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PubMed2006

Evaluating the effect of sulphated polysaccharides on cyclosporine a induced oxidative renal injury.

Cyclosporine A (CsA) has been universally used as an immunosuppressant for the management of organ transplantation and various autoimmune diseases. However, nephrotoxicity due to CsA remains to be an important clinical challenge. In the present investigation, an attempt has been made to appraise the effect of sulphated polysaccharides on oxidative renal injury caused by CsA. Adult male Wistar rats were divided into four groups. Two groups received CsA by oral gavage (25 mg/kg body weight) for 21 days to provoke nephrotoxicity, one of which simultaneously received sulphated polysaccharides subcutaneously, (5 mg/kg body weight). A vehicle (olive oil) treated control group and sulphated polysaccharides drug control were also built-in. An increase in lipid peroxidation along with abnormal levels of enzymic (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase and glucose-6-phosphate dehydrogenase) and non-enzymic antioxidants (glutathione, vitamin C and vitamin E) are the salient features observed in CsA induced nephrotoxicity. CsA induced impairment of renal toxicity was evident from the marked decline in the activities of renal marker enzymes like alkaline phosphatase, acid phosphatase and lactate dehydrogenase, as well as an apparent increase in the serum urea, uric acid and creatinine; diagnostic of renal damage was normalized by sulphated polysaccharides co-administration. Sulphated polysaccharides treatment showed an effectual role in counteracting the free radical toxicity by bringing about a significant decrease in peroxidative levels and increase in antioxidant status. These observations emphasize the antioxidant property of sulphated polysaccharides and its cytoprotective action against CsA induced nephrotoxicity.

Animals↗
PubMed1986

Structure of the extracellular gelling polysaccharide produced by Enterobacter (NCIB 11870) species.

The gelling polysaccharide produced by a species of Enterobacter (NCIB 11870) contains L-fucose, D-glucose, and D-glucuronic acid in the ratios 1:2:1. Analysis of the methylated and methylated, carboxyl-reduced polysaccharide revealed terminal non-reducing glucose, (1----3)-linked fucose, (1----3,1----4)-linked glucose, and (1----4)-linked glucuronic acid in the ratios 1:1:1.2:0.8. From the results of Smith degradation of the polysaccharide and spectroscopic studies of the acidic tetra- and octa-saccharides produced by bacteriophage-induced enzymic depolymerization of the polysaccharide, the following tetrasaccharide repeating-unit is proposed. (Formula: see text). This repeating-unit is identical to that of the capsular polysaccharide produced by Klebsiella aerogenes serotype K54 except for the absence of O-acetyl groups. The effects of the O-acetyl groups on the secondary structure and rheological properties of these polysaccharides are discussed.

Carbohydrate Conformation↗
PubMed1987

Structure of the capsular polysaccharide of Escherichia coli O9:K32(A):H19.

The capsular polysaccharide of the bacterium Escherichia coli O9:K32(A):H19 was analyzed using chemical methods (hydrolysis, sequential Smith degradation, methylation analysis) together with 1H- and 13C-n.m.r. spectroscopy. 13C-N.m.r. spectroscopy and chemical analyses indicated that the K32 polysaccharide is composed of equimolar proportions of glucose, galactose, rhamnose, and glucuronic acid, and carries O-acetyl groups. 1H-N.m.r. analysis of native K32 polysaccharide revealed five resonances in the anomeric region (delta 5.52, 5.16, 5.12, 5.02, and 4.73) and the presence of an acetyl group (delta 2.18). O-Deacetylation of the polysaccharide resulted in the loss of the resonance at delta 2.18 and one of the resonances (delta 5.52) in the anomeric region. The "extra" anomeric resonance in the 1H-n.m.r. spectrum of the native K32 polymer was assigned to H-2 of rhamnose, which experiences a large downfield shift when the 2-position is O-acetylated. This was confirmed by a 2D-COSY n.m.r. experiment and studies of model compounds. The K32 capsular polysaccharide is of the "2 + 2" type, comprised of the following repeating unit: (sequence; see text) This structure is identical to that of Klebsiella K55 capsular polysaccharide.

