Tetrasaccharide repeating unit specificity

Mulloy, B., Ribeiro, A. C., Alves, A. P., Vieira, R. P., and Mourao, P. A. (2004). Sulfated fucans from echinoderms have a regular tetrasaccharide repeating unit defined by specific patterns of sulfation at the 0-2 and 0-4 positions. J. Biol. Chem. 269, 22113-22123. 

Another example of O-specific polysaccharides that are assembled through the block mechanism are the polymers from Salmonella serogroups C2 and C3. Their polysaccharide chains (18) are composed97 of linear, tetrasaccharide repeating-units having abequosyl and D-glucosyl branches,... 

Synthesis of the tetrasaccharide repeating-unit of the O-specific polysaccharide from Salmonella senftenberg. Carbohydr. Res. 5 1, 269-27 1... 

Kochetkov, N.K., Torgov, V.I., Malysheva, N.N., Shashkov, A.S., and Klimov, E.M. (1980a). Synthesis of the tetrasaccharide repeating-unit of the O-specific polysaccharide from Salmonella muenster and Salmonella minneapolis. Tetrahedron 36. 1227-1230 Kochetkov, N.K., Torgov, V.I., Malysheva, N.N., and Shashkov, A.S. (1980b). Synthesis of the pentasaccharide repeating-unit of the O-specific polysaccharide from Salmonella Strasbourg. Tetrahedron 36, 1099-1105... 

In addition, to understand the polysaccharide biosynthesis of a species-specific CPS in different Campylobacter species, 6-O-methyl-D-g/ycero-a-L-g/Mco-heptopy-ranose—one of the residues of the tetrasaccharide repeating unit of the CPS of Campylobacter jejuni NCTC 11168—was synthesized [134],... 

P. savastanoi strain isolated from infected oleander plants (see above), proved to be virulent on both oleander and olive plants, while olive strain was shown to be virulent only on the host plant. The molecular basis of this host-pathogen specificity is poorly understood. Exopolysaccharides (EPS) and cell-wall LPS of phytopathogenic bacteria have been correlated with pathogenesis its chemical structure and tridimensional conformation may play a role in the early infection process and in the determination of plant-bacteria interaction specificity [92]. The LPS of three strains of P. savastanoi were isolated and the structure of their O-chain portion were determined by chemical and NMR spectral analysis. For all the strains the O-chain consists of a tetrasaccharide repeating unit of three a-L-Rhap and one terminal non-reducing a-D-Fuc-p3NAc. Two rhamnosyl residues are 3-linked and the third one 2,3-linked as reported [93]. 

Chemical and enzymic studies have shown that the O-specific side-chains of the lipopolysaccharide from E. coli O 69 are composed of the tetrasaccharide repeating-unit (6) " and that the hexose region of the lipopolysaccharide from E. coli C is composed of the pentasaccharide (7). ... 

The structure of the tetrasaccharide repeating-unit of the O-specific antigen of Sh. flexneri variant Y has been established as (16) on the basis of methylation analysis, H n.m.r. spectroscopy, and analysis of the product of de-A -acetylation-deamination. ... 

A search for its epitope revealed it to be a- D-Glcp(l-3)-a-L-Rhap, which is present in the serogroup 6 PSs, as well as in serotype 19A PS. The synthesis of the tetrasaccharide repeating units of 6A/ and 6C/ and their BSA conjugates were accomplished. Preliminary studies with the synthetic compounds confirm the recognition by Sp-specific rabbit antiserum of serotypes 6A, 6B, and 6C, with significant cross-reactivily. 

UDP-D-galactose to the terminal, non-reducing D-glucosyl residues of these oligosaccharides. The tetrasaccharide repeating unit (8) of the O-specific side-chains of the cell-wall lipopolysaccharide from E. colt 075 has been established by methylation analysis and Smith degradation. ... 

In the tetrasaccharide series the 2 + 2 approach is illustrated (Scheme 3) by the synthesis of the repeating unit of the O-specific polysaccharide of 5. muensler and S. minneapolis. The same strategy has led to lacto-iV-tetraose (Scheme 4). However, the alternative sequential approach was used in the synthesis of 6>-a-L-rhamnopyranosyl-(l-> 2)-0-Q -L-rhamnopyranosyl-(l 3)-0-o -L-rhamno-pyranosyl-( 1 3 )-2-acetamido-2-deoxy-D-glucose as its 8-8-methoxycarbonyloctyl glycoside, which was required for bonding to proteins and cell surfaces. ... 

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