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Research paper thumbnail of Complex-type Asparagine-linked Oligosaccharides on Phosphacan and Protein-tyrosine Phosphatase-ζ/β Mediate Their Binding to Neural Cell Adhesion Molecules and Tenascin

Journal of Biological Chemistry, 1995

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Research paper thumbnail of Characterization of the N- and O-Linked Oligosaccharides in Glycoproteins Synthesized by Schistosoma mansoni Schistosomula

Journal of Parasitology, Aug 1, 1988

This report describes the structural analyses of the O- and N-linked oligosaccharides contained i... more This report describes the structural analyses of the O- and N-linked oligosaccharides contained in glycoproteins synthesized by 48-hr-old Schistosoma mansoni schistosomula. Schistosomula were prepared by mechanical transformation of cercariae and were then incubated in media containing either [2-3H] mannose, [6-3H]glucosamine, or [6-3H]galactose to metabolically radiolabel the oligosaccharide moieties of newly synthesized glycoproteins. Analysis by SDS-polyacrylamide gel electrophoresis and fluorography demonstrated that many glycoproteins were metabolically radiolabeled with the radioactive mannose and glucosamine precursors, whereas few glycoproteins were labeled by the radioactive galactose precursor. Glycopeptide were prepared from the radiolabeled glycoproteins by digestion with pronase and fractionated by chromatography on columns of concanavalin A-Sepharose and pea lectin-agarose. The structures of the oligosaccharide chains in the glycopeptides were analyzed by a variety of techniques. The major O-linked sugars were not bound by concanavalin A-Sepharose and consisted of simple O-linked monosaccharides that were terminal O-linked N-acetylgalactosamine, the minor type, and terminal O-linked N-acetylglucosamine, the major type. The N-linked oligosaccharides were found to consist of high mannose- and complex-type chains. The high mannose-type N-linked chains, which were bound with high affinity by concanavalin A-Sepharose, ranged in size from Man6GlcNAc2 to Man9GlcNAc2. The complex-type chains contained mannose, fucose, N-acetylglucosamine, and N-acetylgalactosamine. No sialic acid was present in any metabolically radiolabeled glycoproteins from schistosomula.

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Research paper thumbnail of Expression Cloning of a New Member of the ABO Blood Group Glycosyltransferases, iGb3 Synthase, That Directs the Synthesis of Isoglobo-glycosphingolipids

Journal of Biological Chemistry, Aug 1, 2000

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Research paper thumbnail of Cloning of Gb3 Synthase, the Key Enzyme in Globo-series Glycosphingolipid Synthesis, Predicts a Family of α1,4-Glycosyltransferases Conserved in Plants, Insects, and Mammals

Journal of Biological Chemistry, Aug 1, 2000

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Research paper thumbnail of Schistosoma mansoni synthesizes glycoproteins containing terminal O-linked N-acetylglucosamine residues

Journal of Biological Chemistry, Jun 1, 1987

In this report, we describe our studies on the structures of the O-linked oligosaccharides in gly... more In this report, we describe our studies on the structures of the O-linked oligosaccharides in glycoproteins synthesized by the human blood fluke Schistosoma mansoni. Adult male schistosomes were incubated with either [2-3H]mannose, [6-3H]glucosamine, or [6-3H]galactose to metabolically radiolabel newly synthesized glycoproteins. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis and fluorographic analyses indicated that many glycoproteins were labeled by each of the radioactive precursors. Glycopeptides were prepared from radiolabeled glycoproteins by pronase treatment and fractionated on columns of concanavalin A-Sepharose and pea lectin-agarose. The O-linked oligosaccharides were released from glycopeptides by treatment with mild base/borohydride. All O-linked material was found in glycopeptides not bound by either of the immobilized lectins. The structures of the released chains were then analyzed by a variety of techniques. Our results demonstrate that the schistosomes synthesize glycoproteins containing two major types of simple O-linked sugar chains. One type, which represents a minor fraction of the O-linked oligosaccharides, contains N-acetylgalactosamine linked to peptide. These O-linked chains occur as terminal O-linked N-acetylgalactosamine and the O-linked disaccharide, galactose----N-acetylgalactosamine. Sialic acid was not present in either of these O-linked chains or in any other glycopeptides derived from adult male schistosomes. However, the major type of O-linked chain in glycoproteins synthesized by adult schistosomes is an unusual terminal O-linked N-acetylglucosamine linked to peptide. This latter structure represents approximately 10% of the total radioactive N-acetylglucosamine recovered in all glycopeptides. Our results also suggest the possibility that the O-linked oligosaccharides are highly clustered on the glycopeptides.

