Polysaccharides of Pneumococcus types

Barker and coworkers have applied gel chromatography in studies of pneumococcal polysaccharides.121 Purification of the type-specific polysaccharide of Pneumococcus Type II was effected by chromatography on Sephadex G-200 in M sodium chloride in this way, the ribonucleic acid, a persistent impurity in preparations of this polysaccharide, was almost completely removed. The complex formed between the polysaccharide and the nucleic acid is largely dissociated in M sodium chloride, so that the two are free in this solvent and may be separated on the basis of their differing molecular size. 

The capsular polysaccharide of Pneumococcus type 22 is composed of residues of D-glucose, D-galactose, L-arabinose, L-rhamnose, o-glucuronic acid, erythritol, and phosphate.Structural studies of two fragments released on successive treatments of pneumococcal S22 polysaccharide with acid phosphatase and alkali suggested that it is possibly composed of the repeating-unit (25). 

Ohno, N., T. Yadomae, and T. Miyazaki Structure of the type-specific polysaccharide of Pneumococcus type XIX. Carbohydr. Res. 80, 297 (1980). 

Chemical determination of the structure of the capsular polysaccharide of RhiziAnum radicicolum (377) showed the presence of the cellobiuronic acid unit, thus also relating this polysaccharide immunologically to the specific polysaccharide of pneumococcus type III. The structural unit is thought to contain a second molecule of glucose. 

In 1967, Heidelberger, Stacey et al. reported the purification, some structural features, and the chemical modification of the capsular polysaccharide from Pneumococcus Type I. Difficulties of direct hydrolysis of the polysaccharide were overcome and it was possible to identify some of the fragments in the hy-drolyzate. At least six products resulted from nitrous acid deamination. Two were disaccharides, which were identified, and sequences of linked sugar units were proposed. As modification of the polysaccharide decreased the amounts of antibody precipitated by anti-pneumococcal Type I sera, the importance of the unmodified structural features in contributing to the specificity of the polysaccharide was indicated. 

In 1947, L-rhamnose was first recognized by Stacey as a constituent of Pneumococcus Type II specific polysaccharide. This finding was confirmed, in 1952, by Kabat et al. and in 1955 again by Stacey when 2,4- and 2,5-di-O-methyl-L-rhamnose were synthesized and the former was shown to be identical with a di-O-methylrhamnose, obtained by hydrolysis of the methylated polysaccharide. This result indicated a pyranose ring structure for the rhamnose units in the polysaccharide. Announcement of the identification of D-arabinofuranose as a constituent of a polysaccharide from M. tuberculosis aroused considerable interest. The L-enantiomer had been found extensively in polysaccharides, but reports of the natural occurrence of D-arabinose had been comparatively rare. To have available reference compounds for comparison with degradation products of polysaccharides, syntheses of derivatives (particularly methyl ethers) of both d- and L-arabinose were reported in 1947. 

L-Fucosamine was found as a constituent of Pneumococcus Type V capsular polysaccharide and as a constituent of the mucopolysaccharides (glycosamino-glycans) of certain enteric bacteria A new synthesis was devised to make the amino sugar more available. 

The separation and identification of disaccharides is often an important step in the elucidation of the structure of a natural polysaccharide, and Percival484 has published useful data on the O-trimethyl-silyl derivatives of a variety of disaccharides and their reduction products. In some instances, the trimethylsilyl ethers of the disaccharide alditols have lower retention times than those of the disaccharide derivatives. The per-O-trimethylsilyl derivatives of gentiobi-itol and maltitol were encountered in studies on the structure of Pneumococcus Type II capsular polysaccharide.4843... 

Structural Feature of Pneumococcus Type XIX Specific Polysaccharide, T. Miyazaki and J. K. N. Jones, Chem. Pharm. Bull., 17 (1969) 1531-1533. 

The uridine diphosphate ester derivatives in a non-capsulated. Type II pneumococcus and a capsulated. Type III pneumococcus were investigated by Smith, Mills, and Harper." The capsule of the Type III pneumococcus is composed of a polysaccharide having 4-0-( 8-D-glucopyranosyluronic acid)-D-glucose as a repeating unit. n-Glucuronic acid, D-glucose, and L-rhamnose are constituents of the capsular polysaccharide of the Type II pneumococcus. 

