2 Department of Molecular Cell Biology, Glycoimmunology Group, Vu University Medical Center, Van Der Boechorststraat 7, 1081 BT Amsterdam, the Netherlands
3 Department of Parasitology, Center of Infectious Diseases, Leiden University Medical Center, Leiden, the Netherlands
4 Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Biomedical Research Center, 975 NW 10th Street, Oklahoma City, OK 73104, USA
Received on September 16, 2002; revised on October 15, 2002; accepted on October 15, 2002
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Abstract |
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Key words: anti-carbohydrate monoclonal antibodies / antigenicity / N-glycans / schistosomes
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Introduction |
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Recently, several monoclonal antibodies (mAbs) have been identified that bind to carbohydrate structures of schistosomes. These mAbs recognize carbohydrate structures that may be specifically related to schistosomes and/or other helminths (e.g., GalNAcß1-4[Fuc1-2Fuc
1- 3] GlcNAc [LDN-DF] and Fuc
1-3GalNAcGlcNAc [F-LDN]) (Kantelhardt et al., 2002
; Khoo et al., 1995
, 1997a; Van Remoortere et al., 2000
)) as well as glycan structures that are found on glycoconjugates of both mammals and helminths (e.g., Galß1-4[Fuc
1-3]GlcNAc (Lewisx, Lex), GalNAcß1-4GlcNAc [LDN], and GalNAcß1-4[Fuc
1-3]GlcNAc [LDNF]) (Dell et al., 1999
; Huang et al., 2001
; Nyame et al., 1997
, 1998
, 2000
; Van Dam et al., 1996
; Van den Eijnden et al., 1998
; Van Remoortere et al., 2000
; Wuhrer et al., 1999
). Most of these mAbs were isolated from Schistosoma-infected mice, indicating that the glycan antigens are immunogenic during the course of infection. In addition, humans and primates infected with schistosomes show elevated levels of IgM and/or IgG antibodies against these carbohydrate structures (Van Remoortere et al., 2001
; Nyame et al., 1998
), establishing the importance of these glycan epitopes in induction of an anti-glycan humoral immune response.
In schistosomes and other helminths, some N-glycans contain an 1
3-fucose (
3-Fuc) linked to the proximal core GlcNAc and/or a ß1
2-xylose (ß2-Xyl) linked to the core ß-mannose (Khoo et al., 1997b, 2001
; Van Die et al., 1999
). These N-glycans not only are found on helminth glycoproteins but are typical for glycoproteins derived from plants, insects, and mollusc, but are not found in mammalian glycoproteins (D'Andrea et al., 1988
; Kubelka et al., 1993
; Lerouge et al., 1998
; Van Die et al., 1999
; Van Kuik et al., 1985
, 1986
). Cross-reactive carbohydrate antigens observed in immunoassays of helminth, plant, arthropod, and mollusc extracts have been thought to be due to the presence of these unusual N-glycan core structures. Both core
3-Fuc and/or ß2-Xyl residues are epitopes for the binding of IgE antibodies to plant allergens, horseradish peroxidase (HRP), honeybee venom phospholipase A2 (PLA2), and helminth glycoproteins (Tretter et al., 1993
; Van Die et al., 1999
; Van Ree et al., 2000
). This is of particular interest as a Th2 type immune response, and high serum IgE levels are typical for helminth-infected hosts as well as for individuals suffering from atopic diseases (Bell, 1996
).
To unravel the role of these cross-reactive glycoconjugates in the host immune response in helminth infections and allergenicity, we set out to identify and characterize mAbs that bind to carbohydrate epitopes shared by helminths and plants. Here we report the isolation and characterization of mAb 100-4G11-A that recognizes a truncated high-mannose-type N-glycan, Man3GlcNAc2-R, which is expressed on many glycoproteins of invertebrate organisms, as well as on a limited amount of mammalian glycoproteins.
