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Biomedical subjects

L Dorland

Publications and source records attributed to L Dorland.

At least 109 records · Page 6Linked to original sources
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↗
PubMed1982

Characterization of the primary structure and the microheterogeneity of the carbohydrate chains of porcine blood-group H substance by 500-MHz 1H-NMR spectroscopy.

In blood-group H substance from pig stomach cell linings, carbohydrate structures are known to occur which are O-glycosidically linked via GalNAc to Ser or Thr of the polypeptide backbone. They have in common the Gal(beta 1 leads to 3)GalNAc core unit, which bears one or more N-acetyllactosamine branches. The latter are terminated either by Fuc in (alpha 1 leads to 2) linkage or by GlcNAc in (alpha 1 leads to 4) linkage to Gal. Both terminal sequences are considered to be porcine blood-group H antigenic determinants. Employing 500-MHz 1H-NMR spectroscopy, the spectral features of the oligosaccharide-alditols corresponding to these chains were established. Insight could be gained into the microheterogeneity displayed by some of the alditol fractions as to the distribution of the terminating Fuc and GlcNAc residues over the various branches. Such information can hardly be obtained using other approaches.

ABO Blood-Group System↗
PubMed1981

Structure determination of oligosaccharides isolated from A+, H+ and A-H- hog-submaxillary-gland mucin glycoproteins, by 360-MHz 1H-NMR spectroscopy, permethylation analysis and mass spectrometry.

Alkaline borohydride reductive cleavage (beta-elimination) of hog submaxillary glycoproteins from three immunologically determined phenotypes, viz. A+, H+ and A-H-, resulted in the release of a series of neutral and acidic oligosaccharide-alditols. 360-MHz 1H-NMR spectroscopy in combination with methylation analysis and mass spectrometry were used for reinvestigation of the structures of these oligosaccharide-alditols. All are partial structures representing the possible complete and biosynthetically incomplete stages of the chain of a pentasaccharide-N-acetylgalactosaminitol, present in the glycoprotein with blood-group-A activity: (formula: see text) In this way, a prolonged argument about the occurrence of a NeuGc(alpha 2 leads to 6) Gal moiety in these carbohydrate chains, suggested by Aminoff et al. [Aminoff, D., Baig, M. M. and Gathmann, W. D. (1979) J. Biol. Chem. 254, 1788-1793 and 8909-8913] has been brought to a definite end. In the investigated oligosaccharide-alditols N-glycoloylneuraminic acid (NeuGc) is in no case attached to galactose (Gal), but, if present, it is (alpha 2 leads to 6)-linked to N-acetylgalactosaminitol (GalNAc-ol).

Animals↗
PubMed1981

Primary structure of the carbohydrate chain of soybean agglutinin. A reinvestigation by high resolution 1H NMR spectroscopy.

In an earlier report (Lis, H., and Sharon, N. (1978) J. Biol. Chem. 253, 3468-3476) it was concluded that the plant glycoprotein soybean agglutinin contains two types of N-glycosidically linked carbohydrate units, both consisting of mannose and N-acetylgucosamine, in a molar ratio of 9:2. Both were described to have the same core structure, Man alpha (1 leads to 6)[Man alpha (1 leads to 3)]Man beta (1 leads to 4)GlcNAc beta (1 leads to 4)GlcNAc, but different patterns of branching. Here we present data showing that the asparagine-linked carbohydrate moiety of soybean agglutinin is homogeneous and possesses the following structure: (formula, see text) This conclusion is based on high resolution 1H NMR spectroscopy at 500 MHz of the isolated glycopeptide, and at 360 MHz of the oligosaccharide Man9GlcNAc obtained after digestion of the crude soybean agglutinin glycopeptide by endo-beta-N-acetylglucosaminidase H. The revised structure is identical in all respects with that of the high mannose N-glycosidic units of porcine thyroglobulin, of bovine lactotransferrin, and of the glycoprotein from Chinese hamster ovary cell membranes.

Carbohydrate Conformation↗
PubMed1981

Characterization of the microheterogeneity in glycoproteins by 500-MHz 1H-NMR spectroscopy of glycopeptide preparations. Application to a monofucosylated tetra-antennary glycopeptide fraction from human plasma alpha 1-acid glycoprotein.

Five hundred-MHz 1H-NMR spectroscopy was employed to study a monofucosylated tetra-antennary glycopeptide fraction which was derived from human plasma alpha 1-acid glycoprotein. This fraction was earlier judged to be homogeneous by 360-MHz 1H-NMR spectroscopic analysis (Fournet, B., Montreuil, J., Strecker, G., Dorland, L., Haverkamp, J., Vliegenthart, J. F. G., Binette, J. P., and Schmid, K. (1978) Biochemistry 17, 5206-5214). The combination of the improved resolving power and the enhanced sensitivity of the 500-MHz 1H-NMR spectrometer afforded the elucidation of a new type of microheterogeneity with regard to the position of attachment of Fuc. Three isomeric compounds were identified. The major form contains Fuc alpha-(1 leads to 3) linked to GlcNac 7 of the tetra-antennary structure, as shown earlier. The two minor compounds, representing new structures, possess Fuc attached in alpha-(1 leads to 3) linkage to GlcNAc 7' or 5'. It is thus noteworthy that this spectral technique allows elucidation of structures of very closely related carbohydrate chains in a glycopeptide mixture.

Carbohydrate Conformation↗
PubMed1981

Structure determination of two oligomannoside-type glycopeptides obtained from bovine lactotransferrin, by 500 MHz 1H-NMR spectroscopy.

