Characterization of the translation products of the major mRNA species from rabbit lactating mammary glands and construction of bacterial recombinants containing casein and alpha-lactalbumin complementary DNA.

Treatment of intact human platelets with chymotrypsin released a glycopolypeptide that was shown to be derived from the major membrane glycoprotein, GPIb. The glycopolypeptide contained 59% carbohydrate on a molar basis and was rich in serine, threonine and proline. Almost all the carbohydrate could be released from the glycopolypeptide by treatment with alkali in the presence of NaBH4. The major component (comprising 80% of the released sugar) was purified and shown to be a hexasaccharide containing sialic acid, galactose, N-acetylglucosamine and N-acetylgalactosaminitol in the molar ratios 2:2:1:1. Two possible structures for this hexasaccharide are proposed on the basis of the known biosynthetic pathways of mucus-type glycoproteins. Our data is consistent with the occurrence of an O-glycosidically linked oligosaccharide on one amino acid in four of the glycopolypeptide. These results suggest that glycoprotein Ib can best be described as a membrane-bound mucus-type glycoproteins. Our data are consistent with the occurrence of an O- in the process by which platelets adhere to the exposed subendothelium of damaged blood-vessel walls. The possible role of the glycopolypeptide portion of GPIb in this process was investigated. Neither the major oligosaccharide nor the glycopolypeptide itself inhibited ristocetin-induced platelet agglutination at the concentrations tested. It is suggested that the carbohydrate moieties of GPIb molecules at the cell surface interact to form a barrier to macromolecules. Such a barrier could play a major role in modulating platelet function.     

The formation of a β-(1→4)-d-galactan chain catalysed by a Phaseolus aureus enzyme

With a particulate enzyme preparation from Phaseolus aureus hypocotyls, UDP-alpha-d-[U-(14)C]galactose served as a precursor for a number of products. One of these products was characterized as a beta-(1-->4)-linked galactan. The ADP-, GDP-, TDP- and CDP- derivatives of alpha-d-galactose did not serve as biosynthetic precursors for any products insoluble in 70% ethanol, nor as substrates for a sugar nucleotide 4-epimerase which is present in the particulate enzyme preparation. The (14)C-labelled beta-(1-->4)-galactan is alkali-insoluble and was characterized by analysis of partial acetolysis products. The labelling pattern of the [(14)C]oligosaccharides derived from acetolysis indicates that (1) only slightly more than two [(14)C]galactose moieties are added to the growing polysaccharide chain on average, and (2) these additions take place at the reducing end of the polysaccharide chain. The radioactive beta-(1-->4)-linked galactan chain represented 8.5% of the radioactivity initially added, and 20% of the water- and butanol-insoluble products derived from UDP-alpha-d-[(14)C]galactose. Total hydrolysis of the alkali-insoluble fraction of Phaseolus aureus hypocotyl yielded d-glucose and d-mannose in a 5:1 ratio but no detectable quantities of d-galactose. A trace quantity of a radioactive disaccharide, identified as (1-->3)-linked galactobiose, was isolated from the partial acetolysate of the alkali-insoluble [(14)C]polysaccharide material. Also isolated from this partial acetolysate was a C-1 derivative of [(14)C]galactose, which could not be identified. An alkali-soluble galactose-containing polysaccharide was also synthesized in this enzymic reaction, and represented 20% of the water- and butanol-insoluble products derived from UDP-alpha-d-[(14)C]galactose. The spectrum of radioactive oligosaccharides produced by partial acetolysis of this alkali-soluble polysaccharide material was different from that obtained from the alkali-insoluble polysaccharide, indicating a different structure.     

