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PubMed1980

Composition of the Capsular and Extracellular Polysaccharides of Rhizobium japonicum: CHANGES WITH CULTURE AGE AND CORRELATIONS WITH BINDING OF SOYBEAN SEED LECTIN TO THE BACTERIA .

The chemical compositions of the capsular and extracellular polysaccharides of two strains of Rhizobium japonicum (311b 138 and 110) have been determined and correlated as a function of culture age with the ability of the bacteria from which they were obtained to bind soybean seed lectin.Each of the polysaccharides contains approximately constant amounts of mannosyl, glucosyl, and galacturonosyl residues in a molar ratio of 1:2:1. In addition they contain variable amounts of galactosyl and 4-O-methyl galactosyl residues. The total of galactose plus 4-O-methyl galactose, however, is constant and equivalent to the amount of mannose, indicating that the 4-O-methyl galactose residues arise by methylation of galactose residues in the polysaccharides. In both strains the proportion of galactose to methyl galactose is considerably greater in the polysaccharide from bacteria which do bind lectin than in the polysaccharide from bacteria which do not bind lectin.In addition to the changes in polysaccharide composition, there is a reduction of about 50% in the percentage of cells which are encapsulated as the cultures mature from early to late log phase. Since only capsulated cells bind lectin, the combination of the change in capsular composition and loss of encapsulation is probably sufficient to account for the loss of lectin binding capacity during growth of cultures of Rhizobium japonicum 311b 138 and 110.

Journal Article↗

PubMed1987

Structure of Plant Cell Walls : XIX. Isolation and Characterization of Wall Polysaccharides from Suspension-Cultured Douglas Fir Cells.

The partial purification and characterization of cell wall polysaccharides isolated from suspension-cultured Douglas fir (Pseudotsuga menziesii) cells are described. Extraction of isolated cell walls with 1.0 m LiCl solubilized pectic polysaccharides with glycosyl-linkage compositions similar to those of rhamnogalacturonans I and II, pectic polysaccharides isolated from walls of suspension-cultured sycamore cells. Treatment of LiCl-extracted Douglas fir walls with an endo-alpha-1,4-polygalacturonase released only small, additional amounts of pectic polysaccharide, which had a glycosyl-linkage composition similar to that of rhamnogalacturonan I. Xyloglucan oligosaccharides were released from the endo-alpha-1,4-polygalacturonase-treated walls by treatment with an endo-beta-1,4-glucanase. These oligosaccharides included hepta- and nonasaccharides similar or identical to those released from sycamore cell walls by the same enzyme, and structurally related octa- and decasaccharides similar to those isolated from various angiosperms. Finally, additional xyloglucan and small amounts of xylan were extracted from the endo-beta-1,4-glucanase-treated walls by 0.5 n NaOH. The xylan resembled that extracted by NaOH from dicot cell walls in that it contained 2,4- but not 3,4-linked xylosyl residues. In this study, a total of 15% of the cell wall was isolated as pectic material, 10% as xyloglucan, and less than 1% as xylan. The noncellulosic polysaccharides accounted for 26% of the cell walls, cellulose for 23%, protein for 34%, and ash for 5%, for a total of 88% of the cell wall. The cell walls of Douglas fir were more similar to dicot (sycamore) cell walls than to those of graminaceous monocots, because they had a predominance of xyloglucan over xylan as the principle hemicellulose and because they possessed relatively large amounts of rhamnogalacturonan-like pectic polysaccharides.

Journal Article↗

PubMed1983

Cell-wall lipopolysaccharide of the urinary-tract-infective Escherichia coli 04:K12:H-. Structure of the polysaccharide chain.

