The Mechanism of Decreased IgG/IgE-Binding of Ovalbumin by Preheating Treatment Combined with Glycation Identified by Liquid Chromatography and High-Resolution Mass Spectrometry

Abstract

Ovalbumin is one of the most important sensitizing ingredients in allergens of egg albumin, which restricts the application of egg in the field of food processing. Previous research has indicated that glycation could cause the protein to partially expand, which may bring about the destruction of the structural IgG and IgE epitopes and induce the decline of the IgG-and IgE-binding ability of ovalbumin. In this research, the effect of a preheating treatment integrated with glycation on the IgG-and IgE-binding capability and the conformation changes of ovalbumin was studied by detecting the glycated sites and the values of degree of substitution per peptide (DSP) by liquid chromatography and high-resolution mass spectrometry (LC-HRMS). Interestingly, we found that a glycation site (K227) attached by two ribose molecules was detected in glycated ovalbumin with preheating treatment. In addition, a new glycation site (K323) appeared in G-60. The results displayed that preheating treament could strengthen the changes in the secondary and tertiary structure of ovalbumin by enhancing glycation and further reduce the IgG/IgE-binding ability by integrating with glycation because of the cover of IgG and IgE epitopes. Therefore, preheating treatment integrated with glycation may offer a way for ovalbumin to reduce sensitization.

Mechanism of the Reduced IgG/IgE Binding Abilities of Glycated β-Lactoglobulin and Its Digests through High-Resolution Mass Spectrometry

“…These results indicated that glycation could reduce the IgG binding ability possibly by masking the linear allergic epitopes of β-Lg. Liao et al 36 reported that glycation reduces the IgG binding ability of ovalbumin by masking the linear allergic epitopes.…”

Double enzyme hydrolysis for producing antioxidant peptide from egg white: Optimization, evaluation, and potential allergenicity

“…To evaluate the potential allergenicity of prepared antioxidant peptide, IgG and IgE binding capacities were assessed. In high concentrations, the IgG binding ability of EWP was considerably lower than that of HEW, indicating that IgGspecific epitopes of egg white proteins could be distrusted after hydrolysis (Liao et al, 2018). The IgG binding ability of PLMW was considerably lower than that of EWP and PHMW, which indicated that the peptide with less IgG-specific epitopes may be selected after ultrafiltration.…”

“…In high concentrations, the IgG binding ability of EWP was considerably lower than that of HEW, indicating that IgGspecific epitopes of egg white proteins could be distrusted after hydrolysis (Liao et al, 2018). To evaluate the potential allergenicity of prepared antioxidant peptide, IgG and IgE binding capacities were assessed.…”

Maillard Reaction Induced Changes in Allergenicity of Food

“…It seems that the preheating (60 °C for 1 h, lower preheating temperature) did not show a good effect, while a higher temperature would affect the reconstitution of the allergen, and ultrasound pretreatment (400 W or 600 W for 15 min) helps to further reduce the IgE binding capacity of ovalbumin after glycation, especially when 600 W ultrasound pretreatment was included. The IC50 increased from 10.03 μg/mL of the glycated protein to 28.02 μg/mL of the final sample (ovalbumin glycated with mannose following ultrasound pretreatment at 600 W; IC50 of the native ovalbumin was 3.10 μg/mL) [ 52 , 53 ]. In consideration of its allergenicity change in vivo, glycation with mannose was proven to be a good choice [ 54 ].…”