Insights into proteolytic processing of the major peanut allergen Ara h 2 by endogenous peanut proteases |
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Authors: | Jelena Radosavljevic Dragana Dobrijevic Milka Jadranin Milan Blanusa Jelena Vukmirica Tanja Cirkovic Velickovic |
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Affiliation: | 1. Department of Biochemistry, Faculty of Chemistry, University of Belgrade, Belgrade, Serbia;2. Institute for Chemistry, Technology and Metallurgy, Belgrade, Serbia;3. Jacobs University, Bremen, Germany |
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Abstract: | BACKGROUND: The major peanut allergens are Ara h 1, Ara h 2 and Ara h 6. Proteolytic processing has been shown to be required for the maturation process of Ara h 6. The aim of this study was to examine whether Ara h 2 undergoes proteolytic processing and, if so, whether proteolytic processing influences its ability to bind human immunoglobulin E (IgE). RESULTS: Ara h 2 isolated from peanut extract under conditions of protease inhibition revealed a single additional peak for its two known isoforms (Ara h 2.01 and Ara h 2.02), corresponding to a C‐terminally truncated form lacking a dipeptide (RY). Ara h 2 isolated in the absence of protease inhibition, however, yielded two additional peaks, identified as C‐terminally truncated forms lacking either a dipeptide (RY) or a single tyrosine residue. The IgE‐binding capacity of the Ara h 2 truncated forms was not altered. CONCLUSION: Ara h 2 undergoes proteolytic processing by peanut proteases that involves C‐terminal removal of a dipeptide. Hence Ara h 2 isolated from peanut extract is a complex mixture of two isoforms expressed by different genes, Ara h 2.01 and Ara h 2.02, as well as truncated forms generated by the proteolytic processing of these isoforms. Copyright © 2010 Society of Chemical Industry |
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Keywords: | Ara h 2 Ara h 6 proteolysis IgE binding food allergy |
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