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pH and Heat Resistance of the Major Celery Allergen Api g 1
Author(s) -
RibSchmidt Carina,
Riedl Philipp,
Meisinger Veronika,
Schwaben Luisa,
Schulenborg Thomas,
Reuter Andreas,
Schiller Dirk,
Seutter von Loetzen Christian,
Rösch Paul
Publication year - 2018
Publication title -
molecular nutrition and food research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.495
H-Index - 131
eISSN - 1613-4133
pISSN - 1613-4125
DOI - 10.1002/mnfr.201700886
Subject(s) - isoelectric point , allergen , chemistry , immunoglobulin e , lability , denaturation (fissile materials) , thermal stability , precipitation , food science , chromatography , biochemistry , antibody , allergy , immunology , biology , nuclear chemistry , organic chemistry , enzyme , physics , meteorology
Scope The major celery allergen Api g 1 is a member of the pathogenesis‐related 10 class protein family. This study aims to investigate the impact of heat and pH on the native protein conformation required for Immunoglobulin E (IgE) recognition. Methods and results Spectroscopic methods, MS and IgE‐binding analyses are used to study the effects of pH and thermal treatment on Api g 1.0101. Heat processing results in a loss of the native protein fold via denaturation, oligomerization, and precipitation along with a subsequent reduction of IgE recognition. The induced effects and timescales are strongly pH dependent. While Api g 1 refolds partially into an IgE‐binding conformation at physiological pH, acidic pH treatment leads to the formation of structurally heat‐resistant, IgE‐reactive oligomers. Thermal processing in the presence of a celery matrix or at pH conditions close to the isoelectric point (pI = 4.63) of Api g 1.0101 results in almost instant precipitation. Conclusion This study demonstrates that Api g 1.0101 is not intrinsically susceptible to heat treatment in vitro. However, the pH and the celery matrix strongly influence the stability of Api g 1.0101 and might be the main reasons for the observed temperature lability of this important food allergen.