The structure of the O-glycosidic oligosaccharide chains of the major Zajdela hepatoma ascites-cell-membrane glycoprotein

Glycoprotein MII2, the major cell surface glycoprotein (molecular mass 110 kDa) of Zajdela hepatoma ascites cells, contains about 25 O-glycosidic oligosaccharide chains per molecule. They were released as oligosaccharide-alditols by alkaline borohydride treatment of MII2, and purified by gel filtration on Bio-Gel P-6 followed by high-voltage paper electrophoresis. Four oligosaccharide-alditol fractions (A-D) were obtained in relative yields of 8:6:3:3. The structure of the components of fractions A-C was determined by 500-MHz 1H-NMR spectroscopy in combination with sugar composition analysis, to be as follows. (A) NeuAc alpha(2----3)Gal beta(1----3)[NeuAc alpha(2----3)Gal beta(1----4)GlcNAc beta(1----6)]GalNAc-ol; (B1) NeuAc alpha(2----3)Gal beta(1----3)[Gal beta(1----4)GlcNAc beta(1----6)]GalNAc-ol; (B2) Gal beta(1----3)[NeuAc alpha(2----3)Gal beta(1----4)GlcNAc beta(1----6)]GalNAc-ol; (C) NeuAc alpha(2----3)Gal beta(1----3)GalNAc-ol. On the basis of sugar composition and characteristics on Bio-Gel P-6 filtration, paper electrophoresis and thin-layer chromatography, the structure of the carbohydrate component of fraction D is proposed to be as follows. (D) NeuAc alpha(2----3)Gal beta(1----3)[NeuAc alpha(2----6)]GalNAc-ol     

Characterization of O-glycosidically linked oligosaccharides of rat erythrocyte membrane sialoglycoproteins

The carbohydrate units of the rat erythrocyte membrane sialoglycoprotein rSGP-4 [Edge, A. S. B., & Weber, P. (1981) Arch. Biochem. Biophys. 209, 697-705] have been characterized. All of the carbohydrate of this Mr 19,000 glycoprotein occurs in O-glycosidic linkage to the peptide; following alkaline borohydride treatment and chromatography on Bio-Gel P-2, sialic acid containing oligosaccharides terminating in N-acetylgalactosaminitol were obtained. Their structures were determined by compositional analysis, exoglycosidase digestions, alkaline sulfite degradation, and periodate oxidation. The oligosaccharides were characterized for molecular weight and linkage by direct chemical ionization and gas-liquid chromatography/mass spectrometry, respectively. The structures are proposed to be NeuAc alpha 2----3Gal beta 1----3GalNAc-ol, Gal beta 1----3(NeuAc alpha 2----6)GalNAc-ol, NeuAc alpha 2----3Gal beta 1----3(NeuAc alpha 2----6)GalNAc-ol, and NeuAc alpha 2----3Gal beta 1----3(NeuAc alpha 2----3Gal beta 1----4GlcNAc beta 1----6)GalNAc-ol. Two of the N-acetylglucosamine-containing hexasaccharides were present per molecule of rSGP-4 along with two trisaccharides and seven tetrasaccharides.     

Structure determination of oligosaccharides isolated from Cad erythrocyte membranes by permethylation analysis and 500-MHz 1H-NMR spectroscopy

Alkaline borohydride reductive cleavage (beta-elimination) of glycophorin A isolated from one individual of the rare blood group Cad, resulted in the release of six acidic oligosaccharide-alditols which were separated by high-performance liquid chromatography (HPLC) on an alkyl amine silicagel column. The structure of four of them has been determined by the application of methanolysis, methylation analysis and 1H-NMR spectroscopy at 500 MHz. The structures and relative amounts were as follows: oligosaccharide 1: NeuAc(alpha 2-3)Gal(beta 1-3)GalNAc-ol (3.5%); oligosaccharide 3: GalNAc(beta 1-4)[NeuAc(alpha 2-3)]Gal(beta 1-3)GalNAc-ol (10.5%); oligosaccharide 5: NeuAc(alpha 2-3)Gal(beta 1-3)[NeuAc(alpha 2-6)]GalNAc-ol (10.4%); oligosaccharide 6: GalNAc(beta 1-4)[NeuAc(alpha 2-3)]Gal(beta 1-3)[NeuAc(alpha 2-6)]GalNAc-ol (71.2%). The two other oligosaccharides (2 and 4) were obtained in very low amount. The major pentasaccharide (oligosaccharide 6) carries the blood group Cad determinant and is a potent inhibitor of human anti-Sda antibody.     

