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PubMed1999

New insights on the specificity of heparin and heparan sulfate lyases from Flavobacterium heparinum revealed by the use of synthetic derivatives of K5 polysaccharide from E. coli and 2-O-desulfated heparin.

The capsular polysaccharide from E. Coli, strain K5 composed of ...-->4)beta-D-GlcA(1-->4)alpha-D-GlcNAc(1-->4)beta-D-GlcA (1-->..., chemically modified K5 polysaccharides, bearing sulfates at C-2 and C-6 of the hexosamine moiety and at the C-2 of the glucuronic acid residues as well as 2-O desulfated heparin were used as substrates to study the specificity of heparitinases I and II and heparinase from Flavobacterium heparinum. The natural K5 polysaccharide was susceptible only to heparitinase I forming deltaU-GlcNAc. N-deacetylated, N-sulfated K5 became susceptible to both heparitinases I and II producing deltaU-GlcNS. The K5 polysaccharides containing sulfate at the C-2 and C-6 positions of the hexosamine moiety and C-2 position of the glucuronic acid residues were susceptible only to heparitinase II producing deltaU-GlcNS,6S and deltaU,2S-GlcNS,6S respectively. These combined results led to the conclusion that the sulfate at C-6 position of the glucosamine is impeditive for the action of heparitinase I and that heparitinase II requires at least a C-2 or a C-6 sulfate in the glucosamine residues of the substrate for its activity. Iduronic acid-2-O-desulfated heparin was susceptible only to heparitinase II producing deltaU-GlcNS,6S. All the modified K5 polysaccharides as well as the desulfated heparin were not substrates for heparinase. This led to the conclusion that heparitinase II acts upon linkages containing non-sulfated iduronic acid residues and that heparinase requires C-2 sulfated iduronic acid residues for its activity.

Bacterial Capsules↗
PubMed1960

Relation of particle size of C polysaccharide complexes of group A streptococci to toxic effects on connective tissue.

The component of Group A streptococci which is responsible for the chronic, remittent, multinodular lesion of connective tissue is derived from the cell wall. Further evidence is given to support the essential role of the group-specific C polysaccharide in the production of this lesion. A series of particles containing the group-specific C polysaccharide was prepared, ranging in size from large cell wall fragments to the relatively small hapten. A comparison of the lesion producing capacity of the particles in this spectrum revealed that maximum toxic activity is associated with C polysaccharide complexes of intermediate size. The discussion considers colloidal properties associated with C polysaccharide complexes of a certain size, and the influence particle size has on persistence in tissue, as possible explanations of the relationship between the size of the C polysaccharide complex and its ability to produce the chronic lesion of connective tissue.

Cell Wall↗
PubMed1965

THE DETERMINATION OF ANTIBODY TO GROUP A STREPTOCOCCAL POLYSACCHARIDE IN HUMAN SERA BY HEMAGGLUTINATION.

A hemagglutination method employing tanned human O erythrocytes sensitized with purified Group A streptococcal polysaccharide has been developed to measure A polysaccharide antibody in antistreptococcal rabbit and human sera. The reaction of sensitized RBC with known Group A streptococcal rabbit antisera, inhibition of hemagglutination with A polysaccharide, and abolition of hemagglutination and hemagglutination-inhibition by exposure of polysaccharide antigen to A enzyme, which destroys the specific immunologic determinant of A carbohydrate, were utilized to demonstrate the specificity of this hemagglutinating system. The results of A polysaccharide antibody determinations on sera from normal persons, patients convalescent from streptococcal infection, and patients with non-suppurative streptococcal sequelae are presented.

Animals↗
PubMed1950

Localization of antigen in tissue cells; V. Capsular polysaccharide of Friedländer bacillus, type B, in the mouse.

