β(1,2)-Xylose and α(1,3)-Fucose Residues Have a Strong Contribution in IgE Binding to Plant Glycoallergens

• Published in: The Journal of biological chemistry Vol. 275; no. 15; p. 11451
• Main Authors: Ronald van Ree, Marion Cabanes-Macheteau, Jaap Akkerdaas, Jean-Pierre Milazzo, Corinne Loutelier-Bourhis, Catherine Rayon, Mayte Villalba, Stef Koppelman, Rob Aalberse, Rosalia Rodriguez, Loı̈c Faye, Patrice Lerouge
• Format: Journal Article
• Language: English
• Published: American Society for Biochemistry and Molecular Biology 14.04.2000
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.275.15.11451

Primary structures of the N- glycans of two major pollen allergens (Lol p 11 and Ole e 1) and a major peanut allergen (Ara h 1) were determined. Ole e 1 and Ara h 1 carried high mannose and complex N- glycans, whereas Lol p 11 carried only the complex. The complex structures all had a β(1,2)-xylose linked to the core mannose. Substitution of the proximal N- acetylglucosamine with an α(1,3)-fucose was observed on Lol p 11 and a minor fraction of Ole e 1 but not on Ara h 1. To elucidate the structural basis for IgE recognition of plant N- glycans, radioallergosorbent test analysis with protease digests of the three allergens and a panel of glycoproteins with known N- glycan structures was performed. It was demonstrated that both α(1,3)-fucose and β(1,2)-xylose are involved in IgE binding. Surprisingly, xylose-specific IgE antibodies that bound to Lol p 11 and bromelain did not recognize closely related xylose-containing structures on horseradish peroxidase, phytohemeagglutinin, Ole e 1, and Ara h 1. On Lol p 11 and bromelain, the core β-mannose is substituted with just an α(1,6)-mannose. On the other xylose-containing N- glycans, an additional α(1,3)-mannose is present. These observations indicate that IgE binding to xylose is sterically hampered by the presence of an α(1,3)-antenna.