Bet v 1 homologues in strawberry identified as IgE-binding proteins and presumptive allergens

Allergy. 2004 Dec;59(12):1277-84. doi: 10.1111/j.1398-9995.2004.00585.x.


Background: No strawberry allergen has so far been identified and characterized.

Methods: Serum samples were collected from patients with a suggestive case history of adverse reactions to strawberry and other fruits. Extracts from fresh and frozen strawberries were analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting and mass spectrometry. Patient blood samples were analysed for inhibition of IgE binding and basophil degranulation.

Results: Several IgE-binding proteins could be detected. In more than half of the patient sera, a 20/18-kDa doublet band was observed in Western blotting. These two bands were excised and analysed by mass spectrometry showing the presence of proteins belonging to the Bet v 1 family of allergens. Inhibition of the IgE binding to the 20/18-kDa doublet was obtained by addition of two recombinantly expressed allergens belonging to the Bet v 1 family (Bet v 1 and Mal d 1) and strawberry protein extract. In a cell-based assay of patient blood samples, basophil degranulation could be induced by strawberry protein extract and by Bet v 1 and Mal d 1.

Conclusions: We conclude that strawberry homologues to Bet v 1 may be allergens of importance for adverse reactions to strawberry.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Allergens / chemistry
  • Allergens / immunology
  • Allergens / isolation & purification*
  • Amino Acid Sequence
  • Antigens, Plant
  • Basophil Degranulation Test
  • Blotting, Western
  • Electrophoresis, Polyacrylamide Gel
  • Female
  • Food Hypersensitivity / blood
  • Food Hypersensitivity / etiology
  • Food Hypersensitivity / immunology*
  • Fragaria / adverse effects
  • Fragaria / immunology*
  • Humans
  • Immunoglobulin E / blood
  • Immunoglobulin E / immunology*
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Molecular Weight
  • Plant Extracts / immunology
  • Plant Proteins / chemistry
  • Plant Proteins / immunology
  • Plant Proteins / isolation & purification*
  • Sequence Alignment


  • Allergens
  • Antigens, Plant
  • Bet v 1 protein, Fragaria
  • Plant Extracts
  • Plant Proteins
  • Immunoglobulin E