Analysis of Immunoreactivity of α/α<sub>2</sub>-Tropomyosin from <i>Haliotis discus hannai</i>, Based on IgE Epitopes and Structural Characteristics
Nai-Ru Ji, Xinyu Han, Chenchen Yu, Yujia Wang, Xinrong He, Hong Liu, Fei Huan, Dong Lai, Min‐Jie Cao, Guang‐Ming Liu
Abstract
Tropomyosin (TM) was reported to be a supercoil allergen of shellfish. However, little information is available about its link between structure and allergenicity. In this study, the subunit of TM (α-TM) and supercoil of TM (α2-TM) were identified from Haliotis discus hannai. α2-TM showed higher immunoreactivity than α-TM. Meanwhile, seven linear epitopes in α-TM and α2-TM were verified, and two conformational epitopes in α2-TM were predicted. The physicochemical properties and chemical bond assays confirmed the existence of the disulfide bond in α2-TM. According to spectroscopy and hydrophobicity analysis, α-TM showed higher α-helix features and blueshift of the fluorescence intensity peak compared with those of α2-TM. The structure analysis revealed the possibility of conformational epitopes in α2-TM, which could explain the immunoreactivity differences between α-TM and α2-TM further. These results improved the understanding of Haliotis discus hannai TM, which lay the foundation for the food processing of abalone.