Gluten immunochemistry motif", which is found in wheat and other "Triticeae" genera.(see also: ). Alpha-2 secalin, the glutinous protein in rye, is composed of two amino-terminal overlapping T-cell sites at positions (8-19) and (13-23). Although T-cell responses to many prolamins can be found in coeliac disease, one particular gliadin, α2-gliadin appears to be the focus of T-cells. These responses were dependent on prior treatment with tissue transglutaminase. Α2-gliadin differs from the other α-gliadins, specifically because it contains an insert of 14 amino acids. This particular insertion creates 6 T-cell sites where, in the most similar gliadins, there are 2 or less sites.
Anti-gliadin antibodies in food products. Some of these antibodies can recognize only wheat prolamins or very closely related grass seeds; others can detect antigens over broad taxa. The G12 antibody is the newest example which detects the most immunotoxic fragment, a 33-mer peptide from �-2 gliadin; available from Romer Laboratories and the Spanish company Biomedal. It recognizes the toxic fraction of wheat, barley, rye and also of oat. The R5 sandwich assay is another such assay. This assay can recognize wheat, barley and rye, which makes it ideal for evaluating the presence of contaminants in gluten-free foods that do not contain oat.