A B72.3 second-generation-monoclonal antibody (CC49) defines the mucin-carried carbohydrate epitope Gal beta(1-3) [NeuAc alpha(2-6)]GalNAc

Mucus glycoproteins from bovine seminal plasma were demonstrated to express the MAbs CC49- and B72.3-defined epitopes on TAG 72 antigen. Inhibition studies with reductively cleaved mucin O-glycans from bovine seminal plasma and submaxillary glands revealed that CC49 binds specifically to a core-type sialyl-oligosaccharide alditol (fraction 2c), which could be defined with regard to its primary structure by FAB- and EI-mass spectrometry combined with methylation analysis: (formula; see text) Structurally related alditols NeuAc alpha(2-6)-GalNAc-ol, Gal beta(1-3)GalNAc-ol, NeuAc alpha(2-3)-Gal beta(1-3) [NeuAc alpha(2-6)] GalNAc-ol, GlcNAc beta(1-3) [NeuAc alpha(2-6)] GalNAc-ol or NeuAc alpha(2-3) Gal beta(1-3)GalNAc-ol were not inhibitory.     

The structures of the carbohydrate moieties of bovine blood coagulation factor X

Bovine blood coagulation factor X contains both asparagine-linked and threonine-linked oligosaccharides. The asparagine-linked chain is a mixture of a tridecasaccharide NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc and a dodecasaccharide NeuAc alpha 2 leads to 6 Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc and their partial desialylation products. The threonine-linked chain is a mixture of NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GalNAc, NeuAc alpha 2 leads to 3Gal beta 1 leads to 3(NeuGly alpha 2 leads to 6)GalNAc, NeuGly alpha 2 leads to 3Gal beta 1 leads to 3 (NeuAc alpha 2 leads to 6)GalNAc, and NeuGly alpha 2 leads to 3Gal beta 1 leads to 3(NeuGly alpha 2 leads to 6)GalNAc, and their partial desialized forms. The carbohydrate moieties of the factor X subgroups, factors X1 and X2, are identical.     

Biosynthesis of the O-glycosidically linked oligosaccharide chains of fetuin. Indications for an alpha-N-acetylgalactosaminide alpha 2 leads to 6 sialyltransferase with a narrow acceptor specificity in fetal calf liver

Fetal calf liver microsomes were found to be capable of sialylating 14C-galactosylated ovine submaxillary asialomucin. The main oligosaccharide product chain could be obtained by beta-elimination under reductive conditions and was identified as NeuAc alpha 2 leads to 3Gal beta 1 leads to 3GalNAcol (where GalNAcol represents N-acetylgalactosaminitol) by means of high performance liquid chromatography (HPLC) analysis and methylation. The branched trisaccharide Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)-GalNAcol and the disaccharide NeuAc alpha 2 leads to 6GalNAcol were not formed. Very similar results were obtained when asialofetuin and antifreeze glycoprotein were used as an acceptor. When 3H-sialylated antifreeze glycoprotein ([3H]NeuAc alpha 2 leads to 3Gal beta 1 leads to 3GalNAc-protein) was incubated with fetal calf liver microsomes and CMP-[14C]NeuAc, a reduced tetrasaccharide could be isolated. The structure of this product chain appeared to be [3H]NeuAc alpha 2 leads to 3Gal beta 1 leads to 3([14C]NeuAc alpha 2 leads to 6)GalNAcol, as established by means of HPLC analysis, specific enzymatic degradation with Newcastle disease virus neuraminidase, and periodate oxidation. These data indicate that fetal calf liver contains two sialyltransferases involved in the biosynthesis of the O-linked bisialotetrasaccharide chain. The first enzyme is a beta-galactoside alpha 2 leads to 3 sialyltransferase which converts Gal beta 1 leads to 3 GalNAc chains to the substrate for the second enzyme, a (NeuAc alpha 2 leads to 3Gal beta 1 leads to 3)GalNAc-protein alpha 2 leads to 6 sialyltransferase. The latter enzyme does not sialylate GalNAc or Gal beta 1 leads to 3GalNAc units but is capable of transferring sialic acid to C-6 of GalNAc in NeuAc alpha 2 leads to 3Gal beta 1 leads to 3GalNAc trisaccharide side chains, thereby dictating a strictly ordered sequence of sialylation of the Gal beta 1 leads to 3 GalNAc units in fetal calf liver.     

