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Biomedical subjects

G Lamblin

Publications and source records attributed to G Lamblin.

At least 91 records · Page 5Linked to original sources
PubMed1983

Structural studies of the carbohydrate component of a human, parotid-saliva, proline-rich glycoprotein.

The carbohydrate chains of the human, parotid-saliva, proline-rich glycoprotein were released as oligosaccharides by hydrazinolysis and were fractionated by high-pressure-liquid chromatography. Four oligosaccharides were characterized. On the basis of compositional analysis, sequential enzymic degradation, and methylation data, the carbohydrate moiety of the glycoprotein was found to be a complex-type oligosaccharide containing a tri-D-mannosyl-di-N-acetylchitobiose core with two and three lactosamine branches, and an L-fucosyl group linked to O-6 of the asparagine-linked 2-acetamido-2-deoxy-D-glucose residue. In addition, several L-fucosyl groups, linked at O-6 of the penultimate D-galactose residues, are present in variable proportions. The biological significance of these results is discussed.

Carbohydrates↗
PubMed1982

Primary-structure determination of fourteen neutral oligosaccharides derived from bronchial-mucus glycoproteins of patients suffering from cystic fibrosis, employing 500-MHz 1H-NMR spectroscopy.

The structure of carbohydrate units of bronchial-mucus glycoproteins obtained from cystic fibrosis patients was investigated by 500-MHz 1H-NMR spectroscopy and methylation analysis. To that purpose, the mucin was subjected to alkaline borohydride degradation. Neutral oligosaccharide-alditols, ranging in size from disaccharides to pentasaccharides, were isolated. Eight compounds could be purified to homogeneity; furthermore, three fractions were obtained consisting mainly of two components. For all 14 compounds the primary structure could be elucidated. 500-MHz 1H-NMR spectroscopy was found to be effective in detecting heterogeneity and to be invaluable for the determination of structures in mixtures of oligosaccharide-alditols. The structures can be divided into two groups depending on the core disaccharide. One group contains Gal(beta 1 leads to 3)GalNAc-ol as common structural element, the other GlcNAc(beta 1 leads to 3)GalNAc-ol. Both disaccharides were identified as such; the other compounds can be conceived as extensions thereof. The most complex representatives of the two groups are: (formula; see text) The italicized structural elements, comprising the SSEA-1 determinant and the type-1 blood-group-H determinant, are novel sequences in oligosaccharide chains of mucin-type glycoproteins.

Chemical Phenomena↗
PubMed1981

Evidence for the presence of the trimannosyl-di-N-acetylchitobiose core in the carbohydrate chains of human-parotid, proline-rich glycoprotein.

The carbohydrate chains of the human-parotid, proline-rich glycoprotein are linked through a single type of carbohydrate-peptide linkage (asparaginyl-N-acetylglucosamine). The structure of the internal part of the carbohydrate chains, determined by chemical, enzymic, and g.l.c.--m.s. methods, includes the trimannosyl-di-N-acetylchitobiose core involved in the carbohydrate-peptide linkage. Furthermore, an L-fucose residue is linked to the 2-acetamido-2-deoxy-D-glucosyl residue linked to the L-asparaginyl residue. The sequence of the peripheral part of the chains has also been determined as alpha-L-Fuc rho leads to beta-D-Gal rho leads to beta-D-Glc rho NAc leads to alpha-D-Man rho, suggesting a double-branched, basic carbohydrate structure.

Glucans↗
PubMed1981

Comparative action of reducing agents on fibrillar human bronchial mucus under dissociating and non-dissociating conditions.

Gel=like or fibrillar human bronchial mucus was reduced with mercaptoethanol under dissociating and non-dissociating conditions. Bronchial mucus was solubilized in both conditions; but reduction in phosphate buffer induced more extensive depolymerization of mucus glycoproteins than obtained under reduction in guanidine. Moreover, mucins prepared by reduction in non-dissociating conditions contained less amino acid and more carbohydrate. These data strongly suggest that reduction under non-dissociating conditions does not act only on disulfide bridges but also induces the activation of a mucolytic enzymatic system. They also would explain some of the discrepancies observed in the molecular weight determination and chemical composition of human bronchial mucus glycoproteins purified after reduction of gel-like mucus under different conditions.

