Allergenicity and IgE Recognition of New Dau C 1 Allergens from Carrot.

SCOPE
Carrot (Daucus carota) allergy is caused by the major carrot allergen Dau c 1, which is a mixture of several isoallergens and variants with sequence identities of > 67 % or > 90 %, respectively. However, little is known about the qualitative and quantitative composition of natural Dau c 1.


METHODS AND RESULTS
Mass spectrometry of isolated natural Dau c 1 revealed the existence of several yet unknown Dau c 1-like proteins. We expressed four Dau c 1-like proteins in Escherichia coli. Two of the purified proteins, designated Dau c 1.0501 and 1.0601, exhibit sequence identities to Dau c 1.0101 and 1.0401 between 54 and 87 %. They possess allergenic potential and were accepted as new isoallergens. One protein, designated Dau c 1-like is > 50 % identical with the new isoallergens but exhibited no allergenicity. Sequence and structural comparisons of this protein with the known Dau c 1 isoallergens offered relevant clues about putative structural IgE epitopes.


CONCLUSION
Identification of new isoallergens and the identification of IgE epitopes may contribute to a more refined component resolved diagnosis and may lay ground for further epitope mapping and personalized targeted treatment approaches of carrot allergy in preclinical and clinical studies. This article is protected by copyright. All rights reserved.