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PubMed2002

The wavB gene of Vibrio cholerae and the waaE of Klebsiella pneumoniae codify for a beta-1,4-glucosyltransferase involved in the transfer of a glucose residue to the L-glycero-D-manno-heptose I in the lipopolysaccharide inner core.

Vibrio cholerae WavB protein showed some similarity to WaaE of Klebsiella pneumoniae and Serratia marcescens. From previous data obtained by us and by chemical analyses of a K. pneumoniae non-polar waaE mutant from strain 889 (08:K69), its lipopolysaccharide (LPS) core structure has recently been elucidated. We demonstrated that WaaE is a beta-1,4-glucosyltransferase involved in the transfer of a glucose residue to the L-glycero-D-manno-heptose I in the LPS inner core. Complementation of this K. pneumoniae non-polar waaE mutant with gene wavB obtained, either from V. cholerae or V. mimicus, showed a full complementation either by chemical studies or by a biological test (susceptibility to non-immune serum). The V. cholerae wavB gene is located in a putative core oligosaccharide (OS) gene cluster and the V. cholerae OS core structure showed the same beta-1,4-glucose residue attached to Hep I as is observed for the K. pneumoniae 889 OS core structure. No other glucose residue is found in the ligosaccharide core structure of K. pneumoniae 889. We concluded that WavB protein is able to perform the same function as WaaE.

Bacterial Proteins↗
PubMed1989

Gas chromatographic determination of (phosphorylated) 2-keto-3-deoxyoctonic acid, heptoses and glucosamine in bacterial lipopolysaccharides after treatment with hydrofluoric acid, methanolysis and trifluoroacetylation.

Quantification of phosphorylated sugar constituents of lipopolysaccharides has been performed by the following sequence: dephosphorylation by treatment with hydrofluoric acid, cleavage to monomeric constituents by methanolysis and analysis of the released sugars by capillary gas chromatography. Lipopolysaccharides of Salmonella minnesota Rd1P+, Bordetella pertussis NIH 114 and Vibrio cholerae, NAG and 95R strains, were used as model substances. Comparison of the chromatographic data obtained from hydrofluoric acid-treated and untreated lipopolysaccharide preparations indicated that all lipopolysaccharides examined contained one moiety of glucosamine bound to phosphate in a stable linkage. 2-Keto-3-deoxyoctonic acid appeared phosphorylated to a variable extent. Lipopolysaccharides of the two V. cholerae strains contained one moiety of fully phosphorylated 2-keto-3-deoxyoctonic acid, whereas in that of S. minnesota Rd1P+ only one of the three moieties was phosphorylated. Lipopolysaccharide of B. pertussis had one moiety of 2-keto-3-deoxyoctonic acid, ca. 70% phosphorylated. All four of the preparations examined contained L-glycero-D-manno-heptose in amounts varying from 2.6 to 5.2 moieties. In the lipopolysaccharides of B. pertussis and strain 95R of V. cholerae this sugar was unphosphorylated, whereas the two remaining strains contained one phosphorylated moiety of this sugar. Phosphorylated lipopolysaccharide constituents can be analysed by this approach on a 50-100 micrograms scale.

Bordetella pertussis↗
PubMed1976

7-O-(2-Amino-2-deoxy-alpha-D-glucopyranosyl)-L-glycero-D-manno-heptose. A constituent of the endotoxin of Bordetella pertussis.

Hydrolysis of the Bordetella pertussis endotoxin, extracted from both "phase I" and "phase IV" bacteria, with 4 M HCl for 1 h at 100 degrees C, released the disaccharide named in the title; it was isolated by paper electrophoresis or by ion-exchange chromatography in about 1% yield (w/w). The structure of the heptose could be rigorously established by chemical degradation; the facts that the glucosaminidic linkage was hydrolysed by an enzyme preparation containing both, alpha and beta-N-acetylglucosaminidase activities, whereas it was resistant to cleavage by pure beta-N-acetylglucosaminidase strongly support the assumption that the disaccharide contains an alpha-D-glucosaminide linkage.

Bordetella pertussis↗
PubMed1974

Heptose-containing pentaglycosyl diglyceride among the lipids of Acholeplasma modicum.

A pentaglycosyl diglyceride with the tentative structure of galactosyl-galactosyl-mannoheptosyl-glucosyl-glucosyl diglyceride was found to be the major glycolipid in Acholeplasma modicum. The heptose is d-glycero-d-mannoheputose. The diglyceride-terminating moiety possesses the structure O-alpha-d-glucopyranosyl-(1 --> 2)-O-alpha-d-glucopyranosyl-sn-1,2-diglyceride. Other glycolipids occurring in this organism are a diglucosyl diglyceride and a monoglucosyl diglyceride with structures identical to the terminal segments of the pentaglycosyl diglyceride. More fully acylated derivatives of these two glycolipids also occur. The phospholipids are all of the glycerophosphoryl type. The neutral lipids are composed of diglycerides and four polyterpenes. The polyterpenes consist of both colored and colorless carotenoids and become radiolabeled with both [(14)C]acetate and [(14)C]mevalonate.

