IgE epitopes on the cat (Felis domesticus) major allergen Fel d I: A study with overlapping synthetic peptides

摘要: Abstract Background: The major cat allergen Fel d I is composed of two disulfide-linked polypeptide chains, chain 1 (70 amino acid residues) and 2 (92 residues). Reduction alkylation eliminates almost all antigenic allergenic activity, detection linear epitopes with synthetic peptides therefore not expected. Methods: We synthesized both chains about 14 residues, overlapping by 7 residues. were coupled to Sepharose (Pharmacia, Uppsala, Sweden) tested sera patients allergy. Results: Three showed specific binding human IgE, residues 25–38 46–59 residue 15–28 2. IgE was inhibited the corresponding peptide. Of 61 allergy tested, 65% at least one peptides; 46% peptide 25–38, 11% 46–59, 28% 15–28. Each recognized only 78 negative RAST results. By affinity chromatography peptide-Sepharose anti- antibodies isolated, also confirming specificity peptides. percentage against reactive varied serum used ranged from 2% 55%. Conclusions: Because very low samples high titers I-specific (RAST 4 + /5+) significant binding, these are suitable for diagnostic purposes. However, useful tools comparing IgG responses studying relationship T-cell on this molecule.