D-glucosyl Residues Research Articles

Primary structure of the Klebsiella serotype 16 capsular polysaccharide

The primary structure of the Klebsiella serotype 16 capsular polysaccharide consists of tetrasaccharide repeating-units comprising a/ar3)-α- D-Glc p-(1/ar4)β- D-GlcA p-(1/ar4)-α- L-Fuc p-(1/ar chain with a β- D-Gal p-(1→ branch at position 4 of the D-glucosyl residue.

Interaction of pneumococcal S-14 polysaccharide with lectins from Ricinus communis, Triticum vulgaris, and bandeiraea simplicifolia

Two purified lectins, namely, wheat-germ agglutinin (from Triticum vulgaris) and the hemagglutinin from Ricinus communis seeds, readily form a precipitate with pneumococcal S-14 polysaccharide, whereas the Bandeiraea simplicifolia lectin (BS 1) does not. Exhaustive periodate oxidation and borohydride reduction of S 14 modifies terminal β- D-galactopyranosyl residues, as well as chain D-glucopyranosyl residues, and abolishes reactivity with both the R. communis lectin and wheat-germ agglutinin. Controlled periodate oxidation followed by Smith degradation cleaves only terminal β- D-galactopyranosyl residues, giving a linear polymer, the structure of which was determined by methylation analysis. This derived polymer, containing (1→6)-linked 2-acetamido-2-deoxy-β- D-glucosyl residues, readily precipitated wheat-germ agglutinin, but not the R. communis lectin.

Purification of some glycoside hydrolases by affinity chromatography

Two glycoproteins have been isolated from the cell walls of baker's yeast. One is a glucan-protein complex which has been partially characterised as having a branched carbohydrate structure composed of chains of (1→3)-linked β- d-glucosyl residues, some of which are attached by (1→6)-linkages to the main chain. Immobilization of this glycoprotein was achieved by covalent attachment to Sepharose, and the product was used to isolate a number of (1→3)-β- d-glucan hydrolases from Helix pomatia, malted barley, and Basidiomycete QM806. The second glycoprotein, a mannan-protein complex, after immobilization, has been used in the purification of an α- d-mannosidase from jack-bean meal.

Glucosyltransferase activity in calf pancreas microsomes. Formation of dolichyl D[14C]glucosyl phosphate and 14C-labeled lipid-linked oligosaccharides from UDP-D-[14C]glucose.

Calf pancreas microsomes incorporated radioactively labeled D-glucose from UDP-D-glucose into products extracted with chloroform/methanol (2:1, v/v), chloroform/methanol/water (10:102.5, v/v), and into the residual precipitate, with a pH optimum in Tris/maleate buffer of about 5.3. The chloroform/methanol extract contained a single 14C-labeled acidic product, which was identified as dolichyl beta-D-glucosyl phosphate. It was stable to mild alkali, yielded D-[14C]glucose upon mild acid hydrolysis, and a 14C-labeled compound with the chromatographic mobility of 1,6-anhydro-beta-D-glucopyranosyl upon hot alkali treatment. The [14C]glucolipid had the same chromatographic mobility as dolichyl beta-D-[14C]mannosyl phosphate, and its formation was stimulated by exogenous dolichyl phosphate. The chloroform/methanol/water extract contained radioactive lipid-bound oligosaccharides which were retained on DEAE-cellulose more strongly than dolichyl D-[14C]glucosyl phosphate. They were stable to mild alkali, but labile to acid and hot alkali. Acid treatment yielded a D-glucose-labeled oligosaccharide fraction which was shown by gel filtration to be slightly larger than most of the D-mannose-labeled oligosaccharides. About 80% of the radioactive D-glucose residues could be removed with alpha-glucosidase, but not with beta-glucosidase. Pancreatic dolichyl beta-D-[14C]glucosyl phosphate incubated with calf pancreas microsomes served as direct donor of D-glucosyl residues to lipid-bound oligosaccharides and to the precipitate. These oligosaccharides had the same size as those labeled from UDP-D-[14C]glucose, and the D-[14C]glucose residues could also be removed with alpha-glucosidase.

Étude complémentaire de la structure de trois galactoxyloglucanes (amyloïdes) de graines

D-Galacto- D-xylo- D-glucans (amyloids) from Balsamina, Tropaeolum, and Tamarindus seeds behave in a similar manner in the presence of various glycosidase preparations: slow depolymerization by enzymes from several germinated or non-germinated seeds, and hydrolysis into monosaccharides and oligosaccharides by commercial cellulase and hemicellulase preparations from fungi. A purified cellulase from Penicillium notatum gave a dialyzable fraction almost exclusively composed of α- D-xylopyranosyl-(1→6)- D-glucose residues and a nondialyzable fraction composed of chains of β- D-(1→4)[withsome (1→3)]-glucopyranosyl residues; β- D-galacto-pyranosyl-(1→2)-α- D-xylosyl groups are linked to some of the β- D-glucosyl residues at 0-6. The presence of (1→3)-linkages in the D-glucan chain of the Balsamina was verified by methylation and sequential periodate oxidation-borohydride reduction; the distribution of the substituents on the D-glucan chain is not regular. The main D-glucan backbone, where the β- D-glucosyl residues are partly linked at 0-6 to β- D-galactosyl-(1→2)- D-xylosyl groups, is linked to D-glucan chains where almost all the D-glucose units are linked at 0-6 by one α- D-xylosyl group. The presence of 3,6-di- O-methyl- D-glucose after permethylation and hydrolysis suggests that the xyloglucan chains are linked to 0-2 of the D-glucosyl units of the galactoxyloglucan backbone.

