Analysis of the allergenicity and B cell epitopes in tropomyosin of shrimp (Litopenaeus vannamei) and correlation to cross-reactivity based on epitopes with fish (Larimichthys crocea) and clam (Ruditapes philippinarum)

Li Li Xu; Jin Chen; Li Rui Sun; Xiang Gao; Hong Lin; Ishfaq Ahmed; S N Pramod; Zhen Xing Li

doi:10.1016/j.foodchem.2020.126763

Analysis of the allergenicity and B cell epitopes in tropomyosin of shrimp (Litopenaeus vannamei) and correlation to cross-reactivity based on epitopes with fish (Larimichthys crocea) and clam (Ruditapes philippinarum)

Food Chem. 2020 Apr 7:323:126763. doi: 10.1016/j.foodchem.2020.126763. Online ahead of print.

Authors

Li Li Xu¹, Jin Chen¹, Li Rui Sun¹, Xiang Gao², Hong Lin¹, Ishfaq Ahmed¹, S N Pramod³, Zhen Xing Li⁴

Affiliations

¹ College of Food Science and Engineering, Ocean University of China, No. 5, Yushan Road, Qingdao, Shandong Province 266003, PR China.
² Department of Allergy, Affiliated Hospital of Qingdao University, Qingdao, Shandong Province 266071, PR China.
³ Department of Studies in Biochemistry, Sahyadri Science College, Kuvempu University, Shimoga-577203, Karnataka 560037, India.
⁴ College of Food Science and Engineering, Ocean University of China, No. 5, Yushan Road, Qingdao, Shandong Province 266003, PR China. Electronic address: lizhenxing@ouc.edu.cn.

PMID: 32334299
DOI: 10.1016/j.foodchem.2020.126763

Abstract

Tropomyosin (TM) is a highly conserved protein that considered as the major allergen of crustacean and mollusk species, while, fish-TM also shares high homology with low allergenicity. In this study, the amino acid sequence, B cell epitopes and allergenicity of shrimp (Litopenaeus vannamei), which is widely consumed, were evaluated by using immunoinformatic tools, dot-blot, enzyme-linked immunosorbent assay (ELISA) and mediator release assay. Meanwhile, cross-reactivity of allergic epitopes of fish-TM, shrimp-TM and clam-TM were assessed. Results showed that three IgE-binding epitopes (X1: 47-61, QKRMQQLENDLDQVQ; X2: 97-108, EDLERSEERLNT and X3: 244-257, RSVQKLQKEVDRLE) of shrimp-TM also exhibited degranulation ability. In comparison with epitopes from shrimp-TM, those from clam-TM showed high cross-reactivity (>80%) and degranulation ability, while those from fish-TM showed low cross-reactivity (<20%). These findings would apply a new understanding of the cross-reactivity of TM from fish, shrimp and clam in terms of allergenic epitopes.

Keywords: Allergenicity; B cell epitope; Clam; Cross-reactivity; Shrimp; Tropomyosin.