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Results |
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The results suggested the possibility that 100-4G11-A might recognize a truncated high-mannose-type N-glycan smaller than Man59-GlcNAc2. To address this, we treated both as/agGP-F2-BSA and as/agGP-F2-1,3Fuc-BSA with N-acetylglucosaminidase to generate the core N-glycan Man3-GlcNAc2-R. Likewise, GST-SfManI was treated with both ß-galactosidase and N-acetylglucosaminidase to generate Man3-GlcNAc2-R. The resulting Man3-GlcNAc2-R structures on as/agGP-F2-BSA, as/agGP-F2-
1,3Fuc-BSA, and GST-SfManI were strongly bound by 100-4G11-A (Figure 4). These results demonstrate that 100-4G11-A recognizes the truncated high-mannose-type N-glycan Man3-GlcNAc2-R. Our data strongly suggest that the antibody requires both a free terminal
1,3-linked and
1,6-linked mannose in the trimannosyl core structure Man
1-3(Man
1-6)Manß- to recognize its ligand. 100-4G11-A does not recognize either Man5GlcNAc2-R, the major N-glycan on RNAse B that contains a free
1,3-mannose, or the monoantennary N-glycan on GST-SfManI that has a free
1,6-mannose. The presence of a core
1,3-Fuc linked to the inner GlcNAc does not affect the binding (Figure 4).
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Discussion |
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Relatively large amounts of the truncated N-glycan recognized by 100-4G11-A have been found previously on type II variant surface glycoproteins of the parasite protozoan Trypanosoma brucei (Zamze et al., 1991), and on immunodominant antigens of the parasite helminth Trichinella spiralis (Reason et al., 1994
). Here we show that other helminths from different orders of the phyla platyhelminths and nematodes also synthesize glycoproteins containing this truncated N-glycan. In some helminths, such as H. contortus and the free-living nematode C. elegans, expression of this glycan epitope is developmentally regulated. In invertebrates, the truncated N-glycan structure is apparently occurring abundantly. Recently, the presence of these structures has been demonstrated on recombinant neuropsin, synthesized in insect cells (Takahashi et al., 1999
). 100-4G11-A may therefore be a useful tool in identifying the glycosylation on recombinant glycoproteins produced in insect cells. As far as we know, however, this is the first report that shows the presence of these truncated structures in vertebrates, and this observation poses questions about the role or significance of such N-glycans that may be formed by degradation of complex-type N-glycans.
Despite the isolation of mAbs from infected mice against the Man3GlcNAc2 glycan structure, we could not detect significantly higher levels of antibodies against this epitope in sera of individuals infected with S. mansoni in comparison with sera of controls. The Man3GlcNAc2-R epitope is found on human endogenous glycoproteins, which may explain why only low antibody levels against this glycan epitope are found in infected individuals. Similarly, antibody levels against the endogenous monomeric Lex carbohydrate epitope are low in individuals infected with schistosomes, whereas mAbs recognizing this structure have been isolated, as reported previously (Nyame et al., 1998; Van Remoortere et al., 2001
). Despite the low antibody levels against Lex, however, LNFPIII, which contains Lex, is a potent inducer of a Th2 response and acts as an adjuvant (Okano et al., 2001), indicating that glycan structures may have indirect effects on the host humoral immune system.
Unexpectedly, none of the 188 mAbs tested recognized neoglycoproteins carrying N-glycans with a core ß1,2-Xyl or a core 1,3-Fuc. Because these core modifications have been demonstrated on both adult worms and the eggs of schistosome glycoproteins (Khoo et al., 1997b, 2001
; Van Die et al., 1999
) and do not occur on mammalian glycoproteins, they are expected to be immunogenic in mice. The reason for our failure to detect hydridomas secreting such mAbs is not known.
Our data indicate that the generation of antibodies against glycan antigens differs in mouse and human infections. The murine model has been widely used to dissect the immune responses in S. mansoni infection. Recently it has become clear that immunological data obtained from schistosome-infected mice and humans may differ profoundly, one of the differences being that a Th2 response in infected mice is associated with pathology, whereas in infected humans the same type of response is thought to be beneficial for the host (Boros, 1994; Cheever et al., 1997
; Fallon, 2000
). Because glycoconjugates play an important role in the pathogenesis and host immune responses in schistosomiasis, such differences may be partially due to differences in endogenous glycosylation between mice and humans, contributing to differences in the discrimination between self and non-self antigens upon infection.
Characterization of the structure of parasite glycans by conventional analytical methods such as mass spectrometry and nuclear magnetic resonance (NMR), and analysis of their functions is hampered by the small amounts of parasite material that are usually available. Anti-glycan mAbs with a well-defined specificity, such as 100-4G11-A, will be very valuable research tools to provide us with more insight in the expression, distribution, and function of glycan epitopes in the different life-stages of schistosomes and other parasites and, importantly, also in defining interactions between parasite glycans and the host immune system.
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Materials and methods |
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mAbs
Production of mAbs used in this study has been described previously (Van Dam et al., 1993). From a few thousand hybridomas produced over the years in the Department of Parasitology (LUMC), a panel of 188 mAbs was selected for screening based on putative reactivity with carbohydrate epitopes (Van Remoortere et al., 2000
).