Changes in cell-wall polysaccharides in relation to seedling development and the mobilisation of reserves in the cotyledons of Lupinus angustifolius cv. Unicrop

Some 22% of the dry weight of the cotyledons of resting seeds of Lupinus angustifolius cv. Unicrop has been shown to be non-starch polysaccharide material comprising the massively thickened walls of the storage mesophyll cells. On hydrolysis this material released galactose (76%), arabinose (13%), xylose (4%), uronic acid (7%): only traces of glucose were detected indicating the virtual absence of cellulose from the walls. Changes in the amount and composition of this material following germination have been studied in relation to parameters of seedling development and the mobilisation of protein, lipid and oligosaccharide reserves. Starch, which was not present in the resting seed, appeared transitorily following germination: under conditions of continuous darkness starch levels were reduced. During the period of bulk-reserve mobilisation, 92% of the non-starch polysaccharide material disappeared from the cotyledons. The residual cell-wall material released galactose (14%), arabinose (19%), xylose (24%) and uronic acid (43%). The galactose and arabinose residues of the cotyledonary cell walls clearly constitute a major storage material, quantitatively as important as protein. The overall role of the wall polysaccharides in seedling development is discussed.     

麦冬多糖精制方法的比较

Five preparation methods were used to purify the crude polysaccharide which was the co-products of preparation saponin from Ophiopogonis japonicus (Thunb.)Ker-Gawl.The results indicate that the method of enzyme hydrolysis could purify the crude polyseccharide efficiently.The content of polysaccharide is more than 85% and could be used as the foods and medicine raw material.Aduanced test showcd that the polysaccharide is mainly consist of glucose,fructose,xylose,rhannose and galactose.     

Production of carbohydrates by the marine diatom Chaetoceros affinis var. willei (Gran) Hustedt. II. Preliminary investigation of the extracellular polysaccharide

The isolation of an extracellular polysaccharide from cultures of Chaetoceros affinis var. willei (Gran) Hustedt is described. The polysaccharide behaved as a homogeneous, polyanionic compound in free-boundary electrophoresis at both pH 2 and 7. It contained sulphur, presumably as sulphate half ester groups (8.7% of SO₂Na), and the following monosaccharides were tentatively identified: rhamnose, fucose, arabinose, and galactose, with the two former constituting 63% of the polysaccharide preparation. The main cellular polysaccharide was a glucan and could be extracted from the cells by dilute acid. The remaining material gave, after hydrolysis, a complex mixture of monosaccharides with rhamnose as the major component. It is concluded that the extracellular polysaccharide is probably excreted from healthy cells.     

Attempted isolation of a heparin proteoglycan from bovine liver capsule

(1) Polysaccharides were isolated from bovine liver capsule by extraction with 2m-potassium chloride followed by precipitation from 0.8m-potassium chloride with cetylpyridinium chloride. Chondroitin sulphate was eliminated by digestion with hyaluronidase. The yield of heparin was approx. 40% of that obtained after extraction of the papain-digested tissue. (2) The macromolecular properties of the hyaluronidase-digested polysaccharide were studied by gel chromatography on Sephadex G-200 of the intact, as well as of the alkali-degraded, material. The results suggested the presence of single heparin chains in addition to a dermatan sulphate proteoglycan. (3) A purified heparin preparation was analysed for amino acids and neutral sugars. Xylose, galactose and serine were found in amounts corresponding to 0.1, 0.2, and 0.4 residue/polysaccharide chain (mol.wt. 7400), respectively. It is suggested that the isolated material had been degraded by a polysaccharidase with endo-enzyme properties.     

A lipopolysaccharide fromAspergillus flavus conidia

A lipopolysaccharide was isolated by extraction ofAspergillus flavus conidia with 45 % phenol at 68–70 °C. Quantitative analysis revealed 7 % nucleic acids, 5.5 % proteins, 46 % polysaccharides and 49 % lipids, of which 12 % were covalently bound. Glucose, mannose, galactose and fucose were detected as monosaccharide components of the polysaccharide moiety by gas chromatography; palmitic acid, stearic acid, oleic acid, linoleic acid and myristic acid were mainly present in the lipidic fraction. This material differs from the bacterial lipopolysaccharides, both in composition of the polysaccharide moiety and representation of fatty acids in the lipidic fraction.     

A cellulosic exopolysaccharide produced from sugarcane molasses by a Zoogloea sp.

