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1.
A major protein of the endotoxin from Yersinia pseudotuberculosis was isolated from the complex lipid A--protein by treatment with SDS and triton X-100 followed by gel-chromatography on Sephacryl S-300. Protein has apparent molecular mass 40 kDa and alanine as N-terminal amino acid residue. CD and IR spectroscopy conformational changes of the protein molecule in the process of its isolation. The thermal and pH stabilities of the protein were investigated by the methods of intrinsic fluorescence and differential scanning microcalorimetry. The isolated protein revealed two thermal transitions (at 30-35 and 50-55 degrees C), which depend on Ca2+ concentration. 相似文献
2.
The serologically active O-specific polysaccharide has been isolated from the lipopolysaccharide of Yersinia enterocolitica, serovar O: 6.31. Using methylation, partial acid hydrolysis and 13C NMR spectroscopy, the main structural moiety of the O-specific polysaccharide is shown to be the following disaccharide repeating unit: (Formula: see text). 相似文献
3.
R P Gorshkova E N Kalmykova V V Isakov Y S Ovodov 《European journal of biochemistry》1986,156(2):391-397
Lipopolysaccharides of Yersinia enterocolitica serovars O:5 and O:5,27 were shown to have a similar sugar composition, consisting of L-rhamnose, D-glucose, D-galactose, D- and L-glycero-D-manno-heptose, 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose, 3-deoxy-D-manno-octulosonate and D-threo-pent-2-ulose (D-xylulose). Partial hydrolysis of lipopolysaccharides with acetic acid produced rhamnans with the following repeating unit: ----3)-L-Rha rho(alpha 1----3)-L-Rha rho(alpha 1----3)-L-Rha rho(beta 1----. 13C-NMR and methylation studies of the lipopolysaccharides gave the following structure for the repeating unit of the two O-specific polysaccharides: ----3)-L-Rha rho(alpha 1----3)-L-Rha rho(alpha 1----3)-L-Rha rho(beta 1----. (formula; see text) 相似文献
4.
Isolation and characterization of lipopolysaccharides from cell walls of blue-green algae of the genus Phormidium. 下载免费PDF全文
Lipopolysaccharide (LPS) fractions were isolated from three species of blue-green algae of the genus Phormidium, namely, P. africanum, P. laminosum, and P. uncinatum, by using a phenol-water procedure followed by exhaustive extraction with ammonium oxalate. The materials obtained were shown to be closely related biochemically. Nearly 60% of the LPS consisted of the polysaccharides galactose, glucose, mannose, xylose, arabinose, and rhamnose and an unidentified, fast-moving sugar residue. In addition, glucosamine, galactosamine, and 2-keto-3-deoxyoctonate were detected. Oleic, stearic, and palmitic acids were found in the hydrolysate of the lipid component, which averaged 1.5% of the LPS. Concomitantly, the protein component (7 to 20%) was shown to contain the following amino acids: aspartic acid, threonine, serine glutamic acid, proline, glycine, alanine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, lysine, histidine, and arginine. Whole cells, as well as the LPS, of Phormidium possessed antigenic properties. 相似文献
5.
Raisa P. Gorshkova Natalia I. Korchagina Tatianna A. Medonova Elena N. Kalmykova Natalia N. Besednova Yury S. Ovodov 《Carbohydrate research》1980,84(2):237-243
Lipopolysaccharides (LPS) from various strains of Yersinia pseudotuberculosis type V have been isolated and characterised. Differences in sugar composition and serological activity of LPS from various strains within the same subtype of Y. pseudotuberculosis have been revealed. 相似文献
6.
Yury S. Ovodov Raisa G. Ovodova Valenthina I. Shibaeva Lidia V. Mikheyskaya 《Carbohydrate research》1975,42(1):197-199
Traces of either ferrous or ferric salts greatly increase the rate of the stepwise degradation of reducing sugars by alkaline hydrogen peroxide, as measured by formation of formic acid; addition of larger proportions of iron salts causes relatively smaller effects. The results showed that, unless unusually strict precautions are taken to exclude traces of iron, the free-radical cleavage of the hydroperoxide adducts of reducing sugars is far more rapid than the ionic cleavage. The catalytic effect of iron salts is counteracted by addition of magnesium salts. With d-glucose, inhibition of the catalytic effect of iron by magnesium depends on both the magnesium-iron ratio and the concentration at a given ratio. Measurements with various molar proportions of the salts indicated that a magnesium-iron complex, containing six atoms of magnesium to one of iron, is formed. Presumably, removal of iron by formation of this complex inhibits the free-radical degradation of hydroperoxide adducts. In marked contrast to the results obtained with reducing sugars, the degradation of potassium glyoxylate and of glyoxal by alkaline hydrogen peroxide is extremely rapid, and not catalyzed by iron or inhibited by magnesium. The results are in accord with an ionic, rather than a free-radical, cleavage of the hydroperoxide adducts of these compounds. The rapidity of the ionic reaction may be attributed to the ready availability of an electron pair from the adjoining carbon atom. 相似文献
7.