Construction of neoglycoproteins
Asialo/agalacto glycopeptides from human fibrinogen (as/agGP-F2) were prepared from asialo-fibrinogen by extensive pronase digestion as described previously (Nemansky and Van den Eijnden, 1993) followed by enzymatic degalactosylation with jackbean ß-galactosidase. Core
3-fucosylated as/agGP-F2 (as/agGP-F2-
1,3Fuc) was synthesized as described in Van Tetering et al. (1999)
. All products were structurally characterized by 1H-NMR spectrometry as described (Van Tetering et al., 1999
). The glycopeptides as/agGP-F2 and as/agGP-F2-
1,3Fuc (75 nmol each) were activated with ninhydrin and coupled to bovine serum albumin (BSA) by reductive amination essentially as described in Mencke et al. (1987)
. Subsequently, the resulting neoglycoproteins were separated from unincorporated BSA by ConA lectin affinity chromatography. Matrix-assisted laser desorption and ionization time-of-flight analysis showed the presence of about two N-glycans per molecule BSA. The oligosaccharides LDN and LDN-F were enzymatically synthesized and coupled to BSA as described previously (Van Remoortere et al., 2000
).
ELISA
Flat-bottom 96-well polystyrene microtitration plates (Maxisorp, Nunc, Roskilde, Denmark) were coated with 50 µl antigen (5 µg/ml in 0.035 M phosphate buffered saline [PBS], pH 7.8) for 1 h at 37°C. After each incubation step, the plates were washed with 20-fold diluted PBS. Nonspecific binding sites were blocked with 100 µl 0.3% BSA in PBS. Sera and secondary antibodies were diluted in PBS containing 0.1% BSA and 0.3% Tween 20. For detection of bound antibodies, alkaline phosphatase (AP)- or peroxidase (PO) conjugates of anti-mouse or anti-rabbit immunoglobulin were used. As substrate for AP, 3 mM 4-nitrophenyl phosphate (Boehringer Mannheim, Mannheim, Germany) in 0.1 M diethanolamine containing 0.5 mM MgCl2, pH 9.6, were used; the absorbance was read after 30 min and overnight at a wavelength of 405 nm. 3,3,5,5'-Tetramethylbenzidine and H2O2 in 0.1 M acetate, pH 5.5, was used as a substrate for PO, the reaction was terminated with H2SO4, and the absorbance was measured at 450 nm.
In the inhibition study 100-4G11-A was preincubated with -D-mannopyranoside, D-mannose, L-fucose, D-xylose, and D-GlcNAc in a final concentration range of 2.5 to 500 mM for 1 h at 37°C before use.
When indicated, neoglycoproteins were treated after coating with N-acetylglucosaminidase (12 mU/ml) in 50 mM sodium citrate, pH 5.0, at 37°C overnight.
To identify the presence of human antibodies binding to PLA2 and N-acetylglucosaminidase-treated as/agGP-F2-BSA, human sera were diluted 1/200 for IgM and IgG and 1/10 for IgE and biotin-conjugated goat anti-human IgG (1/10,000 dilution; Vector, Burlingame, CA), goat anti-human IgE (1/1000; Vector), or goat anti-human IgM (1/5000, Vector) were used. Bound antibodies were detected after incubation with streptavidin-AP (1/4000) as described.
Fractionation of different glycoforms of honeybee PLA2
Honeybee PLA2 (500 µg) was subjected to FPLC ConA-affinity chromatography using a flow rate of 0.5 ml/min with detection at 280 nm. Coupling of 30 mg Con A (Sigma) to a 1 ml HiTrap-column (Amersham Biosciences AB, Uppsala, Sweden) was performed according to the manufacturer's instructions. The column was equilibrated with PBS. Elution of ConA binding PLA2 glycoforms was performed by gradient elution with 033 mM methyl -D-mannopyranoside in PBS in 40 min, followed by elution with 33 mM methyl
-D-mannopyranoside in PBS for 20 min.
SDSPAGE and western blotting
Helminth extracts and control samples were separated by sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDSPAGE) on 12.515% gels using the Mini-Protean II system (Bio-Rad, Veenendaal, the Netherlands). Western blotting and antibody reactions were performed essentially as described previously (Agterberg et al., 1993). For detection of 100-4G11-A and polyclonal anti-core
3-Fuc antibodies, AP or PO conjugates of anti-mouse or anti-rabbit immunoglobulins, respectively, were used. Bound antibodies were detected using x-phosphate/5-bromo- 4-chloro-3-inodyl-phosphate (Boehringer Mannheim) and 4-nitrobluetetrazoliumchloride (Boehringer Mannheim) in the case of AP conjugates or using Enhanced ChemiLuminescence reagent (Amersham) and autoradiography in the case of PO conjugates.
