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G Lamblin

Publications and source records attributed to G Lamblin.

At least 73 records · Page 4Linked to original sources
PubMed1988

Primary structure of neutral oligosaccharides derived from respiratory-mucus glycoproteins of a patient suffering from bronchiectasis, determined by combination of 500-MHz 1H-NMR spectroscopy and quantitative sugar analysis. 1. Structure of 16 oligosaccharides having the Gal beta(1----3)GalNAc-ol core (type 1) or the Gal beta(1----3)[GlcNAc beta(1----6)]GalNac-ol core (type 2).

Carbohydrate chains of respiratory-mucus glycopeptides from a patient (blood group O) suffering from bronchiectasis with a Kartagener's syndrome have been released by alkaline borohydride treatment. Application of high-performance liquid chromatography using subsequently two silica columns, one bonded with aminopropyl groups and the other with octadecyl groups, afforded 39 neutral fractions; 35 oligosaccharide-alditol structures have been characterized by employing 500-MHz 1H-NMR spectroscopy in conjunction with sugar analysis. Here, 16 oligosaccharide structures, possessing a core consisting of Gal beta(1----3)GalNAc-ol branching through a GlcNAc residue linked beta(1----6) to the GalNAc residue (core type 2 or core type 1, respectively), are described. Ten oligosaccharide-alditols with these types of cores (2, 3, 10a, 14, 7, 11a, 15a, 16a, 12 and 16c) have been identified previously in human bronchial mucins of patients suffering from cystic fibrosis [Lamblin, G., Boersma, A., Lhermitte, M., Roussel, P., Mutsaers, J.H.G.M., Van Halbeek, H. and Vliegenthart, J.F.G. (1984) Eur. J. Biochem. 143, 227-236]. Of the remaining six compounds, one is a partial structure of oligosaccharides previously described: (Formula: see text). The structures 17a and 20 contain the Y determinant, i.e., Fuc alpha(1----2)Gal beta(1----4)[Fuc alpha(1----3)]GlcNAc beta(1----). High-resolution 1H-NMR spectroscopy is able to distinguish whether the Y determinant is beta(1----3) or beta(1----6) linked in such oligosaccharide-alditols.

Bronchiectasis↗
PubMed1988

Primary structure of neutral oligosaccharides derived from respiratory-mucus glycoproteins of a patient suffering from bronchiectasis, determined by combination of 500-MHz 1H-NMR spectroscopy and quantitative sugar analysis. 2. Structure of 19 oligosaccharides having the GlcNAc beta(1----3)GalNAc-ol core (type 3) or the GlcNAc beta(1----3)[GlcNAc beta(1----6)]GalNAc-ol core (type 4).

A pool of neutral carbohydrate chains was prepared from respiratory mucins of a patient suffering from bronchiectasis. Fractionation by HPLC led to 35 smaller-size oligosaccharide-alditols; the structure of 16 oligosaccharide-alditols with core type 1 or type 2 has been established (Klein, A., Lamblin, G., Lhermitte, M., Roussel, P., Breg, J., Van Halbeek, H. & Vliegenthart, J.F.G., preceding paper in this journal). In this second part, we identified 19 oligosaccharide-alditols possessing core types 3 and 4. Nine of the structures (1, 5, 9, 6, 10b, 13, 19, 15b and 18.1) have been described previously to be present in cystic fibrosis mucins [Lamblin, G., Boersma, A., Lhermitte, M., Roussel, P., Mutsaers, J.G.H. M., Van Halbeek, H. & Vliegenthart, J.F.G. (1984) Eur. J. Biochem. 143, 227-234]. The remaining ten are new structures isolated from bronchial mucins; they are all extensions of the above-mentioned nine oligosaccharides. These compounds are octassaccharide-alditols containing the Y determinant together with the H determinant of either backbone-type 1 or 2, and partial structures thereof: (Formula: see text) and 21b, which is 23c without Fuc alpha(1----3), 18.2, which is 23c without any Fuc in the 6-branch, and 22b, which is 23c without Fuc in the 3-branch.

Bronchiectasis↗
PubMed1988

The complexity of mucins.

