[Isolation of nucleotide sequences, possessing enhancer functions from the Saccharomyces cerevisiae genetic library]. / Vydelenie nukleotidnykh posledovatel'nostei, obladaiushchikh énkhansernoi funktsiei, iz genoteki Saccharomyces cerevisiae.

We propose a method for isolation of enhancer-like sequences from a yeast genomic library. The method was used to identify DNA inserts capable of increasing bacterial bla gene expression when located downstream from the transcription initiation site. Plasmids carrying different fragments of one such insert were used to localize the enhancer-like function on a 1.2 kb fragment.

[Circular dichroism study of amphotericin B interaction with the sterols of Candida albicans strains sensitive and resistant to polyene antibiotics]. / Izuchenie vzaimodeistviia amfoteritsina B so sterinami chuvstvitel'nogo i rezistentnogo k polienovym antibitokam shtammov Candida albicans metodom krugovogo dikhroizma.

The method of circular dichroism (CD) was used to study interaction of amphotericin B with liposomes of egg lecithin containing sterols isolated from sensitive and resistant strains of Candida albicans. Analysis of the CD spectra showed that the antibiotic spectral parameters in the dispersion of liposomes modified with sterols underlie definite changes. In case of sterol isolated from the sensitive culture they were evident from an increase in the relative intensity of the negative extremes at 415, 390 and 370 nm. The contours of the CD spectrum in the region of 350 nm significantly changed proportionally to the antibiotic concentration and during incubation. The CD spectra of amphotericin B in the dispersions of the lecithin liposomes containing sterols isolated from the resistant strain of C. albicans were characterized by an increase in the relative intensity of the negative extremes at 415, 390 and 370 nm. These changes also took place during incubation. Still, the frequency character of the spectrum did not practically change. Only the intensity in the spectral region tested somewhat changed proportionally within an hour. The results indicate that the character of antibiotic interaction with liposomes containing sterols of the sensitive and resistant cultures significantly differs. This means that the changes in the membrane sterol composition (ergosterol and delta 7.22-ergostadien-3 beta-ol were the main sterols of the sensitive and resistant cultures respectively) have a marked effect on the character of the antibiotic interaction with them.

[Effect of levorin on the activity of facilitated diffusion systems in murine Ehrlich cancer cells]. / Deistvie levorina na aktivnost' nekotorykh sistem oblegchennoi diffuzii v kletkakh myshinogo raka Erlikha.

Five-minute incubation of the cells of Ehrlich's mouse carcinoma with levorin in a concentration of 0.25 microgram/ml resulted in a release of 30% of K+ and 40-50% suppression of active transport of neutral amino acids. No changes in incorporation of nitrous compounds, nucleosides and cyclophosphamide, an antitumor drug transported by the systems of facilitated diffusion were observed under the same conditions.

[Lipolytic complex of Penicillium sp]. / Izuchenie lipoliticheskogo kompleksa Penicillium sp.

By gel filtration on Sephadex G-75 it has been demonstrated that the lipolytic complex of Penicillium sp. contains two active components--a high molecular weight (lipase-1) and low molecular weight component (lipase-2). Both components have been isolated by Sephadex gel-filtration and DEAE-cellulose chromatography. It has been shown by discelectrophoresis and isoelectric focusing that lipase-2 is a highly purified protein with the molecular weight of 30,000 (gel-filtration) or 29,000 (electrophoresis) and isoelectric point at pH 4.8 Lipase-1 has been found to contain large quantities of lipids. The conditions of deaggregation of a high molecular weight component have been identified to yield a new active component corresponding to lipase-2 in its gel-filtration and disc-electrophoresis properties. It has been shown that pH 7.5-8.0 and temperature 37-40 degrees are optimal for both lipase-1 and lipase-2. Activities of the two components are inhibited by Na deoxycholate and remain unchanged in the presence of Na cholate and dehydrocholate. On the basis of these findings it is concluded that lipase-1 and lipase-2 are two forms of the same enzyme.

[Changes in the state of plasma membrane proteins of tumor cells exposed to a polyene antibiotic and cyclophosphamide]. / Izmenenie sostoianiia belkov plazmaticheskikh membran opukholevykh kletok pod vozdeistviem polienovogo antibiotika i tsiklofosfana.

The fractional composition of the proteins of the plasmatic membranes of the Ehrlich's tumor cells treated with various drugs was studied with the use of electrophoresis in polyacrylamide gel. It was shown that the character of the changes in the fractional composition of the plasmatic membrane proteins under the effect of levorin and cyclophosphamide was different. When the drugs were used in combination, summation of the changes induced by every drug alone was observed. Possible causes of the changes in the fractional composition of the membrane proteins are discussed.

[Hypocholesterinemic effect of cholesterol oxidase in the rabbit]. / Gipokholesterinemicheskoe deistvie kholesterinoksidazy v éksperimentakh na krolikakh.

