Abstract: In the present study, an approach to detect the binding capacity between peanut protein and serum IgE from patients with peanut allergy was explored using biolayer interferometry (BLI). For this purpose, the experiment was designed using a streptavidin (SA) dip and read biosensor, biotin labeled goat anti-human IgE antibody, the serum pool of patients with peanut allergy and peanut proteins. The optimized conditions for sensor modification were as follows: immobilization of the 100-fold diluted IgE for 20 min before being bound to the 10-fold diluted serum overnight. After being washed to baseline online, peanut protein (1 mg/mL) was bound to the sensor for 3 600 s and then dissociated for 120 s. This method was applied to detect the IgE binding capacity of peanut protein subjected to different thermal treatments and compare with enzyme linked immunosorbent assay (ELISA). The results showed that this method could directly evaluate the IgE binding capacity of allergenic protein and had good consistency with the ELISA results with correlation coefficient of 0.91. After frying treatment, the IgE binding capacity of peanut protein increased but decreased after boiling and roasting treatments. Protein extracted from thermally processed peanuts without shells had a stronger IgE binding capacity than that from thermally processed peanuts with shells.

Key words: peanut protein, IgE, biolayer interferometry, IgE binding capacity, thermal processing