MdAP, a novel protein in apple, is associated with the major allergen Mal d 1.

Mal d 1, an 18-kDa intracellular pathogenesis-related protein (PR-10), has been known since long as the major apple allergen in Middle and Northern Europe. However, its biological function, as that of many other PR-10 proteins, is still unknown. In order to identify proteins putatively interacting with Mal d 1, an expression library of Malus domestica was screened using the yeast-two-hybrid (Y2H) system.