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Research paper thumbnail of Characterization of the high mannose asparagine-linked oligosaccharides synthesized by Schistosoma mansoni adult male worms

Molecular and Biochemical Parasitology, Apr 1, 1988

This report describes the structures of the high-mannose-type N-linked oligosaccharides in glycop... more This report describes the structures of the high-mannose-type N-linked oligosaccharides in glycoproteins synthesized by Schistosoma mansoni adult male worms. Adult male schistosomes were incubated in vitro in media containing either [2-3H]mannose, [6-3H]glucosamine or [6-3H]galactose to allow metabolic radiolabeling of the oligosaccharide moieties of newly synthesized glycoproteins. Glycopeptides were prepared from the radiolabeled glycoproteins by digestion with Pronase and fractionation by chromatography on concanavalin A-Sepharose. Eleven percent of [3H]mannose incorporated into the schistosome glycopeptides was recovered in high mannose-type Asn-linked oligosaccharides which bound to the immobilized lectin. Upon treatment of [3H]mannose-labeled glycopeptide with endo-beta-N-acetylglucosaminidase H, the high mannose-type chains were released and their structures were determined by high performance liquid chromatography, methylation analysis, acetolysis and exoglycosidase digestion. The major species of high mannose-type chains synthesized by S. mansoni adult males have the composition Man7GlcNAc2, Man8GlcNac2 and Man9GlcNA2. Structural analyses indicate that these oligosaccharides are similar to high mannose-type chains synthesized by mammalian cells.

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Research paper thumbnail of Generation of an IgG Monoclonal Antibody to LacdiNAc (LDN) Glycan Epitopes from Splenocytes of Schistosoma mansoni Infected Swiss Webster Mice

The FASEB Journal, 2012

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Research paper thumbnail of a1,4-Fucosyltransferase Activity in Human Serum and Saliva

Arch Biochem Biophys, 1996

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Research paper thumbnail of Schistosoma mansoni:Characterization of an a1�3 Fucosyltransferase in Adult Parasites

Exp Parasitol, 1996

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Research paper thumbnail of Presence of the LDNF glycan on the host‐protective H‐gal‐GP fraction from Haemonchus contortus

Parasite Immunology, 2005

SUMMARY Immunization of sheep with the gut membrane‐associated protein complex H‐gal‐GP of adult ... more SUMMARY Immunization of sheep with the gut membrane‐associated protein complex H‐gal‐GP of adult Haemonchus contortus induces high levels of protection against a homologous challenge infection. Protection is correlated with a systemic IgG response against the antigen. Analysis of the antibody response showed that the majority of the antigen‐specific IgG was of the IgG2 isotype. A substantial proportion (74%) of this response was directed against the glycan component of H‐gal‐GP. The high immunogenicity of the H‐gal‐GP glycans may be due to the presence of the fucosylated LacdiNAc (LDNF) antigen. 2D electrophoresis, Western blotting and mass spectrometry analysis of H‐gal‐GP showed that this glycan epitope was specifically located on a metalloendopeptidase, MEP3. MEP3 is the most abundant protein in H‐gal‐GP and has been identified as one of the most likely protective components of the complex. Here, we present evidence that the LDNF glycan does not contribute to the protective capac...

