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B Fournet

Publications and source records attributed to B Fournet.

At least 37 records · Page 2Linked to original sources
PubMed1991

Collisional-activation tandem mass spectrometry of sodium adduct ions of methylated oligosaccharides: sequence analysis and discrimination between alpha-NeuAc-(2----3) and alpha-NeuAc-(2----6) linkages.

Collision-activated dissociation (c.a.d.) of sodium adducts of molecular ion species have been carried out on methylated beta-D-Galp-(1----4)-beta-D-GlcpNAc- (1----3)-beta-D-Galp-(1----4)-D-Glcp (1), beta-D-Galp-(1----3)-beta-D-GlcpNAc-(1----3)-beta-D-Galp-(1----4)-D-Glcp (2), alpha-D-NeuAc-(2----3)-beta-D-Galp-(1----3)-beta-D-GlcpNAc-(1----3)-beta -D-Galp - (1----4)-D-Glcp (3), alpha-D-NeuAc-(2----6)-beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----3)-beta -D-Galp - (1----4)-D-Glcp (4), and alpha-D-NeuAc-(2----6)-beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----2)-alph a-D- Manp-(1----3)-beta-D-Manp-(1----4)-D-GlcpNAc (5). The numerous daughter ions reflect the sequences, clearly differentiate (1----3) and (1----4) linkages, and discriminate between alpha-NeuAc-(2----3) and alpha-NeuAc-(2----6) linkages.

Carbohydrate Sequence↗
PubMed1991

Yolk protein in leech. Identification, purification and characterization of vitellin and vitellogenin.

Theromyzon tessulatum vitellin was identified as a lipoglycoprotein of 490 kDa. The insolubility of this molecule in low-ionic-strength media was used to extract it from the ovaries. Antiserum prepared against vitellin was shown to react with a coelomic fluid component of 520 kDa. This vitellin precursor, or vitellogenin, was purified by gel permeation and ion-exchange column chromatography. These two lipoglycoproteins were characterized by amino acid, carbohydrate and lipid analysis and subunit composition. In spite of differences in terms of native molecular mass, solubility and isoelectric point, the lipoglycoproteins isolated from the coelomic fluid and the ovary were similar in their subunit components (a single polypeptide of 165 kDa) and in their amino acid and carbohydrate compositions. However, vitellogenin was found to be more highly lipidated (31.8% by mass) than vitellin (24% by mass) and lipid analysis indicated a higher amount of sterols and phospholipids in vitellogenin. From these data, we conclude that vitellogenin and vitellin are probably dimers of two identical subunit polypeptides plus lipid and that, after vitellogenin is sequestered in the oocyte, part of its lipid component is stripped from the molecule to give vitellin. Furthermore, electrophoretic analysis seems to indicate that vitellogenin synthesis and secretion is initiated following the third and last blood meal of the animal but that vitellogenin significantly accumulates in the coelomic fluid before being incorporated in the oocytes suggesting a complex mode of vitellogenesis regulation.

Amino Acids↗
PubMed1991

Structure of the O-specific polysaccharide chain from Klebsiella pneumoniae O1K2 (NCTC 5055) lipopolysaccharide.

The structure of the O-specific polysaccharide of Klebsiella pneumoniae O1K2 lipopolysaccharide was investigated by use of methylation, periodate oxidation, partial hydrolysis, and 1H- and 13C-n.m.r. spectroscopy. It was shown to consist of a linear chain composed of two disaccharide repeating units, [----3)-alpha-D-Galp-(1----3)-beta-D-Galp-(1----] and [----3)-alpha-D-Galp-(1----3)-beta-D-Galf-(1----].

Carbohydrate Sequence↗
PubMed1991

Characterization of a novel type of chain-terminator Gal beta 1-6Gal beta 1-4)GlcNAc in an oligosaccharide related to N-glycosylated protein glycans isolated from GM1 the urine of patients with gangliosidosis.

