Gliadin, a type of prolamin, the major component of wheat gluten, is comprised of single-chain polypeptides with an average molecular weight of 25-100 kDa linked by intramolecular disulfide bonds.1 The term gliadin defines a group of proteins extracted from gluten by 70% ethanol. All fractions have remarkably low solubility in aqueous solution except at extreme pHs2. This low water solubility has been attributed to the presence of disulfide bonds together with cooperative hydrophobic interactions within the protein folding and structure,. The amino acid composition shows that gliadin has equal amounts of polar and neutral amino acids, mainly glutamine (about 40%) in addition to high proline content (14%). As plant proteins, they are recognized as prion-free 2.Gliadin can adhere to the mucus layer of the stomach due to its mucoadhesive property, which is a result of various interactions (e.g., hydrogen bonding, van der Waals force, and mechanical penetration).
Synonyms: Prolamin; alpha-gliadin
Application: The antibody may be used in various immunochemical techniques including Immunoblotting and ELISA.
Biochem Physiol Actions: Gliadins, from an alcohol-soluble fraction of gluten, are storage proteins in wheat, barley, and rye (along with other gluten-containing grains). Glutenins are insoluble in alcohol and differ in their biochemical structure from glutens. It has been hypothesized that the initial immune reaction in celiac disease patients is focused on several of gliadin peptides, while the long-standing inflammatory response may be defined by other gliadin peptides that have been deamidated or cross-linked by tissue transglutaminase. These latter peptides are also more tightly linked to HLA-DQ2 and HLA-DQ83.The tissue transglutaminase-catalyzed changes in gliadin are not restricted to single gliadin types, for example, prolamines in barley and rye (known as hordelin and secalin, respectively) and these may induce a messenger RNA-mediated interferon-gamma response in the small-intestinal mucosa of celiacs. An alpha-2-gliadin-33-mer appears to pass through the enterocyte brush border membrane by a dose-dependent translocation mechanism, and this is further enhanced by interferon-gamma, possibly mediated by a delayed epidermal growth factor endocytosis. In active celiac disease, this immune-mediated response is very complex and involves many different mediators (such as Interlukin-21 from activated CD4+ Tcells) some are still being studied. With genetic susceptibility, gliadin may interact with interenterocyte tight junctions and cause their disassembly. Moreover, Gliadin peptides may bind to the chemokine receptor, CXCR3. This induces zonulin release from the tight junction region and causes a resultant increase in intestinal permeability. Permeability increases have also been demonstrated prior to the onset of clinically apparent celiac disease, and even with a gluten-free diet, this altered tight junction permeability may not completely return to normal3.Anti Gliadin antibody may serve as an important tool in Celiac disease research field.