Showing papers on "Acetylthiocholine published in 1975"
TL;DR: The critical acetylcholinesterase component, that is responsible for the resistance mechanism of decreased sensitivity to the inhibitor in the cattle tick Boophilus microplus, has been isolated from the organophosphorus-susceptible Yeerongpilly and resistant Biarra and Ridgelands strains and with the substrate acetylthiocholine gave a pH activity profile similar for all strains.
33 citations
TL;DR: It is concluded that the enzyme from eggplant, but not that from corn, is a cholinesterase, and the substrate specificity of this enzyme is determined.
18 citations
TL;DR: Polyacrylamide gel electrophoresis of the supernatant fraction of house fly thoracic homogenates demonstrated five electrophoretic bands having cholinesterase activity, and there appeared to be no visual or densitometric difference in the intensity of staining of the isozymes when acetylth Antiocholine was compared with butyrylthiocholine as substrate.
13 citations
TL;DR: The purified Cholinesterase of Pseudomonas aeruginosa A–16 was purified approximately 11,150-fold with an overall recovery of 15.2% and proved to be homogeneous by electrophoresis, ultracentrifugation and chromatography.
Abstract: The Cholinesterase of Pseudomonas aeruginosa A–16 was purified approximately 11,150-fold with an overall recovery of 15.2% and proved to be homogeneous by electrophoresis, ultracentrifugation and chromatography. The molecular weight of the enzyme was determined as approximately 30,000 by equilibrium centrifugation and gel filtration methods. The sedimentation coefficient, S20,w was determined to be 3.3 S. Isoelectric focusing electrophoresis with carrier ampholite revealed that the enzyme had an isoelectric point around pH 8.1.The purified Cholinesterase, which was considered to be an acetylcholinesterase from its substrate specificity, hydrolyzed acetylthiocholine and acetylcholine at the highest rates among the various esters tested.The estimated values of Km at pH 7.5 and 25°C were 1.5 × 10−4 m for acetylthiocholine and 1.9 × 10−4 m for acetylcholine. The enzyme also hydrolyzed the acetyl and propionyl esters of several aliphatic and aromatic alcohols at a lower rate which was entirely dependent on the...
12 citations
TL;DR: The distribution of cholinesterase activity among microorganisms was investigated using three kinds of thiocholine esters as substrate, finding that acetylthiocholine-hydrolyzing activity was present in some species belonging to the fluorescent group in genera Pseudomonas.
Abstract: The distribution of cholinesterase activity among microorganisms was investigated using three kinds of thiocholine esters as substrate. Acetylthiocholine-hydrolyzing activity was present in some species belonging to the fluorescent group in genera Pseudomonas. Ps. aeruginosa species exhibited intense activity. An isolated strain, Ps. aeruginosa A-16, showed the highest activity specific for acetylcholine and acetylthiocholine, and was inhibited by neostigmine. Enzyme formation was induced by choline, and was repressed by glucose. Ps. polycolor IFO 3918, which could grow on butyrylcholine as well as acetylcholine as its carbon and nitrogen source, was found to produce two kinds of esterase which hydroyzed acetylcholine or butyrylcholine. These esterases of Ps. polycolor were fractionated with ammonium sulfate. One of them, the butyrylcholine-hydrolyzing enzyme, was inhibited by atropine and eserine, but was not sensitive to repression by glucose.
6 citations
01 Jan 1975
TL;DR: Homogenates of rat jejunum and heart tissue in 0.3 M sucrose have been separated into different subcellular fractions by centrifugation, finding that the distribution of cholinesterases in these two tissues is different.
Abstract: Homogenates of rat jejunum and heart tissue in 0.3 M sucrose have been separated into different subcellular fractions by centrifugation. The distribution of cholinesterases in these two tissues is different. Acetylthiocholine (Ac), propionylthiocholine (Pc), and butyrylthiocholine (Bc) iodides were used as substrates. Using 1 mmol/1 Ac in the presence of hexafluorenium, a local anaesthetic drug, inhibition percentages of these subcellular cholinesterases were found to be different. The differences in the effect of hexafluorenium were most marked at a concentration of 5 mumol/1. Four electrophoretically distinct subcomponents of cholinesterase have been identified in different subcellular fractions from both jejunum and heart tissues. The electrophoretic profile, as determined by polyacrylamide disc electrophoresis, of different subcellular cholinesterases in these two tissues also appears to be different.
1 citations