Mucins represent the main components of gel-like secretions, or mucus, secreted by mucosae or some exocrine glands. These high-molecular-weight glycoproteins are characterized by the large number of carbohydrate chains O-glycosidically linked to the peptide. The determination of mucin molecular weight and conformation has been controversial for several reasons: 1) the methods used to solubilize mucus and to purify mucins are different and 2) the molecules have a strong tendency to aggregate or to bind to other molecules (peptides or lipids). Recently, electron microscopy has shown the filamentous shape of most mucins and their polydisperse character which, in some secretions, might correspond to a polymorphism of the peptide part of these molecules. The recent development of high pressure liquid chromatography and high-resolution proton NMR spectroscopy has allowed major progress in the structural study of mucin carbohydrate chains. These chains may have from 1 to about 20 sugars and bear different antigenic determinants, such as A, B, H, I, i, X, Y or Cad antigens. In some mucins, such as human respiratory mucins, the carbohydrate chain diversity is remarkable, which raises many questions. Mucins are molecules located at the interface between mucosae and the external environment. The carbohydrate chain diversity might allow many interactions between mucins and microorganisms and play a major role in the colonization or the defense of mucosae.

Animals↗
PubMed1988

Characterization of deglycosylated human urinary colony-stimulating factor (CSF-1).

1. Isolation of CSF-1 from human urine was performed through five purification steps. These include concentration by dialysis, silica gel absorption, hydrophobic chromatography and phenyl-Sepharose CL-6B, Fast Protein Liquid Chromatography (FPLC) and finally preparative electrophoresis on polyacrylamide gels. These methods have been reported in a previous paper (Tao et al., 1987). 2. The isolated CSF-1 which exhibits a one band pattern on SDS-PAGE under non-reducing conditions after Coomassie Blue and silver stainings. CSF-1 was purified 100,000-fold and has a specific activity of 2.16 x 10(7) units/mg protein. Its apparent Mr is 57,000 with an isoelectric point pI = 5.8-6.0 CSF-1 is a glycoprotein with 40% of carbohydrate (w/w). 3. An almost complete removal of the carbohydrate moiety from CSF-1 was obtained after treatment with trifluoromethanesulfonic (TFMS) acid followed by gel filtration on Sephadex G-25 (Fine). The deglycosylated (DG) CSF-1 possesses an apparent Mr of 38,000 and an isoelectric point, pI: 6.2 as compared to native-CSF-1 (N-CSF-1), Mr = 57,000 and pI = 5.8 respectively. 4. The TFMS treatment did not alter the activities of CSF-1 as shown by biological assay and receptor binding assay. The thermostability experiment revealed that DG-CSF-1 was less stable than N-CSF-1. The circular dichroism spectra (CD) of N-CSF-1 and DG-CSF-1 were different. 5. The features of interaction of iodinated-N-CSF-1 and iodinated-DG-CSF-1 with single cell suspensions from human peritoneal macrophage were studied. The binding activity of peritoneal macrophage was the highest among all cells examined.(ABSTRACT TRUNCATED AT 250 WORDS)

Colony-Stimulating Factors↗
PubMed1987

Peptides of human bronchial mucus glycoproteins. Size determination by electron microscopy and by biosynthetic experiments.

Secreted human bronchial mucins, directly collected from macroscopically healthy bronchial mucosa, were prepared in the presence of six proteinase inhibitors, and analysed by electron microscopy. These mucins were similar in length distribution to molecules prepared from sputum [Slayter, Lamblin, Le Treut, Galabert, Houdret, Degand & Roussel (1984) Eur. J. Biochem. 142, 209-218], although they were a little longer, their lengths ranging up to about 1,650 nm. This length corresponds to an extended mucin peptide of about 450 kDa. In order to compare these peptide lengths with the molecular size of biosynthetic precursors, an antiserum raised against trifluoromethanesulphonic acid-treated highly glycosylated regions of human bronchial mucins was used to isolate mucin precursors synthesized in explants of human bronchial mucosa during pulse-labelling with [3H]threonine or [3H]glucosamine. A main precursor labelled with [3H]threonine and with an apparent molecular mass of about 400 kDa was detected by fluorography following SDS/polyacrylamide-gel electrophoresis. This band was observed as early as 20 min; it was more intense after a 40 min chase and had disappeared after a chase period of 280 min in unlabelled medium, presumably owing to glycosylation. Much fainter bands at about 200 kDa and between 200 and 400 kDa, also labelled with [3H]threonine, were observed mainly after a 40 min chase and had disappeared after a 280 min chase. None of these bands was labelled with [3H]glucosamine, nor did they disappear after multiple treatments with immobilized lectins. After a 280 min chase, [3H]threonine-labelled material appeared in the stacking gel, which also contained [3H]glucosamine label. The results indicate that the 200-400 kDa species are mucin precursors, whose size is comparable with that obtained by electron microscopy for respiratory mucins collected directly from the macroscopically healthy bronchial mucosa.