Carbohydrate Conformation↗
PubMed1992

Evidence that the acidic polysaccharide secreted by Agrobacterium radiobacter (ATCC 53271) has a seventeen glycosyl-residue repeating unit.

The extracellular anionic polysaccharide produced by the bacterium Agrobacterium radiobacter (ATCC 53271) contains D-galactose, D-glucose, and pyruvic acid in the molar ratio 2:15:2. Analysis of the methylated polysaccharide indicated the presence of terminal, non-reducing glucosyl, 3-, 4-, 6-, 2,4-, and 4,6-linked glucosyl residues, 3-linked 4,6-O-[(S)-1-carboxyethylidene]glucosyl residues, and 3-linked galactosyl residues. Partial acid hydrolysis of the methylated polysaccharide, followed by reduction with NaB2H4 and then O-ethylation, gave a mixture of alkylated oligoglycosyl alditols that were separated by reversed-phase h.p.l.c. and analyzed by 1H-n.m.r. spectroscopy, g.l.c.-m.s., and glycosyl-linkage composition analysis. Smith degradation of the polysaccharide gave three diglycosyl alditols that were separated by semi-preparative, high-pH anion-exchange chromatography, and were analyzed by 1H-n.m.r. spectroscopy, g.l.c.-m.s., and glycosyl-linkage composition analysis. The polymer obtained by NaBH4 reduction of the periodate-oxidized polysaccharide was methylated, and the noncyclic acetals were hydrolyzed with aq. 90% formic acid to generate a mixture of partially O-methylated mono- and di-glycosyl alditols. The partially O-methylated oligoglycosyl alditols were O-ethylated. The resulting alkylated oligoglycosyl alditols were separated by reverse-phase h.p.l.c. and then characterized by 1H-n.m.r. spectroscopy, g.l.c.-m.s., and glycosyl-linkage composition analysis. The results from the studies described here provide strong evidence that the acidic polysaccharide secreted by A. radiobacter (ATCC 53271) has a heptadecasaccharide repeating unit.

Carbohydrate Sequence↗
PubMed1996

Structure of a new N-acetylisomuramic acid-containing O-specific polysaccharide of Proteus penneri strains 19 and 35.

O-Specific polysaccharides, together with oligosaccharide products of their degradation, were isolated by GPC after mild acid delipidation of lipopolysaccharides of Proteus penneri strains 19 and 35. The polysaccharides had the same trisaccharide repeating unit containing one residue each of D-galactose, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-3-O-[(S)-1-carboxyethyl]-2-deoxy-D-glucose (N-acetylisomuramic acid). On the basis of 1D and 2D 1H and 13C NMR spectroscopy, including 2D correlation spectroscopy (COSY), rotating-frame NOE spectroscopy (ROESY), and H-detected heteronuclear 1H,13C multiple-quantum coherence (HMQC), the following structure of the repeating unit was established: [formula: see text]. The oligosaccharide products formed by cleavage of the glycosidic linkage of GlcNAc represent a chemical trisaccharide repeating unit of the polysaccharide and its oligomer homologs. The ease of hydrolysis of the polysaccharide is associated with the closeness of the glycosyl group and the lactic acid residue in N-acetylisomuramic acid. The polysaccharides studied are structurally related to the O-specific polysaccharides of P. penneri strains 62 and 71 studied by us earlier.

Carbohydrate Conformation↗
PubMed1994

Divalent cation-dependent interaction of sulfated polysaccharides with phosphatidylcholine and mixed phosphatidylcholine/phosphatidylglycerol liposomes.

