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Applied Biochemistry and Microbiology (v.37, #1)
Structures and Functions of Chaperones and Chaperonins (Review) by Z. G. Evstigneeva; N. A. Solov'eva; L. I. Sidel'nikova (pp. 1-13).
Folding and assembling of newly synthesized proteins is directed and effected by a group of relatively recently discovered proteins called molecular chaperones. These proteins not only control the assembling of native structures; they also remodel protein molecules that have wrong conformations. All molecular chaperones perform the same function, but structurally they are divided into groups of chaperones and chaperonins. These proteins are highly conserved in evolution and display an ATPase activity. Certain known chaperones and chaperonins are shown in the table, and their structures and mechanisms of action are described.
Fungal Extracellular RNases (Review) by S. M. Zhenodarova (pp. 14-22).
Studies of certain fungal extracellular RNases mainly isolated from representatives of the genera Aspergillus and Penicillium are reviewed. The isolation of these enzymes in highly purified states in the 1970s and 1980s strongly stimulated further studies of their structure, functions, and mechanisms of action. This also promoted the use of RNases as catalysts in oligoribonucleotide syntheses and as objects of comparative and evolutionary biochemical and other studies. Results of determinations of the primary, secondary, and spatial structures of guanyl-specific fungal RNases are reviewed. These studies revealed considerable homology within the subfamilies of fungal, bacterial, and actinomycete RNases. Characteristics of the nonspecific RNase Pb2 are considered.
Nucleoprotein Complexes of Yeast and Their Biological Effect on T-Lymphocytes by N. S. Sinitskaya; L. K. Shataeva; T. S. Potekhina; A. D. Kas'yanov (pp. 23-28).
Complexes of nucleic acids and acid nuclear proteins that are active toward human T-lymphocytes were isolated from cells of baker's yeastSaccharomyces cerevisiae. The conditions of isolation of nucleoprotein complexes by acid extraction followed by microfiltration for concentration of macromolecular components were optimized. Gel filtration and electrophoresis were used to study the composition and molecular weights of components of the preparations obtained. It was shown that the nucleoprotein complex had a molecular weight of 1430 kDa. However, only one zone was determined by electrophoresis of the protein component with a molecular weight of 30 kDa.
Low-Molecular-Weight Glycoprotein from Cattle Blood Serum: Structure and Properties by I. A. Yamskov; A. A. Vinogradov; A. N. Danilenko; L. A. Maslova; E. Yu. Rybakova; V. P. Yamskova (pp. 29-35).
The amino acid composition, structure, and physicochemical properties of a low-molecular-weight glycoprotein from cattle blood serum (SGP) were studied. The content of carbohydrates (represented by mannose-rich oligosaccharides) amounted to 45–50 wt %. The value of the specific partial heat of SGP, measured by differential scanning calorimetry (DSC), equaled 1.8 J/(g K), which is characteristic of unfolded proteins. Circular dichroic (CD) spectra of SGP led us to conclude that it is not highly structured and that it occurs in the shape of a statistical globule. The protein was deglycated using anhydrous trifluoromethane sulfonate (TFMS), after which its amino acid composition and the sequence of a fragment were determined. The results indicate that SGP is a protein not studied previously.
Endonuclease from Proteus mirabilis by Z. Z. Salikhova; R. B. Sokolova; A. Z. Ponomareva; D. V. Yusupova (pp. 36-40).
Two isoforms of nuclease displaying DNase and RNase activities were found in the culture liquid and periplasm of Proteus mirabilis. The enzyme was isolated from the periplasm and then purified to a functionally homogeneous state. The nuclease was equally potent in cleaving denatured and native DNAs by the endonuclease mechanism and was designated Pm endonuclease. The endonuclease was shown to be a temperature-dependent enzyme with a pH optimum of 10.4–10.6, requiring the presence of bivalent metal ions and inhibited by citrate and ethylenediaminetetraacetate.
