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E E Sochilina

Publications and source records attributed to E E Sochilina.

12 recordsLinked to original sources
PubMed2001

[The inhibition enzymatic hydrolysis of acetylthiocholine by acetylcholinesterase using principal alkaloids isolated from celandine and macleya and their derivatives].

A study was made of a possible inhibitory action on the enzymatic hydrolysis of acetylthiocholine by human erythrocyte acetylcholinesterase of principal alkaloids isolated from Chelidonium majus L. and Macleaya (Bocconia) cordata and microcarpa (namely sanguinarine, chelidonine, berberine), and of drugs "Ukrain" (thiophosphoric acid derivative of a sum of the alkaloids isolated from Chelidonium majus L.) and "Sanguirythrine" (a mixture of unseparated closely related to benzo[c]phenanthridine alkaloids sanguinarine and chelerythrine, isolated from Chelidonium majus L. and other plants of Papaveraceae family). All agents under study have been shown to be reversible inhibitors of the enzymatic hydrolysis of acetylthiocholine. On the basis of the kinetic data it has been determined that chelidonine belonged to reversible inhibitors of a competitive type. All other examined agents have been demonstrated to be inhibitors of a mixed competitive-noncompetitive type, and a greater contribution to the inhibition was made by the competitive constituent. Among all examined agents berberine, sanguinarine and "Sanguirythrine" were the strongest inhibitors of this reaction (the values of generalized inhibitory constants being 0.23, 0.23 and 0.29 microM, respectively) and cheliodonine and "Ukrain" were much weaker (2.0 and 2.5 microM, respectively). Judging from the data obtained, sanguinarine and chelerythrine exert similar inhibitory effects on the reaction of enzymatic hydrolysis of acetylthiocholine, since sanguinarine and "Sanguirythrine" have nearly equal generalized inhibitory constants.

Acetylcholinesterase↗
PubMed1993

[Anticholinesterase activity of certain carboranyl-containing thio- and selenoesters of pentavalent phosphorus acids].

Anticholinesterase activity of carboranyl containing thio- and selenoesters of pentavalent phosphorus acids has been studied. Insertion of the carboranyl substituents in the thioester group of phosphororganic compounds was found to increase the anticholinesterase activity as compared with the thioalkyl analogues. The compounds with B-carboranyl group are less active inhibitors of cholinesterase than their isomers with C-carboranyl group.

Acetylcholinesterase↗
PubMed1992

[The mechanism of anticholinesterase action of acetylene organophosphorus inhibitors].

Introduction of the triple bond in the leaving group of the organophosphorus inhibitor molecule gives a sharp raise of the inhibitor activity but does not change principal characteristics of the cholinesterase inhibition mechanism. The reactivation experiments suggest that inactivation of cholinesterases by these compounds occurs due to phosphorylating of the serine hydroxyl by the corresponding phosphoric acid. A close similarity was shown between acetylenic and saturated organophosphorus inhibitors in altering ka upon change of pH and tetraalkylammonium ions action. It is demonstrated that S-alkynyl esters of thioacetic acid are slowly hydrolyzed by acetylcholinesterase and cholinesterase without irreversible inhibition of the enzymes.

Acetylene↗
PubMedDate not supplied

[Method for determining nitrogen-containing cationic surface-active agents using butyrylcholinesterase].

The biochemical method for determination of cetyltrimethyl ammonium or cetylpyridinium, both being nitrogenated cationic surfactants, has been devised by using horse blood serum butyrylcholinesterase as analytical reagent. The method streams from the fact that surfactants tested are inhibitors of butyrylcholinesterase hydrolysis of butyrylcholin, a cationic substrate, but in this case they activate enzymatic hydrolysis of 1-naphthylacetate, a neutral substrate. Presence two opposite effects enlarges reliability to identifications. Use the sensitive fluorimetric method to registrations of activation of hydrolysis a substrate 1-naphtylacetate vastly to reduce the threshold of determination of surfactants above.

Animals↗
PubMedDate not supplied

[Use of 1- and 2-thionaphthylacetates as cholinesterase substrates].

1- and 2-thionaphthylacetates were tested as cholinesterase substrates. It was shown that the butyrilcholinesterase from horse serum can hydrolize these compounds. The hydrolysis velocity of 1-thionaphthylacetate was comparable with hydrolysis velocity of acetylthiocholine (the well known cholinesterase substrate), but 2-thionaphthylacetate was hydrolysed more slowly. The values of the kinetic parameters V and K(m) for butyrylcholinesterase hydrolysis of 1- and 2-thionaphthylacetates were determined. It was offered to use 1-thionaphthylacetates as the substrate for cholinesterases.