Immunochemical studies on blood groups. Purification and characterization of radioactive 3H-reduced di- to hexasaccharides produced by alkaline beta-elimination-borohydride 3H reduction of Smith degraded blood group A active glycoproteins

Treatment of blood group A active glycoprotein from human ovarian cyst fluid by one stage of Smith degradation followed by alkaline beta-elimination in the presence of NaB[ 3H4 ] (Carlson degradation) liberated tritiated oligosaccharide alditols. The carbohydrate mixture was fractionated by gel filtration, elution from charcoal, paper chromatography, and high pressure liquid chromatography. Structures were established based on sugar composition, periodate oxidation, methylation analysis, and analysis of oligosaccharide alditols as permethylated and N-trifluoroacetylated derivatives by gas-liquid chromatography-mass spectrometry. The following structures have been deduced: Gal beta 1----3GalNAc-ol, GlcNAc beta 1---- 6GalNAc -ol, Gal beta 1---- 3GlcNAc beta 1----6(3-deoxy)GalNAc-ol, Gal beta 1---- 3GlcNAc beta 1---- 6GalNAc -ol, Gal beta 1----4GlcNAc beta 1---- 6GalNAc -ol, GlcNAc beta 1----3Gal beta 1----3GalNAc-ol, Gal beta 1----3[GlcNAc beta 1----6]GalNAc-ol, Gal beta 1----3[Gal beta 1----4GlcNAc beta 1----6]GalNAc-ol, Gal beta 1---- 3GlcNAc beta 1----3Gal beta 1----3GalNAc-ol, GlcNAc beta 1----3Gal beta 1----4GlcNAc beta 1---- 6GalNAc -ol, GlcNAc beta 1----3Gal beta 1----3[Gal beta 1----4GlcNAc beta 1----6]GalNAc-ol, Gal beta 1---- 3GlcNAc beta 1----3Gal beta 1---- 3GlcNAc beta 1----3Gal beta 1----3Gal beta 1----3GalNAc-ol, Gal beta 1---- 3GlcNAc beta 1----3[Gal beta 1----4GlcNAc beta 1----6]Gal beta 1----3GalNAc-ol, Gal beta 1---- 3GlcNAc beta 1----3Gal beta 1----3[Gal beta 1----4GlcNAc beta 1----6]GalNAc-ol. The smaller structures represent pieces of the larger structures. Together they provide direct evidence for the core structure of the carbohydrate side chains in the blood group substances as proposed by K. O. Lloyd and E. A. Kabat [1968) Proc. Natl. Acad. Sci. U.S.A. 61, 1470-1477). Oligosaccharides previously isolated after Carlson degradation of intact human ovarian cyst fluid HLeb , Lea, and B substances and from human and horse B substances contained various alpha-linked L- fucopyranose and alpha-linked Gal substitutions on the composite structure.(ABSTRACT TRUNCATED AT 400 WORDS)     

The structures of N- and O-glycosidic carbohydrate chains of a chondroitin sulfate proteoglycan isolated from the media of the human aorta