The O-specific polysaccharide moiety (04 polysaccharide) of the 04 antigen (lipopolysaccharide) from Escherichia coli 04:K12:H- was isolated in pure form by degradation of the lipopolysaccharide and chromatography on Sephadex G-50. The primary structure of the 04 polysaccharide was elucidated by composition, Smith degradation, nuclear magnetic resonance spectroscopy, methylation and oligosaccharide analysis. Oligosaccharides were obtained by deaminating fragmentation of partially and completely de-N-acetylated polysaccharides. The polysaccharide consists of repeating units of the pentasaccharide (formula; see text) which are joined in the polymer through alpha-1, 4-linkages. The 04 polysaccharide has a mean molecular mass of 13800 Da and consists of the core oligosaccharide and about 14 pentasaccharide repeating units.

Carbohydrate Conformation↗

PubMed1986

Somatic antigens of Pseudomonas aeruginosa. The structure of O-specific polysaccharide chains of P. aeruginosa O10 (Lányi) lipopolysaccharides.

Mild acid degradation of lipopolysaccharides from Pseudomonas aeruginosa O10a and O10a,b (Lányi classification) resulted in O-specific polysaccharides built up of trisaccharide repeating units containing 2-acetamido-2,6-dideoxy-D-glucose (N-acetylquinovosamine, DQuiNAc), 2-acetamido-2,6-dideoxy-D-galactose (N-acetylfucosamine, DFucNAc), and 5-acetamido-3,5,7,9-tetradeoxy-7-[(R)-3-hydroxybutyramido] -L-glycero-L-manno-nonulosonic acid. The latter is a di-N-acyl derivative of a new sialic-acid-like sugar which was called by us pseudaminic acid (PseN2). A 3-hydroxybutyric acid residue was also found in natural carbohydrates for the first time. In the O10a,b polysaccharide pseudaminic acid carried an O-acetyl group at position 4. For selective cleavage of the O10a polysaccharide, solvolysis with hydrogen fluoride was employed which, owing to the relatively high stability of the glycosidic linkage of pseudaminic acid, led to the disaccharide with this sugar on the non-reducing terminus. Performing the solvolysis in methanol afforded the methyl glycoside of this disaccharide which proved to be more advantageous for further analysis. Carboxyl-reduction made the glycosidic linkage of pseudaminic acid extremely labile, and mild acid hydrolysis of the carboxyl-reduced 010a polysaccharide afforded the trisaccharide with a ketose derivative on the reducing terminus. Establishing the structure of the oligosaccharide fragments obtained and interpreting the 13C nuclear resonance spectra of the polysaccharides allowed to determine the following structure for their repeating units: (formula: see text) In the polysaccharides the N-acetylquinovosamine residue is attached not to pseudaminic acid itself, but to its N-acyl substituent, 3-hydroxybutyryl group, and thus the monomers are linked via both glycosidic and amidic linkages.

Acetylation↗

PubMed1990

The structure of Proteus mirabilis O3 O-specific polysaccharide containing N-(2-hydroxyethyl)-D-alanine.

O-Specific polysaccharide was obtained by mild acid degradation of Proteus mirabilis O3 lipopolysaccharide. The polysaccharide was dephosphorylated with 48% HF to give a linear polysaccharide and an amino acid, N-(2-hydroxyethyl)-D-alanine. The structure of the polysaccharide was determined by methylation, Smith degradation and computer-assisted analysis of the 13C-NMR spectra of original and dephosphorylated polymers and oligomers. The structure of the amino acid was investigated by using 1H and 13C-NMR spectroscopy and mass spectrometry (applied to the acetylated methyl ester derivative). Its absolute configuration was established by comparison of the optical rotation value and CD spectrum of the natural and synthetic product. On the basis of the data obtained, it was concluded that the repeating unit of P. mirabilis O3 O-specific polysaccharide has the following structure: (formula; see text) Removal of the amino acid phosphate substituent significantly decreased serological activity of the O-specific polysaccharide, thus showing the immunodominant role of this group. Serological cross-reactions between P. mirabilis O3 and O27 were demonstrated and tentatively substantiated.

Alanine↗

PubMed1996

Structural analysis of the O-antigenic polysaccharide from the enteropathogenic Escherichia coli O125.

