Molecular and immunological characterization of wheat S erpin ( T ri a 33)

Scope Several wheat proteins are responsible for food and respiratory allergies. Due to their large polymorphism, the allergenic potential of a number of them has not yet been precisely established. The aim of this work was to perform a thorough assessment of serpin (Tri a 33) allergenicity. Methods and results Recombinant wheat S erpin‐ Z 2 B isoform (r S erpin‐ Z 2 B ) was expressed in E scherichia coli . Synchrotron radiation circular dichroism data indicated that the recombinant serpin contains slightly more β‐strands than α‐helix structures. I g E reactivity of sera from 103 patients with food allergy and 29 patients with Baker's asthma was evaluated using ELISA , a model of basophil activation and linear epitope mapping ( P epscan). Twenty percent of patients with food allergy to wheat and 31% of those with Baker's asthma displayed r S erpin‐ Z 2 B ‐specific I g E in ELISA . The protein was able to induce I g E ‐dependent basophil degranulation. The P epscan experiment identified four regions involved in I g E binding to serpin. Heating the protein induced its irreversible denaturation and impaired I g E binding, revealing the predominance of conformational epitopes. Conclusion This study confirms wheat serpin allergenicity and shows that recombinant serpin may be a marker of a broad spectrum of sensitization to wheat proteins.