Comprehensive analysis of the peanut allergome combining 2-DE gel-based and gel-free proteomics

In this work, we explored the “deep” seed peanut proteome by using both two dimensional electrophoresis (2- DE)-based analysis run under reducing and non-reducing condition (protein-centric) and LC-MS/MS gel-free proteomic (peptide-centric). The former approach allowed to identify high molecular weight disulfide-linked Ara h 1 and Ara h 3 heteroligomers and Ara h 1 homoligomers linked through covalent bonds other than disulfides. The occurrence of these protein complexes revealed natural interactions between Ara(s) subunits with a possible involvement in the allergenic potential of peanut. The second approach, also referred to as shot-gun proteomics, allowed the identification of 149 gene products, including low-abundance proteins escaped the 2-DE detection. Interestingly, we identified 60 proteins never catalogued previously. The complementary exploitation of two proteomic approaches enabled the access to new relevant information about the complexity of the peanut proteome, with special emphasis to the complement of allergens (allergome).