Heidelberger and Rebers showed that the type specificity of Pneumococcus Type VI comprises three partial specificities, due to multiple residues in the linear polysaccharide chain of (1—>3)-linked L-rhamnose, (1—>3)-linked D-glucose, and (1—>2)-linked D-galactose. The weak, crossagglutination reaction originally observed -i between Types II and IIB (VI) was attributed to the presence in both polysaccharides of multiple units of (1—>3)-linked L-rhamnose within the main chain such a crossreaction would not be so extensive as that due to terminal groupings. ... 

Partial hydrolysis of the capsular polysaccharide from Pneumococcus Type II with acid yielded an aldobiouronic acid that was reduced with lithium aluminum deuteride, and the product trimethylsilylated. The labelled trimethylsilyl ether was characterized, by g.l.c.-m.s., as the iso-maltitol derivative 49. 

C12H20O12 356.283 Reducing disaacharide. Isol. from the partical acid hydrolysates of Pneumococcus type III and type VIII capsular polysaccharides. Constit. of an extracellular polysaccharide of some Rhizobium spp. 

The condensation of hexuronic acid derivatives with hexosaminides to give amide-linked disaccharides is referred to in Chapter D-Galacturonic acid has been identified as a component of Pneumococcus type 25 capsular polysaccharide," and 2-O-methyl-D-glucuronic acid has been isolated for the first time in Nature from an extracellular polysaccharide of a species (Porphyridium cruentum) of red alga. The acidic sugar component in Klebsiella type 37 capsular polysaccharide has been identified as 4-0-[(5)-l-carboxyethyl]-D-glucuronic acid. Antibiotic substances and nucleosides that contain uronic acid components are referred to in Chapters 20 and 21, respectively. 

By 1945, Stacey speculated about the possibility of a structural relationship between Pneumococcus capsular polysaccharides and those produced by other organisms. With Miss Schliichterer, he had examined the capsular polysaccharide of Rhizobium radicicolum. This polysaccharide gave a precipitin reaction in high dilution, not only with Type III Pneumococcus antiserum, but also mixed with antisera from other Pneumococcus types. The chemical evidence indicated that the polysaccharide resembled the specific polysaccharides of Types I and II Pneumococcus. A decade later, the acidic capsular polysaccharide from Azoto-bacter chroococcum, a soil organism, was studied. It, too, produced serological cross-reactions with certain pneumococcal specific antisera. Although the molecular structure of the polysaccharide was not established, adequate evidence was accumulated to show a structural relationship to Type III Pneumococcus-specific polysaccharide. This was sufficiently close to account for the Type III serological cross-relationship. 

Some Physical Properties of the Specific Polysaccharides from the Types I, II and III Pneumococcus," B. R. Record and M. Stacey,/. Chem. Soc., (1948) 1561-1567. 

The polysaccharides of Type VIII pneumococcus,1 1 Friedlander s bacillus,1 2 Rhizobiam and Azotobacter evidently have closely related structures and they contain a high proportion of D-glucose residues. Cross reactions indicated that oxidized cellulose has affinities with this group.1 ... 

In a recent paper650 the relationships between Rhizobium radicicolum polysaccharides and those of pneumococcus are indicated by crossprecipitin reactions of the former with Types III and VI anti-pneumococcus horse sera. In addition, hydrolysis of the methylated polysaccharide of Rhizobium radicicolum yields equal amounts of 2,3,6-trimethyl-D-glucose, 2,3-dimethyl-D-glucose and 2,3-dimethyl-D-glucuronic acid.65 1 The minimum trisaccharide repeating unit consists, in part, of cello-biuronic acid, and may be represented ... 

Reeves and Goebel72 have shown that hydrolysis of the reduced methylated capsular polysaccharide of Type III pneumococcus yields 2,3,6-trimethyl-D-glucose and the anomeric forms of methyl 2,4-dimethyl-D-glucoside. The cellobiuronic acid units in the polysaccharide are thus linked through position 3 of the D-glucuronic acid residue, probably by /3-D-linkages. That is, the polysaccharide contains alternate 1,3-and l,4-/3-D-linkages. 

The pneumococci all belong to different types of the same species, namely, Streptococcus pneumoniae. This was earlier called Diplococcus pneumoniae, but has been renamed.5 6 7 There are some 80 different types of pneumococcus, and two systems of nomenclature, the Danish, used in Europe, and Eddy s, used in the United States.8 Tables correlating the Danish and American designations have been published.8 The Danish system, with Arabic numerals and common abbreviations, such as Phi for Type 1 and SI for its type-specific, capsular polysaccharide, will be used in this article. 

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