Visualizing 33-mer gliadin peptide oligomers by Electron Microscopy and Helium Ion Microscopy

HERRERA, M.G; HÜTTEN. A.; SEWALD. N.; DODERO.V.I

Simposio; 34th European Peptide Symposium and the 8th International Peptide Symposium; 2016

Gliadin is highly immunogenic protein, which is not completely digested by humans. A resistant peptide of 33 amino acids (33-mer), remains intact among other smaller peptides. This 33-mer fragment is the most immunological modulator peptide responsible for celiac disease. Recently, a new pathology named gluten sensitivity has been described. For these diseases, the initiation of the inflammatory events remains obscure. Previously, we showed that the 33-mer peptide self- assembles into nanospheres and fibrils. Moreover, we showed that this process proceeds by a conformational transition from PPII to a parallel beta sheet. The characterization of 33-mer supramolecular structures could therefore be a first step towards the understanding of the early stages of gliadin intolerance disorders. The aim of this study is to obtain a better insight of 33-mer oligomerization process by microscopy.