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PubMed1975

Polysaccharides of metaplastic mucosa and carcinoma of the gallbladder.

The polysaccharide composition of the human gallbladder well was studied in carcinomas and metaplastic changes of various degrees, and the results obtained were compared with those for the normal material previously presented (Terho, T., and Laitio, M. Biochim. Biophys. Acta 338: 135, 1974). Elevated amounts of acid connective tissue polysaccharides (heparitin and dermatan sulfates as well as chondroitin 4- or 6-sulfate, or both, could be observed in carinomas. In histochemical stainings it was found that in carcinomas and in the two specimens classified as group III (containing the most extensive metaplastic changes at disposal), the intracellular mucin was mainly neutral or nonsulfated acidic. The amounts of sulfated mucin were relatively insignificant. This mucin polysaccharide material was isolated and its composition was determined. It was observed to be large polysaccharide material was isolated and its composition was determined. It was observed to be large molecular (approximate molecular sizes 1 to 2 times 10-6), and to be composed of fucose, galactose, glucosamine, and galactosamine as well as small amounts of sialic acid. The basic structure of these polysaccharides is thus similar to that of normal sulfated mucin. The almost total absence of acid groups, however, causes the polysaccharide material in question to stain in a manner identical with neutral mucin when investigated with histochemical methods. The carcinomas also contained some sulfomucin; its proportion, however, was small as compared with the amounts of nonsulfated acid and neutral mucin in biochemical characterization. A small molecular polysaccharide fraction, assumed to originate in membrane-bound glycoproteins, was isolated from the insoluble gallbladder tissue residue. The proportion of this fraction was larger in carcinomas than in normal material. This rise as well as the rise in the quantity of acid connective tissue polysaccharides is presumably due to the large number of cells in the carcinoma tissue as well as to fibrosis.

Adenocarcinoma↗
PubMed1980

[Cross reactions between polysaccharides of group A, L, and A-variant streptococci].

In group A and A-variant streptococcal antisera the presence of antibodies reacting with group L streptococcal polysaccharide (L polysaccharide) was revealed. Group A and A-variant streptococcal polysccharides (A and V polysaccharides) were shown to be partially identical to L polysccharide by means of the precipitation test in agar gel. Experiments in inhibiting the reactions of the above mentioned antisera with A, V and L polysaccharide preparations suggest the presence of a determinant common to all these polysccharides and differing from the "ramnose" determinant of the polysaccharides and from the determinant characteristic of A polysaccharide. In the identification of group A streptococci by the immunological methods, as well as in the study of cross reactions with the tissues of mammals, the possible presence of antibodies against various antigenic determinants of A polysaccharide, one of which is also common to L polysaccharide, should be taken into consideration.

Animals↗
PubMed1993

Anti-capsular polysaccharide antibody deficiency states.

Antibodies directed to capsular polysaccharides form an essential component in the defence against infections with encapsulated bacteria such as Streptococcus pneumoniae and Haemophilus influenzae type b. Immune responses to polysaccharide antigens can occur in the absence of a functional thymus and the antigens are therefore designated as thymus independent. However, regulatory T cells may influence the magnitude of the antibody response to capsular polysaccharide antigens. So-called thymus independent type 2 antigens share several features of their immune response such as late development of antibody synthesis in ontogeny, no memory formation and a restricted isotype (IgM, IgG2) and idiotype usage. In infants and young children up to the age of 2 years the antibody response to capsular polysaccharides is inadequate resulting in an increased incidence of diseases such as pneumonia, meningitis, otitis and other forms of bacteremic disease. Anti-capsular polysaccharide antibody deficiency does occur in a number of well defined immunodeficiency syndromes including hypo- or agammaglobulinaemia, selective IgA and/or IgG subclass deficiency, Wiskott-Aldrich syndrome, DiGeorge anomaly and also in acquired immune deficiencies such as AIDS, and some forms of lymphoid malignancies. In elderly and in conditions such as splenectomy an increased incidence of infections with encapsulated bacteria does occur, sometimes but not always on basis of a defect in antibody formation. Clinicians are often confronted with young patients older than 2 years of age suffering from recurrent severe bacterial infections of the respiratory tract. In these patients no overt immunodeficiency is demonstrable but recent results indicated that a small percentage may show a selective defect in the antibody response since upon vaccination with polysaccharide vaccines no increase in antibody titer does occur. Though antibodies to polysaccharide antigens in young children are mainly of the IgM and IgG1 (IgG3) isotype, in older children and adults the polysaccharide antibodies are predominantly localized in the IgG2 subclass. The bridge between IgG2 type antibodies and phagocytosis of encapsulated bacteria is constituted by Fc gamma receptors for IgG2 on effector cells. The recent finding that allotypes of Fc gamma RIIa do exist that either bind or do not bind IgG2 type antibodies strongly suggests that the defence of a given individual to encapsulated bacteria apart from an intact antibody formation and the complement system also is determined by the allotype of the appropriate Fc gamma receptor.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed2003

Polysaccharide lyases: recent developments as biotechnological tools.

