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The article discusses the development of gas chromatography method of detecting the composition of fat acids in dry blood serum. The comparative analysis of content of fat acids in freshly selected and dry serum. The stability of composition of fat acids in dry serum under its conservation during 2 months was examined. It is demonstrated that qualitative and quantitative compound of fat acids in fresh and dry serum is identical and continue to be unchanged during one month.

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The influence of cationic detergent cetyltrimethylammonium on the human blood cholinesterases activity (erythrocyte acetylcholinesterase and plasma butyrylcholinesterase) in reactions of hydrolysis of alpha-thionaphthylacetat and acetylthiocholine is studied. It is shown, that cetyltrimethylammonium is reversible effector for both cholinesterases. This compound competitively inhibited enzymatic hydrolysis of acetylthiocholine by both cholinesterases, and in the reactions of enzymatic hydrolysis alpha-thionaphthylacetat display as the synergistic activator--in experiments with butyrylcholinesterase, and as the reversible inhibitor--in experiments with acetylcholinesterase. Kinetic constants in reaction of acetylcholinesterase inhibition by cetyltrimethylammonium defined by means of different substrates--alpha-thionaphthylacetat and acetylthiocholin. They are close among themselves and amount (2.5 +/- 0.3) x 10(-5) and (2.8 +/- 0.3) x 10(-5) M, accordingly. Butyrylcholinesterase was more sensitive to influence of cetyltrimethylammonium. The kinetic constants defined for this enzyme by the effect of inhibition of acetylthiocholin hydrolysis or activation of alpha-thionaphthylatcetat hydrolysis, are also close among themselves and amount (3.9 +/- 0.4) x 10(-6) and (4.4 +/- 0.4) x 10(-6) M, accordingly.

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The influence of some cationic detergents on the catalytic activity of the horse blood plasma cholinesterase in reaction of hydrolysis of alpha-naphthylacetate at different pH were investigated. It was shown, that in the absence of detergents in acid pH of the reaction medium the Km value increases, but V remain constant. In the range of pH from 8.5 to 5.0 in the presence of detergents the Km and V values are not practically changed. That is why the activation of cholinesterase hydrolysis of alpha-naphthylacetate in the presence of detergents is considerably higher than that of the neutral pH.

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It has been shown, that some benzo[c]-phenanthridine and diisoquinoline alkaloids isolated from Chelidonium majus L. and Macleaya (Bocconia) cordata and M. microcarpa (berberine, sanguinarine, chelidonine) and of drugs ("Ukrain" and "Sanguirythrine") inhibited the enzyme activity of acetylcholinesterase from human erythrocyte and monoamine oxidase from the rat liver. All agents under study have been shown to be reversible inhibitors of the enzymatic hydrolysis of acetylthiocholine. 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 and chelidonine and "Ukrain" were much weaker. All agents under study have been shown to be irreversible inhibitors of the oxidative deamination reaction of serotonine and tyramine and not to influence the oxidative deamination reaction of benzylamine as a substrate. Among the examined agents, alkaloid sanguinarine and drug "Ukrain" are the strongest inhibitors of the reaction, alkaloids berberine, sanguinarine and "Sanguirythrine" exhibit a weaker action.

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A comparative determination of kinetic parameters V and Km in the reaction of hydrolysis thionaphthylacetate and well known substrate acetylthiocholine by choline esterases from different sources was conducted. It is shown that butyrylcholine esterases hydrolyze thionaphthylacetate with velocity comparable with that of hydrolysis of acetylthiocholine, while acetylcholine esterases and propionylcholine esterases hydrolyze this substrate several times slower than acetylthiocholine. The values of Km in the reactions of hydrolysis of thionaphthylacetate for all studied cholinesterases is an order higher than for acetylthiocholine except cholinesterase of blood serum of fish. This value for the latter enzyme is practically equal.

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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.

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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.

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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.

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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.

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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.

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A new type of organophosphorus compounds-beta, beta-diphenylethylphosphonic acid fluoroanhydride esters-with various alkyl radicals (CH3, C2H5, C3H7, i-C3H7, C4H9, i-C4H9, C5H11, C6H13) and a phenyl radical (C6H5) have been tested as inhibitors of horse serum butyryl cholinesterase (EC 3.1.1.8) and two forms of reindeer liver carboxyl esterase (EC 3.1.1.1). All the tested compounds are strong irreversible inhibitors of butyryl cholinesterase and strong combined type inhibitors of carboxylesterase. The values of inhibitory constants have been found to depend on the structure of the alkyl radical in the inhibitor molecule.

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Catalytic properties of human blood erythrocyte acetylcholinesterase, horse blood serum butyrylcholinesterase and squid visual cholinesterase nonimmobilized and immobilized in N-phthalylchitozane and in gelatin have been comparatively studied. Immobilization of cholinesterases in N-phthalylchitozane does not change its catalytic properties in respect to substrates and inhibitors but increases the enzyme stability. Cholinesterase immobilization in the gelatin membrane increases the Michaelis constants and decreases the maximum velocities in the reaction of enzyme hydrolysis of thiocholine esters and (for squid visual ganglia cholinesterase) of indophenylacetate. The effect of irreversible inhibitor diisopropylfluorophosphate and reversible inhibitors N-methyl-4-piperidinyl benzylate and tacrine on cholinesterases immobilized in the gelatin is weaker as compared with the effect on nonimmobilized enzymes. The results obtained are discussed for the effect of immobilization on the active enzyme surface.

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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.

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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.

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The kinetic analysis of cholinesterase interaction with reversible inhibitors was carried out. It has shown that the existing methods for definition of the type of reversible inhibition of enzyme reactions are not reliable. For example, mixed inhibition with the correlation between the competitive inhibition constant (Kl) and noncompetitive inhibition constant (K'i) less than 0.04, is identified as competitive inhibition. Apparently the ideal competitive inhibition with Ki/Ki = 0 does not exist in reality, because it is unlikely for a reversible inhibitor to decrease the process of the substrate sorption on a catalytical centre of cholinesterase not affecting the deacetylation rate. For objective evaluation of efficiency of reversible inhibitors it is suggested to determine the generalized inhibitory constant Ki at the cholinesterase hydrolysis in acetylcholine or acetylthiocholine. The data about anticholinesterase activity of carbonic and sulfoesters of lupinin are adduced.

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The reversible inhibition of horse blood serum butyrylcholinesterase (Ce 3.1.1.8) hydrolysis of ion substrates of acetyl- and butyrylthiocholines and non-ion substrate of indophenylacetate by N-methyl-4-piperidinylbenzylate and tacrine (1,2,3,4,-tetrahydro-9-aminoacridine) and phosphate buffer and ethanol influence on this process are investigated. The values of competitive Ki, uncompetitive K'i and generalized K sigma inhibitory constants are determined. It is shown that the inhibition effect and reversible inhibition type depend not only on the inhibitor and substrate nature but also on the phosphate buffer concentration and ethanol presence in the reaction mixture.

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