RESUMO
BACKGROUND: Peanut allergy is one of the most serious food allergies, and Ara h 2 is one of the most important peanut allergens as it is recognised by serum immunoglobulin E from more than 90% of peanut-allergic individuals. Dynamic high-pressure microfluidisation has been widely used in food processing as a new technology. The aim of this study was to investigate the effect of high-pressure microfluidisation on the antigenicity and structure of Ara h 2. Extracted peanut allergen Ara h 2 was treated under a continuous pressure array of 60, 90, 120, 150 and 180 MPa. Immunoreactivity was measured by indirect enzyme-linked immunosorbent assay with rabbit polyclonal antibodies. Secondary structure was analysed by circular dichroism. Surface hydrophobicity and sulfhydryl groups were assessed via fluorescence and UV absorption spectra respectively. RESULTS: High-pressure microfluidisation treatment decreased the antigenicity of peanut allergen Ara h 2, changed its secondary structure and increased its UV absorption intensity and surface hydrophobicity. CONCLUSION: The change in conformation contributed to the decrease in antigenicity of Ara h 2, and the spatial conformation of peanut allergen Ara h 2 plays a critical role in its antigenicity.
Assuntos
Albuminas 2S de Plantas/imunologia , Antígenos de Plantas/imunologia , Arachis/imunologia , Manipulação de Alimentos/métodos , Tecnologia de Alimentos/métodos , Glicoproteínas/imunologia , Hipersensibilidade a Amendoim/imunologia , Sementes/química , Albuminas 2S de Plantas/química , Albuminas 2S de Plantas/isolamento & purificação , Animais , Anticorpos Monoclonais , Antígenos de Plantas/química , Antígenos de Plantas/isolamento & purificação , Arachis/química , China , Dicroísmo Circular , Ensaio de Imunoadsorção Enzimática/métodos , Glicoproteínas/química , Glicoproteínas/isolamento & purificação , Humanos , Interações Hidrofóbicas e Hidrofílicas , Imunoglobulina E/sangue , Pressão , Conformação Proteica , Estrutura Secundária de Proteína , Coelhos , Análise Espectral , Compostos de Sulfidrila , Propriedades de Superfície , Raios UltravioletaRESUMO
Peanut allergen Ara h 2 was extracted from peanuts and was identified by SDS-PAGE and MALDI-TOF-MS. Effect of heat treatment on the antigenicity and structure of Ara h 2 was measured by indirect ELISA, CD, fluorescence and UV absorption spectra. The results showed that the antigenicity of Ara h 2 had a slight increase after being heated at 55 or 70 degrees C, while above 85 degrees C the antigenicity decreased significantly, and the antigeicity of Ara h 2 decreased with increasing temperature. The CD showed that the secondary structure of Ara h 2 was changed after heat treatment. The ANS fluorescence probe emission spectra analysis demonstrated that the heat treatment induced an increase in surface hydrophobicity of Ara h 2. The UV absorption spectra showed that the absorption maximum wavelength was increased when Ara h 2 was heated except the sample heating at 50 degrees C for 30 min. So the changes in conformation of Ara h 2 lead to the antigenicity degression.