A large Mr chondroitin sulfate proteoglycan was extracted from the media of human aorta under dissociative conditions and purified by density-gradient centrifugation, ion-exchange chromatography, and gel filtration chromatography. Removal of a contaminating dermatan sulfate proteoglycan was accomplished by reduction, alkylation and rechromatography on the gel filtration column. After chondroitinase ABC treatment, the proteoglycan core was separated from a residual heparan sulfate proteoglycan by a third gel filtration chromatography step. As assessed by radioimmunoassay, the isolated proteoglycan core was free of link protein, but possessed epitopes that were recognized by antisera against the hyaluronic acid binding region of bovine cartilage proteoglycan as well as those that were weakly recognized by anti-keratan sulfate antisera. Following beta-elimination of the protein core, the liberated low Mr oligosaccharides were partially resolved by Sephadex G-50 chromatography, and their primary structure was determined by 500-MHz1H NMR spectroscopy in combination with compositional sugar analysis. The N-glycosidic carbohydrate chains, which were obtained as glycopeptides, were all biantennary glycans containing NeuAc and Fuc; microheterogeneity in the NeuAc----Gal linkage was detected in one of the branches. The N-glycosidic glycans have the following overall structure: (Formula: see text). The majority of the O-glycosidic carbohydrate chains bound to the protein core were found to be of the mucin type. They were obtained as glycopeptides and oligosaccharide alditols, and possessed the following structures: NeuAc alpha(2----3)Gal beta(1----3)GalNAc-ol, [NeuAc alpha(2----3)Gal beta(1----3)[NeuAc alpha(2----6)]GalNAc-ol, and NeuAc alpha-(2----3) Gal beta(1----3)[NeuAc alpha(2----3)Gal beta(1----4)GlcNAc beta(1----6)] GalNAc-ol. The remainder of the O-glycosidic carbohydrate chains bound to the isolated proteoglycan were the hexasaccharide link regions of the chondroitin sulfate chains that remained after chondroitinase ABC treatment of the native molecule. These latter glycans, which were obtained as oligosaccharide alditols, had the following structure (with GalNAc free of sulfate or containing sulfate bound at either C-4 or C-6): delta 4,5GlcUA beta(1----3)GalNAc beta(1----4)GlcUA beta(1----3)Gal beta(1----3)Gal beta(1----4)Xyl-ol.     

A new ganglioside of the lactotetraose series, GalNAc-3'-isoLM1, detected in human meconium

A monoclonal antibody produced by immunization with cells of the human glioma cell line D-54 MG reacted with ganglioside GM2. The binding epitope of the antibody was found to be GalNAc beta 1-4(NeuAc alpha 2-3)Gal. Immunological detection of glycolipid antigens on thin-layer plates with this monoclonal antibody, DMAb-1, revealed the presence of a new ganglioside. This ganglioside, co-migrating with NeuAc alpha 2-6Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer(6'-LM1) and GalNAc beta 1-4(NeuAc alpha 2-3)Gal beta 1-3GalNAc beta 1-4Gla beta 1-4Glc beta 1-1Cer (GalNAc-isoGM1) at chromatographic separation was isolated from human meconium. Its structure was determined by permethylation and fast atom bombardment-mass spectometry analyses. The new ganglioside was found to be a combination of the lacto and ganglio series gangliosides, and the structure found to be GalNAc beta 1-4(NeuAc alpha 2-3)Gal beta 1-3GlcNAc alpha 1-3Gal beta 1-4Glc beta 1-1Cer(GalNAc-3'-isoLM1).     

Gangliosides GM2, IV4GalNAcGM1b, and IV4GalNAcGC1a as antigens for monoclonal immunoglobulin M in neuropathy associated with gammopathy

It was previously reported that monoclonal IgM from two patients with gammopathy and neuropathy showed similar specificity by reacting with the same group of unidentified minor components in the ganglioside fractions of human nervous tissues (Ilyas, A. A., Quarles, R. H., Dalakas, M. C., and Brady, R. O. (1985) Proc. Natl. Acad. Sci. U. S. A. 82, 6697-6700). Enzymatic degradation, ion-exchange chromatography, and immunostaining of purified ganglioside standards on thin-layer chromatograms have now revealed that the antigenic glycolipids recognized by the IgM from these patients are gangliosides GalNAc beta 1-4Gal(3-2 alpha NeuAc)beta 1-4Glc beta 1-1Cer(GM2), GalNAc beta 1-4Gal(3-2 alpha NeuAc)beta 1-3GalNAc beta 1-4Gal beta 1-4Glc beta 1-1Cer (IV4GalNAcGM1b), and GalNAc beta 1-4Gal(3-2 alpha NeuAc)beta 1-3GalNAc beta 1-4 beta Gal(3-2 alpha NeuAc)beta 1-4Glc beta 1-1-Cer (IV4GalNAcGD1a). The monoclonal IgM appears to be reacting with the terminal [GalNAc beta 1-4Gal(3-2 alpha NeuAc)beta 1-] moiety shared by these three gangliosides and is a useful probe for detecting small amounts of GM2, IV4GalNAcGM1b, IV4GalNAcGD1a, and other gangliosides with the same terminal sugar configuration in tissues. Species distribution studies using the antibody revealed that GM2 is present in the brains and nerves of all species examined, while IV4GalNAcGM1b and IV4GalNAcGD1a exhibit some striking species specificity. GM2, but not IV4GalNAcGD1a, is enriched in purified myelin from human brain.     

