glutenins

Glutenins are a class of gluten proteins found in wheat and related species. Along with gliadins, they contribute to the gluten network that gives dough its elasticity and strength. Glutenins are storage proteins synthesized in the wheat endosperm during grain development and assemble into large polymeric molecules that interact with gliadins to form a cohesive gluten matrix.

Glutenins are categorized into two major subfamilies: high-molecular-weight (HMW) glutenin subunits and low-molecular-weight (LMW) glutenin subunits. HMW subunits are encoded by Glu-1 loci on the group 1 chromosomes (Glu-A1, Glu-B1, Glu-D1), while LMW subunits are encoded by Glu-3 loci (Glu-A3, Glu-B3, Glu-D3). The subunits have approximate molecular weights of about 80–90 kDa for HMW and about 30–45 kDa for LMW. They are rich in cysteine residues, which form inter-chain disulfide bonds that link subunits into large glutenin polymers and help create the gluten network together with gliadins.

In dough, HMW glutenin subunits are especially important for elasticity and dough strength, whereas LMW subunits contribute to extensibility and overall dough handling and mixing properties. The specific subunit composition and alleles at the Glu-1 and Glu-3 loci influence breadmaking quality, including loaf volume and texture. Breeding programs often target favorable Glu-1 and Glu-3 alleles to improve baking performance.

Glutenins are a defining component of gluten in wheat (Triticum species) and are absent from non-gluten cereals. Because gluten proteins can trigger reactions in some individuals, glutenins are a focal point in discussions of gluten-related disorders.