Narrow Leafed Lupin Beta-Conglutin Proteins Epitopes Identification and Molecular Features Analysis Involved in Cross-Allergenicity to Peanut and Other Legumes

Abstract

The use of narrow leafed lupin - NLL (Lupinus angustifolius L.) as a new food is resulting in an increasing number of allergic reactions cases, particularly in atopic patients with other pre-existing legume allergies. In the current study, we have performed an extensive in silico analysis of the NLL seed β-conglutin proteins, a new family of major allergen proteins identified in NLL, and a comparison to other relevant food allergens such as peanut Ara h 1. We analysed the variability of surface residues involved in conformational IgE-binding epitopes, lineal B- and T-cell epitopes, and changes in 2-D structural elements and 3D motives, with the aim to investigate cross-allergenicity among lupin, peanut, and other different legumes. Our results revealed that considerable structural differences exist, particularly affecting 2-D elements (loops and coils), and numerous micro-heterogeneities are present in fundamental residues directly involved in epitopes differential variability. Thus, variability of residues involved in IgE-binding epitopes might be a major contributor to the observed differences in cross-allergenicity among legumes.