Two new oligosaccharides were isolated from the urine of a patient with GM1 gangliosidosis. Final purification of the oligosaccharides was accomplished by capillary supercritical fluid chromatography. Structural analysis was by chemical analysis, chemical-ionization mass spectrometry and 400-MHz 1H-NMR spectroscopy, leading to two primary structures. The first is derived from a classical triantennary N-acetyllactosamine-type glycan: Gal beta 1-4GlcNAc beta 1-4(Gal beta 1-4GlcNAc beta 1-2)Man alpha 1-3Man beta 1-4GlcNAc. The second is unusual with a terminal disaccharide Gal beta 1-6Gal, which had not yet been described for glycans of the N-acetyllactosamine type: Gal beta 1-6Gal beta 1-4GlcNAc beta 1-2Man alpha 1-6Man beta 1-4GlcNAc.

Carbohydrate Conformation↗
PubMed1991

Isolation and characterization of methylated sugars from the tube of the hydrothermal vent tubiculous annelid worm Alvinella pompejana.

The tube of Alvinella pompejana contains in its carbohydrate fraction, 3 methylated monosaccharides: 2-mono-O-methyl-L-fucose, 3-mono-O-methyl-L-fucose and 2,4-di-O-methyl-L-fucose. The present work appears to be the first report of the occurrence of 2-mono-O-methyl-L-fucose and 3-mono-O-methyl-L-fucose in the animal kingdom. Moreover, it is the first time that 2,4-di-O-methyl-L-fucose is found in nature.

Animals↗
PubMed1991

Analysis of pyruvic acid acetal containing polysaccharides by methanolysis and reductive cleavage methods.

The mass spectra of permethylated methyl 4,6-O-(1-carbomethoxyethylidene)-D-hexopyranoside and 1,5-anhydro-D-hexitol of glucose, galactose, and mannose and permethylated methyl 5,6-O-(1-carbomethoxyethylidene)-D-galactofuranoside and 1,4-anhydro-D-galactitol have been determined. The stability of each compound toward methanolysis and reductive cleavage is discussed. These techniques permit the identification of the acetalic linkages of pyruvic acid present in polysaccharides.

Acetylation↗
PubMed1991

Studies on the structures of the Tm, Sj, M1, Can, Sext and Hu blood group antigens.

The Glycophorins (GPs = sialoglycoproteins) in erythrocyte membranes from various Black individuals, some of which exhibit the M1, Can, Sj, Tm, Sext and/or Hu antigens, and several Caucasian donors, including pooled fetal red cells, were studied. Using agglutination inhibition assays with GP fractions, GP fragments and chemically modified GPs as well as trypsin treatment of intact red cells, the antigens defined by anti-M1, anti-M+M1, anti-Can and anti-Tm sera were found to be located on the N-terminal tryptic peptide (T2, residues 1-31) of the major GP (GP A = MN sialoglycoprotein). Evidence was obtained that the N-terminal amino-acid residue, NeuNAc and/or (a) different sugar residue(s) are involved in the antigens. Amino-acid sequence and composition analyses excluded an amino-acid exchange within the N-terminal region (residues 1-31) of GP A. Carbohydrate analyses revealed the attachment of GlcNAc residues (up to about five, dependent on the strength of the above-mentioned antigens) to O-glycosidically linked oligosaccharides within the N-terminal portion (residues 1-31) of GP A. As judged from the carbohydrate compositions of peptides, the alteration of the O-glycosidic oligosaccharides is associated with a slight increase of the Gal and Fuc contents and a slight decrease of the NeuNAc level. Analyses of small, secondary cyanogen bromide and V8 proteinase peptides from the N-terminal region of GP A from Blacks, Caucasians and Caucasian fetal cells suggest that the variable attachment of small quantities of GlcNAc (about 0.03 to about 0.2 residues per peptide molecule) accounts, at least in part, for the polymorphisms detected by anti-Can and the original anti-Tm (serum Sheerin). Remarkably, the GlcNAc-containing O-glycosidic oligosaccharides occur only in small quantities, or not all at, within the positions 32-61 of GP A and the glycosylated domains of GP B and GP C.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylglucosamine↗
PubMed1990

Structure of an exocellular beta-D-glucan from Pediococcus sp., a wine lactic bacteria.

Pediococcus sp. produces an exocellular slime containing exclusively D-glucose. The structure of the polysaccharide was determined by methylation analysis, Smith degradation, enzymic hydrolysis, and 13C-n.m.r. spectroscopy as having a trisaccharide repeating unit, ----3)-beta-D-Glcp-(1---- 3)-[beta-D-Glcp-(1----2)]-beta-D-Glcp-(1----.

