Digestion-Resistant Linear Epitopes as Dominant Contributors to Strong Allergenicity of Tropomyosin in Antarctic Krill (Euphausia superba)

Abstract

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).

Investigation into Potential Allergenicity and Digestion-Resistant Linear Epitopes of Fish Skin Gelatin in Cell-Cultured Meat Scaffolds

“…Using bioinformatic tools to predict linear epitopes of FSG, DNAStar protean and Antheprot software used hydrophilicity, flexibility, surface accessibility, and antigenicity index as prediction criteria for candidate allergenic epitopes and the results were displayed in Table S2 and Figures S2c–10c. BepiPred 1.0 server, ABCpred server, and Immunomedicine Group tool were used to analyze potential allergenic epitopes based on amino acid secondary structure, hydrophilicity, accessibility, flexibility, and so on.…”

“…Digestion-Resistant Linear Epitopes Analysis and Mapping of the Major Allergen of FSG. Using bioinformatic tools to predict linear epitopes of FSG, DNAStar protean and Antheprot software used hydrophilicity, flexibility, surface accessibility, and antigenicity index as prediction criteria for candidate allergenic epitopes 46 and the results were displayed in Table S2 and Figures flexibility, and so on. As prediction using a single tool has limitations, overlapping epitopes predicted by more than three kinds of tools were used as linear epitopes of allergens.…”

Conformation-Activity Mechanism of Alcalase Hydrolysis for Reducing In Vitro Allergenicity of Instant Soy Milk Powder

“…Determination of Surface Hydrophobicity. Surface hydrophobicity of instant soy milk powder and the enzymatic hydrolysate was carried out according to the description of Wang et al 27 The relative fluorescence intensities of the gradient-diluted test samples (0.05, 0.10, 0.15, 0.2, and 0.25 mg/mL) reacted with 8-aniline-1-naphthalene sulfonic acid were plotted on the linear curves, and the slopes of the curves were considered to be the surface hydrophobicity of the test samples (H0).…”