The Ca(2+)-dependent interaction of various polyanionic polysaccharides (chondroitin sulfate, heparin, dextran sulfate, beta-cyclodextrin sulfate, hyaluronic acid and carboxymethyldextran) with multilamellar dimyristoyl phosphatidylcholine (DMPC) liposomes was investigated by calorimetric and fluorescence spectroscopic measurements. It was found that an observed polysaccharide-induced phospholipid phase separation depends on the density of the sulfate groups along the polysaccharide chain independent of the presence of additional carboxyl groups. The phase separation resulting from the drastic dehydration of the covered membrane regions is monitored by the upward shift of the lipid phase transition and by the blue shift of the emission spectrum of a headgroup-dansylated phosphatidylethanolamine (DPE). This shift is only observable if the required polysaccharide chain length contains at least three glycosyl units. The Ca(2+)-mediated interaction of dextran sulfate with various phosphatidylcholines, differing in their compressibility, showed the maximal difference between the phase transition temperatures of the lipid phase covered by the polysaccharide and the uneffected lipid domains for dielaidinoyl phosphatidylcholine (DEPC), the most compressible phospholipid investigated here. Mixed negatively charged DMPC/dimyristoyl phosphatidylglycerol (DMPG) liposomes were found to compete with the likewise negatively charged dextran sulfate for the binding of Ca2+. At excess Ca2+ concentrations, the binding of the polysaccharide was strengthened, compared to pure DMPC liposomes. The monovalent cation sodium, was able to inhibit the interaction between the membrane surface and dextran sulfate. Various divalent cations were found to mediate the interaction, depending on their ionic radii and electron configuration. Within the second group of the periodic system Ca2+ is the most effective ion. However, within the horizontal forth period the ability to bind sulfated dextran to membrane surfaces decreases from Ca2+ to Ni2+, but then increases again if Cu2+ or Zn2+ was used as the mediating ion.

Calorimetry, Differential Scanning↗
PubMed1996

Enantiomer separation of basic drugs by capillary electrophoresis using ionic and neutral polysaccharides as chiral selectors.

The enantiomer separation of basic drugs by capillary electrophoresis was investigated employing two types of polysaccharides as chiral selectors. One type consists of electrically neutral polysaccharides such as dextran and dextrin, in which the separation mode is capillary zone electrophoresis (CZE), and ionic drugs are suitable for this mode. The other consists of ionic polysaccharides such as chondroitin sulfate C. Chondroitin sulfates are known as mucopolysaccharides and natural components, being charged, linear, sulfated polysaccharides of high mass. Therefore, the latter approach can be classified as affinity electrokinetic chromatography (AEKC). Both ionic and neutral drugs can be separated by AEKC owing to its separation principle. The separation of enantiomers of some basic drugs such as diltiazem and trimetoquinol was investigated with both CZE and AEKC employing polysaccharides as mentioned above and the enantioselectivity was compared. A brief mechanism of enantiorecognition by polysaccharides is also described.

Chondroitin Sulfates↗
PubMed1988

A simple and sensitive enzyme immunoassay for determination of soluble type-specific polysaccharide from group B streptococci.

A method was developed for the determination of soluble group B streptococcal type-specific polysaccharide in diluted culture supernatant. The type-specific antigen was immobilized to the solid phase of an enzyme immunoassay using wheat germ agglutinin as a link between the plastic surface and the polysaccharide. The binding of monovalent rabbit antiserum to the type-specific polysaccharide was quantitated by an anti-rabbit IgG-enzyme conjugate. Antisera against each of the polysaccharide types Ia, Ib. II and III gave strong and specific reactions against the respective antigen. The ultimate sensitivity of the assay was 70 pg/ml, as determined for type III polysaccharide. Using this technique, it was found that the concentration of soluble type-specific antigen in a GBS, type III culture supernatant reached a steady-state approximately 3 h after the beginning of the stationary growth phase of the bacteria. Ten type III strains were investigated for synthesis of type-specific polysaccharide, and a positive correlation between the production of capsular and soluble type III antigen was found. There was also an inverse correlation between soluble antigen production and the buoyant densities of these strains. The method described may be used for the serotyping of encapsulated GBS and/or determination of soluble type-specific antigen synthesis.

Animals↗
PubMed1992

Monoclonal antibody based ELISAs for cryptococcal polysaccharide.

Mouse monoclonal antibody (MAb)-based enzyme-linked immunosorbent assays (ELISAs) have been developed to detect Cryptococcus neoformans capsular polysaccharide from the four serotypes A, B, C and D. The ELISAs avoid the problem of unreliable polysaccharide binding to polystyrene plates by using MAbs to capture and immobilize the polysaccharide antigen. The presence of polysaccharide is detected using MAbs of a different isotype from that of the capture MAb. The capturing MAbs are themselves immobilized on the plates using commercial goat anti-mouse polyclonal sera. The MAbs bind to the glucuronoxylomannan component of cryptococcal polysaccharide. The ELISAs can be used to measure the concentration of polysaccharide in biological fluids and are potentially useful tools for basic research and clinical studies.

