IgE-binding epitopic peptide mapping on a three-dimensional model built for the 13S globulin allergen of buckwheat (Fagopyrum esculentum).
The three-dimensional model built for the 13S globulin allergen of buckwheat (Fagopyrum esculentum) consists of three protomers exhibiting the cupin motif, arranged in a homotrimer around a three-fold symmetry axis. Using the SPOT technique, 11 continuous IgE-binding epitopic peptides were characterized on the molecular surface of the 13S globulin allergen of buckwheat. Except for one of them, they all correspond to well exposed regions containing electropositiveley and/or electronegatively charged residues, which cover up to 40% of the molecular surface of the allergen. Some of these epitopes come in close contact to probably create more extended discontinuous epitopes, especially those located on the edge of the 13S globulin homotrimer. Half of the identified epitope peptides remain unaltered in a core structure protected against hydrolysis by digestive proteases and are thus assumed to promote the allergenicity of the 13S globulin. In addition, a few of these epitopes coincide with sequential IgE-binding epitopes previously characterized in soybean 11S globulins, that could account for the IgE-binding cross-reactions observed between soybean and buckwheat in Western blot experiments.
Sordet
Camille
C
UMR-CNRS 5546, Université de Toulouse, Castanet Tolosan, France.
Culerrier
Raphaël
R
Granier
Claude
C
Didier
Alain
A
Rougé
Pierre
P
D000485:Allergens / Q000737:chemistry* / Q000276:immunology; D000595:Amino Acid Sequence; D001665:Binding Sites; D015153:Blotting, Western; D018604:Epitope Mapping; D000939:Epitopes / Q000737:chemistry* / Q000276:immunology*; D019612:Fagopyrum / Q000737:chemistry* / Q000276:immunology; D005916:Globulins / Q000737:chemistry* / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology; D012639:Seeds / Q000737:chemistry / Q000276:immunology; D016415:Sequence Alignment; D055672:Static Electricity
D000485:Allergens; D000939:Epitopes; D005916:Globulins; D010446:Peptide Fragments; D007073:Immunoglobulin E