Post-translational modifications (PTMs) of major peanut allergen epitopes occurring as a result of purification process

Abstract

Peanut allergy affects a large portion of world population causing reactions ranging from mild to severe. Seed storage proteins Ara h 1, Ara h 2, Ara h 3 and Ara h 6 are peanut allergens, with well characterized IgE epitopes but little is known about PTMs effect on their properties. Our aim was to investigate PTMs present on known epitopes of said purified proteins using bottom-up proteomcs methods. Out of the 4 allergens, Ara h 2 has the highest number of PTMs (14), while the most common are hydroxylation Pro, dehydration and deamidation (N, Q). Peanut allergen epitopes are indeed carriers of PTMs that could affect protein allergenicity and digestibility. Further investigation on peanut extracts prepared in different ways is necessary in order to fully understand the impact protein modifications could have on their allergenic potential.