Acetates↗
PubMed1975

Comparison of the cell envelope structure of a lipopolysaccharide-defective (heptose-deficient) strain and a smooth strain of Salmonella typhimurium.

The cell envelope structure of Salmonella typhimurium LT2, which has a heptose-deficient lipopolysaccharide (LPS), is significantly different from that of an isogenic strain with a normal LPS. The rough strain, when examined by freeze-etching, lacks most surface structures that are routinely present in the smooth strain (surface particles and flagella) and has few transmemberane studs in the cytoplasmic membrane (those present are generally found in aggregates), and the outer membrane cleavage is substantially stronger than that of the smooth strain. These envelope differences were independent of both growth temperature and culture age. Examination of ultrathin sections indicated that the rough strain has an outer membrane which forms a much more defined double-track artifact than the smooth strain. The addition of MgCl2 to the growth medium of the rough strain decreased the extent of outer membrane cleavage, and flagella became evident in freeze-etched preparations. The presence of supplemental MgCl2 in the growth medium, which resulted in these morphological changes in the rough strain, also produced growth at a previously restrictive temperature and a decrease in the leakage of periplasmic enzymes. The smooth strain was unaltered morphologically or physiologically by MgCl2 under identical conditions. It is suggested that the outer membrane of the rough strain is more planar.

Cell Wall↗
PubMed1981

Structure of the heptose region of lipopolysaccharies from Rhodospirillum tenue.

There is a common structure (core region) in the lipopolysaccharides of Rhodospirillum tenue. It is composed of a branched trisaccharide of L-glycero-D-mannoheptose (and of 2-keto-3-deoxyoctonate), as revealed by methylation analyses of degraded polysaccharides of four different R. tenue strains. The structure is similar or might even be identical to the inner core of enterobacterial O antigens. In addition, each of the four R. tenue lipopolysaccharides contains a strain-specific region that consists of heptose(s) (L-glycero-D-mannoheptose or D-glycero-D-mannoheptose or both) or hexoses. There is a partial substitution of the core region and the strain-specific region by phosphorus, showing microheterogeneity.

Chemical Phenomena↗
PubMed1981

Citrate-tris(hydroxymethyl)aminomethane-mediated release of outer membrane sections from the cell envelope of a deep-rough (heptose-deficient lipopolysaccharide) strain of Escherichia coli O8.

A heptose-deficient lipopolysaccharide strain of Escherichia coli O8, strain F515, was found to release portions of its outer membrane when cells were exposed to 10 mM citrate buffer (pH 2.75) for 30 min and subsequently exposed to 100 mM tris(hydroxymethyl)aminomethane buffer (pH 8.00). The outer membrane component release was found to be composed of protein, lipopolysaccharide, phospholipid (cardiolipin, phosphatidylethanolamine, and phosphatidylglycerol), and alkaline phosphatase. The outer membrane component was released from the cell envelope in the absence of cell lysis, as no glucose-6-phosphate dehydrogenase activity or succinic dehydrogenase activity was detected. Morphologically, the outer membrane component appeared to consist of laminar fragments and vesicles which had an associated alkaline phosphatase activity.

Bacterial Proteins↗
PubMed1979

Structure of the lipopolysaccharide from an Escherichia coli heptose-less mutant. I. Chemical degradations and identification of products.

The structure of lipopolysaccharide from a heptose-less mutant of Escherichia coli K-12 has been investigated. Lipopolysaccharide isolated from 32P-labeled cells was treated with mild alkali to yield two separable components: [OH-LPS]-I (approximately 70%) and [OH-LPS]-II (approximately 30%). Mild acidic treatment of [OH-LPS]-I gave mainly a product which was identified as (4-O-phosphoryl-N-beta-hydroxymyristyl-D-glucosaminyl)-beta(1 leads to 6)-N-beta-hydroxymyristyl-D-glucosamine 1-phosphate (Compound I). Further acidic hydrolysis of both [OH-LPS]-I and [OH-LPS]-II yielded as the main product (4-O-phosphoryl-N-beta-hydroxymyristyl-D-glucosaminyl)-beta(1 leads to 6)-N-beta-hydroxymyristyl-D-glucosamine (Compound II). The structures of the above products were deduced by a combination of compositional analyses, sensitivity to phosphomonoesterase, rates of hydrolysis of the phosphate groups and alkali-catalyzed beta elimination of the phosphate residues following appropriate oxidation of hydroxyl groups. These studies together with work reported in the accompanying papers have led to the identification of two species of lipopolysaccharide in the E. coli strain both of which contain a single glucosamine dissacharide unit but differ in having monosubstituted phosphate or pyrophosphate groups at the glycosidic position. Each species of lipopolysaccharide also appeared to be heterogeneous with respect to the number of esterified fatty acyl groups.