An extracellular polysaccharide producing bacterium Zoogloea sp. was isolated from an agro-industrial environment in the north-eastern region of Brazil. The extracellular polysaccharide produced from sugarcane molasses was hydrolysed with trifluoroacetic acid (mild and strong conditions) giving 88% of soluble material. The main monosaccharides present in the soluble fraction were glucose (87.6%), xylose (8.6%), mannose (0.8%), ribose (1.7%), galactose (0.1%), arabinose (0.4%) and glucuronic acid (0.8%). Methylation analysis of the polysaccharide showed mainly 2,3,6-tri-O-methylhexitol (74.7%) and 2,3,-di-O-methylhexitol (17.7%). Enzyme hydrolysis of the polysaccharide with a cellulase confirmed the presence of (1→4)-β- -glucopyranosyl residues.     

雪松松针多糖超声波酶法提取及其抗氧化性

为优化雪松松针多糖超声波酶法的提取工艺,并研究多糖结构及其抗氧化性。通过响应面法分析确定最佳提取参数为:3. 0 g松针粉末,液料比20∶1(m L∶g),提取温度80℃,超声功率560 W,超声时间47 min,纤维素酶用量12 FPU/g原料,提取两次,多糖得率高达10. 39%。采用高效液相色谱、红外光谱和核磁共振光谱等对松针多糖进行了结构表征,松针多糖以β-糖苷键为主要连接方式,并由葡萄糖、果糖、阿拉伯糖和半乳糖等单糖组成。体外抗氧化性研究结果表明:松针粗多糖对羟基自由基(·OH)和1,1-二苯基-2-三硝基苯肼自由基(DPPH·)的清除能力远高于纯化多糖,呈现出良好的量效关系,粗多糖对·OH和DPPH·的半抑制浓度IC50分别为0. 47 g/L和0. 076 g/L。     

Changes to the galactose/mannose ratio in galactomannans during coffee bean (<Emphasis Type="Italic">Coffea arabica</Emphasis> L.) development: implications for in vivo modification of galactomannan synthesis

Endosperm was isolated from Arabica Caturra coffee beans 11, 15, 21, 26, 31 and 37 weeks after flowering, and the chemical composition and relative solubility of its component polysaccharides determined at each growth stage. Chemical analysis of the total mannan content of the cell wall material was done after solubilisation of galactomannans by alkaline extraction of the cell wall material followed by enzymatic digestion of the alkali-insoluble residue with a mixture of endo-mannanse and endo-glucanase. Eleven weeks after flowering, galactomannans accounted for approximately 10% of the polysaccharides but were highly substituted, with galactose/mannose ratios between 1:2 and 1:7. As the bean matured, galactomannan became the predominant polysaccharide, until 31 weeks after flowering it accounted for approximately 50% of the polysaccharides. However, it was less substituted, possessing galactose/mannose ratios between 1:7 and 1:40. Early in bean growth, up to 50% of the cell wall polysaccharides were extractable but as the galactomannan content of the bean increased there was a reduction in the extractability of all polysaccharides. The decrease in the galactose/mannose ratio of the galactomannans commenced between 21 and 26 weeks after flowering and was in synchrony with a rise in the concentration of free galactose in the beans. The results indicated that the degree of substitution of the galactomannans in coffee beans is developmentally regulated and may result, in part, from the modification of a primary synthetic product by the action of an alpha-galactosidase.     

Chemical Characterization of Polysaccharide from the Slime Layer of the Cyanobacterium Microcystis flos-aquae C3-40

Macromolecular material from the slime layer of the cyanobacterium Microcystis flos-aquae C3-40 was defined as material that adhered to cells during centrifugation in growth medium but was dislodged by washing with deionized water and retained within dialysis tubing with a molecular-weight cutoff of 3,500. At each step of this isolation procedure, the slime was observed microscopically. Cells in the centrifugal pellet were surrounded by large amounts of slime that excluded negative stain, whereas cells that had been washed with water lacked visible slime. Two independently isolated lots of slime contained no detectable protein (<1%, wt/wt) and consisted predominantly of anthrone-reacting polysaccharide. Sugars in a hydrolysate of slime polysaccharide were derivatized with trimethylsilylimidazole and examined by gas chromatography-mass spectrometry. The composition of the slime polysaccharide was 1.5% (wt/wt) galactose, 2.0% glucose, 3.0% xylose, 5.0% mannose, 5.5% rhamnose, and 83% galacturonic acid. This composition resembles that of the plant polysaccharide pectin, which was treated in parallel as a control. Consistent with earlier indications that M. flos-aquae slime preferentially binds certain cations, the ratio of Fe to Na in the dialyzed slime was 10⁴ times that in the growth medium. The composition of the slime is discussed with respect to possible mechanisms of cation binding in comparison with other cyanobacterial exopolysaccharides and pectin.     

