Identification of wheat floor allergens by means of 2-dimensional immunoblotting

Background: Wheat flour proteins are allergens for 60% to 70% of bakers wit h workplace-related respiratory symptoms. Objective: The aim of the study was to investigate the variability of IgE a ntibody patterns of wheat flour-sensitized bakers and to identify the most frequently recognized allergens. Methods: Water/salt-soluble wheat flour proteins from the cultivar Bussard were separated by using 2-dimensional gel electrophoresis with immobilized pH gradients. IgE-reactive proteins were identified by means of immunoblott ing with sera of 10 subjects with baker's asthma. Mass spectrometric finger printing was used to identify the proteins most frequently recognized by Ig E. Results: The IgE immunoblots obtained with 10 different sera exhibited a re markable heterogeneity. Each patient showed an individual IgE-binding patte rn with 4 to 50 different allergen spots. Altogether, more than 100 IgE-bin ding protein spots were detected. Nine of the predominant IgE-binding prote in spots were identified by using mass spectrometric fingerprinting. The ob tained masses matched 2 different isoforms of glycerinaldehyde-3-phosphate dehydrogenase from Hordeum vulgare, triosephosphate isomerase from H vulgar e, and serpin, a serine proteinase inhibitor from Triticum aestivum. Conclusions: The results show a great interindividual variation of IgE-bind ing patterns of wheat flour proteins in baker's asthma, The clinical releva nce of the identified 4 new allergens will be further investigated in the n ear future.