Bronchi↗
PubMed1980

Oligosaccharides of human bronchial glycoproteins. Neutral di- and trisaccharides isolated from a patient suffering from chronic bronchitis.

Human bronchial glycoproteins from a patient suffering from chronic bronchitis were subjected to alkaline borohydride degradation and a heterogeneous mixture of reduced oligosaccharides and glycopeptides was obtained. The shortest neutral oligosaccharides were subsequently fractionated by DAX4 anion exchange chromatography into 12 fractions. Five major oligosaccharides were purified by preparative paper chromatography. Their structures were determined by using periodic oxidation, methylation analysis, gas liquid chromatography-mass spectrometry, and enzymatic degradation. Two oligosaccharides and three trisaccharides were characterized as galactose (Gal) beta 1 leads to 3 N-acetylgalactosaminitol (GalNActitol), N-acetylglucosamine (GlcNAc) beta 1 leads to 3 GalNActitol, Gal 1 leads to 4 GlcNAc 1 leads to 3 GalNActitol, GlcNAc 1 leads to 3 Gal 1 leads to 3 GalNActitol and fucose alpha 1 leads to 2 Gal beta 1 leads to 3 GalNActitol.

Bronchi↗
PubMed1979

Chemical and physical properties of human bronchial mucus glycoproteins.

Human bronchial mucus glycoproteins of different chemical types were isolated by Ecteola and gel exclusion chromatography. Chemical analysis indicated polydispersity with regard to content of sulfate and sialic acid. No blood group A, B or H activity was found in these glycoproteins. Compositions are reported for amino acid and sugar residues for several fractions obtained from both cystic fibrotic and chronic bronchitic mucus. It is noteworthy that glycoproteins extracted from a single subject contain molecules with different acid groups as well as significant differences in carbohydrate chain length.

Amino Acids↗
PubMed1979

[Variations of various plasma (albumin, prealbumin, retinol binding protein), and urinary parameters during measles in Senegalese children].

In order to evaluate the effect of measles on proteins carrying vitamin A, we have examined 58 children with measles (24 have been seen again 2 weeks later) and 52 healthy controls of similar age and nutritional status. During the course of fever we have observed a high urinary excretion of urea and creatinine with proteinuria while the hydroxyproline index is significantly lower than in the controls. Irrespective of the nutritional status the plasma levels of albumin, prealbumin and R.B.P. are consistantly low. Two weeks later, while the albumin level has decreased, the other parameters are aiming towards normal values. The higher levels of prealbumin and R.B.P. suggest a reactivation of the hepatic protein synthesis. The urinary excretion of R.B.P. has not changed significantly during measles. We have observed rather high urinary losses of R.B.P. in the controls. The low levels of plasma prealbumin possibly do not allow the complete binding of the R.B.P.

Age Factors↗
PubMed1977

[Heterogeneity of carbohydrate chains of acidic bronchial mucin isolated from the spatum of two subjects with chronic bronchitis].

Acidic glycoproteins having blood group H activity were isolated from the sputum of two patients suffering from chronic bronchitis by reduction of the fibrillar mucus, chromatography on ECTEOLA-cellulose and gel filtration on Sepharose 4-B. These glycoproteins were degraded with alkaline borohydride and the degradation products were fractionated by chromatography on ionexchange resins and by gel filtration. The carbohydrate chains have a wide heterogeneity with regard to acidity and molecular size. Therefore carbohydrate chain heterogeneity which was already observed for bronchial glycoproteins isolated from a patient suffering from cystic fibrosis is not specific for cystic fibrosis.

Amino Acids↗
PubMed1977

Affinity of bronchial secretion glycoproteins and cells of human bronchial mucosa for Ricinus communis lectins.

The coupling of Ricinus communis lectins to Sephadex G 25 was used in order to study mucins and other glycoproteins from human bronchial secretion. The major part of human bronchial mucins and other glycoproteins such as immunoglobulins A, bronchotransferrin and alpha1-antichymotrypsin were isolated by this procedure. A parallel study of human bronchial mucosa was achieved with peroxidase labeled Ricinus communis lectins; this study characterized goblet cells and mucous cells which contain mucins, and serous cells which are involved in the synthesis or the secretion of the other glycoproteins.

Amino Acids↗