High-throughput NMR authentication of food allergens

For in vitro allergy diagnosis, purified food allergens have to meet high standard quality criteria. 1D 1H-NMR analysis can assess the conformation and contribute to the authentication of allergens. This method allows to i) perform a structural comparison of allergens within a protein family, ii) identify the thermal stability of food allergens and iii) detect structural differences between recombinant and natural allergens. The analysis of the 1D-1HNMR spectra reported here allowed the classification of the allergens into molecules whose spectra showed the unquestionable features of a rigid and extended tertiary structure, molecules without a rigid tertiary structure and allergens which displayed both features, tertiary structure with flexible and mobile regions. Furthermore, differences regarding thermal stability within a protein family were detected based on NMR spectra. In summary, 1D-1H-NMR proved a highly useful method requiring low protein concentrations, without 15N and 13C labeling for the structural authentication of allergens even when there is a limited quantity of protein available.