate selectively in the lungs and the charged ones are distributed evenly in the tissues.
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PMID:[The distribution of cholinesterase charged phosphorganic inhibitors and their uncharged analogues in tissues]. 120 7

The content and hydrophobic properties (distribution coefficient in hexan : water) of organophosphorus inhibitors OPT of the following structure--R-O (CH3)/P/O/S C2H4SC2H5 have been studied in rat brain. On enlargement of the O-alkyl radical from ethyl to isopropyl and pinacolin hydrophobecity increases from 1 to 12 and 39, while the relative content of the chloroform extractable free OPT in brain, under conditions of uniform distribution, decreases from 11--18% to 3.2%. On incubation of the homogenate at 37 degrees C the further inhibition of the specific cholinesterase of the brain indicates the presence of an absolutely free form of OPT, the amount of which is not dependent on the degree of its hydrophobicity.
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PMID:[Forms of deposition of phosphoorganic cholinesterase inhibitors in the brain]. 123 72


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