Polysaccharide lyases, which are polysaccharide cleavage enzymes, act mainly on anionic polysaccharides. Produced by prokaryote and eukaryote organisms, these enzymes degrade (1,4) glycosidic bond by a beta elimination mechanism and have unsaturated oligosaccharides as major products. New polysaccharides are cleaved only by their specific polysaccharide lyases. From anionic polysaccharides controlled degradations, various biotechnological applications were investigated. This review catalogues the degradation of bacterial, plant and animal polysaccharides (neutral and anionic) by this family of carbohydrate acting enzymes.

Animals↗
PubMed1956

Cross-reactions of antityphoid and antiparatyphoid B horse sera with various polysaccharides.

A study was made of cross-reactions of synthetic polyglucose and of numerous plant and bacterial gums in an antityphoid and an antiparatyphoid B horse serum. The observed differences permit conclusions to be drawn regarding certain of the linkages likely to be found in the fine structures of each of the corresponding Salmonella polysaccharides:- 1. Cross-reactions of the antityphoid serum with the specific polysaccharide of Type II pneumococcus and with tamarind seed polysaccharide, glycogen and synthetic polyglucose indicate that the acetic acid-degraded O-polysaccharide of S. typhi, strain O 901, may contain part, at least, of its glucose as 1,4,6-branch points or in 1,6-linkage, perhaps adjacent to a terminal, non-reducing, galactopyranose unit. 2. Cross-reactions of both antisera with arabogalactans point to the existence of (probably beta-) 1,3-, 1,6-, and/or 1,3,6-linkages of galactose in both the typhoid and paratyphoid B polysaccharides. 3. The differential reactivities of the galactomannans and yeast mannan suggest that the mannose in the typhoid polysaccharide is linked 1,2- or 1,3- with possible non-reducing mannopyranose end groups attached 1,6-. In the paratyphoid B polysaccharide the linkages are probably galacto-oligomannose 1,4-, or 1,4,6-, or the corresponding linkages of mannose alone.

Cross Reactions↗
PubMed1964

EXTRACELLULAR POLYSACCHARIDES OF AZOTOBACTER VINELANDII.

Cohen, Gary H. (University of Vermont, Burlington), and Donald B. Johnstone. Extracellular polysaccharides of Azotobacter vinelandii. J. Bacteriol. 88:329-338. 1964.-Extracellular polysaccharides synthetized by Azotobacter vinelandii strains 155, 102, and 3A were shown to be carboxylic acid heteropolysaccharides of apparent high molecular weight. Cells were grown in a nitrogen-free, mineral broth medium with 2% sucrose. Extracellular slime was recovered by centrifugation and purified by repeated alcohol precipitation and Sevag deproteinization. Capsular polysaccharide was recovered from washed cells by mild alkaline digestion. Methods of isolation and purification appeared to provide polysaccharide showing no evidence of heterogeneity when examined by chemical and physical methods. Infrared analysis of purified slime from the three strains suggested fundamental structural similarities. Colorimetric, paper chromatographic, and enzymatic analyses on both intact and acid-hydrolyzed slime polysaccharide indicated that the polymers contained in common galacturonic acid, [alpha] d-glucose, and rhamnose at a ratio of approximately 43:2:1, as well as a hexuronic acid lactone, probably mannurono-lactone. However, as shown by chemical and infrared analysis, minor differences did exist; namely, slime from strain 155 and 102 contained o-acetyl groups, whereas slime from strain 3A contained none. A sialic acid-like component (1.5% of dry weight of the polysaccharide, calculated as N-acetyl neuraminic acid), was found only in the slime of strain 155. Capsular polysaccharide composition closely resembled that for slime. It is of interest that the major slime components were identical whether the energy source provided for the cells was sucrose, glucose, fructose, or ethanol.

Azotobacter↗
PubMed1964

FACTORS INFLUENCING GROWTH AND POLYSACCHARIDE FORMATION BY STRAINS OF CHROMOBACTERIUM VIOLACEUM.