Further characterization of allergenically active oligosaccharitols isolated from a sea squirt H-antigen.

Complete primary structures of five allergenically active oligosaccharitols (HPG-beta 2-N5a, -N6, -N7a, -N7b, and -N9) derived from a sea squirt H-antigen were studied. Structural characterization was carried out by a new method in which products of limited periodate oxidation, followed by derivatization with p-aminobenzoic acid ethyl ester, were analyzed by a combination of HPLC, fast atom-bombardment mass spectrometry, sequential glycosidase digestion, methylation analysis, and 500-MHz 1H NMR. Established structures of GalNAc beta 1-4 (GalNAc alpha 1-2Fuc alpha 1-3) GlcNAc beta 1-3GalNAc-ol, GalNAc beta 1-4GlcNAc beta 1-3 (GalNAc beta 1-4GlcNAc beta 1-6) GalNAc-ol, GalNAc beta 1-4GlcNAc beta 1-3[GalNAc beta 1-4 (Fuc alpha 1-3) GlcNAc beta 1-6] GalNAc-ol, GalNAc beta 1-4 (Fuc alpha 1-3) GlcNAc beta 1-3[GalNAc beta 1-4 (Fuc alpha 1-3) GlcNAc beta 1-6] GalNAc-ol, and GalNAc beta 1-4 (GalNAc alpha 1-2Fuc alpha 1-3)GlcNAc beta 1-3 [GalNAc beta 1-4 (GalNAc alpha 1-2Fuc alpha 1-3)GlcNAc beta 1-6]GalNAc-ol are represented by HPG-beta 2-N5a, -N6, -N7a, -N7b, and -N9, respectively. These structures have not been encountered previously. Oligosaccharide units GalNAc alpha 1-2Fuc alpha 1-, GalNAc beta 1-4GlcNAc beta 1-, and Fuc alpha 1-3GlcNAc beta 1- are considered to be the allergenically specific epitopes. Partial assignments of 500-MHz 1H NMR spectra of these novel O-linked oligosaccharitols were attempted.     

Structures of the major carbohydrates of natural human interleukin-2

Purified human interleukin-2 secreted by peripheral blood lymphocytes from healthy donors was found to exist in several forms. These forms were (partially) resolved by reversed-phase high-performance liquid chromatography and sodium dodecyl sulfate/polyacrylamide gel electrophoresis. Two major polypeptide species (interleukin-2 N1 and N2, 16.5 kDa) were shown to be glycosylated on the basis of [3H]galactose/[3H]glucosamine incorporation and determination of amino sugars after acid hydrolysis. A third component (interleukin-2 M, 14.5 kDa) represents a nonglycosylated form. The amino acid composition and the NH2-terminal sequence of both forms are consistent with the data deduced from the cDNA coding for interleukin-2 after removal of a leader peptide of 20 amino acids. Carbohydrates are O-linked to the IL-2 protein via threonine-3 of the polypeptide chain. The oligosaccharides were released by reductive beta-elimination and were purified by gel filtration and high-performance liquid chromatography. Applying methylation analysis, exoglycosidase digestion and fast atom bombardment mass spectrometry the following major carbohydrate structures were identified: N1, NeuAc(alpha 2-3)Gal(beta 1-3)GalNAc-ol; and N2, NeuAc(alpha 2-3)Gal(beta 1-3)[NeuAc(alpha 2-6)]GalNAc-ol.     

