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 effect of organic and inorganic forms of nitrogen on biomass accumulation and cholinesterase synthesis was studied with Arthrobacter simplex var. cholinesterasus. The culture assimilates nitrogen of ammonium compounds better than other forms of inorganic nitrogen; the best nitrogen source for biosynthesis of cholinesterase is ammonium phosphate. Nitrogen of nitrates is not assimilated. The amount of biomass is almost twice as high on the medium with peptone, casein or casein hydrolysate as on the medium with mineral nitrogen, while the activity of cholinesterase on these nitrogen sources decreases 1.5--2.0 times. Yeast extract as a nitrogen source increases biomass accumulation by a factor of 2.5 and does not supress synthesis of cholinesterase. The concentration of the enzyme synthesized per unit biomass on the medium with yeast extract is the same as on the medium containing ammonium phosphate. The effect of amino acids and amides, i.e. beta-alanine, proline, amides of aspartic and glutamic acids, and their mixtures, is similar to the action of yeast extract: they stimulate biomass accumulation and do not inhibit synthesis of the enzyme. Other amino acids supress synthesis of cholinesterase. The amount of accumulated biomass in the presence of glutamic acid is twice as high as in the case of any other amino acid, and three times as high as on the medium containing ammonium phosphate. Similar action of glutamic acid is manifested when it is used in mixtures with other amino acids. On the medium containing glutamic acid as a sole source of nitrogen, an increase in biomass production is accompanied with a decrease in biosynthesis of the enzyme by 50%. Repression of the biosynthesis is less if glutamic acid is added in mixtures with proline, beta-alanine and asparagine.
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PMID:[Effect of nitrogen source on growth of Arthrobacter simplex and its biosynthesis of cholinesterase]. 97 79

A series of spin labeled acetycholine analogs, in which the number of methylene groups between the quaternary nitrogen and the alcohol oxygen ranged between 1-5, have been examined as inhibitors of electric eel acetylcholinesterase. Evidence is presented suggesting that inhibition of acetylocholinesterase by the spin labeled ACH analogs is due to the high affinity of these compounds for the enzyme, inhibition is competitive and reversible. It has been shown that complex formation is of major importance in the reaction between spin labeled ACH analogs and acetylcholinesterase. The acetylation step has been shown to occur by demonstrating that the leaving group is released as the reaction proceeds. Complex formation has been demonstrated by means of kinetic criteria. Kinetic parameter have been measured for the five compounds, and correlations with alkaline hydrolysis are disussed.
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PMID:Kinetics of inhibition of acetylcholinesterase by spin labeled acetylcholine analogs. 103 14

The levels of acetylcholine and choline were measured in various brain regions of the rat after fixation by microwave irradiation of the head and after decapitation and subsequent freezing in liquid nitrogen. Levels of acetylcholine were increased by approximately 50% after microwave irradiation, while choline levels were reduced. These biochemical findings were correlated with virtually complex loss of acetylcholinesterase and NADH-diaphorase activity after 1 s exposure to microwave irradiation at a level of 5 kW.
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PMID:Fast fixation of brain in situ by high intensity microwave irradiation: application to neurochemical studies. 104 75

15 acetoxyethylenammonium compounds are studied as substrates for acetylcholinesterase (ACE) from bovine erythrocytes and for butyrylcholinesterase (BCE) from horse serum. Substitution of methyl groups of the ammonium grouping with other radicals and incorporation of onium nitrogen in the cycle resulted in the decrease of the hydrolysis rate under the action of BCE and ACE, the effect of BCE being more pronounced. The rate of the hydrolysis of N-acetoxyethylene-N-methylpiperidine iodide in the presence of ACE was 65 times as much as in the presence of BCE. This compound is a new specific substrate of ACE. Dipropylmethyl derivative turned not to be a good substrate for both enzymes. Dibutylmethyl and pyridinic derivatives were not attacked by ACE and BCE. Kinetic analysis of the compounds listed is performed, taking account of non-productive sorbtion. Possible role of hydrofobic regions in the orientation of substrates on the active surface of ACE and BCE is discussed.
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PMID:[Cholinesterase hydrolysis of acetylcholine derivatives with different structures of the ammonium grouping]. 113 4

Inhibition of active cholinesterases in cats with armine or the GT-165 compound (0,0-diethyl-S-/beta-arylmethylamino) ethyl/thiophosphate methylsulphomethylate) potentiases ten- and hundred-fold the blocking action of subecholine and its derivatives on the neuro-muscular condution. The cholinesterase reactivator dipyroxime (2-5 mg/kg) quickly lifts the conduction block, provoked by muscle relaxants of the subecholine type under the cholinesterase inhibition. The subecholine analogue with a single propyl radical at each atom of nitrogen does not display any pressor action and, upon inhibition of cholinesterases, it blocks the neuro-muscular conduction when used in a dose of 0.1-0.2 gamma/kg. The maximal potentiation of the blocking action exerted by subecholine and its analogues is achieved in inhibiting not only pseudocholinesterase but acetylcholinesterase as well.
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PMID:[Effect of cholinesterase inhibitors and reactivators on the blocking action of dicarboxylic acid amino esters on neuromuscular conduction]. 122 2