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Research paper thumbnail of Surface Membrane Proteins of Biomphalaria Glabrata Embryonic Cells Bind Fucosyl Determinants on the Tegumental Surface of Schistosoma Mansoni Primary Sporocysts

Journal of Parasitology, 2007

Previous observations that in vitro adherence of Biomphalaria glabrata embryonic (Bge) cells to s... more Previous observations that in vitro adherence of Biomphalaria glabrata embryonic (Bge) cells to sporocyst larval stages of Schistosoma mansoni was strongly inhibited by fucoidan, a sulfated polymer of L-fucose, suggested a role for lectinlike Bge cell receptors in sporocyst binding interactions. In the present investigation, monoclonal antibodies with specificities to 3 major glycan determinants found on schistosomes, LacdiNAc, fucosylated LacdiNAc (LDNF), and the Lewis X antigen, were used in adhesion blocking studies to further analyze the molecular interactions at the host-parasite interface. Results showed that only the anti-LDNF antibody significantly reduced snail Bge cell adhesion to the surface of sporocysts, suggesting that fucosyl determinants may be important in larval-host cell interactions. Affinity chromatographic separation of fucosyl-reactive Bge cell proteins from fucoidan-bound Sepharose 4B revealed the presence of polypeptides ranging from 6 to 200 kDa after elution with fucoidan-containing buffer. Pre-elution of the Bge protein-bound affinity column with dextran (Dex) and dextran sulfate (DexS) before introduction of the fucoidan buffer served as controls for protein binding based on nonspecific sugar or negative charge interactions. A subset of polypeptides (approximately 35-150 kDa) released by fucoidan elution was identified as Bge surface membrane proteins, representing putative fucosyl-binding proteins. Far-western blot analysis also demonstrated binding reactivity between Bge cell and sporocyst tegumental proteins. The finding that several of these parasite-binding Bge cell proteins were also fucoidan-reactive suggests the possible involvement of these molecules in mediating cellular interactions with sporocyst tegumental carbohydrates. It is concluded that Bge cells have surface protein(s) that may be playing a role in facilitating host cell adhesion to the surface of schistosome primary sporocysts through larval fucosylated glycoconjugates.

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Research paper thumbnail of DIFFERENTIAL EXPRESSION OF LacdiNAc, FUCOSYLATED LacdiNAc, AND LEWIS X GLYCAN ANTIGENS IN INTRAMOLLUSCAN STAGES OF SCHISTOSOMA MANSONI

Journal of Parasitology, 2002

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Research paper thumbnail of The dendritic cell-specific C-type lectin DC-SIGN is a receptor for Schistosoma mansoni egg antigens and recognizes the glycan antigen Lewis x

Glycobiology, 2003

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Research paper thumbnail of Rodents infected with Schistosoma mansoni produce cytolytic IgG and IgM antibodies to the Lewis x antigen

Glycobiology, 1997

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Research paper thumbnail of Mice infected with Schistosoma mansoni generate antibodies to LacdiNAc (GalNAc 1->4GlcNAc) determinants

Glycobiology, 1999

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Research paper thumbnail of Expression of Lex antigen in Schistosoma japonicum and S.haematobium and immune responses to Lex in infected animals: Lack of Lex expression in other trematodes and nematodes

Glycobiology, 1998

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Research paper thumbnail of Vaccination-induced protection of lambs against the parasitic nematode Haemonchus contortus correlates with high IgG antibody responses to the LDNF glycan antigen

Glycobiology, 2003

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Research paper thumbnail of Antibody Responses to the Fucosylated LacdiNAc Glycan Antigen in Schistosoma mansoni-Infected Mice and Expression of the Glycan among Schistosomes

Experimental Parasitology, 2000

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Research paper thumbnail of Schistosoma mansoni:Characterization of an α1–3 Fucosyltransferase in Adult Parasites

Experimental Parasitology, 1996

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Research paper thumbnail of α1,4-Fucosyltransferase Activity in Human Serum and Saliva

