Ga. Mueller et al., Hydrogen exchange nuclear magnetic resonance spectroscopy mapping of antibody epitopes on the house dust mite allergen Der p 2, J BIOL CHEM, 276(12), 2001, pp. 9359-9365
New strategies for allergen-specific immunotherapy have focused on reducing
IgE reactivity of purified recombinant allergens while maintaining T-cell
epitopes. Previously, we showed that disrupting the disulfide bonds of the
major house dust mite allergen Der p 2 resulted in 10-100-fold less skin te
st reactivity in mite-allergic subjects but did not change in vitro T-cell
proliferative responses. To provide a more complete picture of the antigeni
c surface of Der p 2, we report here the identification of three epitopes u
sing hydrogen protection nuclear magnetic resonance spectroscopy. The epito
pes are defined by monoclonal antibodies that are able to inhibit IgE antib
ody binding to the allergen. Each monoclonal antibody affected the amide ex
change rate of 2-3 continuous residues in different regions of Der p 2. Bas
ed on these data, a number of other residues were predicted to belong to ea
ch epitope, and this prediction was tested for monoclonal antibody 7A1 by g
enerating alanine point mutants. The results indicate that only a small num
ber of residues within the predicted epitope are functionally important for
antibody binding. The molecular definition of these three epitopes will en
able us to target limited positions for mutagenesis and to expand our studi
es of hypoallergenic variants for immunotherapy.