Corpe, William A. (Columbia University, New York, N.Y.). Factors influencing growth and polysaccharide formation by strains of Chromobacterium violaceum. J. Bacteriol. 88:1433-1441. 1964.-Gelatinous Chromobacterium violaceum strains elaborate a fibrous exopolysaccharide that forms a matrix in which growing cells are embedded. Stable, nongelatinous variants arising from gelatinous cultures were of two types: (i) those that had lost the ability to produce polysaccharide, and (ii) those that had lost the capacity to bind the polymer into a matrix. Gelatinous strains growing in Tryptone did not produce a matrix, but rather elaborated polysaccharide free into the medium. The effect of Tryptone was not one of selection of nongelatinous variants. Growth and polysaccharide synthesis in a defined medium were greatest when amino acids were substituted for ammonia as a nitrogen source. Best growth and polysaccharide yield occurred when the ratio of carbohydrate to nitrogen was in the order of 10:1. Depolymerization of formed polymer occurred in cultures grown with Casamino Acids as the nitrogen source. Calcium ion stimulated polysaccharide formation. Iron, although stimulating growth, inhibited polysaccharide formation.

Amino Acids↗
PubMed2003

Adjuvant therapy with protein-bound polysaccharide K and tegafur uracil in patients with stage II or III colorectal cancer: randomized, controlled trial.

PURPOSE: Intravenous fluorouracil and leucovorin for six to eight months is currently a standard adjuvant treatment for Stage III colon cancer; however, this regimen is complex, inconvenient, and has a high intolerability. Adjuvant chemotherapies are claimed for objective response rates with an acceptable safety profile and complexity. We investigated the benefits of oral protein-bound polysaccharide K added to oral tegafur/uracil on curatively resected Stage II or III colorectal cancer. METHODS: We prospectively randomized 207 patients to treatments of either oral 3.0 g protein-bound polysaccharide K plus 300 mg tegafur/uracil or 300 mg tegafur/uracil alone for two years following 12 mg/m2 and 8 mg/m2 mitomycin treatment on postoperative Days 1 and 2, respectively. The primary end points were disease-free and overall survival, and recurrence rates. RESULTS: Three (1.4 percent) patients were declared ineligible, and three patients did not start treatment. In total, 201 patients were analyzed. The three-year, disease-free survival rate was 80.6 percent (standard error = 3.4 percent) in the protein-bound polysaccharide K group (P = 0.02) compared with 68.7 percent (SE = 5.7 percent) in the control group after a median follow-up of 3.7 years. The estimated relative risk of recurrence in the control group was 1.87 (95 percent confidence interval, 1.10-3.20) at three years. The three-year, overall survival rate was 87.3 percent (standard error = 2.9 percent) in the protein-bound polysaccharide K group and 80.6 percent (standard error = 4.8 percent) in the control group (P = 0.24). The three-year, overall survival rate in 80 pathological TNM Stage III patients was 83.0 percent (standard error = 5.2 percent) in the protein-bound polysaccharide K group and 59.3 percent (standard error = 9.5 percent) in the control group (P = 0.02). Protein-bound polysaccharide K prevented distant metastases (P = 0.05), particularly lung metastases (P = 0.01). The incidence of adverse effects was minimal, and compliance was good. CONCLUSION: Adjuvant therapy using a combination of oral protein-bound polysaccharide K and tegafur/uracil is highly effective in preventing the recurrence of colorectal cancer in Stage II or III patients, and increases overall survival in pathological TNM Stage III. These results will be a sufficient proof to conduct a larger study to compare tegafur/uracil/protein-bound polysaccharide K with 5-fluorouracil/leucovorin.

Adult↗
PubMed1986

Microbial polysaccharides with actual potential industrial applications.

The microbial polysaccharides reviewed include xanthan gum, scleroglucan, PS-10, PS-21 and PS-53 gums, polysaccharides from Alcaligenes sp., PS-7 gum, gellan gum, curdlan, bacterial alginate, dextran, pullulan, Baker's Yeast Glycan, 6-deoxy-hexose-containing polysaccharides and bacterial cellulose. Factors limiting the commercial potential of certain microbial polysaccharides such as availability, rheological properties, and polyvalency are outlined. The polysaccharides are classified according to their uses as viscosity-increasing agents and as gelling agents. A third category includes polysaccharides with specific applications such as tailor-made dextran and pullulan and polysaccharides used as substrates for the preparation of rare sugars. The difficulties encountered in development of a polysaccharide at the industrial level are pointed out.

