Investigation of Euphausia superba tropomyosin (Eup s 1): Epitope mapping and heat stability assessment via bioinformatics and immunological approaches.

Euphausia superba was recognized as the largest marine protein reservoir, while it faces utilization constraints due to allergenicity concerns. This study revealed the structure-activity relationship between the epitopes of Euphausia superba tropomyosin (Eup s 1) and the IgE/IgG-binding capacity under different heating temperature at the molecular level. As the results, eight antigenic epitopes (AA18-27, AA55-59, AA110-125, AA158-164, AA215-223, AA225-239, AA242-251 and AA258-269) of Eup s 1 were identified. The secondary structure and IgG-binding capacity of Eup s 1 remained relatively stable under low-temperature (20-140 °C). However, IgE/IgG-binding capacity decreases at 180 °C. Circular dichroism spectroscopy and molecular dynamics simulations revealed that this reduction is likely attributed to the heat-induced unfolding of α-helix, disruption of the hydrogen bonding network, and contraction of the conformation. Four epitopes (AA18-27, AA215-223, AA242-251 and AA258-269) are more susceptible to temperature influence. The investigation provided an important theoretical basis for the hypoallergenic processing of Euphausia superba proteins.