title: Absence of continuous epitopes in the house dust mite major allergens Der p I from Dermatophagoides pteronyssinus and Der f I from Dermatophagoides farinae.
abstract: BACKGROUND
  The house dust mite has been shown to be an important source of domestic allergens associated with immediate hypersensitivities. The Group I mite allergens Der p I from Dermatophagoides pteronyssinus and Der f I from D. farinae display extensive amino acid sequence homology and have similarities with cysteine protease enzymes.
  
  
  OBJECTIVE
  The availability of the complete amino acid sequences for these allergens allowed us to search for the allergic determinants within these molecules. The aim of the present investigation was to identify any continuous IgE-binding epitopes within these amino acid sequences. We also sought to test the validity of previously reported Der p I peptide epitope sequences.
  
  
  METHODS
  In order to identify any continuous IgE epitopes, the amino acid sequences of Der p I and Der f I were synthesized as decapeptides overlapping in sequence and coupled to plastic pins. The specific IgE-binding capacity of these peptides was assayed using an enzyme-linked biotin-streptavidin procedure and sera from patients known to be sensitive to these allergens. Previously reported Der p I peptide epitopes were synthesized as free peptides and tested for their ability to inhibit specific IgE binding to allergen extract discs.
  
  
  RESULTS
  None of the pin-coupled Der p I or Der f I peptides was found by the continuous epitope mapping procedure to bind significantly to specific IgE in the sera of hypersensitive patients. The previously reported Der p I peptide epitopes did not inhibit specific IgE binding to mite extract discs.
  
  
  CONCLUSIONS
  The specific IgE binding epitopes of the house dust mite allergens Der p I and Der f I are discontinuous in nature.
authors.affiliation: Department of Surgery, Prince Henry Hospital, Little Bay, NSW, Australia.
authors.forename: S P
authors.initials: SP
authors.lastname: Collins
authors.forename: G
authors.initials: G
authors.lastname: Ball
authors.forename: E
authors.initials: E
authors.lastname: Vonarx
authors.forename: C
authors.initials: C
authors.lastname: Hosking
authors.forename: M
authors.initials: M
authors.lastname: Shelton
authors.forename: D
authors.initials: D
authors.lastname: Hill
authors.forename: M E
authors.initials: ME
authors.lastname: Howden
mesh_terms: D000485:Allergens / Q000032:analysis* / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D001666:Binding Sites, Antibody; D004391:Dust / Q000009:adverse effects; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000097:blood / Q000276:immunology*; D016056:Immunodominant Epitopes / Q000032:analysis* / Q000097:blood / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood; D008925:Mites / Q000276:immunology*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000276:immunology
chemical_list: D000485:Allergens; D004391:Dust; D016056:Immunodominant Epitopes; D009842:Oligopeptides; D007073:Immunoglobulin E