Archives of Biochemistry and Biophysics, 1996

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Research paper thumbnail of Complex-type Asparagine-linked Oligosaccharides on Phosphacan and Protein-tyrosine Phosphatase-ζ/β Mediate Their Binding to Neural Cell Adhesion Molecules and Tenascin

Journal of Biological Chemistry, 1995

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Research paper thumbnail of Characterization of the N- and O-Linked Oligosaccharides in Glycoproteins Synthesized by Schistosoma mansoni Schistosomula

Journal of Parasitology, Aug 1, 1988

This report describes the structural analyses of the O- and N-linked oligosaccharides contained i... more This report describes the structural analyses of the O- and N-linked oligosaccharides contained in glycoproteins synthesized by 48-hr-old Schistosoma mansoni schistosomula. Schistosomula were prepared by mechanical transformation of cercariae and were then incubated in media containing either [2-3H] mannose, [6-3H]glucosamine, or [6-3H]galactose to metabolically radiolabel the oligosaccharide moieties of newly synthesized glycoproteins. Analysis by SDS-polyacrylamide gel electrophoresis and fluorography demonstrated that many glycoproteins were metabolically radiolabeled with the radioactive mannose and glucosamine precursors, whereas few glycoproteins were labeled by the radioactive galactose precursor. Glycopeptide were prepared from the radiolabeled glycoproteins by digestion with pronase and fractionated by chromatography on columns of concanavalin A-Sepharose and pea lectin-agarose. The structures of the oligosaccharide chains in the glycopeptides were analyzed by a variety of techniques. The major O-linked sugars were not bound by concanavalin A-Sepharose and consisted of simple O-linked monosaccharides that were terminal O-linked N-acetylgalactosamine, the minor type, and terminal O-linked N-acetylglucosamine, the major type. The N-linked oligosaccharides were found to consist of high mannose- and complex-type chains. The high mannose-type N-linked chains, which were bound with high affinity by concanavalin A-Sepharose, ranged in size from Man6GlcNAc2 to Man9GlcNAc2. The complex-type chains contained mannose, fucose, N-acetylglucosamine, and N-acetylgalactosamine. No sialic acid was present in any metabolically radiolabeled glycoproteins from schistosomula.

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Research paper thumbnail of Expression Cloning of a New Member of the ABO Blood Group Glycosyltransferases, iGb3 Synthase, That Directs the Synthesis of Isoglobo-glycosphingolipids

Journal of Biological Chemistry, Aug 1, 2000

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Research paper thumbnail of Cloning of Gb3 Synthase, the Key Enzyme in Globo-series Glycosphingolipid Synthesis, Predicts a Family of α1,4-Glycosyltransferases Conserved in Plants, Insects, and Mammals

Journal of Biological Chemistry, Aug 1, 2000

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Research paper thumbnail of Schistosoma mansoni synthesizes glycoproteins containing terminal O-linked N-acetylglucosamine residues

Journal of Biological Chemistry, Jun 1, 1987

In this report, we describe our studies on the structures of the O-linked oligosaccharides in gly... more In this report, we describe our studies on the structures of the O-linked oligosaccharides in glycoproteins synthesized by the human blood fluke Schistosoma mansoni. Adult male schistosomes were incubated with either [2-3H]mannose, [6-3H]glucosamine, or [6-3H]galactose to metabolically radiolabel newly synthesized glycoproteins. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis and fluorographic analyses indicated that many glycoproteins were labeled by each of the radioactive precursors. Glycopeptides were prepared from radiolabeled glycoproteins by pronase treatment and fractionated on columns of concanavalin A-Sepharose and pea lectin-agarose. The O-linked oligosaccharides were released from glycopeptides by treatment with mild base/borohydride. All O-linked material was found in glycopeptides not bound by either of the immobilized lectins. The structures of the released chains were then analyzed by a variety of techniques. Our results demonstrate that the schistosomes synthesize glycoproteins containing two major types of simple O-linked sugar chains. One type, which represents a minor fraction of the O-linked oligosaccharides, contains N-acetylgalactosamine linked to peptide. These O-linked chains occur as terminal O-linked N-acetylgalactosamine and the O-linked disaccharide, galactose----N-acetylgalactosamine. Sialic acid was not present in either of these O-linked chains or in any other glycopeptides derived from adult male schistosomes. However, the major type of O-linked chain in glycoproteins synthesized by adult schistosomes is an unusual terminal O-linked N-acetylglucosamine linked to peptide. This latter structure represents approximately 10% of the total radioactive N-acetylglucosamine recovered in all glycopeptides. Our results also suggest the possibility that the O-linked oligosaccharides are highly clustered on the glycopeptides.