A natural terrestrial biofilm

Material recovered from an extensive and viscous biofilm found on areas of rough hill pasture in Southern Scotland proved to consist of a thick mucilaginous deposit of polysaccharide in which species of green algae, withGleocystis spp as the dominant microorganism and lesser numbers ofOocystis spp. Cyanobacteria were also entrapped. On laboratory culture other green algal and cyanobacterial species were detected. Analysis of the native polysaccharide and of the exopolysaccharide from a mixed culture of the dominant algal species derived from the original material, revealed the major components as glucose, galactose, mannose and rhamnose. The content of uronic acids was very low. The viscosity of the polysaccharide preparations was determined and compared with bacterial biofilm material; viscosity was lost following phenol extraction indicating that the original material was probably closely associated with proteins.     

Utilization of Waste Products of Dehydrated Onion Industry for Production of Fodder Yeast

An organism producing extracellular polysaccharide was isolated from soil and identified as Aeromonas hydrophila (Chester) Stanier. The effects of medium components and cultural conditions on production of the polysaccharide were studied. The optimal concentrations of carbon and nitrogen sources were 5% and 0.3%, respectively, for production of the polysaccharide. The optimal initial pH was 7~9. The maximum polysaccharide yield was obtained at 4~8 days of fermentation. From sucrose and raffinose as carbon source, the organism produced levan and acidic polysac-charide in the ratio of 7:3 and 4:6, respectively. From glucose, galactose, fructose, mannose, maltose and lactose, mainly acidic polysaccharide was produced. The acidic polysaccharide was found to contain galactose, mannose and glucuronic acid in a ratio of 5:4:2. The acidic polysaccharides obtained from sucrose and lactose seemed to be the same polysaccharide.     

马齿苋多糖的研究

用苯酚硫酸法对马齿苋多糖含量进行测定,设计正交实验确定马齿苋多糖提取的最佳工艺,马齿苋多糖的提取率高达9.23%。将其多糖分离纯化,进行理化性质试验测试,利用纸层析和气相色谱对马齿苋多糖中的单糖组成做了分析,马齿苋多糖中的单糖组成有葡萄糖、半乳糖、甘露糖、果糖、木糖、阿拉伯糖。     

On the Steric Configuration of the Urushi Polysaccharide

This paper presents the steric configuration of a polysaccharide obtained from the latex of the Japanese lacquer tree. Thus, the polysaccharide consisted of galactose and galacturonic acid, and the main chain of polysaccharide was proved to be linked with 1 → 3 linkage of galactose residue of 6-O-galacturonosyl galactose unit by the periodate oxidation method. The molecular weight was calculated to be 6 × 10⁴ by Archibald’s ultracentrifugal method. The configuration of the polysaccharide was discussed to be α helical structure of which one turn of the helices consists of 6 to 7 6-O-galacturonosyl galactose units and the diameter of the helix is 21 Å and one pitch is 9.5 Å on the basis of viscosity measurements, color reaction with iodine, crystallization with capronic acid and consideration of molecular models.     

The utilisation of galactose by an Aspergillus nidulans mutant lacking galactose phosphate-UDP glucose transferase and its relation to cell wall synthesis

Summary A mutant of Aspergillus nidulans lacking galactose phosphate-UDP glucose transferase could not grow on galactose but incorporated this sugar into cell constituents when supplied with another carbon source. 75% of the radioactivity taken up was found in the galactose and glucose monomers of the hyphal wall. Most of the remaining label was in a cytoplasmic polysaccharide and in free galactose and galactose phosphate. The composition of the cytoplasmic polysaccharide resembled that of the wall polymers. These findings are taken to indicate that enzymes not connected with the Leloir pathway can activate and epimerise galactose and that polymeric wall precursors may be present in the cytoplasm. The specific labelling obtained with galactose was combined with radioautography to show that glucose and galactose containing polymers are incorporated into the hyphal wall at the growing tip.     