Alkaline Phosphatase↗
PubMed1996

[Synthesis and characteristics of five phosphates of L-glycero-D-manno-heptose].

Five monophosphates of L-glycero-D-manno-heptose having the PO(OH)2 residue at O-2,3, 4, 6, and 7 have been synthesized starting from suitably protected benzyl D-mannopyranoside derivatives. The synthesis involved chain elongation by the reaction of D-mannoside 6-aldehyde with alkoxymethylmagnesium chloride resulting in the desired L-glycero-D-manno-heptopyranoside as the main product. The blocking groups pattern enabled selective deprotection of the hydroxyl groups at C-2, 3, 4, and 7. These substrates were phosphitylated with 2-dimethylamino-5,6-benzo-1,3,2-dioxaphosphepan and oxidized in situ to phosphates. The resulting products were hydrogenolytically deprotected and converted to di(cyclohexylammonium) salts which were characterized by 13C-NMR spectra.

Heptoses↗
PubMed1994

Synthesis of a hexasaccharide corresponding to part of the heptose-hexose region of the Salmonella Ra core, and a penta- and a tetra-saccharide that compose parts of this structure.

The synthesis of the hexasaccharide 2-(4-trifluoroacetamidophenyl)ethyl O-alpha-D-galactopyranosyl-(1-->3)-[O-alpha-D-galactopyranosyl-(1-->6)]- O-alpha-D-glucopyranosyl-(1-->3)-[O-L-glycero-alpha-D-manno-heptopyranos yl- (1-->7)]-O-L-glycero-alpha-D-manno-heptopyranosyl-(1-->3)-L-glycero-alph a-D- manno-heptopyranoside, corresponding to the heptose and part of the hexose region in the Salmonella Ra core, is described. Syntheses of the pentasaccharide 2-(4-trifluoroacetamidophenyl)ethyl O-alpha-D-galactopyranosyl-(1-->3)-O-alpha-D-glucopyranosyl-(1-->3)-[O-L - glycero-alpha-D-manno-heptopyranosyl-(1-->7)]-O-L-glycero-alpha-D-manno- heptopyranosyl-(1-->3)-L-glycero-alpha-D-manno-heptopyranoside and the tetrasaccharide 2-(4-trifluoroacetamidophenyl)ethyl O-alpha-D-glucopyranosyl-(1-->3)-[O-L-glycero-alpha-D-manno-heptopyranos yl- (1-->7)]-O-L-glycero-alpha-D-manno-heptopyranosyl-(1-->3)-L-glycero-alph a-D- manno-heptopyranoside are also described. Coupling of methyl 2,3,4,6-tetra-O-benzyl-1-thio-beta-D- glucopyranoside and methyl 2-O-benzyl-4,6-O-benzylidene-3-O-(2,3,4,6-tetra-O-benzyl-alpha-D- galactopyranosyl)-1-thio-beta-D-glucopyranoside to a triheptoside derivative with a free HO-3', using dimethyl(methylthio)sulfonium triflate and N-iodosuccinimide-silver triflate as promoters, gave the protected tetra- and penta-saccharide, respectively. Removal of the benzylidene group from the pentasaccharide followed by a regio- and stereo-selective coupling using halide-assisted conditions and 2,3,4,6-tetra-O-benzyl-alpha-D- galactopyranosyl bromide as donor gave the protected hexasaccharide. Deprotection then gave the target structures.

Carbohydrate Conformation↗
PubMed1995

Glycan structure of a heptose-containing S-layer glycoprotein of Bacillus thermoaerophilus.

The characterization of the S-layer glycoprotein of Bacillus thermoaerophilus revealed unexpected novelties. The isolation and purification procedure had to be changed due to complete solubility in aqueous buffers of the constituting S-layer protomers. Upon degradation of the S-layer glycoprotein by pronase and purification of the products by gel filtration, ion-exchange chromatography, chromatofocusing and HPLC, one representative glycopeptide fraction was selected for further characterization. From the combined evidence of composition analysis, chemical degradation, NMR spectroscopy experiments and comparison with synthesized model substance, we propose the following repeating unit structure of the glycan chain: -->4)-alpha-L-Rhap-(1-->3)-beta-D-glycero-D-manno-Hepp-(1--> This is the first description of heptose residues occurring as a constituent of S-layer glycoproteins of gram-positive eubacteria.