IFA
The IFA was performed on frozen liver sections (5 µm thick) of S. mansoni-infected hamsters and whole cercariae as reported previously (Van Dam et al., 1993) using 100-4G11-A and a fluorescein isothiocyanate conjugate of rabbit anti-mouse immunoglobulin antibody (Nordic Immunological Laboratories, Tilburg, the Netherlands). The slides were observed with a Leica DM-RB fluorescence microscope.
Analysis of binding of the mAb 100-4G11-A to myelin
Rat myelin was incubated with 100-4G11-A for 30 min on ice. Subsequently, the myelin was incubated with rabbit anti-mouse-phycoerythrin (RM-PE) for 30 min on ice. After each step the myelin was washed with PBS containing 0.1% BSA. As control, myelin was incubated with the second antibody. The binding was analyzed by FACScan (Becton-Dickinson, Franklin Lakes, NJ).
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Acknowledgements |
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1 To whom correspondence should be addressed; e-mail: im.van_die.medchem{at}med.vu.nl
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Abbreviations |
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References |
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Bell, R.G. (1996) IgE, allergies and helminth parasites: a new perspective on an old conundrum. Immunol. Cell Biol., 74, 337345.[ISI][Medline]
Boros, D.L. (1994) The role of cytokines in the formation of the schistosome egg granuloma. Immunobiology, 191, 441450.[ISI][Medline]
Cheever, A.W. and Yap, G.S. (1997) Immunologic basis of disease and disease regulation in schistosomiasis. Chem. Immunol., 66, 159176.[ISI][Medline]
Cummings, R.D. and Nyame, A.K. (1996) Glycobiology of schistosomiasis. FASEB J., 10, 838848.
Cummings, R.D. and Nyame, A.K. (1999) Schistosome glycoconjugates. Biochim. Biophys. Acta, 1455, 363374.[ISI][Medline]
D'Andréa, G., Bouwstra, J.B., Kamerling J.P., and Vliegenthart, J.F.G. (1988) Primary structure of the xylose-containing N-linked carbohydrate moiety from ascorbic acid oxidase of Cucurbita pepo medullosa. Glycoconj. J., 5, 151157.[ISI]
Dell, A., Haslam, S.M., Morris, H.R., and Khoo, K.H. (1999) Immunogenic glycoconjugates implicated in parasitic nematode diseases. Biochim. Biophys. Acta, 1455, 353362.[ISI][Medline]
Fallon, P.G. (2000) Immunopathology of schistosomiasis: a cautionary tale of mice and men. Immunol. Today, 21, 2935.[CrossRef][ISI][Medline]
Faye, L., Gomord, V., Fitchette-Laine, A.C., and Chrispeels, M.J. (1993) Affinity purification of antibodies specific for Asn-linked glycans containing 1,3 fucose or ß1,2 xylose. Anal. Biochem., 209, 104108.[CrossRef][ISI][Medline]
Hokke, C.H. and Deelder, A.M. (2001) Schistosome glycoconjugates in host-parasite interplay. Glycoconj. J., 18, 573587.[CrossRef][ISI][Medline]
Hollister, J.R., Shaper, J.H., and Jarvis, D.L. (1998) Stable expression of mammalian ß1,4-galactosyltransferase extends the N-glycosylation pathway in insect cells. Glycobiology, 8, 473480.
Huang, H.H., Tsai, P.L., and Khoo, K.H. (2001) Selective expression of different fucosylated epitopes on two distinct sets of Schistosoma mansoni cercarial O-glycans: identification of a novel core type and Lewis X structure. Glycobiology, 11, 395406.
Kantelhardt, S.R., Wuhrer, M., Dennis, R.D., Doenhoff, M.J., Bickle, Q., and Geyer, R. (2002) Fuc1,3GalNAc-: major antigenic motif of Schistosoma mansoni glycolipids implicated in infection sera and keyhole limpet hemocyanin cross-reactivity. Biochem. J., 366, 217223.[ISI][Medline]
Kawar, Z., Romero, P. A., Herscovics, A., and Jarvis, D. L. (2000) N-glycan processing by a lepidopteran insect 1,2-mannosidase. Glycobiology, 10, 347355.