The structure of the polysaccharide part of the lipopolysaccharide obtained from the enteropathogenic Escherichia coli O125 has been investigated. Methylation analysis, 1H-NMR spectroscopy and 13C-NMR spectroscopy revealed that the polysaccharide is composed of repeating hexasaccharide units. Smith degradation of the native O-polysaccharide resulted in a polysaccharide with four sugar residues in the repeating unit. Information on the sequence of the native O-polysaccharide and the Smith-degraded product was obtained by two-dimensional techniques, namely heteronuclear-multiple-bond-connectivity and NOESY experiments. The structure of the repeating unit of the O-polysaccharide of E. coli strain O125, which has two adjacent branch-point residues, is [sequence: see text].

Carbohydrate Conformation↗

PubMed1987

Chelating Properties of Extracellular Polysaccharides from Chlorella spp.

Chlorella stigmatophora LB 993 was grown in artificial seawater under controlled conditions. The production of cell wall polysaccharides attached to the cells and dissolved in the growth medium was monitored during algal growth. Preliminary characterization of the dissolved polysaccharides of C. stigmatophora and other Chlorella species is presented. The capacity of dissolved polysaccharides of C. stigmatophora to bind toxic heavy metals was also studied and compared with that of polysaccharides produced by other marine Chlorella species. The differences in metal-complexing capacity observed for dissolved polysaccharides obtained from various Chlorella species is attributable to differences in the composition of the polysaccharides, notably the uronic acids content.

Journal Article↗

PubMed1965

Immunochemistry of the Group-Specific Polysaccharide of Nocardia brasiliensis.

Estrada-Parra, Sergio (Escuela Nacional de Ciencias Biológicas, México, D.F., México), Abel Zamora, and L. F. Bojalil. Immunochemistry of the group-specific polysaccharide of Nocardia brasiliensis. J. Bacteriol. 90:571-574. 1965.-The group-specific polysaccharide of Nocardia brasiliensis was further purified, yielding an amorphous white material with the following characteristics: [alpha](D) (20) = + 48; nitrogen, 0.5%; phosphorus, 0.1%; and ash as sodium, 0.8%. The polymer is made of d-arabinose and d-galactose in a molar ratio of 3:1, and no other sugars were detected. Mild hydrolysis liberates mainly arabinose. The polysaccharide consumes 3.46 mumoles of periodate per mg of polymer in 15 days at 4 C (this value remains constant after 4 more days). Oxidation results in destruction of two of the arabinose, with the formation of two glycerols after borohydride reduction and hydrolysis. The polysaccharide oxidized by periodate and reduced under mild acid hydrolysis at 20 C yields glycerol and a polymer formed by galactose and arabinose (in a ratio of 1:1) which is resistant to a second oxidation. Therefore, the polysaccharide is probably formed by a main chain of glactose linked 1,3 and arabinose linked 1,2 or 1,3 or both, and nonreducing side chains of arabofuranose residues. The intact polysaccharide cross-reacts with sera from patients with active tuberculosis, and this, as well as the homologous reaction, is abolished by oxidation with periodate.

Journal Article↗

PubMed1996

Soluble beta-glucan polysaccharide binding to the lectin site of neutrophil or natural killer cell complement receptor type 3 (CD11b/CD18) generates a primed state of the receptor capable of mediating cytotoxicity of iC3b-opsonized target cells.

