2. Academic Validation
  3. Cross-linked ovalbumin catalyzed by polyphenol oxidase: Preparation, structure and potential allergenicity

Cross-linked ovalbumin catalyzed by polyphenol oxidase: Preparation, structure and potential allergenicity

  • Int J Biol Macromol. 2018 Feb;107(Pt B):2057-2064. doi: 10.1016/j.ijbiomac.2017.10.072.
Ke Liu 1,  Shuguang Chen 1,  Hongbing Chen 2,  Ping Tong 3,  Jinyan Gao 4
Affiliations

Affiliations

  • 1 State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; School of Food Science and Technology, Nanchang University, Nanchang 330031, China.
  • 2 State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China.
  • 3 State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China. Electronic address: tongping@ncu.edu.cn.
  • 4 School of Food Science and Technology, Nanchang University, Nanchang 330031, China. Electronic address: gaojy2013@ncu.edu.cn.
PMID: 29037873 DOI: 10.1016/j.ijbiomac.2017.10.072
Abstract

Ovalbumin (OVA) is described as one of the major allergens in hen's egg, and it is the most abundant protein in egg white. Enzyme-mediated covalent cross-linking of food proteins, can influence their structure and allergenicity. The aim of this study was to investigate the potential of polyphenol oxidase from Agaricus bisporus to cross-link OVA (CL-OVA) in the presence or absence of caffeic acid, followed by characterizing the structure and allergenicity of CL-OVA. A single-factor experiment was designed to assess the optimum conditions for cross-linking of OVA by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Under the optimal conditions, structural changes in OVA were analyzed by circular dichroism, ultraviolet and fluorescence spectra. It was shown that CL-OVA became unordered and unfolded, and more tyrosine and tryptophan residues and hydrophobic groups were exposed onto the surface of molecules when compared to the native OVA. Enzyme-linked immunosorbent assay indicated that IgG and IgE binding abilities to OVA significantly reduced after cross-linking. All the findings demonstrated that enzymatic cross-linking in the presence of caffeic acid as a mediator may decrease the antigenicity and potential allergenicity, and the changes of the modified OVA were most likely a consequence of some changes or adjustment in the local conformation of OVA and the epitopes of OVA by cross-linking.

Keywords

Allergenicity; Cross-link; Ovalbumin; Polyphenol oxidase; Structural changes.

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