Khoo, K.H., Sarda, S., Xu, X.,Caulfield, J.P., McNeil, M.R., Homans, S.W., Morris, H.R., and Dell, A. (1995) A unique multifucosylated-3GalNAcß1-4GlcNAcß1-3Gal1-motif constitutes the repeating unit of the complex O-glycans derived from the cercarial glycocalyx of Schistosoma mansoni. J. Biol. Chem., 270, 1711417123.
Khoo, K.H., Chatterjee, D., Caulfield, J.P., Morris, H.R., and Dell, A. (1997a) Structural characterization of glycosphingolipids from the eggs of Schistosoma mansoni and Schistosoma japonicum. Glycobiology, 7, 653661.[Abstract]
Khoo, K.H., Chatterjee, D., Caulfield, J.P., Morris, H.R., and Dell, A. (1997b) Structural mapping of the glycans from the egg glycoproteins of Schistosoma mansoni and Schistosoma japonicum: identification of novel core structures and terminal sequences. Glycobiology, 7, 663677.[Abstract]
Khoo, K.H., Huang, H.H., and Lee, K.M. (2001) Characteristic structural features of schistosome cercarial N-glycans: expression of Lewis X and core xylosylation. Glycobiology, 11, 149163.
Kubelka, V., Altmann, F., Staudacher, E., Tretter, V., Marz, L., Hard, K., Kamerling, J.P., and Vliegenthart, J.F. (1993) Primary structures of the N-linked carbohydrate chains from honeybee venom phospholipase A2. Eur. J. Biochem., 213, 11931204.[Abstract]
Lerouge, P., Cabanes-Macheteau, M., Rayon, C., Fischette-Laine, A.C., Gomord, V., and Faye, L. (1998) N-glycoprotein biosynthesis in plants: recent developments and future trends. Plant Mol. Biol., 38, 3148.[CrossRef][ISI][Medline]
Mencke, A.J., Cheung, D.T., and Wold, F. (1987) Attachment of oligosaccharide-asparagine derivatives to proteins: activation of asparagine with ninhydrin and coupling to protein by reductive amination. Methods Enzymol., 138, 409413.[ISI][Medline]
Nemansky, M. and Van den Eijnden, D.H. (1993) Enzymatic characterization of CMP-NeuAc:Gal ß1,4GlcNAc-R 2,3-sialyltransferase from human placenta. Glycoconj. J., 10, 99108.[ISI][Medline]
Nyame, A.K., Pilcher, J.B., Tsang, V.C., and Cummings, R.D. (1997) Rodents infected with Schistosoma mansoni produce cytolytic IgG and IgM antibodies to the Lewis X antigen. Glycobiology, 7, 207215.[Abstract]
Nyame, A.K., Debose-Boyd, R., Long, T.D., Tsang, V.C., and Cummings, R.D. (1998) 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, 8, 615624.
Nyame, A.K., Leppanen, A.M., Bogitsh, B.J., and Cummings, R.D. (2000) Antibody responses to the fucosylated LacdiNAc glycan antigen in Schistosoma mansoni-infected mice and expression of the glycan among schistosomes. Exp. Parasitol., 96, 202212.[CrossRef][ISI][Medline]
Okano, M., Satoskar, A.R., Nishizaki, K., and Harn, D.A. (2001) Lacto-N-fucopentaose III found on Schistosoma mansoni egg antigens functions as adjuvant for proteins by inducing Th2-type response. J. Immunol., 167, 442450.
