Forgot your password?
New user?
New Window Opens on the Secret Life of Microbes: Scientists Develop First Microbial Profiles of Ecosystems
CAS announces the release of SciFinder Scholar for Mac OS X
Press Releases
Press Releases
| Check out our New Publishers' Select for Free Articles |
Applied Biochemistry and Microbiology (v.46, #3)
Salicylate-induced modification of plant proteomes (review) by I. A. Tarchevsky; V. G. Yakovleva; A. M. Egorova (pp. 241-252).
Here we present a brief review of the reports concerning proteome modifications under the influence of salicylic acid, which is one of the major mediators of both local and systemic immunity. We describe also the results of our own studies of the salicylate-induced changes in proteomes of pea leaves and roots. Fifteen salicylate-inducible proteins, which were previously unknown, have been identified. Unlike the roots, leaves accumulated some chloroplast proteins and enzymes capable of degrading the pathogen cell walls. In the roots, salicylic acid increased the content of enzymes, improving the resistance of plant cells themselves, and promoted the disappearance of reductase of oxophytodienic acid. The latter could lead to inhibition of jasmonic acid synthesis and stimulation of local immunity. High (apoptotic) concentration of salicylic acid intensified synthesis of root proteins involved in the formation of heteroprotein complexes, which play an important role in the functioning of the signaling system, DNA synthesis and repair, and protein synthesis, refolding, and proteolysis.
Immunochemical methods of mycotoxin analysis (review) by A. E. Urusov; A. V. Zherdev; B. B. Dzantiev (pp. 253-266).
The review is devoted to comparative characterization of immunochemical methods of detection of mycotoxin, which belongs to one of the priority groups of the food contaminants. It has been shown that the high specificity and the possibility of mycotoxin detection in low concentrations combined with existent diverse equipment allow for considering the immunochemical methods of analysis to be the most promising for wide practical application. The analytical characteristics of the existent developments are presented; the merits and demerits of the different kinds of immunoanalytical systems are compared.
Sulfated polysaccharides and their anticoagulant activity: A review by N. M. Mestechkina; V. D. Shcherbukhin (pp. 267-273).
Published data on the sulfated polysaccharides of various origins that display an anticoagulant activity are summarized and analyzed. The methods used for producing semisynthetic derivatives are considered. A key role of the polysaccharide structure in the mechanisms of specific interaction with various blood plasma proteinases is discussed. The effects of the content and location of sulfate groups in polysaccharides and their molecular weight on the degree of the studied activity are assessed.
Variability of light-induced circular dichroism spectra of photosystem I complexes of cyanobacteria by V. V. Shubin; M. Roegner; E. El-Mohsnawy; I. V. Terekhova; E. Schlodder; N. V. Karapetyan (pp. 274-281).
Circular dichroism (CD) spectra of photosystem I (PSI) complexes of the cyanobacteria Thermosynechococcus elongatus, Arthrospira platensis and Synechocystis sp. PCC 6803 were studied. CD spectra of dark-adapted PSI trimers and monomers, measured at 77 K, show common bands at 669–670(+), 673(+), 680(−), 683–685(−), 696–697(−), 702(−) and 711(−) nm. The intensities of these bands are species specific. In addition, bands at 683–685(−) and 673(+) nm differ in intensity for trimeric and monomeric PSI complexes. CD difference spectra (P700+–P700) of PSI complexes at 283 K exhibit conservative bands at 701(−) and 691(+) nm due to changes in resonance interaction of chlorophylls in the reaction center upon oxidation of P700. Additional bands are observed at 671(−), 678(+), 685(−), 693(−) nm and in the region 720–725 nm those intensities correlate with intensities of analogous bands of antenna chlorophylls in dark-adapted CD spectra. It is suggested that the variability of CD difference spectra of PSI complexes is determined by changes in resonance interaction of reaction center chlorophylls with closely located antenna chlorophylls.
The model of resting forms of micobacteria for testing of chemodrugs for latent forms of tuberculosis by A. M. Anuchin; A. V. Goncharenko; I. V. Galon; O. I. Demidenok; Yu. K. Kudykina; M. M. Moisenovich; A. L. Mulyukin; A. S. Kaprelyants (pp. 282-288).
