Effects of heat treatment on the antigenicity, antigen epitopes, and structural properties of β-conglycinin

Food Chem. 2021 Jun 1:346:128962. doi: 10.1016/j.foodchem.2020.128962. Epub 2020 Dec 30.

Abstract

In this study, the effects of heat treatment on antigenicity, antigen epitopes, and structural changes in β-conglycinin were investigated. Results showed that the IgG (Immunoglobulin G) binding capacity of heated protein was inhibited with increased temperature, although IgE (Immunoglobulin E) binding capacity increased. Linear antigen epitopes generally remained intact during heat treatment. After heat treatment, β-conglycinin was more easily hydrolyzed by digestive enzymes, and a large number of linear epitopes was destroyed. In addition, heat denaturation of β-conglycinin led to the formation of protein aggregates and reduction of disulfide bonds. The contents of random coils and β-sheet of heated β-conglycinin decreased, but the contents of β-turn and α-helix increased. Moreover, the protein structure of heated β-conglycinin unfolded, more hydrophobic regions were exposed, and the tertiary structure of β-conglycinin was destroyed. Heat treatment affected the antigenicity and potential sensitization of β-conglycinin by changing its structure.

Keywords: Digestion; Epitope; Heat treatment; Structure; β-conglycinin.

MeSH terms

  • Antigen-Antibody Reactions
  • Antigens, Plant / chemistry
  • Antigens, Plant / immunology*
  • Antigens, Plant / metabolism
  • Digestion
  • Epitopes / chemistry
  • Epitopes / immunology*
  • Globulins / chemistry
  • Globulins / immunology*
  • Globulins / metabolism
  • Hot Temperature
  • Hydrophobic and Hydrophilic Interactions
  • Immunoglobulin E / immunology
  • Immunoglobulin G / immunology
  • Protein Conformation, alpha-Helical
  • Protein Conformation, beta-Strand
  • Protein Unfolding
  • Seed Storage Proteins / chemistry
  • Seed Storage Proteins / immunology*
  • Seed Storage Proteins / metabolism
  • Soybean Proteins / chemistry
  • Soybean Proteins / immunology*
  • Soybean Proteins / metabolism
  • Spectrometry, Fluorescence
  • Spectroscopy, Fourier Transform Infrared

Substances

  • Antigens, Plant
  • Epitopes
  • Globulins
  • Immunoglobulin G
  • Seed Storage Proteins
  • Soybean Proteins
  • beta-conglycinin protein, Glycine max
  • Immunoglobulin E