Carbohydrate Sequence↗
PubMed1990

Structure of an exocellular polysaccharide produced by Streptococcus thermophilus.

Streptococcus thermophilus strains grown on skimmed milk produced a viscosifying, exocellular, and water-soluble polysaccharide which contains D-glucose, D-galactose, and N-acetyl-D-galactosamine in the ratio of 1:2:1. Methylation analysis identified the glycosidic linkages in the tetrasaccharidic repeating-unit, and Smith degradation and nitrous deamination after N-deacetylation gave the sequence of monosaccharides in the repeating-unit. The anomeric configurations of the sugar residues were determined by oxidation of the peracetylated polysaccharide with chromium trioxide and by 1H- and 13C-n.m.r. spectroscopy. The following structure was assigned to the repeating unit of the polysaccharide,----3)-beta-D-Galp-(1----3)-[alpha-D-Galp-(1----6)]-beta- D- Glcp-(1----3)-alpha-D-GalpNAc-(1----.

Acetylation↗
PubMed1990

Primary structure of the oligosaccharide chain of lipopeptidophosphoglycan of epimastigote forms of Trypanosoma cruzi.

The lipopeptidophosphoglycan of epimastigote forms of Trypanosoma cruzi is composed of a glycan linked through a non-N-acetylated glucosamine residue to an inositol phosphorylceramide. Using conventional analysis techniques, including 1H, 13C, and 31P NMR spectroscopy and negative ion fast atom bombardment mass spectroscopy, the structure of the carbohydrate-containing part of the molecule is determined as: (Sequence: see text). There is uncertainty as to which 2-O-substituted alpha-D-Manp unit is attached the side chain or whether it is distributed between the two units. Some of the structures lack the Galf side chain. The inositol unit is linked to ceramide via a phosphodiester bridge. The major aliphatic components of the ceramide portion were lignoceric acid and sphinganine.

Animals↗
PubMed1990

Separation of oligosaccharides by capillary supercritical fluid chromatography and analysis by direct coupling to high-resolution mass spectrometer: application to analysis of oligomannosidic N-glycans.

Supercritical fluid chromatography separations and supercritical fluid chromatography chemical ionization mass spectrometry analysis of permethylated and pertrimethylsilylated oligosaccharides are reported. Supercritical fluid chromatography was carried out using a DB-5 coated capillary column with carbon dioxide as a mobile phase. Peralkylated oligosaccharides were detected by flame ionization and by chemical ionization mass spectrometry using the GC interface. Analysis of permethylated malto-oligosaccharides, as well as oligomannosides from mannosidosis, was achieved by chemical ionization mass spectrometry with ammonia and provided the pseudo-molecular ions (M+H)+ and (M+NH4)+, in addition to some other fragments which allow interpretations of the structure of different oligosaccharides. The good resolution and sensitivity obtained emphasize the potential of supercritical fluid chromatography mass spectrometry for rapid separations and analysis of complex glycan mixtures.

Chromatography↗
PubMed1990

The Mz variety of the St(a+) phenotype--a variant of glycophorin A exhibiting a deletion.

The NeuNAc level of erythrocyte membranes from two related donors exhibiting the Mz variety of St(a+) phenotype within the MNSs blood group system was found to be decreased by about 16%. The quantity of glycophorin A was decreased by about 38%, whereas that of glycophorin B was not significantly different from normal. Mz erythrocyte membranes were also found to contain an abnormal component (molar ratio to glycophorin A about 0.89:1.0) with an apparent molecular mass of about 24,000 Da. Immunoblotting experiments and amino-acid sequence analysis revealed that the novel component (and glycophorin A in one of the donors) carries blood group M activity. Blood group N activity was demonstrable for glycophorin A and glycophorin B from both donors. Amino-acid sequence analysis of chymotryptic, tryptic and cyanogen bromide peptides demonstrated that the novel molecule exhibits the typical structure of a Sta-active molecule. However, since it exhibits blood group M activity, it appears to represent a variant of glycophorin A lacking the residues 27-58 (encoded by exon three of the glycophorin A gene) rather than a glycophorin B-glycophorin A-hybrid molecule of the anti-Lepore type. Since one of the Mz heterozygotes was found to exhibit both M- and N activity on glycophorin A, the Mz gene complex appears to encode a blood group N-active glycophorin A apart from the novel component and a blood group s-active glycophorin B, although the level of glycophorin A in the erythrocyte membranes is decreased by about half.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1989

Identification of peptides, from a peptic haemoglobin hydrolysate produced at pilot-plant scale, by high-performance liquid chromatography and mass spectrometry.

