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)

Exposure of rat brain Na+ + K+-ATPase (ATP phosphohydrolase E.C. 3.6.1.3) to concentrations of cassaine greater than 1 x 10(-4) M resulted in a poorly reversible inhibition of this enzyme. Inhibition did not require the presence of ATP and developed rapidly, but the final amount of inhibition observed was independent of time. The amount of inhibition observed at a given concentration of cassaine was reduced by increasing the concentration of membranes in the system. The inhibition of Na+ + K+-ATPase activity was associated with equivalent inhibition of the phosphorylation and (3H)-ouabain binding reactions of this enzyme, while the uninhibited enzyme was apparently kinetically normal. Concentrations of cassaine which produced this stable inhibition of Na+ + K+-ATPase had no effect on the Mg2+-activated ATPase or the NADH cytochrome-c-reductase activities of crude rat brain microsomal preparations. Cassaine inhibited the cholinesterase activity of rat brain microsomes with a Ki of about 5 x 10(-5) M, but his inhibition was fully reversible. The poorly reversible inhibitory actions of cassaine, thus, appeared specific for Na+ + K+-ATPase. Because this stable pattern of inhibition of the Na+ + K+-ATPase by cassaine required drug concentrations at least one hundred-fold greater than those which produce positive inotropic effects, it appears unlikely that this pattern of Na+ + K+-ATPase inhibition is involved in the cardiotonic actions of this drug.
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PMID:Studies on the stable inhibition of Na+ + K+-ATPase by cassaine. 13 Feb 44

An aqueous two phase polymer system (Dextran-polyethyleneglycol system was developed for isolation of plasma membrane fraction from nerves of the crayfish, Procamburus clarkii. The polymer system effectively reduced both mitochondrial and endoplasmic reticulum marker enzyme activity from a crude membrane fraction. The similar enrichment of (Na+ + K+)-ATPase (ATP phosphohydrolase, EC 3.6.1.3) was shown by the polymer system as well as by the sucrose density gradient centrifugation. The purified plasma membrane fraction (PM) was obtained using the polymer system followed by sucrose density gradient centrifugation. The PM fraction had a high specific activity of (Na + K+)-ATPase of up to 17 times that in the homogenate, with smaller contamination by mitochondria and endoplasmic reticulum enzyme activities than any other membrane fraction. Electron micrographs of the PM fraction also supported the above evidences. The protein recovered from the PM fraction amounted to 1.1% of the total protein in the homogenate. The specific activity of acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) in the membrane fractions was less increased than that of (Na+ + K+)-ATPase. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis suggested that polypeptide chains of estimated molecular weight 115,000 and 31,000 were enriched in the plasma membranes of the crayfish nerves.
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PMID:Isolation of neuronal plasma membranes from the crayfish Procamburus clarkii, with an aqueous two phase polymer system followed by sucrose density gradient centrifugation. 22 29

The activities of acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7), responsible for hydrolysis of acetylcholine and Na+,K(+)-ATPase (Mg(2+)-dependent ATP phosphohydrolase, EC 3.6.1.3), which plays a crucial role in neurotransmission, were determined in four brain regions after 1, 2, and 3 h of insulin administration. Significant decrease in the acetylcholinesterase and Na+,K(+)-ATPase activities was observed in the soluble and total particulate fractions from cerebral hemispheres, cerebellum, brain stem, and diencephalon + basal ganglia after 1, 2, and 3 h of insulin-induced hypoglycemia. Blood glucose level decreased significantly after 1 h of insulin administration and remained at low level for 2 h thereafter, whereas, the protein content in different subcellular fractions from four brain regions did not show any significant change under this physiological stress.
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PMID:Acetylcholinesterase and Na+,K(+)-ATPase activities in different regions of rat brain during insulin-induced hypoglycemia. 817 74