PURIFICATION AND CHARACTERIZATION OF THE MAJOR ALLERGEN FROM APPLE AND ITS ALLERGENIC CROSS-REACTIVITY WITH BET-V-1

The major allergen from apple extract was concentrated by anion exchan ge chromatography and further purified by reverse-phase HPLC. A distin ct peak with a high degree of homogeneity was obtained. The isolated p rotein has a MW of 18 kD and specific IgE-binding capacity (immunoblot ting, IgE-binding inhibition). N-terminal amino acid analyses of the a llergen allowed 37 cleavages and showed 67.6% identity to Bet v 1, the major allergen of birch pollen. Enzyme immunoassay inhibition studies with serum of birch/apple-allergic patients showed that besides cross -reacting structures to Bet v 1, apple-specific IgE antibodies could e xist. Monoclonal antibodies (mAbs) were raised against the 18-kD aller gen from apple and characterized by means of immunoblotting and ELISA. Only three of the eight studied mAbs reacted with Bet v 1.