Responsiveness of the major birch allergen Bet v 1 scaffold to the gastric environment: Impact on structure and allergenic activity
Article first published online: 19 JUL 2011
Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Molecular Nutrition & Food Research
Volume 55, Issue 11, pages 1690–1699, November 2011
How to Cite
Sancho, A. I., Wangorsch, A., Jensen, B. M., Watson, A., Alexeev, Y., Johnson, P. E., Mackie, A. R., Neubauer, A., Reese, G., Ballmer-Weber, B., Hoffmann-Sommergruber, K., Skov, P. S., Vieths, S. and Mills, E. N. C. (2011), Responsiveness of the major birch allergen Bet v 1 scaffold to the gastric environment: Impact on structure and allergenic activity. Mol. Nutr. Food Res., 55: 1690–1699. doi: 10.1002/mnfr.201100025
- Issue published online: 2 NOV 2011
- Article first published online: 19 JUL 2011
- Manuscript Accepted: 22 MAY 2011
- Manuscript Revised: 19 APR 2011
- Manuscript Received: 12 JAN 2011
- EC FP6 project EuroPrevall. Grant Number: FOOD-CT-2005-514000
- BBSRC competitive strategic grant to IFR
- Bet v 1 homologues;
- Food allergy;
- Lipid–protein interaction;
Scope: Four Bet v 1 homologous food allergens from celeriac (rApi g 1), apple (rMal d 1), peach (rPru p 1) and hazelnut (rCor a 1), were used to probe the structural responsiveness of the Bet v 1 scaffold to gastric digestion conditions and its impact on allergenicity.
Methods and results: Low pH induced conformational changes of all homologues, which was reduced at physiological ionic strength for all except rPru p 1 as observed by circular dichroism (CD)-spectroscopy. The homologues were rapidly digested by pepsin, losing their IgE binding activity, although the kinetics and patterns of digestion varied subtly between homologues, rApi g 1 being the most stable. We have demonstrated for the first time that gastric phosphatidyl-choline (PC) induced conformational changes in all homologues but only rMal d 1 penetrated the PC vesicles as detected by fluorescence polarization, slowing its digestion and retaining more of its allergenic activity. PC enhanced basophil activation of all digested allergens except rApi g 1.
Conclusion: The Bet v 1 scaffold is generally susceptible to low pH and pepsinolysis and interacts with PC vesicles, properties which can explain effects of the gastric environment on their allergenicity. These data show the importance of including surfactants in model digestion systems.