When phagocyte CR3 binds to iC3b on bacteria or yeast, phagocytosis and degranulation are triggered because of simultaneous recognition of iC3b via a CD11b I-domain binding site and specific microbial polysaccharides via a lectin site located COOH-terminal to the I-domain. By contrast, when phagocyte or natural killer (NK) cell CR3 adheres to iC3b on erythrocytes or tumor cells that lack CR3-binding membrane polysaccharides, neither lysis nor cytotoxicity are stimulated. This investigation showed that soluble CR3-specific polysaccharides such as beta-glucan induced a primed state of CR3 that could trigger killing of iC3b-target cells that were otherwise resistant to cytotoxicity. Anti-CR3 added before sugars prevented priming, whereas anti-CR3 added after sugars blocked primed CR3 attachment to iC3b-targets. Polysaccharide priming required tyrosine kinase(s) and a magnesium-dependent conformational change of the I-domain that exposed the CBRM1/5 activation epitope. Unlike LPS or cytokines, polysaccharides did not up-regulate neutrophil CR3 expression nor expose the mAb 24 reporter epitope representing the high affinity ICAM-1-binding state. The current data apparently explain the mechanism of tumoricidal beta-glucans used for immunotherapy. These polysaccharides function through binding to phagocyte or NK cell CR3, priming the receptor for cytotoxicity of neoplastic tissues that are frequently targeted with iC3b and sparing normal tissues that lack iC3b.

Animals↗

PubMed1990

Polysaccharide antigens of Pseudomonas aeruginosa.

The major polysaccharide antigens of P. aeruginosa are the cell-wall lipopolysaccharides many of which have an acidic polysaccharide chain (O-antigen) rich in unusual amino sugars. The D-rhamnose-rich polysaccharide antigen common to many serologically distinct strains is also associated with the lipopolysaccharide. The high-molecular-weight polysaccharides with O-specificity are present in extracellular slime produced by strains isolated from the environmental and from the immunocompromised hosts. The extracellular antigenic polysaccharide of another type (bacterial alginate) is expressed by mucoid strains isolated from patients with cystic fibrosis. Serotype-specific immune responses after infection are directed at the lipopolysaccharides and these heat-stable antigens serve as the basis for differentiation of P. aeruginosa strains. Both the cell-wall antigens including conjugates of the O-polysaccharides with different proteins and the extracellular antigens have been used to prepare specific antibodies tested for protection against infections due to P. aeruginosa.

Alginates↗

PubMedDate not supplied

[Evaluation of polysaccharide antigens of Vibrio cholerae O139 of different origin by monoclonal antibodies].

The epitope composition of O-polysaccharides in the lipopolysaccharide (LPS) of V. cholerae, serogroup O139, isolated from clinical material and water of surface reservoirs was analyzed with the use of monoclonal antibodies. The analysis demonstrated that these O-polysaccharides were similar in their structure and chemical composition. In LPS of V. cholerae O139 clinical strains O-polysaccharide determinants occurred more often. Among V. cholerae isolated from water strains on whose surface individual epitopes of O-polysaccharide occurred less frequently or were absent appeared to be more numerous. A decrease in the concentration of microbial cells in the process of their testing by immunological methods led to increased percent of negative reactions with specific antibodies. Some V. cholerae O139 strains isolated from water were similar in the epitope composition of their O-polysaccharide and binding activity to cultures isolated from humans. As indicated by the results of these studies, cholera vibrios Bengal and vibrios isolated from river water on the territory of Russia had quantitative differences due to a higher level of the production of O-polysaccharide determinants and their occurrence in V. cholerae of serogroup O139.

Antibodies, Bacterial↗

PubMed1991

Evidence for the structural heterogeneity of the polysaccharide component of Coxiella burnetii strain Nine Mile lipopolysaccharide.

Highly purified lipopolysaccharide (LPS) preparation obtained from Coxiella burnetii strain Nine Mile in phase I was used to determine the structure and monosaccharide composition of the polysaccharide component. The procedure included sodium dodecyl sulphate-polyacrylamide gel electrophoresis followed by silver staining and gel chromatographic fractionation of acetic acid-hydrolyzed LPS. Five fractions (A-E) were analysed by GLC-mass spectrometry. D-Mannose and D-glycero-D-mannoheptose were present in an appreciable amount in all polysaccharide fractions (A-D), whereas the virenose and dihydrohydroxystreptose contents varied. The highest content of both rhamnose and ribose was found in the low-molecular weight polysaccharide fraction D. The former sugar is being reported for the first time to be a LPS constituent. D-Xylose and D-glucose content varied considerably in the individual fractions and was the highest in fraction A. Glucosamine and galactosaminuronic acid were present in all polysaccharide fractions and, surprisingly, L-glycero-D-mannoheptose was also found, but its presence was limited within the certain degree of polymerisation of the polysaccharide chains. Mild acid hydrolysis of LPS resulted in a partial release of dihydrohydroxystreptose and virenose residues, which were collected and identified in fraction E. The data presented indicate a strong microheterogenity within the individual polysaccharide chains with respect to their sugar composition, size, and shape. Thus, the chemical structure of Coxiella LPS appears to represent a significant departure from the structures described for enteric LPSs.

