Bacterial complexes of the fruiting bodies and hyphosphere of certain basidiomycetes

The surface and internal tissues of the fruiting bodies of basidiomycetes were shown to be specific bacterial habitats characterized by varying diversity and structure of bacterial complexes. On the surface of fruiting bodies, gram-negative bacteria of the genera Pseudomonas, Xanthomonas, and Myxococcus prevailed, while in the internal tissues gram-positive bacteria of the genera Streptomyces, Bacillus, Arthrobacter, and Micrococcus were identified in addition. Bacterial complexes from the surface and inner tissues of the fruiting bodies of the studied basidiomycetes showed significant similarity to each other and differed from those from the hyphosphere and the reference soil. On the surface and in the internal tissues of the fruiting bodies, representatives of the genus Myxococcus were identified for the first time, which could indicate initial decay of the fruiting body.     

Optimal Method for Disulfide Bond Closure in the Synthesis of Atosiban—Antagonist of Oxytocin Receptors

Russian Journal of Bioorganic Chemistry - This work is devoted to the large-scale solid-phase synthesis (SPS) of Atosiban, Mpa1-D-Tyr(OEt)-Ile-Thr-Asn-Cys6-Pro-Orn-Gly-NH2 cyclic 1,6 disulfide, the...     

Population structure of chum salmon Oncorhynchus keta in the Russian Far East, as revealed by microsatellite markers

Chum salmon populations in the Russian Far East have a complex multi-level genetic structure. A total of 53 samples (2446 fish) were grouped into five major regional clusters: the southern Kurils, eastern Sakhalin, southwestern Sakhalin, the Amur River, and a northern cluster. The northern cluster consists of chum salmon populations from a vast geographical region, including Chukotka, Kamchatka, and the continental coast of the Sea of Okhotsk. However, the degree of its genetic differentiation is low, 1.9%. In contrast, the southern population cluster exhibits much higher variation; for example, differentiation between chum salmon groups within Sakhalin Island reaches 4.6%, and the differentiation between Iturup Island and Sakhalin Island chum salmon is 7.7%. This suggests that southern populations of Asian chum salmon have a more ancient evolutionary history than northern populations. In contrast to the available data, our study indicates a great deviation of southwestern Sakhalin populations from other Sakhalin chum salmon. The Russian Far East chum salmon are genetically diverse and show statistically significant differentiation even within small geographic localities. This can be used to assign samples of unknown origins to definite local populations.     

Seasonal dynamics of damage to small-leaved lime trees by phyllophagous arthropods

The seasonal dynamics of damage to the small-leaved lime Tilia cordata by phyllophagous arthropods was monitored in Izhevsk in 1999–2002. The work was carried out in 15 test plots, 10 model trees being selected within each plot. From May 30 to September 10, damage to leaves was assessed every ten days in the same model branch selected from the lower layer in the northern part of the crown. The complex of phyllophagous arthropods of the small-leaved lime includes 33 species from 17 families and 7 orders.     

Similar performance in central and range‐edge populations of a Eurasian steppe grass under different climate and soil pH regimes

The abundant centre hypothesis predicts that changing environmental conditions are detrimental to a species’ abundance and performance towards the periphery of its range. We tested these predictions for the perennial grass Stipa capillata, a species that is commonly found in steppes of Asia but is rare at its north‐western range edge, in central Europe. We compared 21 populations in dry grassland fragments in central Europe and 20 populations in steppe habitats of Kazakhstan. We studied 15 plant performance traits both in situ and under laboratory and common greenhouse conditions, including local density, plant size and biomass production, seed size, weight and viability. To assess environmental conditions, we assembled data on topography, soil properties and climatic parameters. Using variance components analysis and multivariate methods we analyzed whether plant performance and environmental attributes differed more, as predicted, between the core and peripheral regions or whether they differed more among their subregions or populations. Additionally, we tested whether performance was affected by the same set of environmental predictors in each region. Contrary to our expectations, plant performance traits were virtually unchanged between the range periphery and centre. As expected, macroclimatic conditions showed a significant difference between the two regions (annual mean temperature, annual precipitation). The only other measured environmental variable that differed significantly between the two regions was soil pH, which was lower in core‐range populations. Our findings thus do not support the notion of reduced performance at the range edge. Instead, our data lend support to earlier theories of relative habitat constancy, suggesting that peripheral populations can shift to other habitats through plasticity or adaptation.     

