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71.
Perepelov AV Kołodziejska K Kondakova AN Wykrota M Knirel YA Sidorczyk Z Rozalski A 《Carbohydrate research》2004,339(12):2145-2149
On mild acid degradation of the lipopolysaccharide of Proteus vulgaris O34, strain CCUG 4669, the O-polysaccharide was cleaved at a glycosyl-phosphate linkage that is present in the main chain. The resultant phosphorylated oligosaccharides and an alkali-treated lipopolysaccharide were studied by sugar and methylation analyses along with 1H and 13C NMR spectroscopy, and the following structure of the branched tetrasaccharide phosphate repeating unit of the O-polysaccharide was established: [carbohydrate structure: see text]The O-polysaccharide of Proteus mirabilis strain TG 276 was found to have the same structure and, based on the structural and serological data, this strain was proposed to be classified into the same Proteus serogroup O34. 相似文献
72.
Ovchinnikova OG Kocharova NA Bakinovskiy LV Torzewska A Shashkov AS Knirel YA Rozalski A 《Carbohydrate research》2004,339(15):2621-2626
The O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Providencia stuartii O47:H4, strain 3646/51. Studies by sugar and methylation analyses along with Smith degradation and 1H and 13C NMR spectroscopy, including two-dimensional 1H,1H COSY, TOCSY, ROESY and H-detected 1H,13C HSQC and HMBC experiments, showed that the polysaccharide has a branched hexasaccharide repeating unit with the following structure: [carbohydrate structure: see text] 相似文献
73.
Andrei V. Perepelov Sergei D. Shevelev Sof’ya N. Senchenkova Lu Feng Yuriy A. Knirel 《Carbohydrate research》2010,345(11):1594-1006
O-Polysaccharides (O-antigens) were isolated from Escherichia coli O13, O129, and O135 and studied by chemical analyses along with 2D 1H and 13C NMR spectroscopy. They were found to possess a common →2)-l-Rha-(α1→2)-l-Rha-(α1→3)-l-Rha-(α1→3)-d-GlcNAc-(β1→ backbone, which is a characteristic structural motif of the O-polysaccharides of Shigella flexneri types 1-5. In both the bacterial species, the backbone is decorated with lateral glucose residues or/and O-acetyl groups. In E. coli O13, a new site of glycosylation on 3-substituted Rha was revealed and the following O-polysaccharide structure was established:The structure of the E. coli O129 antigen was found to be identical to the O-antigen structure of S. flexneri type 5a specified in this work and that of E. coli O135 to S. flexneri type 4b reported earlier. 相似文献
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Bertrand JY Desanti GE Lo-Man R Leclerc C Cumano A Golub R 《Development (Cambridge, England)》2006,133(18):3619-3628
The role of the fetal spleen in hematopoeisis remains largely unknown. In this particular environment, we show that hematopoietic stem cells do not proliferate, but that they lose multipotency and differentiate exclusively into mature macrophages. B lymphocytes in the spleen derive from committed B cell precursors that are likely to have immigrated from the fetal liver. We developed fetal spleen stromal cell lines that are unique in their capacity to expand myeloid precursors, resulting in large numbers of mature macrophages. These lines secrete high levels of anti-inflammatory molecules. By phenotype, fetal splenic macrophages are reminiscent of their adult counterparts found in the red pulp. We postulate that F4/80(+) splenic macrophages participate in fetal erythropoiesis, as well as in the formation of the splenic architecture. 相似文献
76.
The analysis of the P-selectin/PSGL-1 catch-slip bond that is periodically driven by a detaching force predicts that in the frequency range on the order of 1 s(-1) the bond lifetime undergoes significant changes with respect to both frequency and amplitude of the force. The result indicates how variations in the heart rate could have a substantial effect on leukocyte and lymphoid cell transport and adhesion to endothelial cells and platelets during inflammatory processes. 相似文献
77.
Damek-Poprawa M Golub E Otis L Harrison G Phillips C Boesze-Battaglia K 《Biochemistry》2006,45(10):3325-3336
During endochondral ossification, growth plate chondrocytes release plasma membrane (PM) derived matrix vesicles (MV), which are the site of initial hydroxyapatite crystal formation. MV constituents which facilitate the mineralization process include the integral membrane ectoenzymes alkaline phosphatase (ALPase) and nucleotide pyrophosphatase phosphodiesterase (NPP1/PC-1), along with a phosphatidylserine- (PS-) rich membrane surface that binds annexins and calcium, resulting in enhanced calcium entry into MV. In this study, we determined that chick growth plate MV were highly enriched in membrane raft microdomains containing high levels of cholesterol, glycophosphatidylinositol- (GPI-) anchored ALPase, and phosphatidylserine (PS) localized to the external leaflet of the bilayer. To determine how such membrane microdomains arise during chondrocyte maturation, we explored the role of PM cholesterol-dependent lipid assemblies in regulating the activities of lipid translocators involved in the externalization of PS. We first isolated and determined the composition of detergent-resistant membranes (DRMs) from chondrocyte PM. DRMs isolated from chondrocyte PM were enhanced in ganglioside 1 (GM1) and cholesterol as well as GPI-anchored ALPase. Furthermore, these membrane domains were enriched in PS (localized to the external leaflet of the bilayer) and had significantly higher ALPase activity than non-cholesterol-enriched domains. To understand the role of cholesterol-dependent lipid assemblies in the externalization of PS, we measured the activities of two lipid transporters involved in PS externalization, aminophospholipid translocase (APLT) and phospholipid scramblase (PLSCR1), during maturation of a murine chondrocytic cell line, N1511. In this report, we provide the first evidence that maturing chondrocytes express PLSCR1 and have scramblase activity. We propose that redistribution of PS is dependent on an increase in phospholipid scramblase activity and a decrease in APLT activity. Lastly, we show that translocator activity is most likely to be modulated by membrane cholesterol levels through a membrane raft microdomain. 相似文献
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Nicol AF Lapa e Silva JR Cunha CB Amaro-Filho SM Oliveira N Grinsztejn B Friedman RK Khalil R Russomano F Pires A Golub JE Nuovo GJ 《PloS one》2012,7(4):e32936