Production and characterization of extracellular α-amylases from the thermophilic fungus Thermomyces lanuginosus (wild and mutant strains)

-Amylases from the thermophilic fungus, Thermomyces lanuginosus ATCC 34626 (wild and mutant strains), were purified to homogeneity by a simple procedure including, consecutively, precipitation with ice-cold 2-propanol, anion-exchange and molecular-sieve chromatographic methods. The molecular masses of the purified -amylases (both with pI values of 3.0) were 58 kDa by SDS-PAGE. The optimal pH of -amylase activity was 5.0 for the wild enzyme and 4.5 for the mutant one. 1-Cyclohexyl-3-(2-morpholinyl-4-ethyl)-carbodiimide (40–100 mM) and N-bromosuccinimide (0.1–1 mM) inhibited the enzymes, suggesting the involvement of carboxylic groups and tryptophan residues in the catalytic process.     

Catalytic reduction of acetylene in the presence of molybdenum and iron clusters, including FeMo cofactor of nitrogenase

Acetylene was reduced by zinc amalgam in the presence of three synthetic polynuclear complexes: {[Mg₂Mo₈O₂₂(OMe)₆(MeOH)₄]⁻²·[Mg(MeOH)₆]²⁺}6MeOH (I), (Bu₄N)₂[Fe₄S₄(SPh)₄] (II), [Me₄N][VFe₃S₄Cl₃(DMF)₃]·2DMF (III) and the iron-molybdenum cofactor of nitrogenase Azotobacter vinelandii MoFe₇(S²⁻)₉·homocitrate, FeMo-co (IV). Thiophenol was found to greatly facilitate the reaction in the presence of complexes I, II, IV. The reaction is catalytic and for I and IV proceeds at the amalgam surface. Thiophenol seems to increase the adsorption of the complexes, serving as an electron bridge to transfer electrons to the catalyst. In the case of II a homogeneous reduction of the substrate occurs presumably after the cluster reduction at the surface and with III the catalytic reduction proceeds only under the action of sodium amalgam; no thiophenol cocatalytic action is observed. Relevance to N₂ enzymatic reduction is discussed.     

Effect of point substitutions in the <Emphasis Type="Italic">MnSOD,GPX1</Emphasis>, and <Emphasis Type="Italic">GSTP1</Emphasis> genes on the risk of familial and sporadic breast cancers in residents of Altai Krai

The frequencies of the polymorphic gene variants MnSOD Ala₉Val, GPX1 Pro₁₉₈Leu, and GSTP1 Ile₁₀₅Val were estimated in female residents of Altai krai with breast cancer. The frequency distributions of the genotypes for all genes studied in both patients and control subjects fit the Hardy-Weinberg equilibrium. The estimated frequencies of the genotypes for the studied genes in the control group did not differ from those earlier reported for Caucasoid women living in Europe. The T (rs1050450) allele of the GPX1 gene was demonstrated to protect against sporadic breast cancer (OR = 0.74 (95% CI = 0.58−0.94), p = 0.012). Carriers of the genotype combination MnSOD CC + GPX1 CC were found to have a 1.6 times higher risk of sporadic breast cancer compared to the control group (OR = 1.59 (1.05−2.41), p = 0.0258). The polymorphic loci GSTP1 (rs1695) and MnSOD (rs4880) were not found to be significantly associated with the risk of familial or sporadic breast cancer.     

Detection of two immunochemically identical forms of mannan-binding lectin in the sea urchin <Emphasis Type="Italic">Strongylocentrotus nudus</Emphasis>

This study revealed a new lectin (MBL-SN) in the coelomic fluid of the sea urchin Strongylocentrotus nudus. Based on the peculiarities of molecular structure and carbohydrate specificity, MBL-SN can be assigned to the mannan-binding lectin family. Using polyclonal monospecific rabbit antibodies against MBL-SN, the presence of MBL-SN in the sea urchin was detected in two forms: a soluble form dissolved in the coelomic fluid and an extracellular matrix-bound form. The biosynthesis site of this lectin may be one of the subpopulations of morula cells-coelomic fluid cells that perform heterosynthesis. Our results demonstrate the similarity of the sea urchin lectin MBL-SN to the previously investigated MBLs of the holothurians Cucumaria japonica and Apostichopus japonicus, and suggest a similarity to MBLs of vertebrates, which also have soluble and bound forms.     