Animals↗
PubMed1993

Influence of growth status on composition of extra-cellular polysaccharides from two Chlamydomonas species.

The extracellular polysaccharides released by Chlamydomonas augustae at the beginning of growth contain mainly arabinose, glucose and galactose. Methylation analysis revealed that the major fraction of these extracellular polysaccharides can be described as a highly branched polymer composed of (1, 3, 4)-linked glucose and terminal arabinose and galactose units. The chemical composition of these extracellular polysaccharides varies during growth and in the stationary phase of growth glucose and glucuronic acid are the main components. The major fraction of the extracellular polysaccharides can be then described as a linear polymer composed of (1, 4)-linked glucose and (1, 4)-linked glucuronic acid. In sharp contrast, the extracellular polysaccharides from C. corrosa are independent of growth status and contain arabinose and galactose as major sugars. Methylation analysis indicated a highly branched polysaccharide composed of arabinose as unique branch point units and of terminal galactose residues.

Amino Acids↗
PubMed1993

Anti-complementary acidic polysaccharides from roots of Lithospermum euchromum.

Extremely potent complement activating (anti-complementary) polysaccharides from roots of Lithospermum euchromum were fractionated in a novel way and also assayed for mitogenic and enhancing activity of immune complex binding to macrophages in vitro. Anti-complementary activity and enhancing activity of immune complex binding were observed in the different polysaccharide fractions, but no mitogenic activity was found. The acidic polysaccharide fraction (LR-2) which had the most potent anti-complementary activity was highly heterogeneous, and on further fractionation gave active polysaccharides. Extremely potent anti-complementary polysaccharides, LR-2IId-1a, LR-2IId-1b, LR-2IId-3a and LR-2IId-5a were characterized chemically. These consisted mainly of mannose, galactose, glucose and glucuronic acid, in addition to rhamnose, fucose and arabinose as minor components. Methylation analysis showed that the four polysaccharides contained mainly (1-->3)-linked galactose, (1-->3)-linked fucose and (1-->4)-linked glucose. (1-->3)-Linked mannose was also detected in LR-2IId-1a, 1b and 5a, and (1-->4)-linked glucuronic acid in LR-2IId-1a and 1b as the major glycosidic linkages.

Carbohydrates↗
PubMed1990

Response to a Haemophilus influenzae type b diphtheria CRM197 conjugate vaccine in children with a defect of antibody production to Haemophilus influenzae type b polysaccharide.

A defect in antibody response to immunization with Haemophilus influenzae type b (Hib) capsular polysaccharide vaccine has been reported in children with recurrent infections and normal immunoglobin levels. We identified 15 children, aged 2 to 6 years, with this defect, and we evaluated their response to immunization with an Hib capsular oligosaccharide diphtheria CRM197 protein-conjugate vaccine (HbOC). The children received a series of three vaccines: HbOC at 0 and 8 weeks, and the Hib polysaccharide vaccine at 16 weeks. Levels of antibody to the Hib capsular polysaccharide (polyribosyl ribitol phosphate, PRP) and to diphtheria toxoid were obtained before and 4 weeks after each vaccination. The geometric mean serum anti-PRP concentration was 0.17 microgram/ml before immunization and 29.3 micrograms/ml after the second HbOC immunization (week 12). All 15 children had postvaccination anti-PRP antibody levels greater than 1.0 microgram/ml after receiving the second HbOC (week 12). In addition, booster responses were observed after the second Hib conjugate in 13 of the patients and after the Hib polysaccharide in four of the patients. All patients with low preimmunization diphtheria titers had a response to the diphtheria toxoid. These results suggest that conjugation of Hib polysaccharide with diphtheria CRM197 overcomes the defective antibody response to Hib oligosaccharide in children who are initially observed with recurrent infections and inability to respond to the Hib polysaccharide vaccine.

Antibodies, Bacterial↗
PubMed1995

In vitro antiviral activities of sulfated polysaccharides from a marine microalga (Cochlodinium polykrikoides) against human immunodeficiency virus and other enveloped viruses.