Journal Article↗
PubMed2004

Structure of the neutral O-polysaccharide and biological activities of the lipopolysaccharide of Proteus mirabilis O20.

Mild acid degradation of the lipopolysaccharide (LPS) of Proteus mirabilis O20 resulted in depolymerisation of the O-polysaccharide to give a repeating-unit pentasaccharide. A polysaccharide was obtained by O-deacylation of the LPS followed by nitrous acid deamination. The derived pentasaccharide and polysaccharide were studied by NMR spectroscopy, including 2D 1H,1H COSY, TOCSY, ROESY, 1H,13C HMQC and HMQC-TOSCY experiments, along with chemical methods, and the following structure of the repeating unit of the O-polysaccharide was established: [Carbohydrate structure: see text]. As opposite to most other P. mirabilis O-polysaccharides studied, that of P. mirabilis O20 is neutral. A week serological cross-reactivity was observed between anti-P. mirabilis O20 serum and LPS of a number of Proteus serogroups with known O-polysaccharide structure. The ability of LPS of P. mirabilis O20 to activate the serine protease cascade was tested in Limulus amoebocyte lysate and in human blood plasma and compared with that of P. mirabilis O14a,14c having an acidic O-polysaccharide. The LPS of P. mirabilis O20 was found to be less active in both assays than the LPS of P. mirabilis O14a,14c and, therefore, the structurally variable O-polysaccharide may influenced the biological activity of the conserved lipid A moiety of the LPS.

Animals↗
PubMed1977

The covalent linkage of protein to carbohydrate in the extracellular protein-polysaccharide from the red alga Porphyridium cruentum.

The extracellular anionic polysaccharide isolated from cultures of a unicellular red alga, Porphyridium cruentum, contains a small amount of protein after extensive purification. The polysaccharide and protein are recovered in the same fraction after isopycnic CsCl-density-gradient centrifugation in 4M-guanidinium chloride, under conditions designed to separate proteins from polysaccharide. The peptide portion of the protein-polysaccharide is released from the polysaccharide by alkali under conditions for beta-elimination. The released peptide is non-diffusible, but in can be separated from the polysaccharide by precipitation of the polysaccharide as the cetylpyridinium complex. Under conditions for beta-elimination of certain O-glycosidic carbohydrate-protein linkages, selective destruction of serine and threonine occurs. The addition of a reducing agent to the alkali mixture produces a selective increase in alanine and alpha-aminobutyric acid. Addition of a tritiated reducing agent to the alkali mixture produces radioactive alanine and alpha-aminobutyric acid, and xylitol as the only sugar alcohol. Similar results are obtained from glycopeptides isolated from partial acid hydrolysates. A macromolecular structure of the protein-polysaccharide is suggested by a comparison of the intrinsic viscosity of material before and after treatment with alkali and proteolytic enzymes.

Amino Acids↗
PubMed2000

Characterization of the linkage between the type III capsular polysaccharide and the bacterial cell wall of group B Streptococcus.

The capsular polysaccharide of group B Streptococcus is a key virulence factor and an important target for protective immune responses. Until now, the nature of the attachment between the capsular polysaccharide and the bacterial cell has been poorly defined. We isolated insoluble cell wall fragments from lysates of type III group B Streptococcus and showed that the complexes contained both capsular polysaccharide and group B carbohydrate covalently bound to peptidoglycan. Treatment with the endo-N-acetylmuramidase mutanolysin released soluble complexes of capsular polysaccharide linked to group B carbohydrate by peptidoglycan fragments. Capsular polysaccharide could be enzymatically cleaved from group B carbohydrate by treatment of the soluble complexes with beta-N-acetylglucosaminidase, which catalyzes hydrolysis of the beta-D-GlcNAc(1-->4)beta-D-MurNAc subunit produced by mutanolysin digestion of peptidoglycan. Evidence from gas chromatography/mass spectrometry and (31)P NMR analysis of the separated polysaccharides supports a model of the group B Streptococcus cell surface in which the group B carbohydrate and the capsular polysaccharide are independently linked to the glycan backbone of cell wall peptidoglycan; group B carbohydrate is linked to N-acetylmuramic acid, and capsular polysaccharide is linked via a phosphodiester bond and an oligosaccharide linker to N-acetylglucosamine.

Acetylglucosaminidase↗
PubMed2002

Recognition of bacterial capsular polysaccharides and lipopolysaccharides by the macrophage mannose receptor.