The fate of the capsular polysaccharide of Friedländer B bacillus in the mouse after its intravenous administration was studied by means of homologous antibody labelled with fluorescein. The results indicate that this acid polysaccharide, like pneumococcal polysaccharide, types II and III, was rapidly taken up by phagocytic cells throughout the body, where it persisted in decreasing concentration for more than 33 days. It was widely distributed in the capillary endothelium and on collagenous fibres in all organs. It made a transient appearance in or on lymphocytes in the spleen and lymph nodes. It was found in the hepatic epithelium and in the bile; in the juxtaglomerular segment of the distal renal tubule and in an occasional cast in the lumens of collecting tubules; in the epithelium of some uterine glands; and in cells in the steroid-secreting tissues of the ovary, suprarenal cortex, and perhaps of the testis. In joints the synovial membranes contained large amounts of antigen, and some also penetrated into cartilage cells adjacent to the joint cavity. Osteoblasts and a few osteocytes also took up the polysaccharide. When administered by inhalation, the polysaccharide was found in high concentration in the pulmonary macrophages but could not be found constantly in other lung elements.

Animals↗
PubMed2003

A new in vitro assay of cholesterol adsorption by food and microbial polysaccharides.

The adsorption of total cholesterol by polysaccharides was measured in vitro by enzymatic reactions, including the polysaccharide precipitation procedure. Total cholesterol adsorption capacities, in a mixture of polysaccharide and total cholesterol, were compared for apple pectin, gelrite gellan gum, xanthan gum, high-methoxyl pectin, citrus pectin, high-viscous alginate, low-viscous alginate, dextran, and zooglan. Acidic polysaccharides such as pectins, alginate, and xanthan gum at concentrations of 0.1% (wt/vol) were able to adsorb over 90% of the total cholesterol when dissolved in distilled water, sodium acetate buffer (pH 4.6), or sodium phosphate buffer (pH 7.0). However, total cholesterol adsorptions by gellan and zooglan were dependent upon the salt concentration and pH value, which decreased cholesterol adsorption in the following order by degree: distilled water, acidic pH, and alkaline pH. In particular, total cholesterol adsorption of zooglan was greatly decreased by the addition of sodium chloride. With 0.1% (wt/vol) polysaccharide dissolved in distilled water, the adsorption capacities of alginate, pectins, gellan gum, xanthan gum, and zooglan were 2.9, 2.88, 2.5, 2.9, and 2.4 mg/dL, respectively. However, 0.2% of zooglan was able to completely adsorb the cholesterol (3 mg/dL), whereas dextran did not adsorb cholesterol at all, producing no precipitate with hexadecyltrimethylammonium bromide.

Adsorption↗
PubMed1981

Direct evidence for the involvement of capsular polysaccharide in the immunoprotective activity of Klebsiella pneumoniae ribosomal preparations.

Previous work has demonstrated the capsular serotypic specificity of the protection conferred on mice by Klebsiella pneumoniae ribosomal preparations. The data in these studies support the hypothesis that capsular polysaccharide plays at least some role in the specificity of the protection conferred by ribosomal preparations. In this investigation, the presence of capsular polysaccharide and lipopolysaccharide in K. pneumoniae ribosomal preparations was demonstrated by using immunodiffusion tests. Lipopolysaccharide content was determined for mice treated with actinomycin D. The serotype of O antigen did not play a role in the orientation of the specificity of the protection. The possibility that lipopolysaccharide might act as an adjuvant was not unlikely since the ribosomal preparations which contained the greatest amounts of lipopolysaccharide appeared to be the most immunoprotective preparations. Ribosomal preparations extracted from a noncapsulated mutant of K. pneumoniae did not protect mice. This finding suggested that capsular polysaccharide might play a role in the immunoprotective activity of ribosomes. This hypothesis was tested by using K. pneumoniae K2 bacteriophage-associated-glycanase, which specifically hydrolyzed K. pneumoniae K2 capsular polysaccharide and thereby suppressed the immunoprotective activity of K. pneumoniae K2 ribosomal preparations. In contrast, the K2 bacteriophage-associated glycanase did not interfere with the immunoprotective activity of K. pneumoniae K1 ribosomal preparations. These results clearly demonstrate that capsular polysaccharide, which is an extraribosomal antigen, is involved in the immunoprotective activity of K. pneumoniae ribosomal preparations.