A marine microalga, Cochlodinium polykrikoides, produces extracellular sulfated polysaccharides. Isolation and purification of the polysaccharides were accomplished by precipitation with ethanol and Cetavlon, followed by DEAE-cellulose column chromatography (polysaccharides A1 and A2). These polysaccharides, which were homogeneous when analysed by both ultracentrifugal and electrophoretic methods, were composed of mannose, galactose, glucose and uronic acid, together with sulfate groups (S = 7-8% w/w). Both A1 and A2 inhibited the cytopathic effect of influenza virus types A and B in MDCK cells, that of respiratory syncytial virus types A and B in HEp-2 cells, that of human immunodeficiency virus type 1 in MT-4 cells; and, except A1 for herpes simplex virus type 1 and A2 for parainfluenza virus type 2 in HMV-2 cells, the cochlodinium polysaccharides showed no antiviral activity against parainfluenza virus types 2 and 3, measles virus, mumps virus or herpes simplex virus type 1 in HMV-2 cells. No cytotoxicity for host cells was observed with these polysaccharides at a concentration of 100 micrograms ml-1. Inhibitory effects on various viruses were achieved at concentrations that were not markedly inhibitory to the blood coagulation process.

Animals↗
PubMed1986

Characterization of the serotype e polysaccharide antigen of Streptococcus mutans.

The structure of the Streptococcus mutans serotype e polysaccharide was studied in order to determine the chemical basis of the immunological cross-reactions observed between it and the streptococcal group E polysaccharide. The chemical structure was established using methylation analysis, periodate oxidation, partial methanolysis and 13C NMR spectroscopy. The polysaccharide was found to consist of a polyrhamnose backbone of alternating 2- and 3-linked alpha-L-rhamnose units and sidechain beta-D-glucosyl units linked to the 2-position of rhamnose units in the backbone. This structure of the oligosaccharide repeating unit of the S. mutans serotype e polysaccharide was identical to that of the group-specific polysaccharide of group E Streptococcus. Possible explanations for the previously reported differences in these two polysaccharides are discussed.

Chemical Phenomena↗
PubMed1991

Oral immunization with bacterial polysaccharide and adjuvant enhances antigen-specific pulmonary secretory antibody response and resistance to pneumonia.

Nosocomial pneumonia, often due to Pseudomonas aeruginosa, occurs frequently after haemorrhage and trauma, and contributes to the increased incidence of morbidity and mortality in this clinical setting. In order to determine if enhancement of bacterial antigen-specific secretory IgA (sIgA) titres in the lungs can increase resistance to P. aeruginosa pneumonia following haemorrhage, we investigated oral immunization strategies, using bacterial polysaccharides (levan, from Aerobacter levanicum, and P. aeruginosa polysaccharide type I) and adjuvant (cholera toxin and the B-subunit of cholera toxin), capable of increasing bacterial polysaccharide-specific pulmonary secretory antibody titres. Oral co-administration of 1000 micrograms levan and 10 micrograms cholera toxin resulted in increased titres of levan-specific sIgA in lung lavages and increased numbers of levan-specific pulmonary plasma cells, but no changes in serum anti-levan titres. Similarly, oral co-administration of 1000 micrograms P. aeruginosa polysaccharide and 10 micrograms cholera toxin produced increased anti-P. aeruginosa polysaccharide titres in lung lavages. Significant decreases in anti-levan pulmonary sIgA titres and in numbers of levan-specific pulmonary plasma cells were found when oral immunization with levan and cholera toxin was performed 4 days following haemorrhage, but not if the mice were immunized 8 h after blood loss. Although haemorrhage markedly increased the susceptibility of mice to P. aeruginosa pneumonia, significant protection from mortality could be achieved through oral immunization with 1000 micrograms P. aeruginosa polysaccharide and 10 micrograms cholera toxin 8 h after haemorrhage. These results demonstrate that haemorrhage induces marked alterations in bacterial antigen-specific pulmonary B-cell responses, which contribute to the increased susceptibility to infection in this setting.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1987

Isolation of a novel O-linked, sulfated polysaccharide of high molecular weight from an ovarian cyst glycoprotein having blood group "A" activity.