Assignment of the1H- and13C-NMR spectra of eight oligosaccharides of the lacto-N-tetraose and neotetraose series

The assignment of the 13C- and 1H-NMR spectra of eight oligosaccharides of the lacto-N-tetraose and neotetraose series was obtained from homonuclear and heteronuclear correlation spectroscopy. These analyses were performed on the following compounds: 1. Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc; 2. NeuAc alpha 2-3Gal beta 1-3GlcNAc beta 1-3Gal beta 1-4Glc; 3. Gal beta 1-3[NeuAc alpha 2-6]GlcNAc beta 1-3Gal beta 1-4Glc; 4. NeuAc alpha 2-3Gal beta 1-3[NeuAc alpha 2-6]GlcNAc beta 1-3Gal beta 1-4Glc; 5. NeuAc alpha 2-3Gal beta 1-3[Fuc alpha 1-4]GlcNAc beta 1-3Gal beta 1-4Glc; 6. Fuc alpha 1-2Gal beta 1-3[NeuAc alpha 2-6]GlcNAc beta 1-3Gal beta 1-4Glc; 7. Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc; 8. NeuAc alpha 2-6Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc.     

Presence of an O-glycosidically linked hexasaccharide in fetuin

Examination by gel filtration, thin layer and anion exchange chromatography of the O-linked carbohydrate units released from fetuin by alkaline borohydride treatment indicated the presence in this glycoprotein of an acidic glucosamine-containing hexasaccharide in addition to the previously described tetra- and trisaccharides. The structure of the hexasaccharide was determined to be NeuAc alpha 2----3Gal beta 1----3[NeuAc alpha 2----3Gal beta 1----4GlNAc beta 1----6]GalNAc, on the basis of exoglycosidase digestion, periodate oxidation, and methylation analysis as well as hydrazine-nitrous acid fragmentation. The latter procedure when carried out on the reduced asialohexasaccharide yielded Gal----2-deoxygalactitol and Gal----anhydromannose which were shown to be derived, respectively, from Gal----N-acetylgalactosaminitol and Gal----GlcNAc sequences. Reductive amination of the Gal----anhydromannose disaccharide with [14C] methylamine permitted identification of its linkage as 1----4. While Diplococcus pneumoniae endo-alpha-DN-acetylgalactosaminidase acting on asialofetuin released the sialic acid-free tetra- and trisaccharides (Gal beta 1----3GalNAc), this enzyme did not cleave the peptide attachment of the asialohexasaccharide (Gal beta 1----3 [Gal beta 1----4GlcNAc beta 1----6] GalNAc). The number of O-linked hexa-, tetra-, and trisaccharides per fetuin molecule was determined to be 0.2, 0.7, and 2.1, respectively, on the basis of galactosaminitol analyses. The absence of O-linked N-acetylglucosamine-containing tetra- or pentasaccharides in fetuin suggest that the attachment of this sugar is a rate-limiting step; furthermore, the limited occurrence of the hexasaccharide may indicate that the addition of sialic acid to Gal beta 1----3GalNAc to form the NeuAc alpha 2----3Gal linkage precludes action of the GlcNAc transferase to form the branch point on the GalNAc residue.     

Isolation and characterization of gangliosides from Trypanosoma brucei

Gangliosides were isolated from Trypanosoma brucei and analyzed by thin-layer chromatography (TLC) and TLC immunostaining test. Four species of gangliosides, designated as G-1, G-2, G-3, and G-4, were separated by TLC. G-1 ganglioside had the same TLC migration rate as GM3. In contrast, G-2, G-3, and G-4 gangliosides migrated a little slower than GM1, GD1a, and GD1b, respectively. To characterize the molecular species of gangliosides from T. brucei, G-1, G-2, G-3, and G-4 gangliosides were purified and analyzed by TLC immunostaining test with monoclonal antibodies against gangliosides. G-1 ganglioside showed the reactivity to the monoclonal antibody against ganglioside GM3. G-2 was recognized by the anti-GM1 monoclonal antibody. G-3 showed reaction with the monoclonal antibody to GD1a. G-4 had the reactivity to anti-GD1b monoclonal antibody. Using 4 kinds of monoclonal antibodies, we also studied the expression of GM3, GM1, GD1a, and GD1b in T. brucei parasites. GM3, GM1, GD1a, and GD1b were detected on the cell surface of T. brucei. These results suggest that G-1, G-2, G-3, and G-4 gangliosides are GM3 (NeuAc alpha2-3Gal beta1-4Glc beta1-1Cer), GM1 (Gal beta1-3GalNAc beta1-4[NeuAc alpha2-3]Gal beta1-4Glc beta1-1Cer), GD1a (NeuAc alpha2-3Gal beta1-3GalNAc beta1-4[NeuAc alpha2-3]Gal beta1-4Glc beta1-1Cer), and GD1b (Gal beta1-3GalNAc beta1-4[NeuAc alpha2-8NeuAc alpha2-3]Gal beta1-4Glc beta1-1Cer), respectively, and also that they are expressed on the cell surface of T. brucei.     