Animals↗
PubMed1975

Escherichia coli capsule bacteriophages. VII. Bacteriophage 29-host capsular polysaccharide interactions.

Different interactions between particles of Escherichia coli capsule bacteriophage 29 and its receptor, the E. coli serotype 29 capsular polysaccharide have been studied. The inactivation of phage 29 (8 x 10(3) PFU/ml) by isolated host capsular glycan was found to be physiologically insignificant (50% inactivation dose equals 100 mug after 1 h at 37 C). No adsorption (less than 2 x 10(4) PFU/mug) of the viruses to K29 polysaccharide-coated erythroyctes (at 0 or 37 C) was observed either. The phage particles were, however, found to catalyze the hydrolysis of beta-D-glucosido-(1leads to 3)-D-glucuronic acid bonds (arrow) in the receptor polymer, leading, ultimately, to the formation of a mixture of K29 hexasaccharide (one repeating unit), dodecasaccharide, and octadecasaccharide: (see article). Testing derivatives of K29 polysaccharide, as well as 82 heterologous bacterial (mainly Enteriobactericeae) capsular glycans, the viral glycanase was found to be highly specific; in accordance with the host range of phage 29, only one enzymatic cross-reaction (with the Klebsiella K31 polysaccharide) was observed. These and previous results, as well as the electron optical findings of M. E. Bayer and H. Thurow (submitted for publication), are discussed in terms of a unifying mechanism of phage 29-host capsule interaction. We propose that the viruses penetrate the capsules by means of their spike-associated glycanase activity, which leads them along capsular polysaccharide strands to membrane-cell wall adhesions where ejection of the viral genomes occurs.

Adsorption↗
PubMedDate not supplied

[A study of polysaccharides in fast growing "Rhizobium" (author's transl)].

This work is an attempt to use the composition of exopolysaccharides in the Rhizobium genus as a criterium of taxonomic importance. The organisms were first cultured in media and under conditions which led to the production of as many polysaccharides as possible. The medium chosen for proliferation conditions was Wright's medium; for conditions of non-proliferation conditions was Wright's medium; for conditions of non-proliferation, a minimal medium without nitrogen was used. The polysaccharides synthesised in Wright's medium consists in neutral sugars such as glucose, galactose, mannose and sometimes rhamnose and in uronic acid in various quantities. If no mannose is found in the polysaccharides when they are synthesised in non-proliferation conditions and if mannans are found in yeast broth, it may be thought, as suggested by Humphrey, that mannose would come from those mannans. The study of the composition of these polysaccharides enables us to sort out two groups of fast growing Rhizobium. The first one, relatively uniform, corresponds to the strains of R. leguminosarum, trifolii and phaseoli. In these strains, the polysaccharides are made of about 70% of neutral sugars and 20% of glucuronic acid.

Cell Division↗
PubMedDate not supplied

[Comparative study of the chemical composition and properties of the capsule polysaccharides in M-, S- and R-variants of Mycobacterium lacticolum].

Polysaccharides from the capsules of Mycobacterium lacticolum M, S and R variants were comparatively studied for the first time. The polysaccharides from M and S cells contained galactose, glucose and mannose; however, the polysaccharides must be different since they vary in specific rotation. The capsule polysaccharide from R cells contained also arabinose. Its specific rotation differed considerably from those of M and S cells. The polysaccharides are involved in phage adsorption on mycobacterial cells, and the three variants show differences in this respect. The free exopolysaccharides of M, S and R variants are identical with the corresponding capsule exoglycans, and their proportions differ among the variants.

Free Radicals↗
PubMed1996

A flexible model for the cell wall polysaccharide of Streptococcus mitis J22 determined by three-dimensional 13C edited nuclear overhauser effect spectroscopy and 13C-1H long-range coupling constants combined with molecular modeling.

