Identification and characterization of buckwheat allergen

Jeoung, Byeung Ju; Ryu, Jeung Woo; Yum, Hae Yung; Kim, Kyu Earn; Park, Jung Won; Hong, Chem Soo; Lee, Ki Young

Abstract

BACKGROUND AND OBJECTIVE: Buckwheat is considered one of the most important food allergens in Korea. Although a very small amount is ingested or inhaled, it can cause serious allergic reactions. However, the major allergens of buckwheat still remain to be elucidated. The aim of our study was to identify and characterize the major allergen of buckwheat seed. MATERIAL AND METHOD: Dialysis membrane with a cut-off MW 1kD was used for the preparation of crude buckwheat seed allergen extract. SDS-PAGE under reducing conditions and IgE immunoblotting were performed using sera from 15 buckwheat sensitive subjects. Isoelectric focusing and lectin blotting assay were done. RESULT: Western blot analysis showed more than 15 IgE-reactive buckwheat proteins. Among them, a 24kD protein was shown to be the most frequently bound to sera from allergic subjects (54%). Isoelectric point of 24kD protein was around 5.9. In lectin blotting assay, 24kD protein did not bind to Con A nor five other lectins.
CONCLUSION
A 24kD protein was the most frequently recognized allergenic component in buckwheat seed. Isoelectric point was around 5.9. Glycosylation was not detected in 24kD of buckwheat protein.