Bronchi↗
PubMed1987

Structure of sialyl-oligosaccharides isolated from bronchial mucus glycoproteins of patients (blood group O) suffering from cystic fibrosis.

The carbohydrate chains of the bronchial-mucus glycoproteins of six cystic fibrosis patients with blood group O were released by alkaline borohydride treatment. Low-molecular-mass, monosialyl oligosaccharide-alditols were isolated by anion-exchange chromatography and fractionated by high-performance liquid chromatography. Structural characterization was performed by 500-MHz 1H-NMR spectroscopy in combination with quantitative sugar analysis. The established structures range in size from tetra- up to heptasaccharides. They are all sialyl analogs of neutral oligosaccharides that were characterized previously [Lamblin G., Boersma A., Lhermitte M., Roussel P., Mutsaers J. H. G. M., Van Halbeek H. & Vliegenthart J. F. G. (1984) Eur. J. Biochem. 143, 227-236]. The NeuAc residue was found to occur either in alpha (2----3)-linkage to Gal, or in alpha (2----6)-linkage to GalNAc-ol or Gal.

ABO Blood-Group System↗
PubMed1987

Isolation and characterization of human urinary colony-stimulating factor.

CSF-1 was isolated from a large volume of human normal urine (10,000 l), using the following 5 stages of purification: concentration by dialysis, silica gel adsorption, hydrophobic chromatography on phenyl-Sepharose CL-6B, fast protein liquid chromatography (FPLC) and finally preparative electrophoresis on polyacrylamide gels. We have isolated 8 mg of purified CSF-1 which migrated as a single band under non-reducing conditions in SDS-PAGE (staining with Coomassie Blue and the sensitive silver techniques). But in the presence of dithiothreitol, the SDS-PAGE pattern revealed a minor second band with a molecular mass of 50,000 Da. CSF-1 was purified 100,000-fold and has a specific activity of 2.16 X 10(7) units/mg protein. Its apparent molecular mass is 57,000 Da with an isoelectric point, pI = 5.8-6.0. The amino-acid composition is reported and compared with that of murine CSF-1. The carbohydrate content (sialic acid, sulphate groups, N-acetylglucosamine, N-acetylgalactosamine) was also determined, and it shows that CSF is a glycoprotein.

Amino Acids↗
PubMed1986

Action of trifluoromethanesulfonic acid on highly glycosylated regions of human bronchial mucins.

Highly glycosylated glycopeptides were prepared from human bronchial mucus. They were heterogeneous and contained an average of 45 residues of glycosylated hydroxyamino acid per 100 amino acid residues. The kinetics of deglycosylation of these glycopeptides by trifluoromethanesulfonic acid-anisole mixtures at 25 degrees was monitored by chemical analysis and by polyacrylamide gel electrophoresis. The peripheral sugars were almost completely cleaved in 45 min with 3:2 and 2:1 CF3SO3H-anisole. A maximum of 75% of the O-linked N-acetylgalactosamine residues were released and mixtures of glycopeptides and peptides were obtained. Increasing the reaction time caused peptide bond cleavage. Rather mild conditions (1.2:1 CF3SO3H-anisole at 25 degrees for 90 min) gave limited deglycosylation of highly glycosylated bronchial glycopeptides, allowing the uncovering of GalNAc-peptide linkages and peptide regions able to induce the formation of specific antibodies in the rabbit.

