Source : Escherichia Coli.
Gliadin is a cDNA coding for an epitope-carrying fragment of a wheat gamma-gliadin isoform, having a molecular mass of 18,616 Dalton (high proline content and the low pI are likely causes for the observed discrepancy between calculated molecular weight and the observed electrophoretic mobility of approx. 47 kDa on standard SDS-PAGE), pH 4.6. By sequence design the epitopes correspond to the deamidated neo-epitopes, which in the natural antigen are formed by transglutaminase-mediated glutamine side chain deamidation. Gliadin protein is fused to a hexa-histidine purification tag.
Wheat Gliadin and related gluten components from barley, rye and possibly oats can cause an abnormal immune response called Celiac disease which is a chronic gastrointestinal disorder. Celiac disease characteristics are flattening of the jejunal mucosa and intestinal lesions of variable severity in hereditarily inclined individuals. Even though Celiac disease is not a classic autoimmune disease it is related to anti-tissue transglutaminase antibodies and gliadin antibodies tests are most recommended in screening populations at risk for CD and other gluten-sensitive enteropathies. In the past, serologic tests for gliadin antibodies usually were not very precise and were not enough for accurate diagnosis due to missing deamidated epitopes within the authentic gliadin fraction traditionally used in diagnostic test kits. deamidated Gliadin isoform matches to the deamidated neo-epitopes, which in the natural antigen are formed by transglutaminase-mediated glutamine side chain deamidation.