We report on the conformation of a tetrasaccharide fragment in the repeating subunit of the cell wall polysaccharide of Streptococcus mitis J22, a receptor for the lectin of Actinomyces viscosus T14V in a bacterial coaggregation that is important in the ecological interactions of oral bacteria. Although there is considerable overlap of the 1H-nmr signals, some cross peaks can be extracted from conventional two-dimensional nuclear Overhauser effect spectroscopy (NOESY) data on the polysaccharide. These data cannot be fit to a single conformation of the tetrasaccharide fragment. Therefore we have prepared a polysaccharide sample fully enriched in 13C from which we have determined accurate NOESY cross-peak volumes in a three-dimensional heteronuclear-resolved spectrum that allows accurate determination of many more NOESY cross peaks than does conventional two-dimensional spectroscopy. We have also used the 13C enriched polysaccharide to measure accurate values of long-range 13C-1H coupling constants that can be correlated with glycosidic dihedral angles. Molecular modeling calculations on the polysaccharide fragment, including molecular dynamics simulations, identify multiple low-energy conformations. This result is to be contrasted with previous calculations on blood group oligosaccharides in our laboratory using similar methods that showed relatively rigid conformations with little flexibility of the glycosidic linkages. The present NOESY and 3JCH data can be reconciled with a model for the antigenic tetrasaccharide in which three distinct conformations are in fast exchange. We propose that some carbohydrate epitopes such as those of the blood group oligosaccharides are relatively rigid while others such as the tetrasaccharide fragment in these studies exhibit much greater flexibility.

Carbohydrate Conformation↗
PubMed2003

Determination of the compositions of polysaccharides from Chinese herbs by capillary zone electrophoresis with amperometric detection.

In this paper, capillary zone electrophoresis with amperometric detection (CZE-AD) was applied to determine the compositions of hetero-polysaccharides from Chinese herbs, Angelica sinensis and flax by analyzing their hydrolyzed monosaccharides: fucose, galactose, glucose, arabinose, rhamnose and xylose. Under the selected optimum conditions, the six monosaccharides could be perfectly separated within 25 min and showed significant current responses at copper electrodes. The linear ranges of the six monosaccharides were all from 5.0 x 10(-6) to 2.0 x 10(-4) mol L(-1) and their detection limits were lower or near 1.0 x 10(-6) mol L(-1) (S/N = 3). Experiments showed that the Angelica sinensis polysaccharide was composed of fucose, galactose, glucose, arabinose, rhamnose and xylose (mole ratio 1.0:13.6:15.0:8.7:21.3:3.7), and the flax polysaccharide was composed of galactose, glucose and arabinose (mole ratio 1.0:4.98:1.1). The purity of these polysaccharides leached by the introduced leaching method was 98.3 and 97.6%, respectively. Analyzing polysaccharides by this method has some merits of speed, simple instrumentation and operation, high sensitivity and high reproducibility.

Drugs, Chinese Herbal↗
PubMed1998

Electrophoretic behavior and size distribution of the acidic polysaccharides produced by the bacteria Bradyrhizobium (Chamaecytisus) strain BGA-1 and Bradyrhizobium japonicum USDA 110.

The electrophoretic behavior in polyacrylamide gels of the acidic polysaccharides produced by the soil bacteria Bradyrhizobium (Chamaecytisus) strain BGA1 and Bradyrhizobiumjaponicum USDA1 10 has been studied. Both polysaccharides were polydisperse, producing a ladder-like pattern after fixation with Alcian Blue and silver staining of the gel. The polysaccharide molecules were separated according to their size, and they behaved as a collection of flexible random coils of different size and similar charge/mass ratio. The electrophoretic behavior was not affected by the presence of acetyl groups in the polysaccharide. The range of molecular weights of the exopolysaccharide produced by B. japonicum USDA110 was wider and with larger molecules than that of the polysaccharide produced by strain BGA1. The resolution was dependent on the electrophoresis buffer; the best results were achieved with Tris-borate; in Tris-glycine buffer, the resolution was worse, and it was not improved by the addition of sodium dodecyl sulfate (SDS).