Level of phytohormones in various types of symbiotic pea mutants]

The levels of the phytohormones auxin and gibberellin were studied in the original pea (Pisum sativum L.) cultivars Rondo and Ramonskii 77 and in different types of symbiotic mutants (non-nodulating, with single nodules, and supernodulating) induced from them. The results obtained indicated that the levels of the phytohormones in the symbiotic mutants depend on the plant's genotype, developmental phase, and infection with rhizobia. Two mutants were isolated whose phytohormonal statuses markedly differed from the original forms. These mutants may be used for identification of the genes that determine the auxin and gibberellin statuses.     

Mutant OmpF porins of Yersinia pseudotuberculosis with deletions of external loops: Structure–functional and immunochemical properties

Recombinant mutant OmpF porins from Yersinia pseudotuberculosis outer membrane were obtained using site-directed mutagenesis. Here we used four OmpF mutants where single extracellular loops L1, L4, L6, and L8 were deleted one at a time. The proteins were expressed in Escherichia coli at levels comparable to full-sized recombinant OmpF porin and isolated from the inclusion bodies. Purified trimers of the mutant porins were obtained after dialysis and consequent ion-exchange chromatography. Changes in molecular and spatial structure of the mutants obtained were studied using SDS–PAGE and optical spectroscopy (circular dichroism and intrinsic protein fluorescence). Secondary and tertiary structure of the mutant proteins was found to have some features in comparison with that of the full-sized recombinant OmpF. As shown by bilayer lipid membrane technique, the pore-forming activity of purified mutant porins was identical to OmpF porin isolated from the bacterial outer membrane. Lacking of the external loops mentioned above influenced significantly upon the antigenic structure of the porin as demonstrated using ELISA.     

Synthesis and cardioprotective properties of apelin-12 and its structural analogues

Apelin-12 and a number of its analogues (Nle¹⁰-, MeArg¹, Nle¹⁰, MeArg¹, Nle¹⁰, Phe¹²-NH₂-, Arg¹(NO₂), Nle¹⁰, Phe¹²-NH₂-), resistant to the degradation of proteases, were synthesized by the Fmocmethod of SPPS. By-products of synthesis were examined. It was found that the serine hydroxyl group was sulfating during the final deprotection of apelin-12 and its analogues. The sulfate moiety of the Arg-protecting group transfers into the hydroxyl group of Ser. The amount of by-product depends on the water presence in cleavage mixture. Furthermore, the final deprotection of amide analogues of apelin-12 was accompanied by the formation of a by-product — 4-hydroxybenzylamide; its amount ranged from 20% to 8% in the reaction mixture (according to HPLC data) and also depended on the composition of the cleavage mixture. Effects of the synthesized peptides on recovery of the cardiac function after ischemia were examined in a model of isolated perfused rat heart. Infusions of any of the peptides (I–V) before ischemia resulted in a significant improvement of contractile and pump function recovery compared with the control. Cardioprotective efficacy of the peptides increased in the following rank (I) < (II) = (III) < (IV) = (V).     

Peptide Fragments and Structural Analogues of Chemokine MCP-1: Synthesis and Effect on the MCP-1-Induced Migration of Mononuclear Cells

Fourteen fragments and structural analogues of chemokine MCP-1 were synthesized using the Fmoc-strategy of solid phase peptide synthesis. The effect of synthesized peptides on the MCP-1-stimulated migration of mononuclear cells was examined. Both in vitro stimulants and inhibitors of the monocyte migration were found among the peptides. A possible participation of the C-terminal part of the MCP-1 molecule in the inhibition of the MCP-1-stimulated cell migration was found for the first time.