Prolamins are a group of plant storage proteins having a high proline amino acid content.
They are found in plants, mainly in the seeds of cereal grains such as wheat (gliadin), barley (hordein), rye (secalin), corn (zein), sorghum (kafirin), and oats (avenin).
They are characterised by a high glutamine and proline content, and have poor solubility in water.
They solubilise best in strong alcohol (70–80%), light acid, and alkaline solutions.
[1] Maize and sorghum prolamins are sorted by molecular weight into four classes, α, β, γ and δ. Alpha- and delta- prolamins cluster in a broad phylogenetic group (Group 1).