Bradyrhizobium↗
PubMed2003

Size-exclusion capillary electrochromatographic separation of polysaccharides using polymeric stationary phases.

We report the successful size-based separations of large, neutral polysaccharides using capillary electrochromatography (CEC). As the polysaccharides possessed little chromophore for photometric detection, two separate approaches were taken. In the first approach, indirect detection was combined with size-exclusion chromatography using a sulfonated polystyrene/divinylbenzene stationary phase. The separations were performed using a 300 A pore size stationary phase under aqueous conditions. Non-size based interactions were minimal using this material, resulting in an effective calibration range of molecular masses 180 to 112 000 g.mol(-1) for pullulans. In the second approach, the polysaccharides were derivatized with phenylisocyanate and were subsequently separated on columns made using a combination of high capacity ion-exchanger and a neutral polystyrene/divinylbenzene material of various pore sizes. The sulfonated ion-exchange phase provided the electroosmotic flow, while the mixed pore size material provided the extended calibration range. The linear range for this primarily nonaqueous system using tetrahydrofuran was determined to be from molecular masses 738 to 404 000 g.mol(-1) of the original, untagged pullulan. This approach overcame the limited solubility issue associated with analysis of some polysaccharides. Analysis of pullulan and amylose samples by CEC correlated well with results obtained by conventional high-performance liquid chromatography (HPLC). The size-exclusion electrochromatographic separations provide an alternative mode for determining the relative molecular weights of polysaccharides with reduced sample and solvent consumption, as well as analysis times.

Amylose↗
PubMed2006

Engineered bio-active polysaccharides from heparin.

[Image: see text] Heparin, the well-known anticoagulant polysaccharide, is also active in many other biological systems owing to its structural similarity to HS, but usually lacks selectivity because it is more highly sulfated. A series of straightforward chemical reactions (de-O-sulfation, de-N-sulfation and re-N-acetylation), carried out to partial or complete extent, were combined, resulting in a number of modified heparin polysaccharide derivatives with altered properties. These exhibited a range of abilities to promote cell signalling through the FGF/FGFR tyrosine kinase signalling system, in an in vitro cell assay with combinations of FGF-1, -2, -3 and FGFR 1 and 3. One polysaccharide (N-acetylated, 6-O- and 2-O-sulfated heparin), with only a fraction (<10(-3)) of the anticoagulant activity of heparin (200 U . mg(-1)), promoted FGF-2-mediated angiogenesis (10-fold) and therefore had an improved ratio of pro-angiogenic activity to anticoagulant activity in excess of 10(4) compared to heparin. These results demonstrate that heparin-derived polysaccharides can be engineered for selected activities and have potential in a wide range of medical, biotechnological and tissue-engineering applications. Effect of selected engineered heparin polysaccharides on angiogenesis.

Anticoagulants↗
PubMed2006

Non-covalent interactions in polysaccharide systems.

[Chemical structure: see text] This paper describes the behavior of some polysaccharides with well-known chemical structures and in which the influence of cooperative secondary interactions play an important role. The roles played by hydrophobic and ionic interactions (including ionic selectivity) on polysaccharide conformation and gelation are discussed. Electrostatic attractions are also important in the complexes formed between surfactants and polyelectrolytes of opposite charge. Finally, van der Waals dipolar interactions and particularly hydrogen-bond formation are examined. The role of hydrogen bonds in solubility, conformation, and especially the local stiffness of polysaccharides, but also in polymer-polymer complexes frequently obtained with polysaccharides, is developed. Repeat unit for a number polysaccharides.

Carbohydrate Conformation↗
PubMed2006

Water, solute, and segmental dynamics in polysaccharide hydrogels.

