共查询到20条相似文献,搜索用时 343 毫秒
1.
Perepelov AV Liu B Senchenkova SN Shashkov AS Guo D Feng L Knirel YA Wang L 《Carbohydrate research》2011,(2):381-383
The O-polysaccharide of Salmonella enterica O59 was studied using sugar analysis and 2D 1H and 13C NMR spectroscopy, and the following structure of the tetrasaccharide repeating unit was established:→2)-β-d-Galp-(1→3)-α-d-GlcpNAc-(1→4)-α-l-Rhap-(1→3)-β-d-GlcpNAc-(1→Accordingly, the O-antigen gene cluster of S. enterica O59 includes all genes necessary for the synthesis of this O-polysaccharide. Earlier, another structure has been reported for the O-polysaccharide of Salmonella arizonae (S. enterica IIIb) O59, which later was found to be identical to that of Citrobacter (Citrobacter braakii) O35 and, in this work, also to the O-polysaccharide of Escherichia coli O15. 相似文献
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Yu. P. Fedonenko E. I. Katsy L. P. Petrova A. S. Boyko E. L. Zdorovenko V. V. Kachala A. S. Shashkov Yu. A. Knirel 《Russian Journal of Bioorganic Chemistry》2010,36(2):219-223
The rhizobacteria Azospirillum brasilense Sp245 produce immunochemically different lipopolysaccharides LPSI and LPSII, both
containing identical pentasaccharides built from D-rhamnose residues as the repeating units of O-specific polysaccharides (OPS). In this study, we report the structure of the
OPS from A. brasilense LPSI−LPSII− mutant Sp245.5, which spontaneously lost the p85 and p120 plasmids upon the formation of a new 300-MDa megaplasmid after
the long-term storage of the bacteria in a rich medium. The repeating unit of the OPS of A. brasilense Sp245.5 appeared to be a disaccharide consisting of residues of N-acetyl-D-galactosamine and N-acetyl-D-mannosaminuronic acid:
$
\to 6) - \alpha - D - GalpNAc - (1 \to 4) - \beta - D - ManpNAcA - (1 \to
$
\to 6) - \alpha - D - GalpNAc - (1 \to 4) - \beta - D - ManpNAcA - (1 \to
相似文献
4.
Andrei V. Perepelov Bin Liu Sof’ya N. Senchenkova Lu Feng Alexander S. Shashkov Yuriy A. Knirel 《Carbohydrate research》2010,345(12):1808-2912
The following structure of the O-polysaccharide (O-antigen) of Salmonella enterica O13 was established by chemical analyses along with 2D 1H and 13C NMR spectroscopy:→2)-α-l-Fucp-(1→2)-β-d-Galp-(1→3)-α-d-GalpNAc-(1→3)-α-d-GlcpNAc-(1→The O-antigen of S. enterica O13 was found to be closely related to that of Escherichia coli O127, which differs only in the presence of a GalNAc residue in place of the GlcNAc residue and O-acetylation. The location of the O-acetyl groups in the E. coli O127 polysaccharide was determined. The structures of the O-polysaccharides studied are in agreement with the DNA sequence of the O-antigen gene clusters of S. enterica O13 and E. coli O127 reported earlier. 相似文献
5.
Perepelov AV Zhu H Senchenkova SN Wang Q Shashkov AS Wang L Knirel YA 《Carbohydrate research》2011,(17):2812-2815
The O-polysaccharide (O-antigen) of Escherichia coli O19ab was studied by sugar analysis along with 1D and 2D 1H and 13C NMR spectroscopy. The following structure of the linear pentasaccharide repeating unit was established:→2)-α-l-Rhap-(1→2)-α-l-Rhap-(1→2)-α-l-Rhap-(1→2)-α-d-Glcp-(1→3)-α-d-GlcpNAc6Ac-(1→where the degree of O-acetylation of GlcNAc is ∼33%. The O-antigen gene cluster of E. coli O19ab was sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in full agreement with the E. coli O19ab-antigen structure. 相似文献
6.
Summary A set of three-dimensional triple-resonance experiments is described which provide
,
,
and
coupling constants. The pulse sequences generate E.COSY-like multiplet patterns and comprise a magnetization transfer from
the amide proton to the α-proton or vice versa via the directly bound heteronuclei. For residues with the 1Hα spin resonating close to the H2O signal, a modified HNCA experiment can be employed to measure the vicinal 1HN,1Hα couplings. Ambiguities associated with the conversion of
values into ϕ-angle constraints for protein structure determination can be resolved with the knowledge of the heteronuclear
3J-couplings. In favourable cases, stereospecific assignments of glycine α-protons can be obtained by employing the experiments
described here in combination with NOE data. The methods are applied to flavodoxin from Desulfovibrio vulgaris. 相似文献
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The effect of temperature on post-feeding ammonia excretion and oxygen consumption in the southern catfish 总被引:1,自引:0,他引:1
Yiping Luo Xiaojun Xie 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2009,179(6):681-689
The post-prandial rates of ammonia excretion (TAN) and oxygen consumption in the southern catfish (Silurus meridionalis) were assessed at 2 h intervals post-feeding until the rates returned to those of the fasting rates, at 17.5, 22.5, 27.5,
and 32.5°C, respectively. Both fasting TAN and increased with temperature, and were lower than those previously reported for many fish species. The relationship between
fasting TAN (mmol NH3–N kg−1 h−1) and temperature (T, °C) was described as: fasting TAN = 0.144e
0.0266T
(r = 0.526, n = 27, P < 0.05). The magnitude of ammonia excretion and its ratio to total N intake during the specific dynamic action (SDA) tended to increase initially, and then decrease with increasing temperature. The
ammonia quotient (AQ), calculated as mol NH3–N/mol O2, following feeding decreased as temperature increased. The relationship between AQ during SDA and temperature was described
as: AQduring SDA = 0.303e
−0.0143T
(r = 0.739, n = 21, P < 0.05). Our results suggest that ammonia excretion and oxygen consumption post-feeding are operating independently of each
other. Furthermore, it appears that the importance of protein as a metabolic substrate in postprandial fish decreases with
temperature. 相似文献
9.
Hiroshi Yura 《Ecological Research》1993,8(1):73-80
A new method for analyzing growth is proposed to elucidate factors responsible for the differences in root depth ofLarix kaempferi andAbies veitchii seedlings. Root depth (D) divides into three factors;
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