Which Two Proteins Make Up Gluten?

December 4, 2025 •

3 min read

In dry wheat flour, gluten does not exist as a single substance. It is only when water is added that two specific proteins begin to combine, forming the complex network known as gluten. This critical process explains why the simple act of mixing dough creates its unique, elastic properties.

Quick Summary

The protein network known as gluten is formed from two main proteins found in wheat flour: gliadin and glutenin. Gliadin gives dough its viscous, extensible properties, while glutenin provides strength and elasticity. When flour is hydrated and kneaded, these two proteins link together to create the familiar viscoelastic structure.

Key Points

Two Primary Proteins: Gluten is composed of two main protein types: gliadin and glutenin.
Gliadin's Role: Gliadin is a monomeric protein that provides the dough's extensibility and viscosity, allowing it to stretch.
Glutenin's Role: Glutenin forms large polymers linked by disulfide bonds, providing the dough with elasticity and strength.
Interaction is Key: Gluten forms only when gliadin and glutenin are mixed with water, triggering them to combine and form a cohesive, viscoelastic network.
Baking Impact: The ratio of gliadin to glutenin, along with the degree of mixing, determines the final texture of baked goods, from chewy bread to tender cakes.
Health Significance: For individuals with celiac disease, gliadin's specific peptide sequences trigger an immune-mediated response, leading to intestinal damage.
Network Formation: Kneading or agitation strengthens the gluten network, as the protein strands link and align more effectively.

The Science Behind the Gluten Network

Gluten is not an ingredient but a substance that develops from the proteins already present in flour. Its formation is a fascinating biochemical process essential for creating baked goods ranging from fluffy bread to chewy pasta. This network's unique viscoelastic properties are the result of the interaction between two specific types of proteins: gliadin and glutenin. While the dry flour contains these proteins separately, the introduction of water allows them to bond and form the complex, interwoven structure that is gluten.

Gliadin: The Extensible Component

Gliadin is a class of monomeric proteins, meaning it exists as single, smaller units that are spherical and tightly coiled. These proteins are responsible for the extensibility and viscosity of dough, allowing it to stretch and spread. Gliadin's structure is rich in the amino acids glutamine and proline, but the molecules are linked internally rather than forming bonds with other gliadin units. This monomeric nature is why gliadin provides dough with its flexibility and fluidity. In individuals with celiac disease, gliadin's proline-rich sequences can be resistant to digestion, triggering an autoimmune response that damages the small intestine.

Glutenin: The Elastic Backbone

In contrast to gliadin, glutenin is a large, complex polymeric protein. It is made up of multiple polypeptide chains linked together by disulfide bonds, which are strong covalent bonds between sulfur atoms. These inter-chain bonds allow glutenin subunits to aggregate into a network of high-molecular-weight polymers, giving dough its strength and elasticity. When dough is kneaded, the glutenin polymers align and link more strongly, reinforcing the protein network and enabling it to stretch and then spring back into shape, much like a rubber band. This elastic property is crucial for trapping the gas produced by leaveners like yeast, allowing bread to rise and achieve its light, airy texture.

How Gliadin and Glutenin Work Together

The interplay between gliadin and glutenin is what defines the texture of a baked good. While glutenin provides the dough's structural strength, gliadin acts as a lubricant, enabling the network to stretch without tearing. Without gliadin, the dough would be too elastic and resistant to shaping; without glutenin, it would be too soft and unable to hold its structure. Mixing and kneading manipulate this protein matrix, physically encouraging the gliadin and glutenin to form and strengthen the gluten network. The amount of protein in the flour directly influences the final texture; a high-protein bread flour will produce more gluten and a chewier bread, while a low-protein cake flour will result in a more tender, delicate crumb because less gluten is developed.

Glutenin vs. Gliadin: A Comparison


Characteristic	Gliadin	Glutenin
Molecular Structure	Monomeric, spherical protein units.	Polymeric chains linked by disulfide bonds.
Function in Dough	Contributes extensibility and viscosity, making dough soft and stretchy.	Provides elasticity and strength, allowing dough to rise and hold shape.
Interaction	Interacts with glutenin through non-covalent and some disulfide bonds.	Forms a polymeric backbone with inter-chain disulfide bonds.
Solubility	Soluble in aqueous alcohols but insoluble in water.	Insoluble in water and alcohol; can be broken down into subunits by reducing disulfide bonds.
Contribution to Texture	Makes dough pliable and fluid.	Gives dough its robust, rubbery nature.
Effect on Health	Contains peptide sequences that can trigger immune responses in celiac disease.	Less allergenic than gliadin for those with gluten sensitivities, though still part of the complex.

Conclusion

Understanding which two proteins make up gluten reveals the fundamental science behind baking. Gliadin, the extensible and viscous component, and glutenin, the elastic and strong backbone, work in tandem to create the unique properties of dough. The quantity and interaction of these two proteins determine everything from a bread loaf's rise to a pastry's tenderness. For individuals with conditions like celiac disease or gluten sensitivity, the specific biochemical makeup of gliadin is the key trigger for an immune response, highlighting the importance of this knowledge not only for culinary purposes but for dietary health as well. A deeper scientific insight into these proteins can help bakers, food scientists, and individuals managing their diet to make informed choices.

For more detailed information on gluten protein research and its implications for baking, refer to a publication on the chemistry of wheat gluten proteins.

Frequently Asked Questions

Yes, gliadin and glutenin are both present in dry wheat flour. They exist as separate, inactive proteins until they are combined with water and agitated through mixing or kneading, which triggers them to form the gluten network.

When water is added to flour, the gliadin and glutenin proteins begin to absorb the liquid and form bonds with each other. This process creates the long, elastic chains of gluten that form the network responsible for the dough's structure.

Gliadin contributes to the extensibility and softness of dough, allowing it to stretch, while glutenin provides elasticity and strength, enabling the dough to hold its shape and rise. The balance between these two proteins directly influences the final texture of a baked good.

Gliadin is considered the primary trigger for the immune response in individuals with celiac disease. The body of a person with celiac disease misidentifies specific peptide sequences within gliadin as a threat, causing an autoimmune attack on the small intestine.

Yes, gluten is also found in other grains such as barley, rye, and triticale. Wheat contains the highest levels of the gliadin and glutenin proteins necessary to form gluten, but related proteins like secalins in rye and hordeins in barley also form gluten-like structures.

Kneading affects both proteins, but it is particularly crucial for developing the glutenin network. The mechanical action aligns the glutenin polymers and reinforces their disulfide bonds, increasing the dough's overall elasticity and strength.

The term 'gluten' is used to refer to the entire protein complex, which is a mixture of both gliadin and glutenin. Since gliadin is an integral component of this complex, avoiding gluten is the standard practice for managing celiac disease and other related sensitivities to ensure no gliadin is ingested.