title: Interactions of epigallo-catechin 3-gallate and ovalbumin, the major allergen of egg white.
abstract: Polyphenols, the potent plant secondary metabolites, have beneficial effects on human health, but the mechanism(s) by which these effects are exerted is not well understood. Here, we present the detailed analysis of the interactions between the major green tea catechin, epigallo-catechin 3-gallate (EGCG), and the major dietary protein and allergen, ovalbumin (OVA). We show that EGCG binds to the pocket that partly overlaps with the previously identified IgE-binding region in OVA, and that this interaction induces structural changes in the allergen. Moreover, our ex vivo studies reveal that OVA binds IgE and stimulates degranulation of basophils, and that its uptake by monocytes proceeds at a slower rate in the presence of EGCG. This study provides further evidence in support of the proposed mechanism by which EGCG interactions with the food allergens contribute to its diverse biological activities and may impair antigen uptake by antigen-presenting cells.
authors.affiliation: University of Belgrade, Faculty of Chemistry, Belgrade, Serbia. Electronic address: jognjenovic@chem.bg.ac.rs.
authors.forename: Jana
authors.initials: J
authors.lastname: Ognjenović
authors.affiliation: University of Belgrade, Faculty of Chemistry, Belgrade, Serbia.
authors.forename: Marija
authors.initials: M
authors.lastname: Stojadinović
authors.affiliation: University of Belgrade, Faculty of Chemistry, Belgrade, Serbia.
authors.forename: Miloš
authors.initials: M
authors.lastname: Milčić
authors.affiliation: University of Belgrade, Faculty of Chemistry, Belgrade, Serbia.
authors.forename: Danijela
authors.initials: D
authors.lastname: Apostolović
authors.affiliation: University of Belgrade, Faculty of Chemistry, Belgrade, Serbia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Vesić
authors.affiliation: University of Belgrade, Faculty of Chemistry, Belgrade, Serbia.
authors.forename: Ivan
authors.initials: I
authors.lastname: Stambolić
authors.affiliation: University of Belgrade, Faculty of Medicine, Belgrade, Serbia; University Children's Hospital, Belgrade, Serbia.
authors.forename: Marina
authors.initials: M
authors.lastname: Atanasković-Marković
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, IL, USA.
authors.forename: Miljan
authors.initials: M
authors.lastname: Simonović
authors.affiliation: University of Belgrade, Faculty of Chemistry, Belgrade, Serbia.
authors.forename: Tanja Cirkovic
authors.initials: TC
authors.lastname: Velickovic
mesh_terms: D000485:Allergens / Q000737:chemistry; D000938:Antigen-Presenting Cells / Q000378:metabolism; D001491:Basophils / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry; D002942:Circular Dichroism; D004529:Egg White / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D005512:Food Hypersensitivity; D006801:Humans; D007073:Immunoglobulin E / Q000737:chemistry; D009000:Monocytes / Q000378:metabolism; D010047:Ovalbumin / Q000737:chemistry*; D059808:Polyphenols; D011485:Protein Binding; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D013662:Tea / Q000737:chemistry
chemical_list: D000485:Allergens; D059808:Polyphenols; D013662:Tea; D007073:Immunoglobulin E; D002392:Catechin; D010047:Ovalbumin; C045651:epigallocatechin gallate
keywords: Epigallo-catechin 3-gallate; Fluorophore quenching; Food allergy; IgE binding; Molecular docking; Monocytes; Ovalbumin