Effect of alpha-gliadin-derived peptides from bread and durum wheat on K562(S) cells.

Previous studies suggested that the proteins and peptides that are responsible for coeliac small intestinal lesions, are also able to agglutinate K562(S) cells. On the contrary, peptides from whole gliadins from durum (tetraploid) wheat do not agglutinate these cells. Bread wheat alpha-gliadins have been identified as a major toxic fraction in coeliac disease. In the present research, alpha-gliadins were purified from durum and bread wheat cultivars. alpha-gliadin peptides from bread wheat were active in agglutinating K562(S) cells, whereas alpha-gliadin from durum wheat failed to induce any agglutinating activity. These results suggest that the lack of toxicity of gliadin from durum wheat cultivars is not related to a low content of alpha-gliadins but is mainly due to intrinsic structural differences from bread wheat gliadins.