Anna S. Druzhkova Olaf Thalmann Vladimir A. Trifonov Jennifer A. Leonard Nadezhda V. Vorobieva Nikolai D. Ovodov Alexander S. Graphodatsky Robert K. Wayne 《PloS one》2013,8(3)
The origin of domestic dogs remains controversial, with genetic data indicating a separation between modern dogs and wolves in the Late Pleistocene. However, only a few dog-like fossils are found prior to the Last Glacial Maximum, and it is widely accepted that the dog domestication predates the beginning of agriculture about 10,000 years ago. In order to evaluate the genetic relationship of one of the oldest dogs, we have isolated ancient DNA from the recently described putative 33,000-year old Pleistocene dog from Altai and analysed 413 nucleotides of the mitochondrial control region. Our analyses reveal that the unique haplotype of the Altai dog is more closely related to modern dogs and prehistoric New World canids than it is to contemporary wolves. Further genetic analyses of ancient canids may reveal a more exact date and centre of domestication. 相似文献
8.
Bushneva OA Ovodova RG Shashkov AS Chizhov AO Ovodov YS 《Biochemistry. Biokhimii?a》2003,68(12):1360-1368
A pectic polysaccharide named silenan, [alpha]D20 +148.6 degrees (c 0.1; H2O), was isolated earlier from the aerial part of campion, Silene vulgaris (Moench) Garcke. Silenan has been shown to contain homogalacturonan segments as "smooth regions" and rhamnogalacturonan fragments as "hairy regions". The present study reveals a generalization of structural features of silenan. Silenan was subjected to enzymic digestion with pectinase, to Smith degradation, and to lithium-degradation to determine the conforming poly- and oligosaccharide fragments of "hairy regions" of silenan. The NMR-spectral data and mass-spectrometry confirmed that the core of the ramified region of silenan consisted of residues of alpha-rhamnopyranose 2-O-glycosylated with the residues of alpha-1,4-D-galactopyranosyl uronic acid. The part of the alpha-rhamnopyranose residues of the backbone are branched at O-4. On the basis of the data, the hairy regions of silenan proved to contain mainly linear chains of beta-1,3-, beta-1,4-, and beta-1,6-galactopyranan and alpha-1,5-arabinofuranan. The side chains of the ramified region were shown to have branching points represented 2,3-, 3,6-, 4,6-di-O-substituted beta-galactopyranose residues. 相似文献
9.
F. V. Vityazev V. V. Golovchenko O. A. Patova N. N. Drozd V. A. Makarov A. S. Shashkov Yu. S. Ovodov 《Biochemistry. Biokhimii?a》2010,75(6):759-768
The following pectins were sulfated: bergenan BC (the pectin of Bergenia crassifolia L), lemnan LM (the pectin of Lemna minor L), and galacturonan as a backbone of pectins. Pyridine monomethyl sulfate, pyridine sulfotrioxide, and chlorosulfonic acid
were used as reagents for sulfation. Chlorosulfonic acid proved to be the optimal reagent for sulfation of galacturonan and
other pectins. Galacturonan and pectin derivatives with different degrees of sulfation were synthesized and their anticoagulant
activities were shown to depend on the quantity of sulfate groups in the pectin macromolecules. 相似文献
10.
Ultraviolet radiation (wavelength, 280–315 nm; power, 0.2–13.0 W/m2; exposure, 1 or 3 h) was shown to change the growth of campion callus and the polysaccharide (pectin and arabinogalactan) composition of cell walls. An increase in the concentration of polysaccharides and a decrease in the content of arabinose and galactose residues in pectin and arabinogalactan were noted. For the majority of calluses, growth indices, specific growth rate, and biomass productivity (per 11 medium) were almost the same as in nonirradiated control cells. Maximum values of the growth index and specific growth rate, determined for dry biomass, were observed at a low dose of irradiation (0.2 W/m2) and an exposure of 3 h. A considerable decrease in the content of arabinose and galactose in pectin was noted at high doses of irradiation (exposure, 3 h). Samples of arabinogalactan were characterized by variable arabinose to galactose ratios, which were in the range 1: (3.4–8.3). 相似文献