Cholesterol oxidase (3 beta-hydroxysteroid oxidase) from the Actinomyces lavendulae mycelium oxidizes cholesterol of blood serum in vitro. The half-inactivation time for the enzyme in blood serum (37 degrees) is 90 min. After intravenous injection of the enzyme (1--2 units per kg) to rabbits with experimental hypercholesterinemia the cholesterol content in the blood is decreased directly proportional to the single dose of the enzyme and duration of injection. After 6-8 injections the level of non-esterified and total cholesterol is drastically decreased (by 90-97% and 65-68%, respectively). The acute toxicity of cholesterol oxidase preparations for mice decreases depending on the degree of the enzyme purification.

[Increase in the specific activity of killed influenza vaccines by using polyene antibiotics]. / Povyshenie spetsificheskoi aktivnosti ubitykh grippoznykh vaktsin s pomoshch'iu polienovykh antibiotikov.

It was shown experimentally that polyenic antibiotics, i. e. amphotericin B and sodium levorin markedly increased the specific immunogenic properties and interferonogenic activity of inactivated influenza virus vaccine prepared with various methods from highly reproductive recombinants. The rate of pneumonia and death from influenza among the vaccinated mice treated with inactivated influenza virus vaccine and one of the polyenic antibiotics was lower than that among the animals treated with the vaccine alone (P less than 0.05). Correlation between the increase in the immunological response, the decrease in the virus reproduction rate in the lungs and addition of the antibiotics into the vaccine was also observed. It is recommended that inactivated influenza virus vaccine be used in conjunction with polyenic antibiotics.

[Interrelationship of polyphosphate metabolism and levorin biosynthesis in Streptomyces levoris]. / O vzaimosviazi polifosfatnogo obmena s biosintezom levorina i Streptomyces levoris.

The effect of inorganic phosphate on biosynthesis of the polyene antibiotic levorin by Streptomyces levoris was studied. At phosphate concentration of 4.0 mM levorin biosynthesis is repressed by 90%, resulting in an increase of ATP and a condensed inorganic polyphosphates content in the producer cells. At phosphate concentration optimal for levorin production (0.04 mM) the level of intracellular ATP sharply falls by the beginning of the steady-state phase of the producer growth and that of polyphosphates decreases 3-6-fold. The inorganic phosphate exerts different effects on polyphosphate metabolism enzymes, such as polyphosphate: D-glucose-6-phosphotransferase, polyphosphate phosphohydrolase, tripolyphosphate phosphohydrolase, pyrophosphate phosphohydrolase, alkaline and acid phosphatase. The strongest effect of phosphate excess is observed in the case of polyphosphate: D-glucose-6-phosphotransferase, whose activity decreases 2-5-fold. The activity of this enzyme was shown to be correlated with the antibiotic accumulation. The data obtained are indicative of interrelationship between the polyphosphate metabolism and levorin biosynthesis.

[Effect of cholesterol oxidase on the involution of experimental hypercholesterolemia in rabbits]. / Vliianie kholesterinoksidazy na obratnoi razvitie eksperimental'noi giperkholesterinemii u krolikov.

Cholesterol oxidase (3 beta-hydrosteroid oxidase), isolated from Actinomyces lavendulae, oxidized unesterified cholesterol in rabbit blood serum without detergents in vitro. Intravenous administration of the enzyme into hypercholesterolemic rabbits at a dose of 0.5-2.0 un/kg decrease distinctly the cholesterol content in blood. The rate of the decrease depended on the dose of the preparation. Acute toxicity of the cholesterol oxidase preparations for mice correlated with the degree of purification of the enzyme. Cholesterol oxidase from Act. lavendulae may be considered as a potential hypocholesterolemic drug.

[Action of levorin on amino acid transport in the rat small intestine]. / Deistvie levorina na transport aminokislot v tonkoi kishke krysy.

Levorin, a polyenic antibiotic, in concentration of 2.10(-6) M markedly inhibited the active transport of amino acids in the cells of rat thin intestine, thus decreasing the oxygen dependent transfer of 14C-glycine and 14C-leucine and antigradient accumulation of glycine in the enterocytes. The effect increases with an increase in the period of the intestine mucosa contact with the antibiotic. Introduction of levorin from th serous side had no effect on the glycine transport. Inhibition of the transmembrane transport of glycine by levorin is due to its effect on transfer and accumulation of amino acids in the cells.

[Action of levorin on glucose transport in the rat small intestine]. / Deistvie levorina na transport gliukozy v tonkoi kishke krysy.

The technique of accumulating preparation of the mucosa and "turned out sac" was used to show that levorin, a polyenic antibiotic in a concentration of 10(-6) M, lowered the transport rate and accumulation of glucose by the epithelial cells of the rat thin intestine under conditions of oxygenation. Suppression of the glucose transport in the first stages resulted in partial inhibition of the transmembrane transfer. It is suggested that levorin suppression of the glucose transport through the erythrocyte apical membrane in the thin intestine is associated with a decrease in the electrochemical gradient of Na+.

