0-antigenic polysaccharides chain structures

Figure 3. Structures of the O-antigenic polysaccharide chain in Salmonella bacteria of serogroups C2 and C3 and a synthetic disaccharide glycoconjugate (O-antigen 8-specific). Results of immunofluorescence studies (IFL) of these structures.

The structure of the O-antigenic polysaccharide chain in Salmonella serogroup Cl (0 antigens 6, 7) has not been established in detail (22). Hence, it has not been possible to identify the structural elements representing the determinant of serogroup 0-antigen 07. 

Figure 4. Structures of the O-antigenic polysaccharide chains in Salmonella bacteria ofserogroup E and a synthetic trisaccharide gly coconjugate (O-antigen 3-specific). Results of ELISA and immunofluorescence (IFL) studies. Key m, S. anatum (03, 10) , S. senftenburg (01, 3, 19) , BSA a, S. typhimurium (04, 5,...

The first step in bacteriophage infection is the adsorption of the phage to a receptor on the bacterium. Almost every structure on the surface of a bacterial cell, or extending from it, can act as (or include) phage receptors (29). The 0-antigenic polysaccharide chains of the LPS are no exgeption in this respect. Since it has been estimated that 10 > to 10 LPS molecules are found on each bacterial cell (30), it is evident that part of the... 

B. A. Dmitriev, Y. A. Knirel, N. K. Kochetkov, and I. L. Hofman, Somatic antigens of Shigella. Structural investigation on the O-specific polysaccharide chain of Shigella dysenteriae type 1 lipopolysaccharide, Eur. J. Biochem., 66 (1976) 559-566. 

Structurally, the O-polysaccharide chains of H. pylori clinical isolates have a poly-A-acetyl-lactosamine (-LacNAc) chain decorated with multiple lateral a-L-fucose residues forming internal Lex determinants with terminal Lex or Ley units (Fig. 10.4) or, in some strains with additional, D-glucose or D-galactose residues (Moran 2001 a,b, 2008 Monteiro, 2001). Moreover, Lea, Leb, sialyl-Lex, and H-1 antigens have been structurally described in other strains, as well as the related blood groups A and B (Fig. 10.4), but occur in association with Lex and LacNAc chains (Monteiro et al., 2000a,b Heneghan et al., 2000). 

Y. A. Knirel, A. S. Shashkov, M. A. Soldatkina, N. A. Paramonov, and I. I. Zakharova, Antigenic polysaccharides of bacteria 32. The structure of O-specific polysaccharide chains of Pseudomonas cepacia serotype B and E lipopolysaccharides containing D-fucose, Bioorg. Khim., 14 (1988) 1208-1213. 

Bacterial polysaccharides are a very heterogeneous group and are clearly of several biosynthetic types. Many are closely equivalent to the polysaccharide (O-antigenic-type) chains of lipopolysaccharide and have presumably been released by hydrolysis, rather than transferred to lipid A or core structures. Some, such as bacterial hyaluronate, somewhat resemble wall polymers (some teichuronic acids, in this case), but have no exact counterparts. Others, such as bacterial cellulose and colominic acid (polysialic acid) are very different from... 

Undecaprenol (bactoprenol) from Salmonella contains eleven isoprene units, and two irons and nine cis double bonds In the form of undecaprenyl phosphate, it acts as a carrier of carbohydrate residues in the biosynthesis of bacterial antigenic polysaccharides synthesis of Murein (see) also depends on undecaprenyl phosphate. In eukaryotes the Dolichol phosphates (see) function in the transfer of carbohydrate residues in the synthesis of glycoproteins and glycoli-pids. Probably the long lipid chains of these P serve to anchor them in membranes, while the phosphate group acts as a carrier by protruding into the cytoplasm. It is not known whether all P. function as carbohydrate carriers. The structural relationship between solanesol and plastoquinone-9 and ubiquinone-9, and the joint occurrence of these compounds suggest a precursor role for P. Biosynthesis of P. proceeds from mevalonic acid and the conformation of all double bonds is predetermined in early precursors. 

Capsules of pneumococci consist largely of a polysaccharide slime, but they contain in addition some protein and small amounts of other substances. The type-specificity and virulence of the pneumococci are due to their capsular polysaccharides (see Chapter VIII). The specificity of reaction for different pneumococcal types is due to variation in the capsular polysaccharide molecules. The antigenic polysaccharides are isolable from the bacteria but are more often prepared from the culture broth into which they are liberated by bacterial autolysis. Though there are more than 70 known types of pneumococci, little is known of the structures of their capsular polysaccharides save that from type III pneumococcus. This is shown to be a linear molecule of D-glucose and D-glucuronic acid units in equal amounts. They are linked alternately so that the molecule may be regarded as a chain of aldobiouronic acid units 131) ... 

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