Influence of heat treatment on the structure and core IgE-binding epitopes of rAra h 2.02.

The rAra h 2.02 was studied to determine the influence of heat treatment on its structure and core IgE-binding epitopes. The results of SDS-PAGE, Western blotting, MALDI-TOF-MS, and atomic force microscopy showed that the structure of rAra h 2.02 was altered after boiling (100°C) or autoclaving (121°C) for 20min. Furthermore, some of the protein may be aggregated. Results of circular dichroism spectroscopy showed that the α-helices content was reduced, while β-turns and random coils were increased by 81% and 27%, respectively, after autoclaving. Antibodies of three core IgE-binding epitopes were used to determine the binding capacity of rAra h 2.02 after thermal processing by indirect ELISA. The results showed that the binding capacities of the three core IgE-binding epitopes were changed after different heat treatments.