The in vitro binding of the macrophage mannose receptor to a range of different bacterial polysaccharides was investigated. The receptor was shown to bind to purified capsular polysaccharides from Streptococcus pneumoniae and to the lipopolysaccharides, but not capsular polysaccharides, from Klebsiella pneumoniae. Binding was Ca(2+)-dependent and inhibitable with d-mannose. A fusion protein of the mannose receptor containing carbohydrate recognition domains 4-7 and a full-length soluble form of the mannose receptor containing all domains external to the transmembrane region both displayed very similar binding specificities toward bacterial polysaccharides, suggesting that domains 4-7 are sufficient for recognition of these structures. Surprisingly, no direct correlation could be made between polysaccharide structure and binding to the mannose receptor, suggesting that polysaccharide conformation may play an important role in recognition. The full-length soluble form of the mannose receptor was able to bind simultaneously both polysaccharide via the carbohydrate recognition domains and sulfated oligosaccharide via the cysteine-rich domain. The possible involvement of the mannose receptor, either cell surface or soluble, in the innate and adaptive immune responses to bacterial polysaccharides is discussed.

Animals↗
PubMed1986

Structure of Plant Cell Walls : XVIII. An Analysis of the Extracellular Polysaccharides of Suspension-Cultured Sycamore Cells.

The water-soluble polysaccharides (SEPS) secreted into the medium by suspension-cultured sycamore cells were examined to determine whether the polysaccharides were the same as those present in the walls of sycamore cells. The SEPS were made more amenable to fractionation by treatment with a highly purified alpha-1,4-endopolygalacturonase (EPG). The EPG-treated SEPS were fractionated by anion-exchange and gelpermeation chromatography. The following polysaccharides were found: xyloglucan, arabinoxylan, at least two arabinogalactans, a rhamnogalacturonan-II-like polysaccharide, and a polygalacturonic acid-rich polysaccharide. The oligogalacturonide fragments expected from EPG-digested homogalacturonan were also identified. Evidence was obtained for the presence of a rhamnogalacturonan-I-like polysaccharide. All of the above polysaccharides have been isolated from or are believed to be present in sycamore cell walls. Furthermore, all of the noncellulosic polysaccharides known to be present in sycamore cell-walls appear to be present in the SEPS.

Journal Article↗
PubMed1991

Gum arabic glycoprotein is a twisted hairy rope : a new model based on o-galactosylhydroxyproline as the polysaccharide attachment site.

Separation of the wound exudate from Acacia senegal (L.) Willd., "gum arabic," on a preparative Superose-6 column gave two major fractions: a high molecular weight gum arabic glycoprotein (GAGP) containing about 90% carbohydrate and a lower molecular weight heterogenous gum arabic polysaccharide fraction. Hydrogen fluoride-deglycosylation of GAGP gave a large ( approximately 400 residue) hydroxyproline-rich polypeptide backbone (dGAGP). Alkaline hydrolysis of GAGP showed that most of the carbohydrate was attached to the polypeptide backbone as small ( approximately 30 residue) hydroxyproline (Hyp)-polysaccharide substituents. After partial acid hydrolysis of the Hyp-polysaccharide fraction we identified O-galactosylhydroxyproline as the glycopeptide linkage, identical with that of hydroxyproline-rich arabinogalactan-proteins (AGPs). However, unlike the acidic alanine-rich AGPs, GAGP is basic and notably deficient in alanine. Thus, while the GAGP polypeptide backbone more closely resembles that of the Hyp-rich cell wall protein extensin, the GAGP polysaccharide sidechains resemble AGPs. Possibly all three proteins comprise a phylogenetically related extensin superfamily of extended rod-like macromolecules. The "wattle-blossom" model for AGP and gum arabic predicts a few large polysaccharide substituents along the polypeptide backbone of a spheroidal macromolecule. On the contrary, our data imply a rodlike molecule with numerous small polysaccharide substituents (attached to 24% of the Hyp residues), regularly arranged along a highly periodic polypeptide backbone based, hypothetically, on a 10 to 12 residue repetitive peptide motif. Thus, a simple statistical model of the gum arabic glycoprotein predicts a repeating polysaccharide-peptide subunit of about 7 kilodaltons. The small polysaccharide substituents will maximize intramolecular hydrogen bonding if aligned along the long axis of the molecule, forming in effect a twisted hairy rope. Electron micrographs of rotary shadowed GAGP molecules support that prediction and may also explain how such apparently large molecules can exit the cell by endwise reptation through the small pores of the primary cell wall.

