Scope
Proteolysis‐resistant gliadin peptides are intensely investigated in biomedical research relates to celiac disease and gluten‐related disorders. Herein, the first integrated supramolecular investigation of pepsin‐digested gliadin peptides (p‐gliadin) is presented in combination with its functional behavior in the Caco‐2 cell line.
Methods and Results
First, gliadins are degraded by pepsin at pH 3, and the physicochemical properties of p‐gliadin are compared with gliadin. An integrated approach using interfacial, spectroscopic, and microscopic techniques reveals that the p‐gliadin forms spontaneously soluble large supramolecular structures, mainly oligomers and fibrils, capable of binding amyloid‐sensitive dyes. The self‐assembly of p‐gliadin starts at a concentration of 0.40 µg mL−1. Second, the stimulation of Caco‐2 cells with the p‐gliadin supramolecular system is performed, and the mRNA expression levels of a panel of genes are tested. The experiments show that p‐gliadin composed of supramolecular structures triggers significant mRNA up‐regulation (p < 0.05) of pro‐apoptotic biomarkers (ratio Bcl2/Bak‐1), chemokines (CCL2, CCL3, CCL4, CCL5, CXCL8), and the chemokine receptor CXCR3.
Conclusions
This work demonstrates that p‐gliadin is interfacial active, forming spontaneously amyloid‐type structures that trigger genes in the Caco‐2 cell line involved in recruiting specialized immune cells.