Gliadin

Gliadin is a class of proteins present in wheat and several other cereals within the grass genus Triticum. Gliadins, which are a component of gluten, are essential for giving bread the ability to rise properly during baking. Gliadins and glutenins are the two main components of the gluten fraction of the wheat seed. This gluten is found in products such as wheat flour. Gluten is split about evenly between the gliadins and glutenins, although there are variations found in different sources.

Gliadin is the water-soluble component of gluten, while glutenin is insoluble. There are three main types of gliadin (α, γ, and ω), to which the body is intolerant in coeliac (or celiac) disease. Diagnosis of this disease has recently been improving.

Gliadin can cross the intestinal epithelium. Breast milk of healthy human mothers who eat gluten-containing foods presents high levels of non-degraded gliadin.

The α, γ, and ω gliadin types are separated and distinguished based on their amino acid sequences.

Gliadins are prolamins and are separated on the basis of electrophoretic mobility and isoelectric focusing.

Gliadins are known for their role, along with glutenin, in the formation of gluten. They are slightly soluble in ethanol and contain only intramolecular disulfide links. They also cause some of the best examples of food-derived pathogenesis. People with gluten-sensitive enteropathy (the severe form of which is celiac disease) are sensitive to α, β, and γ gliadins. Those with WD urticaria and Baker's asthma are sensitive to ω-gliadins.

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