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Research paper thumbnail of Characterization of the high mannose asparagine-linked oligosaccharides synthesized by Schistosoma mansoni adult male worms

Molecular and Biochemical Parasitology, Apr 1, 1988

This report describes the structures of the high-mannose-type N-linked oligosaccharides in glycop... more This report describes the structures of the high-mannose-type N-linked oligosaccharides in glycoproteins synthesized by Schistosoma mansoni adult male worms. Adult male schistosomes were incubated in vitro in media containing either [2-3H]mannose, [6-3H]glucosamine or [6-3H]galactose to allow metabolic radiolabeling of the oligosaccharide moieties of newly synthesized glycoproteins. Glycopeptides were prepared from the radiolabeled glycoproteins by digestion with Pronase and fractionation by chromatography on concanavalin A-Sepharose. Eleven percent of [3H]mannose incorporated into the schistosome glycopeptides was recovered in high mannose-type Asn-linked oligosaccharides which bound to the immobilized lectin. Upon treatment of [3H]mannose-labeled glycopeptide with endo-beta-N-acetylglucosaminidase H, the high mannose-type chains were released and their structures were determined by high performance liquid chromatography, methylation analysis, acetolysis and exoglycosidase digestion. The major species of high mannose-type chains synthesized by S. mansoni adult males have the composition Man7GlcNAc2, Man8GlcNac2 and Man9GlcNA2. Structural analyses indicate that these oligosaccharides are similar to high mannose-type chains synthesized by mammalian cells.

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Research paper thumbnail of Generation of an IgG Monoclonal Antibody to LacdiNAc (LDN) Glycan Epitopes from Splenocytes of Schistosoma mansoni Infected Swiss Webster Mice

The FASEB Journal, 2012

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Research paper thumbnail of a1,4-Fucosyltransferase Activity in Human Serum and Saliva

Arch Biochem Biophys, 1996

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Research paper thumbnail of Schistosoma mansoni:Characterization of an a1�3 Fucosyltransferase in Adult Parasites

Exp Parasitol, 1996

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Research paper thumbnail of Presence of the LDNF glycan on the host‐protective H‐gal‐GP fraction from Haemonchus contortus

Parasite Immunology, 2005

SUMMARY Immunization of sheep with the gut membrane‐associated protein complex H‐gal‐GP of adult ... more SUMMARY Immunization of sheep with the gut membrane‐associated protein complex H‐gal‐GP of adult Haemonchus contortus induces high levels of protection against a homologous challenge infection. Protection is correlated with a systemic IgG response against the antigen. Analysis of the antibody response showed that the majority of the antigen‐specific IgG was of the IgG2 isotype. A substantial proportion (74%) of this response was directed against the glycan component of H‐gal‐GP. The high immunogenicity of the H‐gal‐GP glycans may be due to the presence of the fucosylated LacdiNAc (LDNF) antigen. 2D electrophoresis, Western blotting and mass spectrometry analysis of H‐gal‐GP showed that this glycan epitope was specifically located on a metalloendopeptidase, MEP3. MEP3 is the most abundant protein in H‐gal‐GP and has been identified as one of the most likely protective components of the complex. Here, we present evidence that the LDNF glycan does not contribute to the protective capac...