Gel-permeation high-performance liquid chromatography (HPLC) and reversed-phase HPLC were used to separate a mixture of peptides, produced at pilot-plant scale by peptic hydrolysis of bovine haemoglobin. Volatile buffers were employed in both HPLC techniques in order to get an easy recovery of peptides for further applications. The method is more rapid than low-pressure gel filtration. Amino acid analysis and fast atom bombardment mass spectrometry confirmed the purity, and allowed accurate molecular weights to be determined, for isolated peptides. These data demonstrate that such efficient techniques, usually used to resolve hydrolysates obtained in batch with pure substrates and highly specific enzymes, can be employed to resolve complex enzymatic hydrolysates of crude protein.

Amino Acid Sequence↗
PubMed1989

Structures of O-glycosidically linked oligosaccharides isolated from human meconium glycoproteins.

The structure of the major O-glycosidically linked neutral and acidic oligosaccharides isolated from human meconium glycoproteins were established. Neutral and acidic oligosaccharides were released by alkaline borohydride treatment, purified by Biogel P-6 and fractionated by high-performance liquid chromatography. This approach resulted in 50 neutral and 30 acidic oligosaccharides. The present study reports the primary structural analysis of five neutral oligosaccharides, ten monosialylated oligosaccharides, one monosialylated monosulfated oligosaccharide and three disialylated oligosaccharides, by permethylation, fast-atom-bombardment mass spectrometry analysis and 400-MHz 1H-NMR spectroscopy. The following structure have not been described previously: (formula; see text) The intestinal glycoproteins of human meconium are characterized as high molecular mass compounds with numerous carbohydrate chains of the mucin type. These mucins are a rich source of carbohydrate structures which express multiple blood group activities and occur as membrane-associated antigens, recognized by hybridoma antibodies [1-4]. A previous study [5] described the structure of fifteen free oligosaccharides derived from catabolism of O- and N-glycans accumulating in new born meconium. In the same group [6] the research has been extended to glycoasparagines with the description of thirteen of them by high resolution 1H-NMR spectroscopy analysis. From O-glycosidically linked glycoproteins, further studies [7] established the structures of nine major monosaccharides to tetrasaccharides obtained after mild acid hydrolysis and base-borohydride degradation from meconium samples of group O secretors. These oligosaccharides were derived from meconium glycopeptides which had been depleted of I- and i-antigen activities. Recently [8], neutral and acidic oligosaccharide-alditols obtained by alkaline borohydride degradation of human meconium glycoproteins have been separated by HPLC on an anion-exchange column. The neutral fraction was further purified by normal-phase and reversed-phase chromatography while acidic fractions were fractionated only by normal-phase chromatography. Thus, we have isolated several low molecular mass oligosaccharides of different size and composition and also isomers which vary in linkage position or anomer configuration. Using methylation analysis, 1H-NMR spectroscopy and fast-atom-bombardment mass spectrometry (FAB-MS), we propose the primary structure for 19 major oligosaccharides.

Binding Sites↗
PubMed1989

N-terminal sequence extension in the glycosylated forms of human pancreatic stone protein. The 5-oxoproline N-terminal chain is O-glycosylated on the 5th amino acid residue.

The pancreatic stone protein isolated from human calculi (PSP) derives from the immunoreactive protein forms detected in human pancreatic juice (PSP S2-5) through the tryptic cleavage of the Arg-11-Ile-12 bond. Among the eleven amino acids of the PSP S2-5 N-terminal extension Z-E-A-Q-T-E-L-P-Q-A-R, the first residue is an oxoproline and the fifth, a threonine, bears the single carbohydrate chain of the protein molecules. Variations in the glycan chain composition account for the differences in the Mr of PSP S2-5. The PSP S2-5 forms are very soluble in aqueous solutions between the pH values 5.0-9.0, whereas the proteolysated form is scarcely soluble.

Acetylgalactosamine↗