Amino Acids↗
PubMed1986

Structure of sialyloligosaccharides isolated from bonnet monkey (Macaca radiata) cervical mucus glycoproteins exhibiting multiple blood group activities.

Mucin glycoproteins purified from cervical epithelial secretion of the bonnet monkey (Macaca radiata) exhibit multiple blood group activities. Alkaline borohydride reductive cleavage resulted in a mixture of neutral and acidic oligosaccharide-alditols. By high-performance liquid chromatography, seven oligosaccharides (A-4-1 to A-4-7) have been purified from the monosialyloligosaccharide fraction (A-4). Based on the results of 500-MHz 1H NMR spectroscopy, in conjunction with sugar analysis and immunological assays, we propose the following structures for these oligosaccharides. (formula: see text) These structures imply that either the A, B, or H determinant may be found in combination with the Cad/Sda determinant; the oligosaccharides identified, together, account for the blood group activities exhibited by the cervical mucus.

Animals↗
PubMed1986

The high lipid content of respiratory mucins in cystic fibrosis is related to infection.

Seven human bronchial mucins secreted by patients suffering from chronic bronchitis or from cystic fibrosis were prepared by exclusion from a Sepharose CL-2B column in 6 M guanidinium chloride. Their behaviour in CsBr density gradient centrifugation was compared. The mucin fractions were associated with peptides and lipids, the abundance of which decreases with the buoyant density. The lipid content of the mucin fractions appears to be related to the infectious character of the bronchial secretion and seems to be independent of cystic fibrosis. The content of fatty acids remaining after delipidation of mucin fractions from patients with chronic bronchitis or with cystic fibrosis also appears to be related more to the purulent character of the sputum than to cystic fibrosis or chronic bronchitis.

Bronchi↗
PubMed1985

The phosphate diester linkage of the peptidoglycan polysaccharide moieties of Micrococcus lysodeikticus cell wall.

The external polysaccharide is a major component of Micrococcus lysodeikticus cell wall and displays distinct composition. The complete structure of the external polysaccharide had been elucidated as a basis for investigation of the cell wall structure-function relation. However, the mode of attachment of the polysaccharide to the peptidoglycan through a phosphodiester was not clear due to limitations in structural and biosynthetic studies. The present study describes purification of a lysozyme-resistant nondialyzable high-molecular-weight fragment of cell wall and identifies the sugar, D-glucose, as the point of external polysaccharide attachment to the peptidoglycan through a phosphate diester. Kinetic studies for the acid-catalyzed release of external polysaccharide from the peptidoglycan were performed in parallel with synthetic [methyl-2-acetamido-3-O-(D-1-carboxyethyl)-2-deoxy-alpha-D- glucopyranoside-6-yl]-alpha-D-glucopyranosyl phosphate and alpha-D-glucopyranosyl phosphate and showed the presence of a phosphodiester linkage between external polysaccharide and peptidoglycan. In addition, type of phosphate residue and cross-linking between muramic acid and protein part have been determined.

Amino Acids↗
PubMed1984

Further characterization, by a combined high-performance liquid chromatography/1H-NMR approach, of the heterogeneity displayed by the neutral carbohydrate chains of human bronchial mucins.

From bronchial mucins of cystic fibrosis patients with blood group O, the carbohydrate chains were released in the form of oligosaccharide-alditols by alkaline borohydride treatment. Application of high-performance liquid chromatography directly on the pool of neutral oligosaccharides afforded 23 fractions. Twenty oligosaccharide structures were characterized by employing 500-MHz 1H-NMR spectroscopy in conjunction with sugar analysis. Thirteen among these had been revealed before to occur in human bronchial mucins [Van Halbeek, H., Dorland, L., Vliegenthart, J. F. G., Hull, W. E., Lamblin, G., Lhermitte, M., Boersma, A., and Roussel, P. (1982) Eur. J. Biochem. 127, 7-20], when paper-chromatographic fractionation of this pool of neutral oligosaccharides was employed. High-performance liquid chromatography enabled to obtain another seven pentasaccharide and hexasaccharide alditols; the largest-size representatives are: (Formula see text). Thereby, this approach afforded deeper insight into the structural heterogeneity displayed by the carbohydrate chains of bronchial mucins.