The new model of obtaining of ovoid resting forms of Mycobacterium smegmatis, which are morphologically different from vegetative (rod-like) cells, was developed. Ovoid forms were characterized by a drastically decreased level of metabolic activity, an increased stability to heat or antibiotics treatment, and also by prolonged (more than 2 months) storage time preserving colony-forming ability. Obtained resting forms of micobacteria may be used in test-systems for checking efficiency of new medical agents against latent forms of tuberculosis and determination of role of the genes in entering dormant state.
Biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer by Azotobacter chroococcum strain 7B by V. L. Myshkina; E. A. Ivanov; D. A. Nikolaeva; T. K. Makhina; A. P. Bonartsev; E. V. Filatova; A. O. Ruzhitsky; G. A. Bonartseva (pp. 289-296).
The ability of Azotobacter chroococcum strain 7B, producer of poly(3-hydroxybutyrate) (PHB), to synthesize its copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P(3HB-co-3HV)) was studied. It was demonstrated, for the first time, that A. chroococcum strain 7B was able to synthesize P(3HB-co-3HV) with various molar rates of HV in the polymer chain when cultivated on medium with sucrose and carboxylic acids as precursors of HV elements in the PHB chain, namely, valeric (13.1–21.6 mol %), propanoic (3.1 mol %), and hexanoic (2.1 mol %) acids. Qualitative and functional differences between PHB and P(3HB-co-3HV) were demonstrated by example of the release kinetic of methyl red from films made of synthesized polymers. Maximal HV incorporation into the polymer chain (28.8mol %) was recorded when the nutrient medium was supplemented with 0.1% peptone on the background of 20 mM valerate. These results suggest that that the studied strain can be regarded as a potential producer of not only PHB but also P(3HB-co-3HV).
Formation of glycated recombinant leghemoglobin in Escherichia coli cells by O. V. Kosmachevskaya; A. F. Topunov (pp. 297-302).
A nonenzymatic glycation of the recombinant leghemoglobin expressed in Escherichia coli cells was demonstrated for the first time. This process involved the heme pocket and gave low-spin leghemoglobin species. A correlation between the degree of E. coli protein glycation and synthesis of poly-β-hydroxybutyric acid was found, suggesting that the accumulation of reserve carbon sources and nonenzymatic glycation could be alternative processes.
Spectrophometric analysis of volatile compounds in microorganisms by A. G. Voloshin; S. Yu. Filippovich; G. P. Bachurina; S. G. Besaeva; S. G. Ignatov (pp. 303-306).
A simple modification of a spectrophometric method was proposed for the rapid detection of microorganisms based on their ability either to excrete or to absorb volatile compounds. The method provides the possibility of contactless control for bacterial growth at a concentration above 107 cells/ml. In addition, the method allows discriminating mutants of the fungus Neurospora crassa defective in the nitrogen metabolism from the wild type strains. It is likely that nitrite reductase and nitrate reductase enzymes regulated by the nit-2 and nit-6 genes are involved in formation of the water soluble volatile compounds of this organism.
The study of adaptation mechanisms of Yarrowia lipolytica yeast to alkaline conditions by means of proteomics by M. A. Guseva; E. Yu. Epova; L. I. Kovalev; A. B. Shevelev (pp. 307-312).
Using proteomic technologies—two-dimensional electrophoresis in denaturing conditions in combination with mass spectroscopy of MALDI-TOF proteins—we demonstrated, for the first time, that the most noticeable alteration of protein composition of a Yarrowia lipolytica cell during adaptation to alkaline conditions was an increase of mitochondrial proteins relatively to proteins of cytoplasm.
A heterologous production of the Trametes hirsuta laccase in the fungus Penicillium canescens by A. R. Abyanova; A. M. Chulkin; E. A. Vavilova; T. V. Fedorova; D. S. Loginov; O. V. Koroleva; S. V. Benevolensky (pp. 313-317).
