[The effect of liposome phospholipids in collagen-induced platelet aggregation]. / Effekt fosfolipidov liposom pri kollagenindutsirovannoi agregatsii trombotsitov.

Influence of the charge-bearing phospholipids containing in liposome membrane on collagen-induced platelet aggregation was studied. The aggregation was inhibited after preincubation of blood platelets with liposomes containing egg lecithin/cholesterol/phosphatidylserine (stearyl amine); the effect was dose-dependent. Phosphatidylinositol incorporated into liposomes did not affect distinctly thrombocytes activation but decreased the rate of cell disaggregation; this effect was also dose-dependent. Use of phosphatidylinositol containing liposomes did not affect the content of thromboxane and prostacyclin in the system. The effect of the charge-bearing phospholipids on platelet aggregation observed should be considered in production of medicinal drugs.

[Catabolism of amino acids in bacteria of the genus Klebsiella]. / Katabolizm aminokislot u bakterii roda Klebsiella.

Propagation and activity level of 18 enzymes catalyzing deamination reactions of dicarboxylic and oxyamino acids and enzymes of amino acid reamination and amino acid N-acyl-derivatives' deacylation have been studied in Klebsiella bacteria. Klebsiella the most actively utilizes serin, threonine, aspartic and glutamic acids and aromatic amino acids. The first three amino acids are utilized by deamination, aromatic acids- in aminotransferase reaction with alpha-ketoglutaric acid, glutamic acid--by deamination and decarboxylation. Besides, Klebsiella actively deacylates N-acyl-derivatives of amino acids.

[Activity and properties of L-lysine amidase in Salmonella strains]. / Aktivnost' i svoistva L-lizinamidazy u shtammov roda Salmonella.

Distribution, activity level and properties of alpha-lysinamidase have been studied in Salmonella strains. The Km value for L-lysinamide was calculated to be 4.2 mM and for L-alpha-aminocaprolactame--5.1 mM. This enzyme, parallel with lysinamide, catalyzes hydrolysis of alpha-aminocaprolactam and leucinamide. Asparagine, glutamine, caprolactam, triptophanamide were not lysinamidase substrates.

[The effect of liposomes on the hormonal induction of liver tyrosine aminotransferase in an experiment]. / Vliianie liposom na gormonal'nuiu induktsiiu tirozinaminotransferazy pecheni v éksperimente.

Liposomes prevented the hydrocortisone-produced induction of tyrosine aminotransferase in animal liver tissue under conditions of normal state and of alcohol intoxication. The inhibitory effect of liposomes appears to be mainly based on their ability to incorporate into hepatocyte membranes, due to which the membrane permeability towards hydrocortisone was altered.

[The characteristics of amino acid catabolism in bacteria of the genus Citrobacter]. / Osobennosti katabolizma aminokislot u bakterii roda Citrobacter.

The comparison of the occurrence of enzymes effecting the deamination of dicarbon, aromatic and oxyamino acids, as well as transamination enzymes, in Citrobacter bacteria and the activity levels of these enzymes was made. The constant sign of such bacteria was the presence of serine and threonine dehydratase activity. 92% of the strains showed the presence of phenylalanine deaminase. No tryptophan activity was established. 96-98% of Citrobacter strains possessed phenylalanine, tyrosine and tryptophan aminotransferases with alpha-ketoglutaric acid functioning as the acceptor of the amino group.

[The effect of bacterial endotoxin on the activity of liver mitochondria monoamine oxidase]. / Vliianie bakterial'nogo éndotoksina na aktivnost' monoaminoksidazy mitokhondrii pecheni.

An increase of lipid peroxidation and a decrease of the monoamine oxidase (EC 1.4.3.4) activity were found in mice liver mitochondria within 9 hrs of intoxication developed after administration of bacterial endotoxin at a dose corresponding to its LD50. The decrease in the monoamine oxidase activity appears to occur due to some alteration of the enzyme substrate specificity as well as to its partial liberation from mitochondrial membrane.

[Acylase distribution in animal and human tissues]. / Raspredelenie atsilazy v tkaniakh zhivotnykh i cheloveka.

Distribution of acylase in different tissues of nine species of animals was studied. The following types of nitrogen elimination were distinguished: ammoniatelic (fish), uricotelic (birds) and uriotelic (amphibians, mammalians). The enzymic activity was estimated in the tissues of the brain, lung, muscle, liver, kidney, spleen, pancreas, small intestine and blood serum. The acylase activity was found in the kidney, liver and pancreas. Its level in the kidney increases with the animal weight growth, the enzyme activity being observed only in the cortical layer.

[Isolation and properties of aminocaprolactam hydrolase from Providencia alcalifaciens]. / Poluchenie i svoistva aminokaprolaktamgidrolazy iz Providencia alcalifaciens.

L-alpha-aminocaprolactam hydrolase possessing the L-lysinamidase activity was isolated and purified from Providencia alcalifaciens. The purification procedure of enzymes included cell destruction on USDL-1, fractionation by ammonium sulfate, gel-chromatography on G-100, ion exchange chromatography on DEAE-cellulose. The purification resulted in a homogeneous enzyme which possessed the both activities. The enzyme molecular weight (180 kDa) was estimated by gel chromatography on Sephadex G-200. Km was 3.5 mM in the phosphate buffer (pH 7.2). L-alpha-aminocaprolactam hydrolase and L-lysinamidase may be related to metal-dependent enzymes requiring Mg++.