Treatment of a blood group A-active ovarian cyst mucin glycoprotein with alkaline borohydride under conditions expected to cleave O-glycosidic linkages between carbohydrate and peptide releases a sulfated polysaccharide of average molecular weight 20,000. Its peptide and mannose content is less than 1%, and carbohydrate analysis gives Fuc/GalNAc/Gal/GlcNAc in the ratio of 1:1:2.2:2.2. Galactosaminitol is recovered at the level of one residue per 112-residue average polysaccharide chain. The 13C- and 1H-NMR spectra show that the polysaccharide has side chains whose non-reducing terminals have the blood group A structure on a type 1 chain: (Formula: see text). Methylation analysis confirms the presence of these blood group A type 1 sidechains as well as 4-substituted GlcNAc, 3-substituted galactose and 3,6-substituted galactose branch points. Periodate oxidation removes all the fucose and GalNAc from the non-reducing terminal but leaves intact the backbone composed of beta-linked Gal and GlcNAc, as would be expected for a polylactosamine. Although the native polysaccharide is resistant to endo-beta-galactosidase digestion, the product of periodate degradation is partially digested, giving a 30% yield of a trisaccharide shown by 1H-NMR spectroscopy to be: Gal(beta 1----3)GlcNAc(beta 1----3)Gal We conclude that this is a high molecular weight sulfated polysaccharide which is related to the asparagine-linked polylactosamine chains of cell surface glycoproteins which have been implicated in cell differentiation. However, the blood group A polysaccharide from the ovarian cyst mucin is unique in several respects. It is linked to the protein by an O-glycosidic bond rather than the N-asparagine linkage of the previously known polylactosamines which have a trimannosyl core, and its blood group A side chains are on a type 1 core rather than type 2 which is found on other polylactosamines.

ABO Blood-Group System↗
PubMed1989

Modulation of bovine neutrophil antibacterial activities by Pasteurella haemolytica A1 purified capsular polysaccharide.

Preincubation of bovine neutrophils with Pasteurella haemolytica A1 purified capsular polysaccharide markedly diminished their ability to ingest and kill P. haemolytica, but not Escherichia coli, in vitro. Ingestion and killing were impaired even when the P. haemolytica were preopsonized, thus suggesting that the inhibitory effects of the polysaccharide included a direct effect on bovine neutrophils rather than simply competition for serum opsonins. Preincubation of neutrophils with purified polysaccharide did not elicit a chemiluminescence response, nor did it alter the chemiluminescence response of neutrophils to subsequent stimulation with opsonized P. haemolytica or opsonized zymosan. In addition, purified polysaccharide alone was neither chemotactic nor did it induce a shape change in bovine neutrophils. These data suggest that the deposition of capsular polysaccharide in the lung during the onset of pulmonary pasteurellosis might impair the ability of neutrophils to ingest and kill P. haemolytica. The capsular polysaccharide of P. haemolytica, therefore, may contribute in part to the fibrinous pleuropneumonia that characterizes acute pasteurellosis.

Animals↗
PubMed1994

Conformation, order-disorder conformational transitions and gelation of non-crystalline polysaccharides studied using electron microscopy.

Direct imaging of polysaccharides using transmission electron microscopy (EM) is an important alternative to physical characterization of non-crystalline polysaccharides in solution. The polymer nature of stiff-chain polysaccharides is quite apparent from direct visualization of the electron micrographs, despite the fact that commonly employed preparation techniques reduce the resolution limit to about 1-2 nm. Electron microscopy has recently been used to study polysaccharides with emphasis both on quantitative properties like contour length, end-to-end distance and chain stiffness, and on qualitative structural features such as cyclization at the macromolecular level. The structural richness observed for polysaccharides of the beta-D0glucan family after a denaturation-renaturation treatment of the specimen, in particular, illustrates the unique potential of EM as a tool for obtaining conformational information about carbohydrate macromolecules. Examples of the latter also include the recent discoveries of cyclic beta-D-glucan and l-carrageenan structures. The EM technique provides information that is not only complementary to what can be obtained using other physical techniques, but also offers important insight otherwise masked by the averaging implicit in most physical techniques used to study aqueous polysaccharide solutions.

Gels↗