Chemical structure analysis of water-soluble sulfated polysaccharide fromSchizymenia dubyi (Rhodophyta,Gigartinales)

Chemical and spectroscopic methods showed that the water-soluble polysaccharide extracted fromSchizymenia dubyi from Sicily was composed of 1/0.75/1.3 galactose, glucuronic acids and sulfate groups; 45% of total galactose was present as the L-form and no 3,6-anhydrogalactose was detected. The structural characteristics of this galactan of molecular weight 290 000 were close to sulfated polysaccharide with 1,3-, 1,4- and terminal-linked galactose units and secondary ramifications in 1,3,6; 1,4,6; 1,3,4 and 1,6. Permethylation analysis suggested the presence of sulfate groups on positions O-2 and/or O-3 of 1,4-linked galactose and on O-2 and/or O-4 of 1,3-linked residues.Author for correspondence     

Studies of the polysaccharides from sunflower heads

Extraction of sunflower heads with ammonium oxalate afforded water-soluble pectin material and water-insoluble glycoprotein material, the carbohydrate portion of which consisted of galacturonic acid and xylose residues; the pectin material defied fractionation with cetylpyridinium chloride. Extraction with hydrochloric acid (pH 1.5) afforded water-soluble and water-insoluble polysaccharide materials. The former, when fractionated with cetylpyridinium chloride, gave a glycoprotein, the carbohydrate moiety of which was composed of galacturonic acid, galactose (major), glucose, arabinose, and xylose, and also a rhamnan. The latter was a glycoprotein, the carbohydrate portion of which consisted of galactose (major), glucose, xylose, and rhamnose residues. Extraction of the sunflower heads with water also gave glycoprotein material, which was fractionated by paper electrophoresis into a glyco-protein, the carbohydrate moiety ofwhich was composed of galacturonic acid (minor), galactose, glucose, xylose, arabinose, and rhamnose (major) residues, and a heteropolysaccharide composed of galactose (major), glucose, xylose, and arabinose residues.     

Chemical characterization of the hyphal walls of the basidiomyceteArmillaria mellea

Purified hyphal walls ofArmillaria mellea were analyzed and shown to contain glucose (59.0%), mannose (6.9%), galactose (4.2%), xylose (0.2%), ribose (traces), glucosamine (6.7%), protein (10.5%), and some lipid material (8.0%). The mucilaginous surface polysaccharide (fraction I) consisted mainly of (1–3), (1–4), and (1–6)β-glucan chains with mannose, galactose, xylose, and ribose. Fraction II was made mostly of (1–3)-linkedα-glucan. Fraction III contained mainly (1–3)-linkedβ-glucan with small amounts of mannose and galactose, and fraction IV was an alkali-insolubleβ(1–3)-glucan in close association with chitin.     

Studies on the Non-starchy Polysaccharides of the Endosperm of Buckwheat

Water soluble polysaccharides from the buckwheat endosperm was fractionated by salting out and a DEAE-cellulose column (phosphate form) chromatography and the main component (polysaccharide A₁) was isolated as an ultracentrifugally and electrophoretically pure preparation.

The content of polysaccharide A₁ in the buckwheat endosperm was 0.1~0.2%.

Its water solution showed high viscosity and [α]_d was +39.4°. The molecular weight was 240,000~260,000.

Polysaccharide A₁ consisted of xylose, mannose, galactose and glucuronic acid. The hydrolysis of methylated polysaccharide A₁ gave 2,3,4-tri-O-methyl-xylose, 2,3,4,6-tetra-O-methyl-galactose, 2,4,6-tri-O-methyl-galactose, di-O-methyl-mannose and 4-O-methyl- and 5-O-methyl-glucuronic acid. These results suggested that the main chain of this polysaccharide consisted of glucuronic acid, mannose and galactose and the former two occupied branching position with xylose and galactose residues as nonreducing end.