[pH-dependence of the esterolytic activity of terrylytine proteases]. / Zavisimost' esteroliticheskoi aktivnosti proteaz terrilitina ot pH.

The pH-dependences of the kinetic parameters of hydrolysis of alpha-N-henzoyl-L-arginine and N-benzoyl-L-tyrosine ethyl esters by terrylytine proteases I and II were studied. The experimental results proved evidence for the differences in the activities of these enzymes. The active center of protease I contains two groups with close pK values (6,5-7,0), one of which is presumably the imidazole group of histidine. The catalytic action of protease II is determined by the state of the ionizing groups with the ionization constants of about 6 and 8. The former functions in the deprotonated form, whereas the latter--in the protonated form.

[Effect of polyene antibiotics on the increase in specific resistance due to inactivated antiviral vaccines]. / Vliianie polienovykh antibiotikov na povyshenie spetsificheskoi rezistentnosti, vyzvannoi inaktivirovannymi protivovirusnymi vaktsinami.

The capacity of polyenic antibiotics, such as water soluble forms of amphotericin B, mycoheptin, nystatin and levorin to stimulate immunogenicity and interferonogenic activity of inactivated antiviral vaccines was shown. The protective effect of the vaccine against rabies or forest-spring encephalitis in albino mice was more pronounced on its two-fold use in combination with the antibiotic than that on its use alone. The most significant results were obtained with highly diluted vaccines supplemented with amphotericin B. In this case the resistance index was 2 times higher than on vaccination without amphotericin B. In comparative assays of 4 various lots of vaccines against rabies the ED50 of every inactivated vaccine corresponded to thrice as low levels of the antirabies antigen than on vaccination without the polyen. The problems of the mode of action of the polyenic antibiotics and antiviral inactivated vaccines used in combination are discussed.

[Effect of ionic composition of incubation medium on inhibition by levorin of amino acid transfer in Candida albicans]. / Vliianie ionnogo sostava sredy na tormozhenie levorinom transports aminokislot u Candida albicans.

It was demonstrated that K+ and Na+ concentrations in C. albicans cells cultivated on an aerated enriched complex medium do not practically depend on their concentration ratios in the medium. The effect of levorin on the ionic composition of the cells, on the contrary, strongly depends on the composition of the medium. In a Na-containing medium with levorin the bulk of intracellular potassium is substituted by sodium, while in a "potassium" medium no redistribution of the monovalent cations in the cells occurs. The transport of neutral amino acids with a short carbohydrate radical (e. g. glycine, alanine) is largely inhibited by levorin irrespective of the intra- and extracellular concentrations of the movement cations. The inhibition of transport of amino acids with a long carbohydrate radical (e. g. leucine, phenylalanine) by levorin is possibly mediated by its effect on the intracellular concentration of monovalent cations, since in "potassium" medium it is either insignificant or altogether absent. The transfer of neutral amino acids differing in the length of the carbohydrate radical of C. albicans by various systems is discussed.

[Effect of levorin on incorporation of individual amino acids into proteins of membranes, ribosomes and cell sap of Candida albicans]. / Deistvie levorina na vkliuchenie individual'nykh aminokislot v belki membran, ribosom i kletochnogo soka Candida albicans.

The effect of levorin on incorporation of labelled amino acids into the protoplasts and proteins of C. albicans depended on the ionic composition of the medium and on the amino acid tested. In a potassium-enriched medium the predominant effect of levorin on [14C] alanine transport into the protoplasts was decreased, while in case of [14C] leucine transport it was completely eliminated. The incorporation of [14C] alanine into the proteins of ribosomes and cell juice was inhibited by the antibiotic in a greater degree as compared to the membrane proteins, the difference in the rate being more pronounced in a sodium-enriched medium. The incorporation of [14C] leucine was inhibited in all protein fractions in the same degree, which was observed only in a sodium-enriched medium.

[Effect of detergents on the chloramphenicol inactivation process by resistent bacteria]. / Vliianie detergentov na protsess inaktivatsii khloramfenikola rezistentnymi bakteriiami.

The effect of detergents, i. e. cationic, anionic, nonionic and polyelectrolytes of the cationic type on the efficacy of chloramphenicol against resistant strains of E. coli and Staph. aureus was studied. It was found that the detergent effect on inactivation of chloramphenicol by the bacterial resistant strains was inconsistent. The cationic detergents and in particular chlorhexidine had the most pronounced inhibitory effect. In subbacteriostatic concentrations they significantly suppressed inactivation of chloramphenicol in the cells of E. coli and Staph. aureus. The anionic detergents and polyelectrolytes of the cationic type in the above concentrations were effective only with respect to Staph. aureus. It is noted that the detergents increased the activity of chloramphenicol against E. coli and Staph. aureus.