Cloning and IgE binding of a recombinant allergen from the mite Blomia tropicalis, homologous with fatty acid-binding proteins

Int Arch Allergy Immunol. 1997 Apr;112(4):341-7. doi: 10.1159/000237478.


To characterize the allergens of Blomia tropicalis, a cDNA library was constructed and screened with allergic sera from asthmatic patients. One clone, Bt6, was subcloned and sequenced. The nucleotide sequence of 934 bp length shows a 390-bp reading frame which encodes a 130-amino acid protein with a MW 14.8 kD. No potential glycosylation site was found in the predicted protein. The inferred amino acid sequence has no homology to known allergens. It has a cytosolic fatty acid-binding protein (FABP) signature at 5-22 amino acid residues, 42.3% identity with the Sm14-FABP of Schistosoma mansoni and 36% identity with FABPs from rat, mouse, bovine and human. The protein was expressed as a GST fusion protein and the purified GST-Bt6 used for dot blot, RAST and RAST inhibition assays. The frequency of IgE binding of allergic sera to Bt6 was low (11%) and usually weak. One positive serum did, however, show strong reactivity by RAST and dot blot and Bt6 could inhibit 60% of the IgE binding of this serum to the B. tropicalis extract. These data show that Bt6 encodes a mite FABP with allergenic properties, which are pronounced in some atopic subjects.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Allergens / chemistry
  • Allergens / genetics*
  • Allergens / isolation & purification
  • Allergens / metabolism
  • Amino Acid Sequence
  • Animals
  • Antigens, Plant
  • Base Sequence
  • Binding Sites, Antibody*
  • Carrier Proteins / chemistry*
  • Carrier Proteins / genetics
  • Carrier Proteins / immunology
  • Cloning, Molecular
  • Fatty Acid-Binding Protein 7
  • Fatty Acid-Binding Proteins
  • Fatty Acids / metabolism
  • Glutathione Transferase / genetics
  • Humans
  • Immunoglobulin E / blood
  • Immunoglobulin E / metabolism*
  • Mites / immunology*
  • Molecular Sequence Data
  • Myelin P2 Protein / chemistry*
  • Myelin P2 Protein / genetics
  • Myelin P2 Protein / immunology
  • Neoplasm Proteins*
  • Nerve Tissue Proteins*
  • Radioallergosorbent Test
  • Recombinant Proteins / immunology*
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Thrombin
  • Tumor Suppressor Proteins*


  • Allergens
  • Antigens, Plant
  • Carrier Proteins
  • FABP7 protein, human
  • Fabp7 protein, rat
  • Fatty Acid-Binding Protein 7
  • Fatty Acid-Binding Proteins
  • Fatty Acids
  • Myelin P2 Protein
  • Neoplasm Proteins
  • Nerve Tissue Proteins
  • Recombinant Proteins
  • Tumor Suppressor Proteins
  • allergen Bt6, Blomia tropicalis
  • Immunoglobulin E
  • Glutathione Transferase
  • Thrombin

Associated data

  • GENBANK/U58106