Structural characteristics of native and enzymically formed dextran of S. sanguis ATCC 10553

The structure of the native dextran produced by Streptococcus sanguis ATCC 10558 was analyzed by g.l.c.-m.s. of the methylated alditol acetates derived from the polymer. The results indicate that the polymer contains d-glucosyl residues substituted at C-6 or C-3, or both, as well as unsubstituted d-glucosyl residues. These data are correlated with the proportion of C-6 and non-C-6 substitution as measured by p.m.r. Similar data are reported for the analysis performed on a dextran produced by action of a partially purified dextransucrase on sucrose. The proportion of d-glucosyl residues substituted at C-3 is diminished in this case. It is concluded that several enzymes are involved in the dextran synthesis.

Molecular immunological heterogeneity of the salmonella zuerich [1, 9, 12, (46), 27] cell-wall polysaccharides

Extraction of O specific polysaccharide from S. zuerich leads to three fractions (ZA, ZB, ZC). Polysaccharide ZB carries specificities 1, 27, and 46, present on the Salmonella cells. It exhibits a factor 27 that is very similar to that present on the S. typhi T 2 1 - 27 + polysaccharide, a factor 1 that is close to that present on S. senftenberg polysaccharide, and a factor 46 that gives a very weak cross-reaction with anti-46 antibodies. Polysaccharides ZA and ZB are immunologically different and ZB contains two distinct fractions: ZB 1 - devoid of O factor 1 and carrying the specificities 46 and 27 mostly, if not completely, on the same molecule (46, 27); and ZB 1 + carrying O factors 1, (46), 27. Zb 1 + is composed of at least two different molecules: [1, (46)], precipitable with anti-1 antibodies but only coprecipitable with anti-46 antibodies; and (1, 27) precipitable with both anti-1 and anti-27 antibodies. Molecules [1, (46)] precipitate only part of the anti-1 antibodies precipitable by (1, 27). The smaller precipitation of anti-27 antibodies (when factor 27 is present together with factor 1 on the same molecule) and the coprecipitation, instead of precipitation, of anti-46 antibodies (when factors 46 and 1 are present on the same molecule) may be explained by a sterical hindrance between O-factors 1 and 27, and 1 and 46. The molecular, immunological heterogeneity of the polysaccharides extracted from S. zuerich would result from the presence on the cells of two kinds of O polysaccharides: one with, the other without O factor 1, which is related to the presence of a side-chain of an α- D-glucosyl residue. A structure for S. zuerich polysaccharide is proposed.

Determination of position of substitution on 2-acetamido-2-deoxy- D-glucosyl residues in glycolipids

The substitution site on 2-acetamido-2-deoxy-D-galactosyl residues in oligosaccharide chains of glycolipids was determined by permethylation of the glycolipid with methyl iodide in the presence of dimethylsulfinyl carbanion, methanolysis of the permethylated product under mild conditions, acetylation with acetic anhydride-pyridine, and identification of the resulting substituted methyl glycosides of 2-deoxy-2(N-methylacetamido)-D-galactose by g.l.c. The method was applied to glycolipids of known structure, including normal brain ganglioside, Tay-Sachs ganglioside, and Forssman glycolipid.

Separation and characterization of the soluble and insoluble components of insoluble laminaran

Insoluble laminaran, a (1→3)-β- D-glucan from Laminaria hyperborea ( L. cloustoni), has been fractionated by differential solubility into soluble and insoluble fractions. These fractions were degraded with a purified exo-(1→3)-β- D-glucanase from Basidiomycete sp. QM806 giving, as primary hydrolysis products, D-glucose, gentiobiose, laminarabiose, and 1- O-β-laminarabiosylmannitol. Gentiobiose was obtained in only trace amounts from the insoluble fraction of laminaran, suggesting the absence of branching. Successive application of periodate oxidation, reduction, mild acid hydrolysis, and enzymic degradation indicated that the branch in the soluble fraction consists of a single β-(1→6)-linked D-glucosyl residue. The results indicate that “insoluble” laminaran is apparently an aggregate of three closely related polysaccharide species: a soluble, branched, reducing component (soluble laminarose); an insoluble, unbranched, reducing component (insoluble laminarose); and an unbranched, nonreducing component (laminaritol) that has a monosubstituted mannitol residue at the reducing terminal. Laminaritol was found to be about equally distributed between the soluble and insoluble fractions. The average d.p. of the laminaran components is 20–25 residues, as determined from the relative amounts of enzymic hydrolysis products and from periodate-oxidation data.

