Computational characterisation and identification of peptides for in silico detection of potentially celiac-toxic proteins.

摘要

The toxic effects of coeliac disease are linked to the presence of specific amino acid sequences and the properties of their environment. Occurrence of coeliac-toxic peptides occurrence in various animal and vegetable protein isolates was investigated. The analysed coeliac-toxic peptides were found to contain considerable amounts of unordered structures of random coils and beta-turns. Proline and glutamine-rich amino acid sequences from hydrophilic beta-turns were exposed on the surface of the precursor proteins. The sequence motifs represented by gluten peptide epitopes or tetrapeptides with their surroundings seemed to represent an immunodominant structure. The application of MS BLAST software enabled identification of a few fragments with high degrees of identity to the toxic peptides in 1 protein sequence. Rich sources of coeliac-disease-potentiating peptides were wheat gliadins, barley hordeins and rye secalins, as well as low-mol. wt. fractions of glutenin. In addition, amino acid sequences with a high degree of identity to the toxic peptides examined were detected in corn zein, oat avenin, rice protein, yeast and chicken meat, as well as beta-casein and galanin.