Polysaccharide hydrogels have found several applications in the food industry, in biomedicine, and cosmetics. The study of polysaccharide hydrogels offers a challenging scenario of intrinsic heterogeneities in the crosslinking density and large time and space ranges that characterize a number of dynamic processes entailing segmental motions, water diffusion, and small-molecule diffusion. The understanding of such complex features is essential because of the extensive use of polysaccharidic moieties in the food industry, biomedical devices, and cosmetics. The study of phenomena occurring at the nanoscale to the mesoscale requires the combination of investigative tools to probe different time and distance scales and the structural characterization of the networks by established methodologies such as swelling and elastic modulus measurements. Elastic and quasielastic neutron scattering, and fluorescence recovery after photobleaching are emerging methodologies in this field. In this feature article we focus, somewhat arbitrarily, on these new approaches because other techniques, such as low-resolution proton NMR relaxometry and rheology, have been already described thoroughly in the literature. Case examples of polysaccharide hydrogels studied by neutron scattering and fluorescence recovery are presented here as contributions to the comprehension of the dynamic behavior of physical and chemical hydrogels based on polysaccharides. Quasielastic incoherent neutron scattering experiment on a Sephadex hydrogel sample at different temperatures.

Elasticity↗
PubMed2004

Antidepressant evaluation of polysaccharides from a Chinese herbal medicine Banxia-houpu decoction.

Banxia-houpu decoction, a traditional Chinese medicine has been used in the treatment of depression. The present study confirmed that oral administration of polysaccharides from Banxia-houpu decoction, exhibited a reduction in the immobility time in the tail suspension and in the forced swimming tests in mice in a time-dependent manner. This effect at a dose of 320 mg/kg was more potent than that at a dose of 640 mg/kg. The polysaccharides from Banxia-houpu decoction were active in animal models of depression with comparable effects to known antidepressants. The oral administration of the polysaccharides at a low dose for 4 weeks resulted in a significant increase in the monoamine neurotransmitter 5-hydroxytryptamine (5-HT) and dopamine (DA) levels in whole mouse brain, but produced no significant increase in 5-hydroxyindoleacetic acid (5-HIAA) and norepinephrine (NE) concentrations. The effect of polysaccharides on the brain neurotransmitter levels appeared to be quite different from the effect of fluoxetine, a serotonin specific reuptake inhibitor. The results indicate that the mode of action of polysaccharides from Banxia-houpu decoction in depression might be related to both 5-HT and DA systems.

Animals↗
PubMed1994

Isolation and characterization of a novel 20-kDa sulfated polysaccharide from the extracellular slime layer of Staphylococcus epidermidis.

Slime-producing coagulase-negative staphylococci have emerged as important pathogens especially in immunocompromised hosts and patients with implanted devices. Although the extracellular slime layer is considered an important virulence factor, the chemical composition of the slime polysaccharide(s) remains unknown. The crude slime product derived from two reference Staphylococcus epidermidis strains (ATCC 35983 and 35984) and two clinical isolates was found to contain protein (11-20.5%), hexosamines (8-19%), neutral sugars (12.2-14%), phosphates (4-9.5%), uronic acids (1-13%), and small amounts of sulfates (0.5-3%). Preparative anion-exchange chromatography separated a main carbohydrate component which was isolated by combined chromatographies on DEAE-Sephacel and Sepharose CL-6B. HPLC and electrophoreses on polyacrylamide gel and cellulose acetate membrane revealed the presence of one species of low-sulfated polysaccharide with a relative molecular mass of 20-kDa. Chemical analyses of the polysaccharide showed that it is rich in glucosamine (46%) and neutral sugars (30-34%) with small amounts of sulfates (5.7-6.5%) and glucuronic acid (2.9-3.4%). Ten percent of the glucosamine is sulfated at the amino group. The neutral monosaccharides present are glucose, fucose, and xylose with glucose as the predominant one. It is estimated that the polysaccharide consists of 61-65 molecules of glucosamine (6-7 of which are N-sulfated), 30-35 neutral monosaccharides, 3-4 molecules of glucuronic acid, and 1-3 of fucose and xylose. Isolation and characterization of such a polysaccharide from the extracellular slime layer of S. epidermidis has not been previously reported. Its role to pathogenicity remains to be elucidated.

Bacterial Proteins↗