Acetylthiocholine↗
PubMedDate not supplied

[Comparative characterization of the catalytic properties of blood serum cholinesterase in pigeon and hen].

Significant difference in catalytic properties of partially purified cholinesterases from blood serum of pigeon and hen was shown by photometric method using Ellman's reagent. From eight studied thioesters, pigeon cholinesterase hydrolysed with the highest rate butyrylthiocholine but hen cholinesterase--propionylthiocholine. The enzymatic hydrolysis obeyed Michaelis-Menten equation only at low concentration of substrates up to 0.15-0.5 mM. High concentration of substrates activated hen cholinesterase, but inhibited pigeon cholinesterase.

Animals↗
PubMedDate not supplied

[A kinetic study of the blood serum cholinesterase activity in the freshwater fish Abramis ballerus].

In reaction of hydrolysis of choline and thiocholine esters of carbonic acids at 25 degrees C, cholinesterase activity of the blood serum from the fish A. ballerus has been studied by modified Ellman's method and potentiometric titration method. The activity is maximal in pH region 7.5-9.0 and is not inhibited by high concentration of substrates. Michaelis constants and maximal rates for the enzyme reactions were determined. Butyrylcholine and butyrylthiocholine were hydrolyzed with the highest rates by the serum. Some of the organophosphorus inhibitors (diisopropylfluorphosphate and DDVF) inhibit cholinesterase activity of the blood serum significantly faster, whereas some of the carbamates (aminostygmin, eserine, etc.) inhibit it significantly slower than typical butyrylcholinesterase from horse blood serum and typical acetylcholinesterase of human erythrocytes. Besides, with respect to the sensitivity to inhibitors and some other properties, fish blood serum cholinesterase differs from other known cholinesterases.

Acetylcholinesterase↗
PubMedDate not supplied

[Interactions of various cationic detergents with cholinesterase of horse blood serum].

Cetyltrimethyl ammonium and cetylpyridinium, both being cationic detergents, have been studied for their effect on the catalytic activity of horse blood serum cholinesterase (BuHChE) in reactions of hydrolysis of carbonic acid esters. It is shown that the detergents tested are reversible competitive inhibitors of the reaction of butyryl cholinesterase hydrolysis of butyryl choline, a specific cationic substrate, but in this case they activate enzymic hydrolysis of alpha-naphthylacetate, a nonspecific neutral substrate. Values of constants, describing enzyme binding with a detergent, are estimated both by the degree of inhibition of enzymatic hydrolysis of butyryl choline and by the degree of activation of enzymatic hydrolysis of alpha-naphthylacetate and are practically equal. An assumption is made that in both cases the same complex of BuHChE with a molecule of the detergent is formed. The enzyme, as a constituent of such a complex, possesses different substrate specificity as compared with the initial one.

Animals↗
PubMedDate not supplied

[The reversible inhibition of cholinesterases from different biological sources by phosphonium betaines].

The action of some phosphonium betains on cholinesterases from different biological sources has been studied. It has been shown, that all studied betains are reversible inhibitors of cholinesterase hydrolysis of acetyltiocholine. Inhibiting action of these compounds on acetylcholinesterases is about ten times weaker that of the majority of known phosphonium salts, while their action on butyrylcholinesterases has no peculiarities. There were found certain differences for each betain compounds in their action on cholinesterases from different biological sources. These results may be used for detail classification of cholinesterases and allow to extend knowledge in comparative enzymology.

Animals↗
PubMedDate not supplied

[Inhibition of cholinesterases of varying origin by ordinary and betaine vinylphosphates].

The comparative study of irreversible inhibitory action of some substituted vinyl-phosphates (in usual and betaine forms on cholinesterases from different biological sources such as the human blood erythrocytes, the horse and the hen blood serum and optic ganglia of the squid) has been carried out. It is shown that betaines obtain lesser inhibitory activity as compared with the corresponding ordinary vinylphosphates. Some of tested inhibitors display expressed selectivity of action. So, the compound GL-2 reacts with cholinesterase of optic ganglia of the squid 450 000 times faster than with cholinesterase of the hen blood serum. The application of vinylphosphates as inhibitors of cholinesterases allows displaying additional differences in properties of enzymes. It is very important for comparative enzymology. These compounds may be used for detalization of type belonging and to make the classification of cholinesterases more accurate. Moreover, the estimation of anticholinesterase activity of vinylphosphates is important because these compounds may be used both in medicine and agriculture.

Acetylcholinesterase↗