Synthesis and immunological activity of an oligosaccharide-conjugate as a vaccine candidate against Group A Streptococcus

The synthesis and immunogenicity of a tetanus toxoid (TT)-conjugate of the hexasaccharide portion of the cell-wall polysaccharide (CWPS) of the Group A Streptococcus (GAS) is described. The synthesis relies on the reaction of an allyl glycoside of the hexasaccharide with cysteamine, followed by the reaction of the resultant amine with diethyl squarate to give the monoethyl squarate adduct. Subsequent reaction with the lysine ε-amino groups on TT gives the glycoconjugate containing 30 hexasaccharide haptens per TT molecule. The immunogenicity in mice is similar to that obtained with a native CWPS–TT conjugate, validating the glycoconjugate as a vaccine candidate against GAS infections.     

Catheptic and Trypsin-inhibiting Activities in the Nutritional Muscular Dystrophy

From 50 days on, after vitamin E deficient diet was given to guinea pigs, typical symptoms of muscular dystrophy were observed. Muscle protein of these animals was fractionated into 3 fractions, sarcoplasmic fraction, Triton X–100 soluble fraction and myofibrillar fraction.

Free catheptic activity (hemoglobin-splitting activity in the sarcoplasmic fraction), bound catheptic activity (the same in the Triton X–100 soluble fraction) and trypsin-inhibiting activity (in the sarcoplasm fraction) were determined in normal and dystrophic muscles.

In dystrophic muscles, great increase in free and bound catheptic activities was observed.

The increase of free catheptic activity was greater than that of bound catheptic activity.

Trypsin-inhibiting activity was also increased in dystrophic muscles two- or three-fold. At the same time, decrease in the content of myofibrillar protein in dystrophic muscles was observed.

These results were discussed in view of the degradation of protein in dystrophic muscles.     

Studies on Uranium Removal by the Extracellular Polysaccharide of a Pseudomonas aeruginosa Strain

Extracellular polysaccharide (EPS) produced by a Pseudomonas aeruginosa strain BU2 was characterized for its ability to remove uranium from aqueous solution. The EPS was acidic in nature and found as a potent biosorbent for uranium (U), showing pH dependence and fast saturating metal sorption, being maximum (985 mg U g^{? 1} EPS) at pH 5.0. The polymer showed enhanced uranium sorption capacity and affinity with increasing solution pH, suggesting a preferential sorption of monovalent uranyl hydroxide ions over the nonhydroxylated divalent species. Pseudo-first-order and pseudo-second-order kinetic models were applied to the experimental data, assuming that the external mass transfer limitations in the system can be neglected and biosorption is sorption controlled. Equilibrium metal binding showing conformity to the Freundlich model suggested a multilayer sorption involving specific binding sites with affinity distribution. The presence of two types of metal binding sites corresponding to strong and weak binding affinity was interpreted from the Scatchard model equation. Uranium sorption by EPS was unaffected or only slightly affected in the presence of several interfering cations and anions, except iron and thorium. Fourier transform infrared (FTIR) spectroscopy ascertained the strong binding of uranium with the carboxylic groups of uronic acids of bacterial EPS at pH 5.0, whereas at lower pH, amino and hydroxyl groups played a major role in metal binding.     

Circular Dichroism of Trimethylsilyl Derivatives of Aldonic Acid-γ-lactones and the Influences of the Cα Substituent and Ring Conformations on the Sign and the Magnitude

Circular dichroism of trimethylsilyl (TMS) derivatives of seven aldonic acid-γ-lactones were studied. As well as original sugar-γ-lactones the sign of the Cotton effect was determined by the C–2 configuration. The magnitude of CD peak was found to be related with the ring geometry. It leads to a conclusion that the observed molecular elipticities may be the sum of two effects; one effect of configuration at C–2 and the other effect of ring geometry. If these two effects are of the same sign, they overlap each other and give a strong CD peak. When the sign of these effects are opposite, they cancel each other and hence give a weak CD peak. Between the two effects, when C–2 substituent is OH or OTMS, the effect of configuration at C–2 is stronger than that of ring geometry.     