Bacillus↗
PubMed1997

Lipopolysaccharides of Helicobacter pylori serogroups O:3 and O:6--structures of a class of lipopolysaccharides with reference to the location of oligomeric units of D-glycero-alpha-D-manno-heptose residues.

Lipopolysaccharides (LPS) from antigenically different strains assigned to serogroups O:3 and O:6 of Helicobacter pylori were isolated as water-soluble material of high Mr and as water-insoluble gels of low Mr. Chemical and spectroscopic analyses of the soluble LPS and oligosaccharides liberated from the water-insoluble gels led to proposed structures with Lewis (Le) antigen determinants terminating regular repeating units of different types, linked in turn to inner core regions of invariable structure. The O:6 LPS has two populations of related molecules with chains of 3-linked D-glycero-alpha-D-manno-heptose residues similar to those in the MO19 strain, one with and the other without a single terminal Lewis (Le(y)) epitope. In contrast, in the O:3 LPS, Lewis (Le(x) and Le(y)) epitopes terminate a partially fucosylated N-acetyllactosaminoglycan, but a heptan chain similar to that in the O:6 LPS was shown to connect the outer chains to the inner core. These LPS provide examples of the molecular mimicry of cell-surface glycoconjugates. Structural variations of LPS between strains, and differences in some aspects of structure within strains, between high Mr and low Mr LPS indicate a class of LPS whose mechanisms of biosynthesis lead to overall architectures different from those characteristic of most LPS from enteric bacteria.

Amino Sugars↗
PubMed1979

Structural and biochemical examination of ghosts derived from a deep rough (heptose-deficient lipopolysaccharide) strain and a smooth strain of Escherichia coli.

Outer membrane derived 'ghosts' can be readily generated from both smooth and deep rough (heptose-deficient LPS) strains of Escherichia coli 08. MORPHOlogical and biochemical studies confirmed that 'ghosts' of both strains are composed of protein (four major proteins), LPS, and phospholipid (cardiolipin and phosphatidylethanolamine) in the form of a single membrane of roughly the same shape as intact normal cells. The ghost membrane cleaves only slightly in freeze-etch preparations of ghosts derived from the smooth strain as compared to the extensive cleavage plane of ghosts derived from the rough strain. The asymmetrical distribution of ghost proteins was visualized, by critical point drying and shadowing with platinum, as a relatively smooth outer surface with some discernible particles (10-15 nm) and an extremely particulate inner surface (10-15-mm particles. Ghosts derived from the smooth strain retained their structure following chloroform-methanol extraction, while ghosts derived from the rough strain fragmented with chloroform-methanol extraction. Evidence is presented that LPS-protein interactions as well as protein-protein interactions are significant in maintaining the ghost structure.

Bacterial Proteins↗
PubMed1988

[Antigenic polysaccharides of bacteria. 25. Structure of the O-specific polysaccharide chain of Pseudomonas cepacia 673/2 lipopolysaccharide containing L-glycero-D-manno-heptose].

O-Specific polysaccharide, consisting of D-rhamnose and L-glycero-D-manno-heptose (LD-Hep) in a 2 : 1 ratio, was obtained on the mild acid degradation of the Pseudomonas cepacia IMV 673/2 lipopolysaccharide; monosaccharide LD-Hep has not previously been found in O-specific chains of lipopolysaccharides. On the basis of methylation and 13C-NMR data, it was concluded that the polysaccharide is composed of trisaccharide repeating units having the following structure: ----3)-alpha-D-Rha-(1----3)-alpha-D-Rha-(1----2)-alpha-LD-Hep-(1----

Antigens, Bacterial↗
PubMed1983

Immunogenicity of transfer RNA isolated from a two-heptose rough mutant of Salmonella typhimurium LT2 in mouse typhoid infection.

Transfer ribonucleic acid (tRNA) was isolated from a two-heptose mutant of Salmonella typhimurium LT2 (strain SL1004) and was found to afford 100% mouse protection against challenge with 1000 LD50 of strain LT2. The intraperitoneal minimum effective dose of tRNA was 5 micrograms RNA per mouse and this dose was significantly lower than that of ribosomal RNA for ddY mouse strain. The protective immunity was independent of the presence of antibodies to cell-surface antigens, and was transferred mainly by T cells. The protective moiety of tRNA was sensitive to ribonuclease digestion which resulted in 85% reduction in the mouse survival rate, but was completely resistant to protease digestion. The present study demonstrates that the immunogenic activity of salmonella RNA is present in both ribosomal RNA and tRNA.

Animals↗