Conformational Stability of Digestion-resistant Peptides of Peanut Conglutins Reveals the Molecular Basis of Their Allergenicity

Authors

Danijela Apostolovic, University of Belgrade
Dragana Stanic-Vucinic, University of Belgrade
Harmen H.J. de Jongh, TI Food and Nutrition
Govardus A.H. de Jong, TNO
Jelena Radosavljevic, University of Belgrade
Milica Radibratovic, Institute of Chemistry
Julie A. Nordlee, University of Nebraska-LincolnFollow
Joseph L. Baumert, University of Nebraska-LincolnFollow
Milos Milcic, University of Belgrade
Steve L. Taylor, University of Nebraska-LincolnFollow
Nuria Garrido Clua, TI Food Nutrition
Tanja Cirkovic Velickovic, University of BelgradeFollow
Stef J. Koppelman, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2016

Citation

Scientific Reports (2016) 6: 29249

doi: 10.1038/srep29249

Comments

Open access

License: CC BY 4.0 International

Abstract

Conglutins represent the major peanut allergens and are renowned for their resistance to gastrointestinal digestion. Our aim was to characterize the digestion-resistant peptides (DRPs) of conglutins by biochemical and biophysical methods followed by a molecular dynamics simulation in order to better understand the molecular basis of food protein allergenicity. We have mapped proteolysis sites at the N- and C-termini and at a limited internal segment, while other potential proteolysis sites remained unaffected. Molecular dynamics simulation showed that proteolysis only occurred in the vibrant regions of the proteins. DRPs appeared to be conformationally stable as intact conglutins. Also, the overall secondary structure and IgE-binding potency of DRPs was comparable to that of intact conglutins. The stability of conglutins toward gastro-intestinal digestion, combined with the conformational stability of the resulting DRPs provide conditions for optimal exposure to the intestinal immune system, providing an explanation for the extraordinary allergenicity of peanut conglutins.