The molecular structure of the capsular polysaccharide from Klebsiella type 27.

The capsular polysaccharide of Klebsiella serotype K27 had been investigated by techniques involving methylation analysis, autohydrolysis, and graded hydrolysis with acid. The anomeric configurations of the sugar constituents were determined, where possible, on the basis of p.m.r. spectroscopy and optical rotation data. The results of these studies are consistent with a primary structure in which the repeating-unit is the doubly branched hexasaccharide.

Structural investigation of Klebsiella serotype K46 polysaccharide.

The structure of the capsular polysaccharide from Klebsiella type K46 has been investigated by using the techniques of methylation analysis, periodate oxidation, and partial hydrolysis. The anomeric linkages were determined by 1H- and 13C-n.m.r. spectroscopy of the polysaccharide and of derived poly- and oligo-saccharides obtained through degradative procedures. 1H-N.m.r. spectroscopy of the polysaccharide in D2O showed clearly a ratio of one (1-carboxyethylidene) group (CH3, delta 1.47) to six anomeric protons (delta 4.62--5.29). The polysaccharide was shown to consist of the following hexasaccharide repeating unit, which is unique in this series in having a (1-carboxyethylidene) acetal group on a lateral, but nonterminal, sugar residue. (Formula: see text).

Structure of the capsular polysaccharide of Klebsiella serotype K53.

Klebsiella serotype K53 is one of three strains belonging to the chemotype whose capsular polysaccharides consist of D-glucuronic acid, D-galactose, D-mannose, and L-rhamnose residues, and the structure of its polysaccharide was found to be of the "5 + 1 type" shown, of the same structural pattern as the capsule from Klebsiella K52 (Formula, see text). Nimmich has analyzed the capsular polysaccharide of Klebsiella K53 and has shown that it belongs to the chemotype that also comprises K40 and K80. As part of our continuing investigation of these polysaccharides, we now report the structure of the capsular antigen of Klebsiella K53; the structures of those from K40 and K80 are, at present, unknown.

Structure of the capsular polysaccharide of Klebsiella serotype K74.

The capsular polysaccharide of Klebsiella serotype K74 belongs to a chemogroup consisting of seven strains, of which four contain 1-carboxyethylidene groups (pyruvic acid acetals). The polysaccharide from K74 is demonstrated to be of the "3 + 2" type, and to be based on the repeating unit shown (Formula, see text). The capsular polysaccharide from Klebsiella K74 is composed of D-glucuronic acid, D-galactose, and D-mannose, and this chemotype includes a total of seven strains, of which four have 1-carboxyethylidene groups (pyruvic acid acetals). In this chemogroup, the structures of the capsular polysaccharides of the serotypes K20 (ref. 3) and K21 (ref. 4) have been published.

The capsular polysaccharide of Klebsiella serotype K60; a novel, structural pattern.

Non-linear capsular polysaccharides of Klebsiella bacteria usually have a single side-chain per repeating unit, or, less commonly, two side-chains attached to the same unit. The capsular polysaccharide from Klebsiella serotype K60 is unique in having three side-chains in the heptasaccharide repeating-unit shown. The structure, including the configuration of the glycosidic linkages, was established mainly by characterization of the oligosaccharides obtained by partial hydrolysis of both the original, capsular polysaccharide and the polymer resulting from the removal, by Smith degradation, of the side chains (Formula, see text).

Structural studies on the capsular polysaccharide from Klebsiella serotype K64.

Partial hydrolysis with acid, methylation analysis (including uronic acid degradation), Smith degradation, and p.m.r. spectroscopy have been used to determine the primary structure of the capsular polysaccharide of Klebsiella serotype K64. The hexasaccharide repeating-unit, which also contains one O-acetyl substituent, comprises a 4)-alpha-D-GlcpA-(1 leads to 3)-alpha-D-Manp-(1 leads to 3)-beta-D-Glcp-(1 leads to 4)-alpha-D-Manp-(1 leads to chain with a 4,6-O-(1-carboxyethylidene)-beta-D-glucopyranosyl and an L-rhamnosyl group attached to the 4-linked D-mannosyl residue at 0-2 and 0-3, respectively.

Studies of the primary structure of the capsular polysaccharide from Klebsiella serotype K15.

The capsular polysaccharide of Klebsiella serotype K15 has been investigated mainly by methylation analysis, characterisation of the oligosaccharides obtained by partial acid hydrolysis, periodate oxidation, enzymic degradation, and 1H- and 13C-n.m.r. spectroscopy, and shown to have the hexasaccharide repeating-unit 1. The glycan does not contain any pyruvic acetal or O-acetyl substituents. (formula; see text)

A re-investigation of the structure of the capsular polysaccharide of Klebsiella K10.

