Identification of peptides sequence and conformation contributed to potential allergenicity of main allergens in yogurts

Abstract

Yogurts provide a good source of nutrition and may induce tolerance in people with cow’s milk allergy (CMA). This study aimed to investigate the IgE-binding capacity of main allergens in the different yogurts which provide a reference for people with a high risk of CMA, and analyze the epitopes of major allergen peptides in yogurt. We assessed the degradation and the allergenic properties of major allergens in six commercial yogurts and fresh milk. The degradation of major allergens was analyzed by SDS-PAGE and RP-HPLC. Western blot and ELISA experiments detected allergenic characteristics by using specific sera. The results showed that β-lactoglobulin (Bos d 5) and α-lactalbumin (Bos d 4) were obviously degraded in yogurts but caseins were still present in abundance, which indicated that the proteases in yogurts were specific to whey proteins. IgE and IgG binding ability of major allergens were obviously reduced in yogurts, especially GuMi yogurt. In addition, 17 peptides of major allergens in GuMi yogurt were identified by LC-MS/MS and most of them were located in the interior of the spatial structure of proteins. Among them, 8 peptides had specific biological functions for health benefits, such as antibacterial, antioxidant, and ACE-inhibitory. We also found that 6 and 14 IgE epitopes of Bos d 5 and caseins were destroyed in GuMi yogurt, which could lead to the reduction of IgE-binding capacity. Meanwhile, peptides [Bos d 5 (AA15–40), Bos d 9 (AA120–151, AA125–151)] also preserved T cell epitopes, which might also induce the development of oral tolerance. Therefore, this study suggested that the sequence and conformation of peptides in yogurts contributed to hypoallergenicity.

One-Step Purification of IgE Epitope-Specific Antibody Using Immunomagnetic Beads and Highly Sensitive Detection of Bovine β-Lactoglobulin for the Prediction of Milk Allergenicity in Foods

“…As shown in Figure B, no significant difference was observed between the ratios of C samples to C M ( C S / C M ) and the ratios of IC 50(samples) to IC 50(M) (IC 50(S) /IC 50(M) ), except for C yoghurts / C M , which was significantly lower than IC 50(yoghurts) /IC 50(M) . These differences could be attributed to the varying degrees of hydrolysis of different IgE epitopes of BLG in yoghurts due to microbial fermentation . Moreover, the sera from CMA patients can recognize more IgE epitopes than IgE-EsAb, leading to lower binding ability of yoghurts with IgE-EsAb than with sera from CMA patients.…”

“…These differences could be attributed to the varying degrees of hydrolysis of different IgE epitopes of BLG in yoghurts due to microbial fermentation. 47 Moreover, the sera from CMA patients can recognize more IgE epitopes than IgE-EsAb, 28 leading to lower binding ability of yoghurts with IgE-EsAb than with sera from CMA patients.…”

Unleashing the power of chlorogenic acid: exploring its potential in nutrition delivery and the food industry

“…An example is its application in addressing milk protein allergies, a substantial impediment to the advancement of dairy products in the food industry, primarily due to β-lactoglobulin (βLG) and α-lactalbumin (αLA) as major allergens. 114 To mitigate milk allergies, effective methods are crucial to reduce the allergenicity of milk proteins. Studies propose that polyphenols, such as CGA, can interact with milk proteins, forming complexes that potentially alter protein functional properties.…”