Immune-modulating activities of polysaccharides extracted from brown algae Hizikia fusiforme

The immuno-modulating activities of seaweed (Hizikia fusiforme) extracts on murine macrophage and splenocyte were studied in vitro. Polysaccharide (HFP) exhibited the potential macrophage stimulating effects than water extract (HFW) such as NO production and enhanced pro-inflammatory cytokines on the Raw 264.7 cells and splenocytes. From the mono-sugar composition, HFP-associated fucose based on HFP of H. fusiforme acts as immune modulator.     

Composition,Characteristic and Activity of Rare Earth Element-Bound Polysaccharide from Tea

The compositions and structural characteristics of rare earth elements-bound polysaccharides from tea (REE-TPS) were studied with the methods of Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Gas Chromatography (GC) and Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. The results show that polysaccharide from tea (TPS) was a sort of glycoprotein and coordinated with Rare Earth Elements (REE) closely. The sugar fraction was composed of Rha, Ara, Xyl, Fuc, Glc, and Gal. There existed almost all natural amino acids with Glx, Asx, and Hyp as the major parts in the protein fraction. The REEs in REE-TPS were mainly composed of La, Ce, and Nd, especially, more than 75% of them was La. The coordination atom of the first coordination shell of La in REE-TPS was oxygen, the coordination number of which was 6, and the average distance between the atoms was 2.52 Å. The second shell was formed from sulfur atoms, the coordination number and the average distance were 3 and 2.91 Å, respectively. The bio-experiments show that REE-TPS could decrease the content of blood glucose in mice significantly.     

Improvement of the Antitumor Activity of Black Currant Polysaccharide by an Enzymatic Treatment

A polysaccharide-rich substance isolated from black currant, named cassis polysaccharide (CAPS), was partially digested with β-galactosidase from Aspergillus oryzae and its immunostimulatory activity was investigated. The in vitro cytokine-inducing effect of CAPS on RAW264 cells was gradually decreased along with lowering of the average MW of CAPS. In vivo, partially digested CAPS with a mean MW of approximately 20,000 showed the most potent antitumor activity against Ehrlich carcinoma in mice.     

Detection of enzyme-catalyzed polysaccharide synthesis on surfaces

Abstract

Strategically important cellular components, such as the cell wall and the starch granule, present surfaces during their biosynthesis and degradation. The enzymology of such surfaces is experimentally challenging and goes well beyond classical solution-state analyses. The kinetics of surface catalysis is complex but tractable. A number of approaches to monitor surface catalysis are reviewed and each is suited to a different biological problem. Particular attention is paid to a method we have recently developed for quantitatively monitoring polysaccharide synthesis on a surface in real time using surface plasmon resonance spectroscopy. This method has many attractive features with the potential to tackle both biological and industrial problems.     

DISTRIBUTION OF CARBON AMONG PHOTOSYNTHETIC END-PRODUCTS IN PHYTOPLANKTON OF THE EASTERN CANADIAN ARCTIC1

The distribution of ¹⁴C among photosynthetic end-products was examined in eastern Canadian arctic phytoplankton, with particular emphasis on the synthesis of lipids. The pattern of ¹⁴C distribution for phytoplankton at each of three depths was generally similar among populations from 12 stations. About 18% of the total ¹⁴C fixed was incorporated into lipids. At one station, phytoplankton were experimentally subjected to temperature and light conditions different from those in situ: lipid-¹⁴C did not exceed 30% of total ¹⁴C fixed within the temperature range -1.0 to 6.0° C and irradiance range 1 to 700 W · m^?2. It is suggested that low temperatures and low light intensities, even when, maintained for prolonged periods, are not fully sufficient conditions for eliciting high relative rates of ¹⁴C incorporation into lipids. It is possible that differences in species composition may be a factor accounting for different patterns of ¹⁴C distribution between north and south polar phytoplankton under apparently similar environmental conditions.