β-Galactosidase of the Extreme Thermophilic Anaerobic Bacterium Thermoanaerobium sp. 2905 and Its Immobilization by I. V. Ulezlo; A. K Tsereteli; I. B. Portnaya; A. M. Bezborodov (pp. 41-44).
The composition of a nutrition medium for cultivating the extreme thermophilic anaerobe Thermoanaerobium sp. 2905 was optimized, which enabled the bacterial β-galactosidase production to be substantially enhanced. Xylan and ammonium phosphate were selected as optimal carbon and nitrogen sources, respectively. The enzyme was purified fivefold by precipitation of the aqueous cell extract with alcohol (1 : 1, v/v), and a crude preparation with a specific activity of 46 U per mg protein was obtained. Cells of the extreme thermophile were entrapped in natural or synthetic latex.
Coimmobilization of Superoxide Dismutase, Catalase, and Peroxidase by A. N. Eremin (pp. 45-54).
Various orders of sequential coimmobilization of superoxide dismutase (SOD), catalase, and horseradish peroxidase (HRP) were tested in order to prepare a multienzyme antioxidant complex of these enzymes. Simultaneous coimmobilization of catalase with a preliminarily cross-linked complex between SOD and HRP was found to be the optimum procedure. The catalytic enzyme activity and working stability of catalase was tested kinetically in the multienzyme complexes prepared by different methods. The effects of ascorbic acid, glutathione, and ethanol on the kinetic parameters of catalase were studied. A possible scheme of H2O2 degradation catalyzed by coimmobilized SOD, catalase, and HRP in the presence of reducing substrates is suggested.
Isolation and Characterization of Immobilized Aminoacylase from Streptoverticillium olivoreticuli by A. B. German; A. D. Neklyudov (pp. 55-58).
Immobilization of aminoacylase from Streptoverticillium olivoreticuli by incorporation into acrylamide gel has been investigated. The data showed that the process should be carried out at constant pH. Thermal inactivation of the immobilized enzyme under the reaction conditions was studied. The kinetics of enzymatic stereospecific deacylation of N-acetyl-DL-phenylalanine was analyzed. The results of this study may be used in the synthesis of amino acid enantiomers.
Search for Micromycetes Producing Extracellular Catalase and Study of Conditions of Catalase Synthesis by A. V. Kurakov; M. B. Kupletskaya; E. V. Skrynnikova; N. G. Somova (pp. 59-64).
Production of extracellular catalase by microscopic mycelial fungi (255 strains) belonging to different taxonomic groups was studied. Producers of extracellular catalase were found among fungi of the genera Penicillium, Talaromyces, and Aspergillus. Strains of the genus Penicillium were the most active producers. The formation of catalase depended on the initial pH, carbon and nitrogen sources and their ratio, and the content of microelements in the medium. The yield of extracellular catalase produced by the strains selected (P. chrysogenum, P. funiculosum, P. Pinophilum, and P. minioluteum) was not less than 400–1400 U per ml culture liquid.
The Use of Micromycetes for Cleaning Parts of Aircraft Engines by G. N. Dotsenko; E. P. Feofilova; V. M. Tereshina; A. C. Memorskaya (pp. 65-67).
Mycelial fungi Penicillium funiculosum, P. citrinum, P. expansum, P. chrysogenum, Aspergillus ochraceus, A. alliaceus, A. luchaensis, A. flavus, and A. niger were isolated from enrichment cultures. These fungi actively destruct carbon deposits formed during operation of aircraft. A biotechnological method for removing fouling from parts of aircraft engines (PAE) was developed. This method is less laborious, more rapid, and ecologically cleaner than contemporary chemical methods. Scanning microscopy was suggested for estimating the degree of decarbonization of PAE surfaces.
A New Oil-Oxidizing Micromycete Fusarium sp. by G. G. Yagafarova; E. M. Gataullina; V. B. Barakhnina; I. R. Yagafarov; A. Kh. Safarov (pp. 68-70).