Conformational possibilities of pirrolidine analogues of acetylcholine beta-(N-methyl pirrolidinium)-ethyl ester of acetic acid and beta-(N-ethyl pirrolidinium)-ethyl ester of acetic acid and beta-(N-ethyl pirrolidinium)-ethyl ester of acetic acid were investigated by the method of atomic potentials. The conformational energy was considered as a sum of non-bonded and electrostatical interactions, torsional energy and distortions of bond angles. It has been shown that the replacement of the nitrogen methyl group to ethyl group results in decrease of the average barrier height between two gauche conformations of the O--C--C--N fragment. Comparison of conformational properties of some cholinesterase substrates permit to draw a suggestion that the barrier height influences the rate of the enzymatic hydrolysis.
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PMID:[A theoretical conformational analysis of several substrates of cholinesterase having a cyclic ammonium group structure]. 122 66

The hydrochlorides and methiodides of 1-methyl-3- and 4-acetoxypiperidine and their sulphonium analogues are cholinergic agonists. They are substrates for acetylcholinesterase. The sulphonium compounds have a 78(-524)-fold higher activity than its nitrogen analogues.
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PMID:Structure-activity relationships of cyclic acetylcholine analogues of the piperidinol and thiacyclohexanol series. 125 11

The combined effects of ozone and nitrogen dioxide were assessed in an in vitro test system utilizing human red cells. In general, these two pollutants had additive effects on the parameters measured which included osmotic fragility, acetylcholinesterase activity, lipid peroxidation, reduced glutathione and methemoglobin levels. However, at lower pollutant doses a synergistic increase in lipid peroxides was noted while at higher doses the effect became less than additive. Further studies of this observation suggested that ferrous hemoglobin potentiates ozone-induced lipid peroxidation while methemoglobin, resulting primarily from nitrogen dioxide, inhibits this process. Ozone was also found to potentiate the methemoglobinemic effects of nitrogen dioxide, particularly in sequential studies in which ozone exposure preceded nitrogen dioxide. Inasmuch as the effects of these two pollutants vary from protective to synergistic depending on the pollutant concentration, duration and sequence of exposure, as well as on the parameter assayed, it would appear that the approach to in vivo study of the combined effects of ozone and nitrogen dioxide should be aimed at simulating ambient conditions as closely as possible.
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PMID:Combined exposure to ozone and nitrogen dioxide. 126 95

A 28-day oral toxicity test of tetrachlorvinphos (TCV) was conducted in male and female Slc: Wistar rats by gavage at dose levels of 0, 10, 100 or 1000 mg/kg/day. The male and female rats showed dose-related inhibition of serum cholinesterase activity and erythrocyte acetylcholinesterase activity. At a dose of 1000 mg/kg, body weight gain was decreased in males, and there were 6 deaths in females. Adrenal gland, liver, kidney and thyroid gland weights were increased. The adrenal lesions were characterized by vacuolization and swelling of the cortex cells. The hepatic lesions consisted of vacuolization and necrosis of the hepatocytes. The renal lesions consisted of regeneration and necrosis of the tubular epithelial cells. These lesions were mostly observed at a dose of 1000 mg/kg. After a 14-day recovery period in the 1000 mg/kg group, the changes of cholinesterase, total cholesterol, gamma-glutamyltransferase, alkaline phosphatase, aspartate aminotransferase and blood urea nitrogen in serum were restored or showed a tendency toward recovery. However, the lesions in the kidney and adrenal remained. More than 14 days are therefore considered to be needed for recovery. At doses of more than 10 mg/kg, significant inhibition of the serum cholinesterase activity in both sexes, erythrocyte acetylcholinesterase activity in males, and lesions of the adrenal gland in females were observed. Target organs for TCV-treated rats were the adrenal, liver and kidney. It was concluded that the NOEL under this experimental condition is less than 10 mg/kg/day.
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PMID:[Twenty-eight-day repeated dose toxicity test for tetrachlorvinphos in Wistar rat]. 136 60

Following the discovery of a new series of 1-benzyl-4-[2-(N-benzoyl-N-methylamino)ethyl]piperidine (2) derivatives with a potent anti-acetylcholinesterase (anti-AChE) activity, we extended the structure-activity relationships (SAR) to rigid analogues (4) and 1-benzyl-4-[2-(N-benzoyl-N-phenylamino)ethyl]piperidine derivatives (3). Introduction of a phenyl group on the nitrogen atom of the amide moieties resulted in enhanced activity. The rigid analogue containing isoindolone (9) was found to exhibit potent anti-AChE activity comparable to that of 2. Furthermore, replacement of the isoindolone with other heterobicyclic ring systems was examined. Among the compounds prepared in these series, 1-benzyl-4-[2-[4-(benzoylamino)phthalimido]ethyl]piperidine hydrochloride (19) (IC50 = 1.2 nM) is one of the most potent inhibitors of AChE. Compound 19 showed a definite selectivity to AChE over the BuChE (about 34700-fold) and, at dosages of 10-50 mg/kg, exerted a dose-dependent inhibitory effect on AChE in rat brain.
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PMID:Synthesis and structure-activity relationships of acetylcholinesterase inhibitors: 1-benzyl-4-(2-phthalimidoethyl)piperidine and related derivatives. 146 86


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