The capsular polysaccharide of Klebsiella K10 was investigated by methylation analysis and 1H-n.m.r. spectroscopy, and the deacetylated bacteriophage-degraded polysaccharide by 1D- and 2D-n.m.r. spectroscopy. The repeating unit was shown to be a branched hexasaccharide (see text). OAc substituents were located on the terminal and 2-linked galactopyranosyl residues by Prehm methylation of a low-molecular-weight fraction obtained by bacteriophage degradation.

Structural investigation of the capsular polysaccharide from Klebsiella K19 by chemical and N.M.R. analyses.

Sugar analysis of the capsular antigen K19 from Klebsiella and of the carboxyl-reduced derivative confirmed its classification into the chemotype containing rhamnose, galactose, glucose, and glucuronic acid residues. Partial acid hydrolysis and phage depolymerization of K19 provided respectively a modified, linear form of the polysaccharide and oligosaccharides of the repeating unit, these were used for the structural elucidation of the original polymer. Methylation analysis, Smith degradation, and 1H- and 13C-n.m.r. spectroscopy of the polysaccharide and derivatives permitted formulation of the following structure for K19: (formula; see text)

Proof of the occurrence of 5,6-O-(1-carboxyethylidene)-D-galactofuranose units in the capsular polysaccharide of Klebsiella K12.

The 13C-n.m.r. spectra of the capsular polysaccharide of Klebsiella K41 and phage-derived oligosaccharides K41-P1 and K41-P2 were compared with spectra from the structurally similar polysaccharide of Klebsiella K12 and oligosaccharides K12-P1 and K12-P2. This led to the conclusion that K41 and K12 contain one and two galactofuranose residues per repeating unit, respectively, and that the terminal, lateral residue in K12 has the 5,6-O-(1-carboxyethylidene)-D-galactofuranose structure rather than that of a 4,6-acetal of D-galactopyranose as originally stated. This is the first reported occurrence in Nature of such a structural unit.

Structural studies of an extracellular polysaccharide (K21b) elaborated by Klebsiella type 21b.

The capsular polysaccharide from a new capsular serotype of Klebsiella, K21b, has been investigated, using n.m.r. spectroscopy, methylation analysis, and specific degradations as the main methods. It is concluded that the polysaccharide is composed of pentasaccharide repeating-units having the following structure. (formula; see text)

Determination of the absolute configuration of mono-saccharides in complex carbohydrates by capillary G.L.C.

The absolute configuration of neutral monosaccharides, 2-acetamido-2-deoxy sugars, and uronic acids can be determined by capillary g.l.c. on SE-30 after glycosidation with (-)-2-butanol and protection of the remaining polar groups. The method is illustrated by application to mixtures of the constituent sugars of the capsular polysaccharide from Klebsiella type 57, alpha 1-acid glycoprotein, mucus glycoproteins, and the methylated, acidic polysaccharide from the coccoliths of Emiliania huxleyi (Lohmann) Kamptner.

Modification of polysaccharides containing uronic acid residues.

Klebsiella Type 47 capsular polysaccharide has side chains attached to the main chain via D-glucuronic acid residues. The side chains have been removed to yield an essentially linear polysaccharide by the following sequence of reactions: (1) substitution of hydroxyl and carboxyl groups with methyl vinyl ether; (2) beta-elimination by treatment with base; (3) removal of modified uronic acid residues and protecting groups by mild acid hydrolysis. The possibility of modifying other uronic acid-containing polysaccharides by this method is discussed.

Depolymerization of the capsular polysaccharide from Klebsiella K19 by the glycanase associated with particles of Klebsiella bacteriophage luminal diameter 19.

The site of cleavage of the capsular polysaccharide from Klebsiella K19 by the endoglycanase associated with particles of Klebsiella bacteriophage luminal diameter 19 was determined. The specific cleavage of the bond Rhap-(1----2)-Rhap provided a series of oligosaccharides having rhamnose at the reducing end. The enzyme is thus an alpha-rhamnosidase. Structural studies on the oligomers confirmed the sequence of the repeating unit of the polysaccharide from K19. The 1H- and 13C-n.m.r. spectra of the homologous series of oligosaccharides corresponding to one, two, three, and four repeat-units exhibit important differences that denot variation of conformation with chain length. The bacteriophage acted on modified forms of K19 polysaccharide to provide a series of linear oligomers, and emphasized the essential role of the negative charge on the uronic acid in the action of the glycanase.