A heterologous protein expression in the fungus Penicillium canescens is described for the first time. The fungal strains producing Trametes hirsuta 072 accase under control of a highly efficient promoter of the P. canescens gene bgaS has been constructed. These strains efficiently transcribe the T. hirsuta 072 laccase gene with a correct intron splicing. Activity of the secreted heterologous laccase in the culture liquid reaches 3 U/ml, accounting for 98% of the total laccase activity, which demonstrates a high efficiency of heterologous secretion. The synthesized P. canescens laccase has the same molecular weight as the enzyme produced by T. hirsuta 072.
Comparative analysis of respiratory activity in the wild type strain of Neurospora crassa and its photoreceptor complex mutants by E. P. Isakova; Yu. I. Deryabina; N. N. Gessler; T. A. Belozerskaya; Ya. M. Rabinovich (pp. 318-323).
Cell respiratory activity of protoplasts obtained from the wild type of Neurospora crassa and photoreceptor complex WCC—white collar 1 (wc-1) and white collar 2 (wc-2)—mutants of Neurospora crassa strains was investigated. Respiration inhibition by KCN in the presence of 25 mM succinate was similar in all strains and did not exceed 83–85% against control. The significant induction of KCN-resistant respiratory pathway occurred under 1% glucose oxidation in wc-1 and wc-2 mutants if compared with the wild type strains. The inhibitors of the main (cytochrome) pathway of electron transfer in mitochondria—1 mM KCN and antimycin A (4 μg/ml)—blocked the respiration rate of the protoplasts from N. crassa wild type by 75%, while the cell respiration of wc-1 and wc-2 strains was suppressed by approximately 50%. The specific inhibitor of alternative oxidase—10 mM salicylhydroxamic acid (SHAM)—in combination with the blockers of mitochondrial electron transfer chain caused the total suppression of respiratory activity of protoplasts in all studied strains. It is supposed that an increase of KCN-resistance in WCC mutants under glucose oxidation is connected with alternative oxidase activation as the result of failure in reception and signal transduction of active oxygen species.
The influence of cultural medium composition on the proteolytic enzyme secretion of fungus Rhizoctonia solani by N. N. Kudryavtseva; E. L. Gvozdeva; A. V. Sof’in; T. A. Valueva (pp. 324-330).
It was shown that change of medium growth composition of photopathogenic fungus Rhizoctonia solani Kühn, especially accessible sources of nutrition, leads to change of both quantity of produced proteinases and their action specificity. The mineral source of nitrogen suppressed the fungus proteinase secretion on cultivatiin medium containing potato thermostable proteins but an organic source of nitrogen accelerated mycelium growth and increased proteinase secretion. On the basis of an analysis of a fungus extracellular proteinase substrate-specificity, it is established that the presence of thermostable proteins of a potato in the cultural liquid induces the secretion of trypsin-like proteinases mainly, and the addition of yeast extract to this growth medium induces the secretion of subtilisin-like ones, thus suppressing the trypsin-like enzymes production. This fact can indicate that mycelium of fungus R. solani loses pathogenic properties and becomes saprophytes when the growth medium was enriched by an organic source of nitrogen.
The influence of light, hormonal, and carbohydrate signal systems on ELIP gene expression in gun-mutants Arabidopsis thaliana by O. V. Osipenkova; M. S. Odintsova; N. P. Yurina (pp. 331-338).
It is proven that retrograde tetrapyrrole-induced plastid signals, light signals, and signals induced by hormones and carbohydrates influence expression of nuclear genes of plastid stress ELIP in Arabidopsis thaliana L. Plastid signals differently regulated expression of genes from multigene family of photosynthesis proteins (ELIP and Lhcb2) and were modulated by light. The influence of a regulator of plant growth—abscisic acid—led to activation of expression of ELIP genes in the light. Carbohydrates suppressed transcription of ELIP genes. Thus, signals of exogenous (light) and endogenous (retrograde signals, hormones, carbohydrates) origin influence the expression of ELIP genes. These types of signals probably interact with each other and favor the increase of resistance of plants to the action of stress factors of the environment.
Photobiochemistry of folates: A photochemical reduction of folic acid by Yu. L. Vechtomova; T. A. Telegina; M. P. Kolesnikov; M. S. Kritsky (pp. 339-345).
