Although
tropomyosin has been identified as a major
allergen in Antarctic krill, the digestive fate of Antarctic krill
tropomyosin and its relationship with allergenicity are unknown. In this study, Antarctic krill
tropomyosin was administered to BALB/c mice via both gavage and
intraperitoneal injection to explore its sensitizing and eliciting capacity, and its digestion products were analyzed for structural changes and digestion-resistant linear
epitopes. Mice gavaged with
tropomyosin exhibited lower levels of specific
IgE and
IgG1, mast cell degranulation, vascular permeability, and
anaphylaxis symptoms than those in the
intraperitoneal injection group. This may be due to the destruction of macromolecular aggregates, loose expansion of the tertiary structure, complete disappearance of α-helix, and significant changes in molecular force upon the digestion of
tropomyosin. Nevertheless, the intragastric administration of Antarctic krill
tropomyosin still triggered strong
allergic reactions, which was attributed to the existence of seven digestion-resistant linear
epitopes (Glu26-His44, Thr111-Arg125, Glu157-Glu164, Glu177-Gly186, Val209-Ile225, Arg244-Arg255, and Val261-Ile270).