Methods: Recombinant 23-kDa allergen from the Asian needle ant was expressed in Pichia pastoris and purified by ammonium sulfate precipitation and Ni-affinity chromatography. IgE reactivity was demonstrated by ELISA and immunoblotting.
Results: The recombinant protein was recognized in 5 of 6 serum samples (83.3%) from patients with demonstrated anaphylaxis to ants. IgE reactivity to a 23-kDa allergen from venom sac extract was specifically inhibited by the recombinant protein.
Conclusion: A recombinant 23-kDa allergen from the Asian needle ant was successfully produced in the methylotrophic yeast P. pastoris. This protein could be useful for the development of component-resolved diagnostics.