Carbohydrate Sequence↗

PubMed1985

Evaluation of two tetravalent (ACYW135) meningococcal vaccines in infants and small children: a clinical study comparing immunogenicity of O-acetyl-negative and O-acetyl-positive group C polysaccharides.

Two different tetravalent polysaccharide vaccines against group A, C, Y, and W135 meningococci were given to 118 infants aged 6 to 23 months; the same vaccines were administered in a second dose 12 months later to those infants aged 6 to 11 months at first vaccination. Forty of the infants received vaccine containing the nonacetylated group C polysaccharide C(OAc-) and 78 the acetylated group C polysaccharide C(OAc+) together with group A, Y, and W135 polysaccharides. All polysaccharides, at a dose of 30 micrograms, induced antibody responses after administration of both vaccines in all age groups although the responses were better in the older infants. Acetylation of the sialic acid of the group C polysaccharide did not significantly influence the response. Rapid decreases in the antibody titers after the first vaccination stressed the need for one or more revaccinations. Vaccination elicited mild local and systemic reactions. Elevated temperatures were more common in the youngest infants but only four developed fever exceeding 38.5 degrees C (101.3 degrees F). We conclude that tetravalent (ACYW135) meningococcal vaccine is safe and immunologically effective in children younger than age 2 years. However, revaccinations may be required to maintain immunity.

Age Factors↗

PubMed1976

Dietary fibre and cholesterol metabolism: effect of fibre rich polysaccharide from blackgram (Phaseolus mungo) on cholesterol metabolism in rats fed normal and atherogenic diet.

The effect of the fibre rich polysaccharide from black gram was studied on the concentration of cholesterol in the tissues, bile salts in the liver and faecal excretion of sterols and bile salts in rats fed normal and high fat cholesterol diet as compared to glucose and sucrose. The binding of bile salts "in vitro" by the polysaccharide was also studied. The rats fed polysaccharide showed the lowest level of cholesterol in the serum, liver and aorta both in normal and high fat -- cholesterol diet groups. Excretion of faecal sterols and bile salts was maximum in the animals fed polysaccharide. The concentration of bile salts in the liver was also maximum in the animals of this group. There was significant binding of bile salts by the polysaccharide when either natural bile or pure bile salt solution was shaken with it. The extent of binding of bile salts was however decreased in the presence of fatty acids, which also released some of the absorbed bile salts from the polysaccharide on subsequent shaking.

Animals↗

PubMed1979

Effect of bacterial polysaccharides on the growth of Gaeumannomyces graminis var. tritici and wheat roots.

Agrobacterium sp. and related species which in the soil and in the rhizosphere of wheat accompany the fungus Gaemannomyces graminis var. tritici and cause take-all of the wheat roots produced polysaccharides in pure cultures (glucans, mannoglucans and galactomannoglucans). These polysaccharides were utilized better by the mycelium of G. graminis than glucose and polysaccharides of plant origin that occurred on the surface of wheat roots (the so-called mucigel). At lower concentrations these bacterial polysaccharides stimulated growth of wheat roots, higher concentrations (more than 0.1%) were inhibitory. Bacteria inoculated on the surface of wheat first inhibited and then stimulated the development of the plants and their growth. Changes in the growth rate of wheat, the rhizosphere of which was colonized by bacteria simultaneously with the fungus G. graminis and also some changes in the course of the disease of wheat roots caused by the fungus can be explained by the inhibitory or stimulatory effect of polysaccharides of accompanying bacteria.

