High hydrostatic pressure treatment reduces the potential antigenicity of β‐conglycinin by changing the protein structure during in vitro digestion

Abstract

BACKGROUND High hydrostatic pressure (HHP) treatment has been used to alleviate the allergenicity of soybeans, but there are little data about the potential antigenicity of β‐conglycinin after HHP treatment. RESULTS We examined the effects of HHP treatment on the antigenicity and structure of β‐conglycinin. When the pressure was 300 and 400 MPa, HHP treatment reduced the immunoglobulin (Ig)G binding capacity of β‐conglycinin, while its IgE binding capacity did not change significantly. After in vitro digestion, both the IgE and IgG binding of β‐conglycinin was obviously inhibited after HHP treatment at 400 MPa and 60 °C, although its binding capacity with linear epitope antibodies increased. Moreover, HHP treatment changed the secondary structure of β‐conglycinin, the content of α‐helix and random coils increased, while the β‐sheet and β‐turn decreased. After HHP treatment, the conformational structure was unfolded so that a large number of hydrophobic regions were exposed. CONCLUSION HHP treatment alleviated the potential antigenicity of β‐conglycinin by modifying its structure, which facilitated in vitro digestion and destroyed epitopes. This research provides a new insight into the mechanism of HHP treatment that affects the sensitization of soy protein allergens. © 2022 Society of Chemical Industry.

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

“…Similar results were obtained by Lu et al and Bu and Li for the potential allergenicity of the major allergic proteins in soymilk and β-conglycinin, respectively. 17,52 However, the remaining seven potential epitopes were intact in the stable peptides and did not break down with proteolytic hydrolysis and were ultimately screened as potential digestion-resistant linear epitopes of TM in Antarctic krill (Table 2). It has been confirmed in previous studies that some linear epitopes of food allergens are destroyed during gastrointestinal digestion, while only those stable epitopes can truly exert their sensitizing potential.…”

Heat/non‐heat treatment alleviates β‐conglycinin‐triggered food allergy reactions by modulating the Th1/Th2 immune balance in a BALB/c mouse model

“…10,11,13,16 In our previous work, we explored the effects of heat treatment and HHP treatment on the antigenicity, antigen epitopes and structure of ⊎-conglycinin. 15,16 Heat treatment and HHP treatment expanded the protein structure and exposed new enzyme cleavage sites, which facilitated protease digestion and destroyed most linear epitopes. To date, the mechanism of ⊎-conglycinin sensitization has not been systematically studied.…”

“…The procedures of heat and HHP treatment of ⊎-conglycinin were carried out according to the method we described before. 15,16 First, the protein sample (2 mg mL −1 ) was dissolved in phosphate-buffered saline (PBS, pH 7.0) and heated in an oil bath at 125 °C for 1 h; second, ⊎-conglycinin was diluted with PBS (pH 7.0) to 2 mg mL −1 and packed in polyethylene bags; the solution was then subjected to HHP treatment using an S-FL-850-9-W/ FPG5620YHL HHP vessel (Stansted Fluid Power Ltd, Harlow, UK). The protein solution was subjected to HHP treatment at 400 MPa and 60 °C for 20 min.…”

“…Then, we explored the effects on the antigenicity, antigen epitopes and structural properties of ⊎-conglycinin under different temperature conditions and high hydrostatic pressure (HHP) treatment. 15,16 After heat treatment and HHP treatment, the conformational structure of ⊎-conglycinin unfolded, exposing more cleavage sites, which facilitated proteolytic hydrolysis and destroyed the original epitope.…”

Effects of Chlorogenic Acid on Lowering IgE-Binding Capacity of Soybean 7S: Comparison between Covalent and Noncovalent Interaction

“…The extraction of soybean 7S was performed according to Bu & Li with some modifications. 17 Defatted soybean powder of 100 g was mixed with 1.5 L of distilled water and then adjusted to pH 8.5 by 2 M NaOH solution, which was subsequently stirred for 1 h at room temperature and centrifuged at 4 °C, 12,000 rpm (15,609 g) for 15 min. NaHSO 3 of 1.05 g was added to the supernatant and adjusted to pH 6.4 by 2 M HCl for preserving at 4 °C overnight.…”