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Research paper thumbnail of Surface Membrane Proteins of Biomphalaria Glabrata Embryonic Cells Bind Fucosyl Determinants on the Tegumental Surface of Schistosoma Mansoni Primary Sporocysts

Journal of Parasitology, 2007

Previous observations that in vitro adherence of Biomphalaria glabrata embryonic (Bge) cells to s... more Previous observations that in vitro adherence of Biomphalaria glabrata embryonic (Bge) cells to sporocyst larval stages of Schistosoma mansoni was strongly inhibited by fucoidan, a sulfated polymer of L-fucose, suggested a role for lectinlike Bge cell receptors in sporocyst binding interactions. In the present investigation, monoclonal antibodies with specificities to 3 major glycan determinants found on schistosomes, LacdiNAc, fucosylated LacdiNAc (LDNF), and the Lewis X antigen, were used in adhesion blocking studies to further analyze the molecular interactions at the host-parasite interface. Results showed that only the anti-LDNF antibody significantly reduced snail Bge cell adhesion to the surface of sporocysts, suggesting that fucosyl determinants may be important in larval-host cell interactions. Affinity chromatographic separation of fucosyl-reactive Bge cell proteins from fucoidan-bound Sepharose 4B revealed the presence of polypeptides ranging from 6 to 200 kDa after elution with fucoidan-containing buffer. Pre-elution of the Bge protein-bound affinity column with dextran (Dex) and dextran sulfate (DexS) before introduction of the fucoidan buffer served as controls for protein binding based on nonspecific sugar or negative charge interactions. A subset of polypeptides (approximately 35-150 kDa) released by fucoidan elution was identified as Bge surface membrane proteins, representing putative fucosyl-binding proteins. Far-western blot analysis also demonstrated binding reactivity between Bge cell and sporocyst tegumental proteins. The finding that several of these parasite-binding Bge cell proteins were also fucoidan-reactive suggests the possible involvement of these molecules in mediating cellular interactions with sporocyst tegumental carbohydrates. It is concluded that Bge cells have surface protein(s) that may be playing a role in facilitating host cell adhesion to the surface of schistosome primary sporocysts through larval fucosylated glycoconjugates.

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Research paper thumbnail of DIFFERENTIAL EXPRESSION OF LacdiNAc, FUCOSYLATED LacdiNAc, AND LEWIS X GLYCAN ANTIGENS IN INTRAMOLLUSCAN STAGES OF SCHISTOSOMA MANSONI

Journal of Parasitology, 2002

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Research paper thumbnail of The dendritic cell-specific C-type lectin DC-SIGN is a receptor for Schistosoma mansoni egg antigens and recognizes the glycan antigen Lewis x

Glycobiology, 2003

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Research paper thumbnail of Rodents infected with Schistosoma mansoni produce cytolytic IgG and IgM antibodies to the Lewis x antigen

Glycobiology, 1997

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Research paper thumbnail of Mice infected with Schistosoma mansoni generate antibodies to LacdiNAc (GalNAc 1->4GlcNAc) determinants

Glycobiology, 1999

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Research paper thumbnail of Expression of Lex antigen in Schistosoma japonicum and S.haematobium and immune responses to Lex in infected animals: Lack of Lex expression in other trematodes and nematodes

Glycobiology, 1998

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Research paper thumbnail of Vaccination-induced protection of lambs against the parasitic nematode Haemonchus contortus correlates with high IgG antibody responses to the LDNF glycan antigen

Glycobiology, 2003

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Research paper thumbnail of Antibody Responses to the Fucosylated LacdiNAc Glycan Antigen in Schistosoma mansoni-Infected Mice and Expression of the Glycan among Schistosomes

Experimental Parasitology, 2000

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Research paper thumbnail of Schistosoma mansoni:Characterization of an α1–3 Fucosyltransferase in Adult Parasites

Experimental Parasitology, 1996

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Research paper thumbnail of α1,4-Fucosyltransferase Activity in Human Serum and Saliva

Archives of Biochemistry and Biophysics, 1996

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