A comparative study of the biophysical and biochemical properties of allergenic legumins in select oilseeds

ABSTRACT Legumins are seed storage proteins and major allergens in many oilseeds. Despite belonging to the same protein superfamily, legumins from different oilseed sources exhibit distinct immunoreactivity. Such discrepancy could be partly attributed to their structural differences. In a study of its first kind, native legumin allergens were purified from different oilseed sources such as tree nuts (almonds, cashews, and pistachios), legume (soybean), and non-tree nut, non-legume (sesame) species using low pressure liquid chromatography. Protein purity and identity were confirmed using LC-MS/MS analysis. Purified allergens showed significant ( P < 0.05) differences in their molecular mass (269‒331 kDa), hydrodynamic radii (61‒80 Å), sedimentation coefficients (11.9S‒13.4S), and amino acid composition. Furthermore, distinct electrophoretic profiles and variable secondary and tertiary structures were observed between proteins. These results could lay the ground for a better understanding of the distinct allergenic potential of these homologous proteins.