Molecular cloning and characterization of an IgE-reactive protein from Anisakis simplex: Ani s 1

Ingestion of the parasitic nematode Anisakis simplex in undercooked fish can cause severe allergic reactions in some individuals. Using pooled human sera from sensitized patients we have probed an expression library for A. simplex antigens. One positive clone was found to encode a full length 21 kDa protein with strong homology to nematode troponins. The recombinant protein was expressed as a GST-fusion protein and found by immunoblot analysis to react with sera from 20% of allergic patients. The presence of functional EF-hand Ca(2+) binding motifs was demonstrated by gel-shift analysis.