Newcastle disease virus contains a linkage-specific glycoprotein sialidase. Application to the localization of sialic acid residues in N-linked oligosaccharides of alpha 1-acid glycoprotein

Newcastle disease virus sialidase was found to exhibit strict specificity for hydrolysis of the NeuAc alpha 2 leads to 3Gal linkage contained in glycoprotein oligosaccharides both N-linked to asparagine and O-linked to threonine or serine under conditions that left oligosaccharides containing the NeuAc alpha 2 leads to 2 leads to 6Gal and NeuAc alpha 2 leads to 6GallNAc linkages intact. This was determined, in part, by examining the viral sialidase for its ability to hydrolyze glycoprotein oligosaccharides derivatized with purified sialyltransferases to contain the [14C]NeuAc alpha 2 leads to 3Gal, [14C]NeuAc alpha 2 leads to 6GalNAc, and [14C]NeuAc alpha 2 leads to 6Gal linkages. The viral sialidase was also tested for hydrolysis of the NeuAc alpha 2 leads to 3Gal and NeuAc alpha 2 leads to 6Gal linkages on the N-linked oligosaccharides of alpha 1-acid glycoprotein. Selective hydrolysis of the NeuAc alpha 2 leads to 3Gal linkage was shown by periodate oxidation and by 500-MHz 1H-NMR spectroscopy of native and sialidase-treated glycopeptides. The NMR spectra, together with composition data, further indicated that the NeuAc alpha 2 leads to 3Gal and NeuAc alpha 2 leads to 6Gal linkages were localized to specific branches of the major tri- and tetraantennary oligosaccharides of alpha 1-acid glycoprotein. The results indicate that the Newcastle disease virus sialidase can initiate the selective degradation of N-linked oligosaccharide branches containing the NeuAc alpha 2 leads to 3Gal linkage.     

Primary structure of the glycan chains of normal C 1 esterase inhibitor (C 1-INH) after NMR analysis at 400 MHz

The primary structural analysis of O- and N-linked carbohydrate chains of the C-1-esterase inhibitor purified from normal serum was carried out by 400-MHz 1H-NMR spectroscopy. C-1-esterase inhibitor protein of a molecular weight of 116,000 daltons contains 24 O-glycans: NeuAc (alpha 2-3) Gal (beta 1-3) GalNAc, 4 N-glycans: NeuAc (alpha 2-6) Gal (beta 1-4) (GlcNAc (beta 1-2) Man (alpha 1-3) [NeuAc (alpha 2-6) Gal (beta 1-4) GlcNAc (beta 1-2) Man (alpha 1-6)] Man (beta 1-4) GlcNAc (beta 1-4) GlcNAc and 2 N-glycans: NeuAc (alpha 2-3) Gal (beta 1-4) GlcNAc (beta 1-2) Man (alpha 1-3) [NeuAc (alpha 2-3) Gal (beta 1-4) GlcNAc (beta 1-2) Man (alpha 1-6)] Man (beta 1-4) GlcNAc (beta 1-4) GlcNAc. 30% of the N-glycans are fucosylated.     

Isolation and NMR spectroscopic characterization of sialic acid compounds and hemofiltrate of chronic uremia patients

Eight sialyloligosaccharides have been isolated from the hemofiltrate of a patient with end stage renal disease using reverse osmosis, gel filtration, ion-exchange and high-performance liquid chromatography. The structures were predominantly elucidated by one- and two-dimensional 1H- and 13C-NMR spectroscopy: 1 NeuAc alpha 2-3Gal beta 1-4Glc; 2 NeuAc alpha 2-6Gal beta 1-4Glc; 3 NeuAc alpha 2-3Gal beta 1-4GlcNAc; 4 NeuAc-alpha 2-6Gal beta 1-4GlcNAc; 5 NeuAc alpha 2-3Gal beta 1-4-GlcNAc alpha 1-P; 6 NeuAc alpha 2-6Gal beta 1-4GlcNAc alpha 1-P; 7 NeuAc alpha 2-3Gal beta 1-3GalNAc alpha 1-P; 8 NeuAc alpha 2-8NeuAc. While compounds 1-7 are also components of normal human urine, di-N-acetyl-D-neuraminic acid (8) could be isolated for the first time from biological material. The origin and possible clinical relevance of these compounds have to be proved in further investigations.     