Bronchi↗
PubMed1984

Primary structure determination of five sialylated oligosaccharides derived from bronchial mucus glycoproteins of patients suffering from cystic fibrosis. The occurrence of the NeuAc alpha(2----3)Gal beta(1----4)[Fuc alpha(1----3)] GlcNAc beta(1----.) structural element revealed by 500-MHz 1H NMR spectroscopy.

The structure of sialylated carbohydrate units of bronchial mucins obtained from cystic fibrosis patients was investigated by 500-MHz 1H NMR spectroscopy in conjunction with sugar analysis. After subjecting the mucins to alkaline borohydride degradation, sialylated oligosaccharide-alditols were isolated by anion-exchange chromatography and fractionated by high performance liquid chromatography. Five compounds could be obtained in a rather pure state; their structures were established as the following: A-1, NeuAc alpha(2----3)Gal beta(1----4) [Fuc alpha(1----3)]GlcNAc beta(1----3)Gal-NAc-ol; A-2, NeuAc alpha(2----3)Gal beta(1----4)GlcNAc beta(1----6)-[GlcNAc beta (1----3)]GalNAc-o1; A-3, NeuAc alpha(2----3)Gal beta-(1----4)[Fuc alpha(1----3)]GlcNAc beta(1----3)Gal beta(1----3) GalNAc-o1; A-4, NeuAc alpha(2----3)Gal beta(1----4)[Fuc alpha(1----3)]Glc-NAc NAc beta(1----6)[GlcNAc beta(1----3)]GalNAc-o1; A-6,NeuAc alpha-(2----3) Gal beta(1----4)[Fuc alpha(1----3)]GlcNAc beta(1----6)[Gal beta-(1----4) GlcNAc beta(1----3)]GalNAc-o1. The simultaneous presence of sialic acid in alpha(2----3)-linkage to Gal and fucose in alpha(1----3)-linkage to GlcNAc of the same N-acetyllactosamine unit could be adequately proved by high resolution 1H NMR spectroscopy. This sequence constitutes a novel structural element for mucins.

Bronchi↗
PubMed1984

Complex structure of human bronchial mucus glycoprotein.

Human bronchial mucus glycoproteins or mucins were isolated from the sputum of two patients by a method avoiding reducing agents and involving water extraction and gel filtration on Sepharose CL-2B in 6 M guanidinium chloride. The chemical analysis indicated approximately 25-40% lipid. The amino acid and carbohydrate analysis differ quantitatively from that of mucins purified after prior reduction of mucus. These fractions also have a higher proportion of aspartic and glutamic acids than that of the mucins from reduced sputum. These mucins are still contaminated by small amounts of peptides but do not seem to contain disulfide-attached cross-linking protein. Human bronchial mucins have a strong tendency to form aggregates except in 6 M guanidinium chloride. Electron microscopy performed with various procedures indicates the presence of both micelles and flexible threads measuring 200-1000 nm. Delipidation removes most of the micellar forms. Thereafter mucins appear mainly as polydisperse flexible extended threads and also as aggregates. These features of bronchial mucins do not fit with the generally accepted idea of mucin subunits linked by disulfide bridges (unless they are linked end to end) and alternatively favour a model where mucin molecules behave like filaments that could easily aggregate according to the solvent system (mucin concentration, absence of dissociating conditions).

Amino Acids↗
PubMed1983

Activation of bronchial mucin proteolysis by 4-aminophenylmercuric acetate and disulphide bond reducing agents.

High molecular weight bronchial glycoproteins, as nearly native as possible, were treated with either 2-mercaptoethanol or 4-aminophenylmercuric acetate (APMA): analytical electrophoresis revealed that a decrease in molecular weight of glycoproteins coincided with the disappearance of some proteins associated with high molecular weight bronchial glycoproteins. These modifications were not observed if high molecular weight bronchial glycoproteins were incubated with paramethylsulphonyl fluoride and EDTA, two synthetic protease-inhibitors, prior to 2-mercaptoethanol or APMA action. These data suggest that protease-antiprotease complexes are associated with bronchial mucins and that reducing agents or APMA activate proteases.

Bronchi↗