Effect of critical amino acids’ properties on potential allergenicity of Ara h 2 epitopes

Abstract

Peanuts are one of the most common allergenic foods in the world and can cause severe allergic reactions. Ara h 2 is the most allergenic components of peanut allergens. Although critical amino acids at the epitopes were identified, the effect of their physicochemical properties remained unclear. The critical amino acids in epitopes of Ara h 2 (epitope 1: 26ELQGDRRCQSQLER39 and epitope 2: 62RDPYSPSQDPYSPS75). The critical amino acids were substituted by amino acid with different physicochemical properties. Then, the potential allergenicity of those peptides was assessed by IgE binding and cell model. Changing the properties of amino acids by mutation affects potential sensitisation. The charge distribution and molecular weight of critical amino acids in the epitope affected the IgE binding capacity significantly. The conclusion based on peptide might be different from that on whole protein, and our study provided direction of amino acids mutation in desensitisation therapy.

Keywords

• Ara h 2
• epitope
• critical amino acids
• potential allergenicity
• physicochemical properties