Maintaining high anaerobic succinic acid productivity by product removal

During dual-phase fermentations using Escherichia coli engineered for succinic acid production, the productivity and viable cell concentration decrease as the concentration of succinic acid increases. The effects of succinic acid on the fermentation kinetics, yield, and cell viability were investigated by resuspending cells in fresh media after selected fermentation times. The cellular succinic acid productivity could be restored, but cell viability continuously decreased throughout the fermentations by up to 80% and subsequently the volumetric productivity was reduced. Omitting complex nutrients in the resuspension media had no significant effect on cellular succinate productivity and yield, although the viable cell concentration and thus the volumetric productivity was reduced by approximately 20%. By resuspending the cells, the amount of succinate produced during a 100-h fermentation was increased by more than 60%. The results demonstrate that by product removal succinic acid productivity can be maintained at high levels for extended periods of time.     

Prolyl iminopeptidase from seeds of sunflower (Helianthus annuus L.)

Prolyl iminopeptidase from sunflower seed (Helianthus annuus L.) was purified to molecular homogeneity. It is a 105-kDa heterodimer consisting of two subunits: 53 and 55 kDa. It has pI of 6.2 and optimal activity at pH 8.0–8.5 and 45–50°C. The inhibitory analysis was inconclusive about its catalytic machinery, as a significant degree of modification was not observed with any of the used diagnostic inhibitors. Its specificity is restricted to removal of N-terminal prolyl residues.     

Polymorphic variants of folate metabolizing genes (C677T and A1298C MTHFR, C1420T SHMT1 and G1958A MTHFD) are not associated with the risk of breast cancer in West Siberian Region of Russia

Breast cancer is the most incident cancer among women. We investigated the role of polymorphisms of folate metabolizing genes MTHFR (C677T and A1298C), SHMT1 (C1420T) and MTHFD (G1258A) in genetic susceptibility to this type of cancer. We determined allele and genotype frequencies in case (850 women with sporadic form of breast cancer) and control (810 women) groups. None of these polymorphisms was significantly associated with breast cancer risk. To increase statistical power of our study, we conducted a meta-analysis which included published genotype data and the results of our work. Meta-analysis also revealed no significant association of studied SNPs with breast cancer.     

Identification of <Emphasis Type="Italic">Wx</Emphasis> genotypes among different varieties of soft winter wheat

The use of PCR analysis with allele-specific primers in testing the allelic state of Wx genes in genomes registered in the State Registry of Wheat Varieties (2006) made it possible to identify the absence of mutations with respect to these genes in the group of varieties studies. Variations in the dimension and intensity of staining of the starch granules in these varieties are noted.     

Cytogenetic analysis of the noxious bloodsucker Boophthora erythrocephala (Diptera: Simuliidae) from different geographic zones

Boophthora erythrocephala is a widely spread species inhabiting both small polluted water-bodies and large rivers. Three populations from Samara region in Russia and from Donetsk and Chernigov regions in the Ukraine have been studied. Five populations of this species in Russia were described earlier (Polyanskaya, Tsapygina, 1968; Petrukhina, 1972). For identification of this species the chromosome map of Adler and Werner (personal communication) was used. Comparison of 8 populations studied was performed. All of them belong to the species B. erythrocephala but everyone has its own individual characteristics. Inversion polymorphism was observed in each population comprising from 88 to 100 %. Mean number of heterozygous inversions per individual is low fluctuating around 3.6. There is one inversion in IIS observed in all populations that proves panmixy among them. Other inversions occur in a part of the individuals.     

Genetic structure of the Udmurt population

Integrated study of the genetic structure of the Udmurt population with respect to different genetic systems has been performed. Data on the genes of genetic diseases, abiotic parameters analyzed by population statistic methods, and DNA polymorphism are summarized. The populations of six raions (districts) of Udmurt Republic (the Mozhga, Malaya Purga, Sharkan, Debesy, Igra, and Glazov raions) have been studied. The total population studied was 267 655 people (an urban population of 150 119 people and a rural population of 117 536 people), including 155 346 Udmurts. The population structure has been studied in six districts on the basis of the vital statistics, Crow’s indices, Malecot’s isolation by distance parameters, ethnically assortative marriage parameters, endogamy indices, inbreeding-endogamy (ie) indices, and frequencies of the genotype and allele frequencies of four DNA markers (17 alleles). The prevalences of hereditary diseases have been calculated for different population groups: urban and rural populations, Udmurts and other ethnic groups. These groups, especially the urban and rural populations, substantially differed from one another in the prevalences of autosomal dominant (AD) and autosomal recessive (AR) diseases. The correlation between the prevalence of AD and AR diseases and the ie index is positive and significant. The spectrum of hereditary diseases detected in six districts of Udmurtia comprises 149 diseases (80, 57, and 12 AD, AR, and X-linked diseases, respectively). Accumulation of individual diseases in districts of Udmurtia and accumulation of diseases in Udmurtia as compared to regions studied earlier has been found. Cluster analysis of the frequencies of genes of AD and AR diseases and DNA markers has determined the gene geographic position of Udmurts.