Reason, A.J., Ellis, L.A., Appleton, J.A., Wisnewski, N., Grieve, R.B., McNeil, M., Wassom, D.L., Morris, H.R., and Dell, A. (1994) Novel tyvelose-containing tri- and tetra-antennary N-glycans in the immunodominant antigens of the intracellular parasite Trichinella spiralis. Glycobiology, 4, 593603[Abstract]
Takahashi, N., Tsukamoto, Y., Shiosaka, S., Kishi, T., Hakoshima, T., Arata, Y., Yamaguchi, Y., Kato, K., and Shimada, I. (1999) N-glycan structures of murine hippocampus serine protease, neuropsin, produced in Trichoplusia ni cells. Glycoconj. J., 16, 405414.[CrossRef][ISI][Medline]
Tretter, V., Altmann, F., Kubelka, V., Marz, L., and Becker, W.M. (1993) Fucose 1,3-linked to the core region of glycoprotein N-glycans creates an important epitope for IgE from honeybee venom allergic individuals. Int. Arch. Allergy Immunol., 102, 259266.[ISI][Medline]
Van Dam, G.J., Kornelis, D.,Van Zeyl, R.J., Rotmans, J.P., and Deelder, A.M. (1993) Schistosoma mansoni analysis of monoclonal antibodies reactive with gut-associated antigens. Parasitol. Res., 79, 5562.[ISI][Medline]
Van Dam, G.J., Bogitsh, B.J., Van Zeyl, R.J., Rotmans, J.P., and Deelder, A.M. (1996). Schistosoma mansoni: in vitro and in vivo excretion of CAA and CCA by developing schistosomula and adult worms. J. Parasitol., 82, 557564.[ISI][Medline]
Van den Eijnden, D.H., Neeleman, A.P., Bakker, H., and Van Die, I. (1998) Novel pathways in complex-type oligosaccharide synthesis. New vistas opened by studies in invertebrates. Adv. Exp. Med. Biol., 435, 37.[ISI][Medline]
Van Die, I., Gomord, V., Kooyman, F.N., Van den Berg, T.K., Cummings, R.D., and Vervelde, L. (1999) Core 1,3-fucose is a common modification of N-glycans in parasitic helminths and constitutes an important epitope for IgE from Haemonchus contortusinfected sheep. FEBS Lett., 463, 189193.[CrossRef][ISI][Medline]
Van Kuik, J.A.,Van Halbeek, H., Kamerling, J.P., and Vliegenthart, J.F. (1985) Primary structure of the low-molecular-weight carbohydrate chains of Helix pomatia alpha-hemocyanin. Xylose as a constituent of N-linked oligosaccharides in an animal glycoprotein. J. Biol. Chem., 260, 1398413988.
Van Kuik, J.A., Hoffmann, R.A., Mutsaers, J.H.G.M., Van Halbeek, J.P., Kamerling, J.P., and Vliegenthart, J.F. (1986) A 500-MHz H-1-NMR study on the N-linked carbohydrate chain of bromelain; H-1-NMR structural-reporter-groups of fucose 1,3-linked to asparagine-bound N-acetylglucosamine. Glycoconj. J., 3, 2734.[ISI]
Van Ree, R., Cabanes-Macheteau, M., Akkerdaas, J., Milazzo, J.P., Loutelier-Bourhis, C., Rayon, C., Villalba, M., Koppelman, S., Aalberse, R., Rodriguez, R., and others. (2000) ß1,2-Xylose and 1,3-fucose residues have a strong contribution in IgE binding to plant glycoallergens. J. Biol. Chem., 275, 1145111458.
Van Remoortere, A., Hokke, C.H., Van Dam, G.J., Van Die, I., Deelder, A.M., and Van den Eijnden, D. H. (2000) Various stages of schistosoma express Lewis x, LacdiNAc, GalNAcß1,4 (Fuc1,3) GlcNAc and GalNAcß1,4(Fuc
1-2Fuc
1,3)GlcNAc carbohydrate epitopes: detection with monoclonal antibodies that are characterized by enzymatically synthesized neoglycoproteins. Glycobiology, 10, 601609.
Van Remoortere, A., Van Dam, G.J., Hokke, C.H., Van den Eijnden, D.H., Van Die, I., and Deelder, A.M. (2001) Profiles of immunoglobulin M (IgM) and IgG antibodies against defined carbohydrate epitopes in sera of Schistosoma-infected individuals determined by surface plasmon resonance. Infect. Immun., 69, 23962401.
Van Tetering, A., Schiphorst, W.E., Van den Eijnden, D.H., and Van Die, I. (1999) Characterization of a core 1,3-fucosyltransferase from the snail Lymnaea stagnalis that is involved in the synthesis of complex-type N-glycans. FEBS Lett., 461, 311314.[CrossRef][ISI][Medline]
Wuhrer, M., Dennis, R.D., Doenhoff, M.J., Bickle, Q., Lochnit, G., and Geyer, R. (1999) Immunochemical characterisation of Schistosoma mansoni glycolipid antigens. Mol. Biochem. Parasitol., 103, 155169.[CrossRef][ISI][Medline]
Zamze, S.E., Ashford, D.A., Wooten, E.W., Rademacher, T.W., and Dwek, R.A. (1991) Structural characterization of the asparagine-linked oligosaccharides from Trypanosoma brucei type II and type III variant surface glycoproteins. J. Biol. Chem., 266, 2024420261.