Ascomycota↗

PubMed2004

An electrodynamics-based model for ion diffusion in microbial polysaccharides.

An electrodynamics-based model was formulated for simulation of ion diffusion in microbial polysaccharides. The fixed charges and electrostatic double layers that may associate with microbial polysaccharides and their effects on ion diffusion were explicitly built into the model. The model extends a common multicomponent ion diffusion formulation that is based on irreversible thermodynamics under a zero ionic charge flux condition, which is only applicable to the regions without fixed charges and electrostatic double layers. An efficient numerical procedure was presented to solve the differential equations in the model. The model well described key features of experimental observations of ion diffusion in negatively charged microbial polysaccharides including accelerated diffusive transport of cations, exclusion of anions, and increased rate of cation transport with increasing negative charge density. The simulated diffusive fluxes of cations and anions were consistent with a cation exchange diffusion concept in negatively charged polysaccharides at the interface of plant roots and soils; and the developed model allows to mathematically study such diffusion phenomena. An illustrative example was also provided to simulate dynamic behavior of ionic current during ion diffusion within a charged bacterial cell wall polysaccharide and the effects of the ionic current on the compression or expansion of the bacterial electrostatic double layer at the interface of the cell wall and bulk solution.

Cell Wall↗

PubMed2005

The examination of polysaccharides as potential antioxidative compounds for topical administration using a lipid model system.

Aim of this study was the detection of polysaccharides with antioxidative properties as potential lipid protectors for topical administration. The effects of eight different polysaccharides on UV irradiation induced lipid peroxidation were investigated in a concentration dependent manner. An aqueous linolenic acid dispersion was used as an in vitro test system to examine the influences of acacia gum, agar agar, alginic acid, guar gum, novelose 330 and xanthan gum on the lipid peroxidation level after UV exposure. Four different samples of pectin and locust bean gum resulting from a swing mill grinding series were tested as well. Iron ions were added as transition metal catalysts. A UV irradiation device was used to create high level radiation. The amount of lipid peroxidation secondary products was quantified by the thiobarbituric acid assay detecting malondialdehyde. All of the tested polysaccharides showed antioxidative effects at least at one concentration. For acacia and xanthan gum, a concentration dependency of the protective effects was measured. The samples of agar agar, guar gum and novelose 330 acted antioxidatively without showing any concentration dependency. For alginic acid, prooxidative effects were determined. A correlation between grinding time and the effects of pectin and locust bean gum on the model lipid was not observed. The administration of lipid protective polysaccharides in cosmetic formulations or sunscreens could be helpful for the protection of the human skin against UV induced damage. In vivo experiments with the lipid protective polysaccharides found in this study should follow.

Administration, Topical↗

PubMed1999

The structure of the specific capsular polysaccharide of Rhodococcus equi serotype 4.

The specific capsular polysaccharide produced by Rhodococcus equi serotype 4 was found to be a high-molecular-weight acidic polymer composed of D-glucose, D-mannose, pyruvic acid and a previously unidentified 5-amino-3,5-dideoxynonulosonic (rhodaminic) acid in the proportions 2:1:1:1. Structural analysis, employing a combination of microanalytical methods, nuclear magnetic resonance spectroscopy, and mass spectrometric techniques, established that the polysaccharide consisted of linear repeating tetrasaccharide units having the sequence of residues shown below. In the native polysaccharide, the rhodaminic acid residues were present as their acetamido derivatives (RhoANAc) and carried 1-carboxyethylidene groups that bridged the O-7 and O-9 positions. Treatment of the capsular polysaccharide with dilute acetic acid and/or anhydrous hydrogen fluoride under hydrolytic/solvolytic conditions, resulted in the formation of four different oligosaccharide species. The 1H and 13C NMR resonances of these oligosaccharide fragments and of the native serotype 4 capsular polysaccharides were fully assigned by homo- and heteronuclear chemical shift correlation methods.

Animals↗