Cross-reactivity and conserved epitope analysis of tropomyosin from Lateolabrax japonicus and shellfish species

The phenomenon of cross-reactivity within TM between fish and shellfish has received scant attention. In the study, TM of Lateolabrax japonicus, Scylla paramamosain and Mactra quadrangularis were considered as research objects. The results indicated L. japonicus TM exhibited weak binding for both rabbit anti-S. paramamosain/M. quadrangularis TM antibody. However, a significant IgE-binding capacity was observed for three TM in 11 of 18 fish-sensitised patients. Additionally, three TM also could activated basophils in 6 fish-sensitised patients. Subsequently, seven IgE epitopes of L. japonicus TM were confirmed. Two conserved epitopes (LERTEERA, LKTVQNN) and four critical amino acids (E, A, L, and R) were found across L. japonicus and shellfish TM, suggesting these could be responsible for cross-reactivity. These findings were expected to reduce the allergenicity of fish by destroying IgE epitopes through food processing or deleting IgE epitopes using molecular biotechnology, which have important implications for food safety and allergy management.