Les polysaccharides des graines de quelques liliacees et iridacees

The alkali-soluble polysaccharides have been surveyed in the seeds of 7 species of the Liliaceae and 2 species of the Iridaceae. All appear to contain galactoglucomannans and/or glucomannans. The structure of the water-soluble galactoglucomannan from the endosperm of Asparagus officinalis has been studied in detail. It contains residues of glucose, mannose and galactose in the ratio 43:49:7. Hydrolysis of the fully methylated polysaccharide released 2,3,4,6-tetra- O-methyl- d-hexoses (mannose and glucose), 2,3,4,6-tetra- O-methyl- d-galactose, 2,3,6-tri- O-methyl- d-mannose, 2,3,6-tri- O-methyl- d-glucose, 2,3-di- O-methyl- d-mannose and 2,3-di- O-methyl- d-glucose in the molar proportions of 1:4.5:50:41:2:1·5. The following oligosaccharides were identified on partial hydrolysis of the galactoglucomannan: mannobiose, mannotriose, mannotetraose, cellobiose, glucopyranosylmannose, mannopyranosylglucose and a trisaccharide composed of two mannosyl residues and one glucosyl residue. The galactoglucomannan consists of a linear chain of β(1 → 4)-Iinked d-mannosyl and d-glucosyl residues, to which are attached single-unit galactosyl side chains. The galactose residues are linked 1 → 6, probably α. The terminal, non-reducing residues of the main chain may be either glucosyl or mannosyl units but the former predominate.

D-glucosylation des phytostérols et acylation des stéryl- D-glucosides en présence d'enzymes de plantes

Starting from wheat root homogenates, particles catalyzing the transfer of D-glucosyl residues from UDPGlc to phytosterols and the acylation of steryl D-glucosides were purified by sucrose gradient centrifugation. The enzymes responsible for these reactions seem to be localized on a specific species of membranous organelle. After acetone extraction of the endogenous lipid material from the particles, the insoluble fraction retained its enzymic activities. The UDPGlc:sterol glucosyltransferase could then be solubilized with Triton X-100. By mixing the Triton X-100 supernatant with the substrates UDPGlc and sterol, the transglucosylation system was reconstituted. After addition of the acetone powder to the sterylglucoside and phosphatidyl ethanolamine, which has been identified as an acyl donor, the formation of steryl acyl- D-glucoside was observed.

Metabolism of the reserve polysaccharide of Streptococcus mitis. Properties of glycogen synthetase

The presence of glycogen synthetase has been demonstrated in cell extracts of five strains of S. mitis. The purified enzyme was free from transglucosylase, α-(1→6)- d-glucosidase, pullulanase, phosphorylase, and 5′-adenylate kinase, but contained a trace of branching enzyme. The enzyme transferred d-glucosyl residues from ADPG to the acceptor with the formation of α-(1 → 4)- d-glucosidic linkages. The preferred acceptors were highly branched polysaccharides. The efficiency (relative to S. mitis glycogen) of various acceptors, present in excess in activity digests, was as follows: glycogen phosphorylase limit-dextrin (107), glycogen (100), amylopectin phosphorylase limit-dextrin (78), amylopectin (65), amylopectin β-amylase limit-dextrin (30), and amylose (23). For branched oligosaccharide and polysaccharide acceptors, the side chain was the favoured site of d-glucosyl transfer. The enzyme displayed an absolute requirement for three or more d-glucosyl residues in the side chain of branched oligosaccharides of low molecular weight.

Studies on carbohydrate-metabolising enzymes : Part XVII. The enzymic synthesis of some disaccharides containing α- D-glucosyl residues

By the action of an enzyme preparation from Tetrahymena pyriformis, α- D-glucosyl residues may be transferred from phenyl α- D-glucopyranoside to various carbohydrates. By this means, the following disaccharides have been prepared and characterised: 6- O-α- D-glucopyranosyl- D-galactose and - D-mannose, 4- O-α- D-glucopyranosyl- L-xylose, 1- O-α- D-glucopyranosylribitol, 1- O-α- D-glucopyranosylerythritol, 1- O-α- D-glucopyranosyl- D-mannitol, and a mixture of 1- O- and 6- O-α- D-glucopyranosyl- D-glucitol. These results show the preferential transfer of α- D-glucosyl residues to primary alcohol groups in carbohydrate acceptor substrates.

Studies on carbohydrate-metabolising enzymes : Part XV. The enzymic synthesis of some O- D-glucosylpentose disaccharides

By transfer of an α- D-glucosyl residue from phenyl α- D-glucopyranoside to a pentose, using an enzyme preparation from Tetrahymena pyriformis, 4- O-α- D-gluco-pyranosyl- D-xylose and- D-ribose, and mixtures of three O-α- D-glucosyl- D-lyxoses and four α- D-glucosyl- D-arabinoses have been prepared. An enzyme preparation from barley transfers a β- D-glucosyl residue from salicin to D-xylose, giving a mixture of (1→3)- and (1→4)-linked O-β- D-glucosyl- D-xyloses.