A Recombinant omega-Gliadin-like D-Type Glutenin and an alpha-Gliadin from Wheat (Triticum aestivum): Two Immunoglobulin E Binding Proteins, Useful for the Diagnosis of Wheat-Dependent Allergies
Résumé
Among the wheat prolamins, D-type glutenins display a highly repetitive sequence similar to omega-gliadins, but they contain a cysteine, that allows them to be included in the gluten macropolymers. An omega-gliadin-like D-type glutenin, an alpha-gliadin, and an omega 5-gliadin-like D-type glutenin were obtained as recombinant proteins and compared using synchrotron radiation circular dichroism. This technique evidenced the strong thermostability of the omega 5-gliadin-like protein. The IgE reactivity of recombinant proteins was evaluated using 45 sera from wheat-allergic patients. The sera from patients diagnosed with cutaneous hypersensitivity to hydrolyzed wheat proteins often reacted with the omega-gliadin-like D-type glutenin and alpha-gliadin, whereas the IgE reaction was less frequent after dietary sensitization. So, these two proteins could be useful to diagnose these diseases. The sera from patients with exercise-induced anaphylaxis recognized the omega 5-gliadin-like protein as a positive control and, less frequently, the other proteins tested. Only some sera from patients with baker's asthma reacted with the proteins tested.
Mots clés
allergy
D-type glutenin
gliadins
IgE reactivity
synchrotron radiation circular dichroism
wheat (Triticum aestivum)
EXERCISE-INDUCED ANAPHYLAXIS
CIRCULAR-DICHROISM SPECTROSCOPY
HIGH-MOLECULAR-WEIGHT
MAJOR ALLERGEN
FOOD ALLERGY
SECONDARY STRUCTURE
ANTIGENIC RELATIONSHIPS
BAKERS ASTHMA
C-HORDEIN
SDS-PAGE