Understanding the Mechanism of Increased IgG/IgE Reactivity but Decreased Immunodetection Recovery in Thermally Induced Shrimp (Litopenaeus vannamei) Tropomyosin via Multispectroscopic and Molecular Dynamics Simulation Techniques

Abstract

Despite the fact that tropomyosin (TM) has highly stable structural characteristics, thermal processing can adversely influence its immunodetection, and the mechanism involved has not been elucidated. Purified TM was heated at various temperatures, and then the IgG/IgE-binding capacity and immunodetection recovery were determined; meanwhile, the structural alterations were analyzed via spectroscopic and molecular dynamics simulation techniques. The obtained results demonstrated that heat-treated TM showed significantly increased IgG/IgE reactivity, confirmed by indirect ELISA and immunoblotting analysis, which might be attributed to the increased structural flexibility, and thus allowed TM to be recognized IgG/IgE easily. However, these structural alterations during thermal processing would contribute to the masking of some epitopes located in TM’s surface due to the presence of curled or folded conformation with a considerable reduction of the solvent-accessible surface and radius of gyration, which primarily caused immunodetection recovery reduction in the sandwich ELISA (sELISA) test. The number of antigen binding sites might play a crucial role in a sandwich immunodetection system for sensitive and precise analysis in processed foods.

Investigation of the allergenicity alterations of shrimp tropomyosin as glycated by glucose and maltotriose containing advanced glycation end products

“…Shrimp has become a prevalent allergic food owing to its high consumption and delicacy properties, and exposure to shrimp allergen could trigger food allergic reactions among some consumers. 2 With the growing consumption of shrimp, the incidence of food allergy induced by shrimp has also shown an upward trend. The main allergen in shrimp is tropomyosin (TM), which is responsible for at least 80% of the allergic reactions that are induced by shrimp.…”

Dual Action of Reduced Allergenicity and Improved Memory of Instant Soybean Powder Hydrolysates

“…44 HIS in plasma was mainly produced by mast cells or basophils and was one of the crucial indicators of the degree of allergy. 45 As shown in Figure 3C, the HIS level in the ISP group was significantly increased to (74.45 ± 6.34) ng/mL (P < 0.05), which was 122.90% higher compared to the BC group. The HIS level was significantly lower in the ISPH group as (65.08 ± 3.37) ng/mL than that in the ISP group (P < 0.05).…”

“…At the same time, INF-γ and IL-10 mediated immune cell responses, and there was an antagonistic relationship between Th1 and Th2 type cytokines. 45 From Figure 3F,G, INF-γ lungs, and jejunum were performed to observe the effect of enzymatic hydrolysis treatment on pathological changes in ISPsensitized mice. As depicted in Figure 4, the spleen, lungs, and jejunum of the BC group were in normal morphological conditions, and no obvious pathological changes were observed.…”

Mechanism of Targeted Regulation of Ovalbumin Epitopes by Pulsed Electric Field-Assisted Alcalase Treatment

“…Additionally, 142 peptides in HOVA and 189 peptides in HOVA-PP′ cut off the predicted linear epitopes. Allergic reaction was mainly due to the adverse reaction caused by the binding of antigenic epitopes in antigens to specific antibodies, , and PEF-assisted Alcalase treatment significantly reduced the antigenic epitopes in HOVA-PP′. Previous studies have shown that PEF treatment inhibited OVA-induced allergic reactions to some extent by altering the conformational epitopes of OVA.…”