The c-series gangliosides GT3, GT2 and GP1c are formed in rat liver Golgi by the same set of glycosyltransferases that catalyse the biosynthesis of asialo-, a- and b-series gangliosides.

Biosynthesis of the c-series gangliosides GT3, GT2 and GP1c was studied in Golgi derived from rat liver. Competition experiments show that the synthesis of ganglioside GT2 (GalNAc beta 1----4-(NeuAc alpha 2----8NeuAc alpha 2----8NeuAc alpha 2----3)Gal- beta 1----4Glc beta 1----1Cer) from GT3 (NeuAc alpha 2----8NeuAc alpha 2----8-NeuAc alpha 2----3Gal beta 1----4Glc beta 1----1Cer) seems to be catalysed by the same N-acetylgalactosaminyl-transferase (GalNAc-T), which converts GM3 (NeuAc alpha 2----3Gal beta 1----4Glc beta 1----1Cer) to GM2 (GalNAc beta 1----4(NeuAc alpha 2----3)Gal beta 1----4Glc beta 1----1Cer). Similar competition experiments suggest moreover that the sialytransferase V (SAT V), which catalyses the synthesis of GT1a (NeuAc alpha 2----8NeuAc alpha 2----3Gal beta 1----3GalNAc beta 1----4- (NeuAc alpha 2----3)-Gal beta 1----4Glc beta 1----1Cer) from GD1a (NeuAc alpha-2----3Gal beta 1----3GalNAc beta 1----4(NeuAc alpha 2----3)Gal beta 1----4Glc beta 1----1-Cer) appears to be identical to the enzyme that catalyses the synthesis of GP1c (NeuAc alpha 2----8NeuAc alpha 2----3Gal beta 1----3-GalNAc beta 1----4(NeuAc alpha 2----8-NeuAc alpha 2----8NeuAc alpha 2----3)Gal beta-1----4Glc beta 1----4Glc beta 1----1Cer) from GQ1c (NeuAc alpha 2----3Gal beta 1----3Gal-NAc beta 1----4 (NeuAc alpha 2----8NeuAc alpha 2----8NeuAc alpha 2----3)Gal beta 1----4-Glc beta 1----1Cer).(ABSTRACT TRUNCATED AT 250 WORDS)     

Chemical structure of neutral sugar chains isolated from human mature milk kappa-casein

The carbohydrate chains linked to human kappa-casein from mature milk were released by alkaline borohydride treatment as reduced oligosaccharides. The neutral oligosaccharides of lower molecular weight were fractionated and purified by gel filtration and preparative thin layer chromatographies. Seven neutral oligosaccharides (a di- (0.5%), two tetra- (30.5%), two penta- (5.4%) and two hexasaccharide alditols (10.9%] were obtained in homogeneity, and followed by methylation analysis with gas-liquid chromatography-mass spectrometry and by anomer analysis with 13C nuclear magnetic resonance. Their chemical structures were identified to be Gal beta 1----3GalNAc-ol (I), Gal beta 1----3[Gal beta 1----4GlcNAc beta 1----6]GalNAc-ol (II), Gal beta 1----3[Fuc alpha 1----4GlcNAc beta 1----6]GalNAc-ol (III), GlcNAc beta 1----3/6Gal beta 1----3[Gal beta 1----4GlcNAc beta 1----6]GalNAc-ol (IV), GlcNAc beta 1----3/6Gal beta 1----3[Fuc alpha 1----4GlcNAc beta 1----6]GalNAc-ol (V), Fuc alpha 1----4GlcNAc beta 1----3/6Gal beta 1----3[Gal beta 1----4GlcNAc beta 1----6]GalNAc-ol (VI) and Fuc alpha 1----4GlcNAc beta 1----3/6Gal beta 1----3[Fuc alpha 1----4GlcNAc beta 1----6]GalNAc-ol (VII). Five oligosaccharide alditols (III-VII) were the novel carbohydrate chains of kappa-casein from mammalian milk.