1. Cor a 14, the allergenic 2S albumin from hazelnut, is highly thermostable and resistant to gastrointestinal digestion.
- Author
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Pfeifer S, Bublin M, Dubiela P, Hummel K, Wortmann J, Hofer G, Keller W, Radauer C, and Hoffmann-Sommergruber K
- Subjects
- Allergens isolation & purification, Amino Acid Sequence, Antigens, Plant isolation & purification, Hot Temperature, Humans, Immunoglobulin E metabolism, Molecular Sequence Data, Protein Isoforms chemistry, Protein Isoforms metabolism, Protein Stability, Protein Structure, Secondary, Proteolysis, Allergens chemistry, Allergens metabolism, Antigens, Plant chemistry, Antigens, Plant metabolism, Digestion
- Abstract
Scope: Allergens from nuts frequently induce severe allergic reactions in sensitive individuals. The aim of this study was to elucidate the physicochemical characteristics of natural Cor a 14, the 2S albumin from hazelnut., Methods and Results: Cor a 14 was purified from raw hazelnuts using a combination of precipitation and chromatographic techniques. The protein was analyzed using gel electrophoresis, MS, and far-UV circular dichroism (CD) analyses. The immunoglobulin E (IgE) binding of native, heat-treated, and in vitro digested Cor a 14 was studied. We identified two different Cor a 14 isoforms and showed microclipping at the C-terminus. CD spectra at room temperature showed the typical characteristics of 2S albumins, and temperatures of more than 80°C were required to start unfolding of Cor a 14 demonstrating its high stability to heat treatment. In vitro digestion experiments revealed that Cor a 14 is resistant to proteolytic degradation. Native and heat-treated protein was recognized by sera from hazelnut allergic patients. However, denaturation of the allergen led to significantly reduced IgE binding., Conclusion: We identified two different isoforms of Cor a 14 displaying high stability under heating and gastric and duodenal conditions. Data from IgE-binding experiments revealed the existence of both, linear and conformational epitopes., (© 2015 The Authors. Molecular Nutrition & Food Research published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2015
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