The strain Fusarium sp. no. 56 isolated from natural oil-containing soil samples taken near the city of Oktyabr'skii, Republic of Bashkortostan, displayed a pronounced capability of biotransforming oil and its light and heavy fractions. This micromycete is nonpathogenic and can grow at 5–10°C. The latter property is of practical significance for its uses in soil and water bioremediation under the cold climatic conditions of Bashkortostan and other regions.
A Biosurfactant-Producing Pseudomonas aeruginosa Strain by O. V. Turkovskaya; T. V. Dmitrieva; A. Yu. Muratova (pp. 71-75).
A Pseudomonas aeruginosa strain producing an extracellular surfactant (biosurfactant) was isolated. The growth of this strain, referred to as 50.3, on a mineral glycerol-containing medium produces an emulsifying activity (60%) and decreases the surface tension of the culture liquid by a factor of 2.8 (to 25 mN/m). The optimum conditions for its growth and production of biosurfactants are intense aeration, pH 7.0–8.0, and the presence of Mg2+. The optimum biosurfactant properties were achieved when glucose was used as the only source of carbon and energy and NH4Cl was used as a source of nitrogen. The biosurfactant was isolated from the culture liquid by extraction and precipitation.
Use of Cellulose-Degrading Nitrogen-Fixing Bacteria in the Enrichment of Roughage with Protein by I. E. Smirnova; M. G. Saubenova (pp. 76-79).
A new strain of acid-tolerant facultative anaerobic cellulose-degrading bacteria Bacillus cytaseus 21 (Mc Bethe ef Scales, 1912), which are capable to fixing atmospheric nitrogen, was isolated. This strain is intended for solid-phase fermentation and enrichment with protein of cellulose-containing waste of plant cultivation.
A Comparative Study of Certain Parameters of Energy Metabolism in Two Strains of Saccharomyces cerevisiae by D. A. Aliverdieva (pp. 80-84).
A comparative study of energy metabolism in two strains Saccharomyces cerevisiae (the initial strain no. 73 and laser-irradiated mutant strain Y-503) was performed. In all growth phases, the rates of oxygen consumption by cells of Y-503 were higher than in the initial strain. The maximum (threefold) increase in the rate of oxygen consumption was observed in the linear phase. The effects of respiratory chain inhibitors rotenone, antimycin A, and cyanide on cellular and mitochondrial respiration were identical. There are two sites of energy coupling in the respiratory chain of mitochondria in S. cerevisiae no. 73 and Y-503, and electron flow is mainly mediated by cytochrome oxidase. The data suggest that the higher respiratory activity ofS. cerevisiaeY-503 cells in comparison with no. 73 is associated with greater amounts of mitochondria and total surface area of coupling mitochondrial membranes, which appears to be a factor contributing to the high physiological and biochemical activity of this strain.
Toxicity of Mercaptoethanol to Mutant Strains of the Yeast Pichia methanolica Growing on Different Carbon Sources by S. A. Leonovich; N. N. Serkova; Ya. M. Rabinovich (pp. 85-88).
Addition of β-mercaptoethanol at a concentration of 2–3 mM to media containing methanol, glucose, or yeast extract caused a 50% inhibition of the growth of wild-type yeastPichia methanolica; mercaptoethanol at a concentration of 0.7 to 25 mM inhibited the growth of the mutant strain ecr1. The mutation mth1 of P. methanolica repressed its ability to consume methanol and was accompanied by the loss of alcohol oxidase (EC 1.1.3.13) activity. β-Mercaptoethanol restored the ability of mth1 mutant cells to grow on methanol and stimulated their growth under derepression conditions. The growth effect of β-mercaptoethanol during derepression was accompanied by partial restoration of alcohol oxidase activity.
A Protein Inhibitor of Polygalacturonase in Apple Fruits Treated with Aminoethoxyvinylglycine and Cobalt Chloride by E. A. Bulantseva; E. M. Glinka; M. A. Protsenko; E. G. Sal'kova (pp. 89-92).
