Purification and characterisation of relevant natural and recombinant apple allergens

Mol Nutr Food Res. 2008 Nov;52 Suppl 2:S208-19. doi: 10.1002/mnfr.200700522.


Apple (Malus domestica) is the most widely cultivated fruit crop in Europe and frequently causes allergic reactions with a variable degree of severity. So far, four apple allergens Mal d 1, Mal d 2, Mal d 3 and Mal d 4 have been identified. Mal d 1, a Bet v 1 related allergen, and Mal d 4, apple profilin, are sensitive to proteolytic degradation, whereas Mal d 2, a thaumatin-like protein and Mal d 3, a nonspecific lipid transfer protein, are rather stable to proteolytic processes. Mal d 1 and Mal d 4 were purified after expression in Escherichia coli expression system, while Mal d 2 and Mal d 3 were purified from apple fruit tissue. All purified proteins were subjected to detailed physicochemical characterisation to confirm their structural integrity and maintained IgE binding capacity. Detailed investigations of carbohydrate moieties of Mal d 2 demonstrated their involvement in the overall IgE binding capacity of this allergen. It was concluded that the folded structure and IgE binding capacity of all four allergens were preserved during purification.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allergens / chemistry
  • Allergens / immunology
  • Allergens / isolation & purification*
  • Antigens, Plant / chemistry
  • Antigens, Plant / immunology
  • Antigens, Plant / isolation & purification*
  • Carrier Proteins
  • Humans
  • Immunoglobulin E / metabolism
  • Malus / immunology*
  • Plant Proteins / chemistry
  • Plant Proteins / immunology
  • Plant Proteins / isolation & purification*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / isolation & purification


  • Allergens
  • Antigens, Plant
  • Carrier Proteins
  • MALD1 protein, Malus domestica
  • Mal d 2 allergen, Malus domestica
  • Mal d 3 allergen
  • Mal d 4 allergen, Malus domestica
  • Plant Proteins
  • Recombinant Proteins
  • Immunoglobulin E