[Hormonal induction of liver tyrosine aminotransferase in animals with chronic poisoning by hepatotropic poisons]. / Gormonal'naia induktsiia tirozinaminotransferazy pecheni zhivotnykh v usloviiakh khronicheskoi intoksikatsii nekotorymi gepatotropnymi iadami.

A study has been made of the effect of ethanol and CCl4 on hormonal induction of tyrosine aminotransferase in mouse liver. Both the hepatotropic poisons administered for a long time lose the induction effect and considerably reduce the same effect exerted by hydrocortisone. Microscopic study has revealed fatty dystrophy of the liver cells and even the formation of the areas of necrosis as a result of administering CCl4. The liver tissue stroma has been shown to develop reactive inflammation.

[Metabolism of dicarboxylic amino acids and their amides in bacteria of the genus Klebsiella]. / Obmen dikarbonovykh aminokislot i ikh amidov u bakterii roda Klebsiella.

The pathways of the utilization of dicarboxylic amino acids and their amides in 55 Klebsiella strains have been studied. These organisms have been found to be capable of carboxylating glutaminic acid with the subsequent utilization of the product of this reaction, gamma-amino butyric acid, by reamidization with alpha-glutaric acid. Aspartate decarboxylase with low activity has been detected only in a small number of strains. Most of the strains have been shown to be capable of deamidizating equally asparaginic and glutaminic acids. The presence of active asparaginase and glutaminase has been detected in a considerable number of these strains. Microorganisms of the genus Klebsiella have low asparagine synthetase and glutamine synthetase activity. Aspartate aminotransferase has been found to occur twice as frequently as alanine aminotransferase, both having the same level of activity.

[Immobilization of Citrobacter L-asparaginase in polyacrylamide gel]. / Immobilizatsiia L-asparaginazy iz Citrobacter v poliakrilamidnom gele.

Bacterial L-asparaginase, immobilized on polyacrylamide gel, exhibited higher stability to denaturation and to the effect of a proteolytic enzyme. The immobilized enzyme exhibited the pH optimum of activity displaced by one pH unit to the acid side as compared with the free enzyme. The apparent Km value was approximately 200-fold higher as compared with the free L-asparaginase. The immobilized asparaginase hydrolyzed both L- and D-asparagine isomers but the free enzyme was highly stereospecific.

[Metabolism of dicarboxylic amino acids and their amides in bacteria of the genus Citrobacter]. / Obmen dikarbonovykh aminokislot i ikh amidov u bakterii roda Citrobacter.

In 58 Citrobacter strains the pathways of the utilization of dicarbonic amino acids and their amides were studied. These organisms were found to be incapable of decarboxylating glutaminic and asparaginic acids, as well as their amides. All the strains could actively desamidizate asparagine. Not all of these strains showed glutaminase activity. Aspartate-aminotransferase occurred twice as often as alanine-aminotransferase, the level of activity being approximately the same. The Citrobacter strains desamidizated asparaginic acid with great constancy, but only in 1/3 of them this reaction occurred via an aspartase route. The desamidization of asparaginic acid in Citrobacter seemed to proceed in different ways. The desamidization of glutaminic acid was observed only in a part of the strains, and the reaction proceeded less actively.

[Aromatic amino acid metabolism in Enterobacteriaceae microorganisms]. / Obmen aromaticheskikh aminokislot u mikroorganizmov Enterobacteriaceae.

The authors revealed phenylalanine deaminase (PAD) in the majority of the Citrobacter strains investigated; the activity of PAD varied within a rather considerable range (0.3--4.58 micrometer of phenylpiruvate in 1 hr per 1 mg of bacterial protein). The presence of this enzyme thus served as an auxiliary biochemical test characterising this group of conditionally pathogenic microbes of the Enterobacteriacea family. Tyrosine decarboxylase was absent in 26 of 50 strains of Citrobacter examined. In the rest of the strains the activity of this enzyme was low. Consequently, tyrosine decarboxylase could not be used for identification of microorganisms of the Citrobacter genus.

[Arginine metabolism in Citrobacter]. / K obmenu arginina u Citrobacter.

The authors studied ways of utilization of arginine and of the products of its metabolism (ornithine, agmatine, and urea) in the microoganisms of Citrobacter genus. Arginine- and ornithine-decarboxylase activity was revealed by spectrophotometric method of decarboxylation products in the form of dinitrophenyl-derivatives in a small number of strains. Almost all the strains studied demonstrated a sufficiently high agmatine-ureohydrolase reaction. Arginase was constantly revealed. These microbes were capable of urea utilization in prolonged incubation.

[Oxidation of putrescine, spermidine and spermine by diamino-oxidase from mouse liver]. / Okislenie putrestsina, spermidina i spermina diaminooksidazoi pecheni myshei.

Optimal conditions to determine the activity of diaminooxidase in mouse liver homogenate are described. Maximal oxidation rate for putrescine was found to take place at a concentration of 20 mM and pH 9.5, and for spermidine and spermine--at 10 mM concentration and pH 9.2. The rate of tyramine oxidation was maximal at pH 7.8. Apparent KM values were 4.98-10(-3 M, 1-10(-3) M and 0.8-10(-3) M for putrescine, spermidine and spermine respectively. Hydroxylamine did not inhibit the rate of putrescin oxidation at optimal pH value.