Exposure of deaerated folic acid solutions containing an electron donor to UV radiation (310–390 nm, I = 0.4 W m−2) induced formation of dihydrofolic acid (DHFA), a photoexcitation which gave tetrahydrofolic acid (THFA). Only DHFA was formed in the presence of EDTA (E′o = +0.40 V), while the presence of stronger reductants—NADH (E′o = −0.32 V) and boron hydride (E′o = −0.48 V)—induced photoreduction to THFA. It was demonstrated that UV radiation had no effect on the THFA formylation, giving the coenzyme 5,10-methenyltetrahydrofolic acid and its transformation into another coenzyme, 5-formyltetrahydrofolic acid.
Immunomodulating activity of chitosan derivatives with salicylic acid and its fragments by N. I. Vasyukova; O. L. Ozeretskovskaya; G. I. Chalenko; N. G. Gerasimova; A. A. L’vova; A. V. Il’ina; A. N. Levov; V. P. Varlamov; I. A. Tarchevsky (pp. 346-351).
A study of biological activity of the derivatives of the chitin-chitosan oligomer with salicylic acid and its fragments showed that chitosan salicylate actively protected potato tubers against Phytophthora infestans but sharply inhibited reparation of potato tissues. N-(2-hydroxybenzyl)chitosan exhibited good protective properties but did not influence wound reparation. N-(2-hydroxy-3-methoxybenzyl)-N-pyridoxchitosan, which contained the pyridoxal and 2-hydroxy-3-methoxy fragments, was the most efficient, stimulating both defense against late blight and wound reparation in potato tissues.
Changes in the plastid apparatus of apical meristem cells of potato tubers upon growth regulation with jasmonic acid by T. A. Platonova; A. S. Evsyunina; N. P. Korableva (pp. 352-358).
A comparative ultramorphometric study of the effect of jasmonic acid (JA) on the plastid apparatus in apical cells of potato tubers varying in physiological state was performed. When tubers were treated with JA at forced rest, the plastid apparatus of apical cells decreased in area and plastid proliferation was suppressed. When treatment was performed during growth, the area of the plastid apparatus remained unchanged, division was suppressed, and plastid budding was stimulated in apical cells. There was also a common response to JA that was independent of the physiological state of tubers. JA stimulated the development of the internal membrane system in plastids, reduced the amount of protein inclusions, and increased the portion of plastids having cisterns of the granular endoplasmic reticulum (GER) around their envelopes. The ultrastructural changes in plastids made it possible to assume that JA increases the biosynthetic activity of the plastid apparatus in apical meristem cells of potato tubers.
Melafen effect on ATP-dependent accumulation of calcium in plasma membrane vesicles from cells of potato tubers by E. P. Ladyzhenskaya; N. P. Korableva (pp. 359-362).
Synthetic growth regulator melafen (10−5–10−10 M) was tested for aneffect on the Ca2+ accumulation in plasma membrane vesicles (PMVs) isolated from potato Solanum tuberosum L. tubers at forced rest and sprouting. Melafen proved to regulate the Ca2+ accumulation in PMVs by changing the activity of Ca2+, Mg2+-ATPase of the plasma membrane, while no effect was observed with respect to Ca2+ outflow from vesicles. The melafen effect on Ca2+, Mg2+-ATPase activity depended on the physiological condition of tubers and the melafen concentration.
Influence of the cycle number in processing of cellulose from waste paper on its ability to hydrolysis by cellulases by V. V. Morozova; M. V. Semenova; A. M. Rozhkova; E. G. Kondrat’eva; O. N. Okunev; A. O. Bekkarevich; E. V. Novozhilov; A. P. Sinitsyn (pp. 363-366).
Hydrolytic ability of laboratory enzyme preparations from fungus of the Penicillium genus was investigated using kraft pulp from nonbleached softwood and bleached hardwood cellulose as substrates. The enzyme preparations were shown to efficiently hydrolyze both softwood and hardwood cellulose. The yields of glucose and reducing sugars were 24–36 g/l and 27–37 g/l from 100 g/l of dry substrate in 48 h, respectively, and depended on the number of substrate grinding cycles.
Erratum to: “Function Analysis of a New Type I PKS-SAT Domain by Sat-Eat Domain Replacement”
by Y. L. Jiao; L. H. Wang; B. H. Jiao; S. J. Wang; Y. W. Fang; S. Liu (pp. 367-367).