The elucidation of the structures of two carbohydrate units, N-glycosidically linked to an asparagine residue of bovine lactotransferrin, is described. These carbohydrate structures are of the oligomannoside type and contain eight or nine mannose residues, respectively. The potency of 500 MHz 1H-NMR spectroscopy in primary structure determination of two closely related carbohydrate chains present in a mixture is demonstrated. This implies that 500 MHz 1H-NMR spectroscopy can disclose microheterogeneity which is almost untraceable using other approaches.

Animals↗
PubMed1981

Structure determination by 360-MHz 1H-NMR spectroscopy and methylation analysis of a biantennary glycan of the N-acetyllactosaminic type isolated from rat-liver plasma membrane.

Glycopeptides obtained by exhaustive pronase digestion of delipidated rat liver plasmic membranes were purified by gel filtration on Sephadex G-25. These glycopeptides were further fractionated by affinity chromatography on a concanavalin-A--Sepharose 4B column into the following fractions: (a) glycopeptides which did not bind to the column (fraction 1); (b) glycopeptides with weak affinity for concanavalin-A--Sepharose, which could be eluted with buffer only (fraction 2); (c) glycopeptides retained on the column and which could be eluted specifically with buffer containing 0.2 M methyl alpha-glucoside (fraction 3). On the basis of the carbohydrate composition, methylation analysis and 360-MHz 1H-NMR spectroscopy, the following primary structure of a glycan in fraction 2 is proposed: (see formula in text).

Amino Acids↗
PubMed1981

Structures of fifteen oligosaccharides isolated from new-born meconium.

New born meconium contains at least a hundred oligosaccharides. In this study the isolation and characterization of the major constituents is described. The structure elucidation of 15 neutral and acidic oligosaccharides was carried out by methylation analysis, mass spectrometry and 360-MHz 1H-NMR spectroscopy. The results show that the oligosaccharides accumulating in human meconium are probably products of the catabolism of the O- and N-linked carbohydrate chains of glycoproteins. It is proposed that endo-N-acetyl-alpha-D-galactosaminidase, endo-beta-D-galactosidase and endo-N-acetyl-beta-D-glucosaminidase are involved in the production of these compounds.

Carbohydrate Conformation↗
PubMed1980

A 360-MHz 1H-NMR study of three oligosaccharides isolated from cow kappa-casein.

360-MHz 1H-NMR spectra were recorded of NeuAc alpha(2 leads to 3)Gal beta (1 leads to 3)GalNAc-ol (I), Gal beta(1 leads to 3)[NeuAc alpha(2 leads to 6)] GalNAc-ol (II) and NeuAc alpha (2 leads to 3)-Gal beta(1 leads to 3) [NeuAc alpha(2 leads to 6)]GalNAc-ol (III). The chemical shifts and coupling constants of the anomeric protons, the H-3ax and H-3eq of NeuAc, the GalNAc-ol skeleton protons, the H-3 of Gal and the N-acetyl protons of GalNAc-ol and NeuAc provide conclusive evidence for the identification of the primary structures. Compound II represents a novel carbohydrate chain of kappa-casein.

Amino Acid Sequence↗
PubMed1979

The primary structure of the asialo-carbohydrate units of the first glycosylation site of human plasma alpha 1-acid glycoprotein.

The elucidation of the structures of the carbohydrate units linked to glycosylation site I of human plasma alpha 1-acid glycoprotein is described. These carbohydrate units can be grouped into compounds with bi- (class A) and triantennary (class B) structures and the triantennary structure with a fucose residue (class BF) (Fig. 1). The structural variability of the carbohydrate units of glycosylation site I and also of glycosylation sites II to V (Fournet, B., Montreuil, J., Strecker, G., Dorland, L., Haverkamp, J., Vliegenthart, J.F.G., Binette, J.P. and Schmid, K. (1978) Biochemistry 17, 5206--5214) accounts largely for the microheterogeneity of alpha 1-acid glycoprotein.

Carbohydrate Conformation↗
PubMed1979

Investigation by 360-MHz 1H-nuclear-magnetic-resonance spectroscopy and methylation analysis of the single glycan chain of chicken ovotransferrin.

The primary structure of two glycopeptides obtained by pronase digestion of chicken ovotransferrin has been investigated by 360-MHz proton nuclear magnetic resonance (NMR) spectroscopy and methylation analysis. The two glycopeptides differ in amino acid composition but contain the same carbohydrate moiety, viz: (formula: see text). Using the NMR data of some reference compounds the chemical shifts of the anomeric protons and mannose H-2 protons could be predicted with an accuracy of 0.01 ppm.

Animals↗
PubMed1979

2-Acetamidoglucal, a new metabolite isolated from the urine of a patient with sialuria.

A new metabolite, namely 2-acetamidoglucal, has been found in the urine of a patient with sialuria in addition to the metabolites N-acetylneuraminic acid, N-acetylmannosamine, N-acetylglucosamine and 2-deoxy-2,3-dehydro-N-acetylneuraminic acid reported earlier. the structure has been identified by mass spectrometry and 360 MHz proton nuclear magnetic resonance spectroscopy and verified by synthesis. All accumulated compounds fit into the metabolic pathway for the biosynthesis of CMP-N-acetylneuraminic acid. Sialuria is discussed in terms of a failure of regulation of UDP-N-acetylglucosamine 2-epimerase.

Acetylglucosamine↗