Assignment of the disulfide bonds of Ole e 1, a major allergen of olive tree pollen involved in fertilization

The most prevalent allergen from olive tree pollen, Ore e 1, consists of a single polymorphic polypeptide chain of 145 amino acids which includes six cysteine residues at positions 19, 22, 43, 78, 90 and 131. By using an homo geneous form of the allergen expressed in Pichia pastoris, the array of the disulfide bridges has been elucidated. Specific proteolysis with thermolys in and reverse-phase HPLC separation of the peptides allowed the determinat ion of the disulfide bond between Cys43 and Cys78. Another thermolytic prod uct, which contained three peptides linked by the remaining four cysteines, was digested with Glu-specific staphylococcal V8 protease and the products isolated by reverse-phase HPLC. Amino acid compositions and Edman degradat ion of the peptide products indicated the presence of the disulfide bonds a t Cys19-Cys90 and Cys22-Cys131. These data can help in the analysis of the three-dimensional structure of the protein as well as in studies, of its al lergenic determinants.