Separation of jumper ant (Myrmecia pilosula) venom allergens: a novel group of highly basic proteins

The sting of the jumper ant (Myrmecia pilosula) causes severe allergic reactions, including anaphylaxis in sensitized individuals. Two of the major allergens, Myr p I and Myr p II, have been cloned, immunocharacterized and nucleotide-sequenced and they encode 112 and 75 residue polypeptides, respectively. Both allergens are highly basic proteins having isoelectric point values greater than 10. However, electrophoretic analysis has generated conflicting results as to the actual sizes of the allergens in the native venom. Electrophoretic, immunological and N-terminal analyses suggested that these allergens undergo extensive post-translational processing to final forms of 45 and 27 residues, respectively. The results highlight the difficulties in the study of small, basic proteins and polypeptides by electrophoretic techniques.