Primary structure of Klebsiella serotype K22 capsular polysaccharide: another glycan containing 4-O-[(S)-1-carboxyethyl]-D-glucuronic acid.

The primary structure of the acidic capsular polysaccharide isolated from Klebsiella serotype K22 has been investigated using methylation analysis, hydrolysis, bacteriophage-borne enzyme degradation, and n.m.r. spectroscopy. The repeating unit comprises the chain disaccharide----3)-beta-D-Galp-(1----4)-beta-D-Glcp-(1---- substituted by 4-O-[(S)-1-carboxyethyl]-beta-D-GlcpA-(1----6)-alpha-D-Glcp-(1---- at O-4 of the galactose. The galactose carries an O-acetyl group on position 6.

The use of bacteriophage-mediated depolymerisation in investigations of the structure of the capsular polysaccharide from Klebsiella serotype K71.

The structure (1) of the heptasaccharide repeating-unit of the capsular polysaccharide from Klebsiella serotype K71 follows from methylation analysis and n.m.r. and mass-spectrometric studies of the oligosaccharides obtained on depolymerisation of the polysaccharide with a bacteriophage-borne endo-rhamnosidase. [formula; see text].

Klebsiella serotype-13 capsular polysaccharide: primary structure and depolymerization by a bacteriophage-borne glycanase.

Periodate oxidation and Smith degradation, methylation analysis including uronic acid degradation, partial hydrolysis with acid, bacteriophage degradation, and p.m.r. spectroscopy have been used to elucidate the primary structure of the Klebsiella serotype-13 capsular polysaccharide. The polymer consists of pentasaccharide repeating-units comprising a 4)-beta-D-Manp-(1 leads to 4)-alpha-D-Glcp-(1 leads to 3)-beta-D-Glcp-(1 leads to chain with a 3,4-O-(1-carboxyethylidene)-beta-D-Galp-(1 leads to 4)-alpha-D-GlcAp-(1 leads to branch at position 3 of the mannose. It is shown that there is a glycanase activity associated with particles of Klebsiella bacteriophage No. 13, which catalyses hydrolysis of chain beta-D-Glcp-(1 leads to 4)-beta-D-Manp linkages in the type-13 polysaccharide. The chemical basis of some serological cross-reactions of the Klebsiella K13 antigen is discussed.

Structural studies of the capsular polysaccharide of Klebsiella type 81.

The structure of the capsular polysaccharide from Klebsiella Type 81 has beeninvestigated. Methlylation analysis, uronic acid degradation, Smith degradation, andgraded acid hydrolysis were the principle methods used. Theanomeric nature of theglycosidic linkages was determined by characterization of fragments obtained from thevarious methods of degradation used. One of the L-rhamnosidic linkages was notpresent in any of these fragments, but is assumed to be an alpha-linkage from consideerationsof optical-rotation data. These studies show that they polysaccharide consits of thefollowing hexasaccharide repeating-unit: yield2)-alpha-L-Rhap-(1yields3)-alpha-L-Rhap-(1-yields4)-beta-D-GlcAP-(1-yields2)-alpha-L-Rhap-(1-yields3)-alpha-L-Rhap-(1-yields3)-beta-D-Galp-(1-yields.

Structural studies of the capsular polysaccharide of Klebsiella type 28.

The capsular polysaccharide from Klebsiella type 28 has been studied by methylation analysis, a modified Smith-degradation procedure, and uronic acid degradation with subsequent oxidation and elimination of the substituents of the oxidized residue. The polysaccharide contained the hexasaccharide repeating-unit shown below. The terminal D-glucopyranose residue was hydrolysed by emulsin, indicating a beta linkage. The anomeric natures of other glycosidic linkages were determined by characterization of fragments obtained during the degradative studies. The D-galactopyranose residue was not present in any fragment, but is assumed to be alpha-linked from optical-rotation considerations. (see article)

Structural studies of the capsular polysaccharide of Klebsiella type 59.

The structure of the capsular polysaccharide from Klebsiella type 59 has been investigated by methylation analysis, a modified Smith-degradation procedure, and uronic acid degradation followed by oxidation and elimination of the substituents of the oxidized residue. The oligomeric fragments produced by these degradative procedures were isolated and characterized. O-Acetyl groups were identified and their position determined. The polysaccharide consists of the following pentasaccharide repeating-unit (dotted lines indicate that only some of the residues carry the O-acetyl substituent). See article.