Ethylene evolution changes were monitored during storage of apple fruits (Malus domestica Borkh., winter cultivar Mantuanskoe) treated with aminoethoxyvinylglycine and CoCl2. The storage of fruits was shown to be accompanied by changes in the activity of a protein inhibitor of polygalacturonase (PIPG). This inhibitor has been previously isolated from apple fruit tissues. The protein inhibitor of polygalacturonase was also shown to inhibit the activity of an enzyme produced by certain nonpathogenic fungi. The role of PIPG in apple fruit resistance to these fungi is discussed.
Effects of Melanins on Lipid Peroxidation by L. N. Byshneva; V. V. Senchuk (pp. 93-97).
Effects of melanins obtained from cultured Cladosporium cladosporidae fungi and Alpha grape on Fe2+-induced, Fe2+–ascorbate-induced, and NADPH-induced lipid peroxidation in rat liver, brain, and eye were studied. Melanins were shown to inhibit the accumulation of lipid peroxidation products in vitro. The inhibitory effects of melanins were not due to direct interactions of these pigments with superoxide anion (O 2 ∸ ). However, melanins may interact with other free radicals. Melanins were demonstrated to have the ability to oxidize NADPH, which is probably one of the mechanisms of their antioxidant effects.
Studies of Mycofungicid, a Preparation Based on Trichoderma viride, for Plant Infection Control by L. V. Kolombet; S. K. Jigletsova; V. V. Derbyshev; D. V. Ezhov; N. I. Kosareva; E. V. Bystrova (pp. 98-102).
A technology was designed for manufacturing a preparation based on Trichoderma viride Pers ex S.F. Gray that strongly suppresses the development of causative agents of certain plant diseases and displays a growth-stimulating activity. Cultivation of the strain in a liquid medium for 18–24 h produced up to 60 g dry biomass per liter nutrient medium. A marketable form created in this work conserves the activity of the mycelial preparation for six months. The preparation is compatible with insecticides (carbofos, vismetrin, talstar, and applaud) and certain fungicides (such as baitan). Tests performed with the liquid form of Mycofungicid (seeds were treated with this preparation at a dose of 20–30 g per metric ton before sowing) showed its high efficiency in protecting cereal crops from plant pathogens. The incidence of plant diseases decreased by 65%, and crop yields increased by 15–20%.
Modulation of Plant Resistance to Diseases by Water-Soluble Chitosan by N. I. Vasyukova; S. V. Zinov'eva; L. I. Il'inskaya; E. A. Perekhod; G. I. Chalenko; N. G. Gerasimova; A. V. Il'ina; V. P. Varlamov; O. L. Ozeretskovskaya (pp. 103-109).
Low-molecular-weight water-soluble chitosan (5 kDa) obtained after enzymatic hydrolysis of native crab chitosan was shown to display an elicitor activity by inducing the local and systemic resistance of Solanum tuberosum potato and Lycopesicon esculentum tomato to Phytophthora infestans and nematodes, respectively. Chitosan induced the accumulation of phytoalexins in tissues of host plants; decreased the total content; changed the composition of free sterols producing adverse effects on infesters; activated chitinases, β-glucanases, and lipoxygenases; and stimulated the generation of reactive oxygen species. The activation of protective mechanisms in plant tissues inhibited the growth of taxonomically different pathogens (parasitic fungus Phytophthora infestans and root knot nematode Meloidogyne incognita).
Rapid Assay for Assessment of the Potential of Chemical Biocides against Microbial Destructors of Industrial Materials by I. A. Novikov; B. N. Gurov; G. V. Shtuchnaya; V. M. Fomchenkov; V. P. Kholodenko (pp. 110-114).
A colorimetric rapid assay for estimating the biocide potential of various chemicals towards metal- biocorrosive and petroleum-product-degrading microbes was developed based on the reducing potential of live microbial cells. A water-soluble organic redox indicator, blue in the oxidized form and pink in the reduced form, was used as an indicator of the reducing potential of microbial cells. Once added to a suspension of vital microbial cells, it was reduced and changed in color. A good correlation between the results of this assay and viability control was obtained by employing surfactants and heavy metal ions.