Journal Article↗
PubMed1983

Somatic antigens of Pseudomonas aeruginosa. The structure of O-specific polysaccharide chains of P. aeruginosa O:3(a),c and O:3a,d,e lipopolysaccharides.

On mild acid degradation of Pseudomonas aeruginosa O:3(a),c, O:3a,d,e and O:3(a),d,f lipopolysaccharides O-specific polysaccharides were isolated. The trisaccharide repeating units of O:3(a),c and O:3a,d,e polysaccharides contained 2-acetamido-2,6-dideoxy-D-galactose and 2,3-(1-acetyl-2-methyl-2-imidazolino-5, 4)-2,3-dideoxy-D-mannuronic acid, which were identified previously as the constituents of P. aeruginosa O:3a,b and O:3a,d O-specific polysaccharides, as well as 2,3-diacetamido-2, 3-dideoxyl-L-guluronic acid, which has never before been found in nature. The last monosaccharide was identified without being isolated in the free state, by means of 13C nuclear magnetic resonance spectroscopy. The structures of O:3(a),c and O:3a,d,e polysaccharides were established by selective hydrogen fluoride solvolysis followed by modification of the trisaccharides obtained and analysis of the 13C nuclear magnetic resonance spectra at each modification stage. The polysaccharides possessed similar structures of repeating units differing from each other in the anomeric configuration of the N-acetylfucosamine residue only: leads to 4)DManImU-(beta 1 leads to 4) LGul(NAc)2U(alpha 1 leads to 3)DFucNAc(beta 1-and leads to 4)DManImU(beta 1 leads to 4)LGul(NAc)2U(alpha 1 leads to 3)DFucNAc(alpha 1-, where DManImU = 2,3-(1-acetyl-2-methyl-2-imidazolino-5,4)-2,3-dideoxy-D-mannuronic acid, LGul(NAc)2U = 2,3-diacetamido-2,3-dideoxy-L-guluronic acid, DFucNAc = 2-acetamido-2,6-dideoxy-D-galactose. The same components were detected in the O:3(a),d,f polysaccharide but not in the same stoichiometric ratio; this polysaccharide possessed no regular structure. The immunochemical study of lipopolysaccharides of all five P. aeruginosa O:3 serotypes showed a definite interrelation between their serological properties and structures of the corresponding O-specific polysaccharides.

Antigens, Bacterial↗
PubMed1988

Effect of Nitrogen on Polysaccharide Production in a Porphyridium sp.

Porphyridium cultures grown on either nitrate or ammonium as the nitrogen source showed similar patterns of growth and cell wall polysaccharide production. The effect of nitrogen on growth and cell wall polysaccharide production was studied by applying three regimens of supply: batch mode, in which nitrate was supplied at the beginning of the experiment and became depleted at day 6; continual mode, in which nitrate was added daily; and deficient mode, in which the cells were cultured in a nitrate-free medium. Growth was similar in the batch- and continual-mode cultures, whereas it was totally inhibited in the deficient-mode culture. Polysaccharide content (per volume) was highest in the batch-mode culture and lowest in the deficient-mode culture. However, polysaccharide production per cell was similar in the continual- and deficient-mode cultures, the highest value being found in the batch-mode culture. In addition to its effect on polysaccharide content, nitrogen affected the polysaccharide distribution between soluble and bound polysaccharides. In the deficientmode culture, most of the cell wall polysaccharide was dissolved in the medium.

Journal Article↗
PubMed2002

Anti-viral activity of red microalgal polysaccharides against retroviruses.

Red microalgal polysaccharides significantly inhibited the production of retroviruses (murine leukemia virus- MuLV) and cell transformation by murine sarcoma virus(MuSV-124) in cell culture. The most effective inhibitory effect of these polysaccharides against both cell transformation and virus production was obtained when the polysaccharide was added 2 h before or at the time of infection. Although, addition of the polysaccharide post-infection significantly reduced the number of transformed cells, but its effect was less marked than that obtained when the polysaccharide was added before or at the time of infection.The finding that the inhibition of cell transformation by MuSV-124 was reversible after removal of the polysaccharide suggested that microalgal polysaccharides inhibited a late step after provirus integration into the host genome. In conclusion, our findings could support the possibility that the polysaccharide may affect early steps in the virus replication cycle, such as virus absorption into the host cells, in addition to its effect on a late step after provirus integration.

Journal Article↗