nutrient

Proline

An amino acid whose ring structure changes the shape of protein chains.

Proline is common in collagen and can introduce bends into protein backbones. The body can also synthesise it.

A ring that bends the chain

Proline’s side chain loops back to its amino nitrogen, restricting the chain’s geometry and often introducing a bend in an alpha helix.

Related topics

  • Proline is used to build Protein

    Proline is one of the amino acids used to assemble proteins.

Worth knowing

  • It is common in collagen. Proline and hydroxyproline are abundant in collagen and help shape its triple helix.

A closer look

Some residues are hydroxylated

During collagen synthesis, selected proline residues are hydroxylated after translation; the modified residues help stabilise the collagen helix.

Hydroxyproline is a modified residue

Collagen synthesis modifies selected proline residues after translation, changing the stability of the collagen helix.

References

Source-checked local draft.
Human editorial review pending.

  1. NIH National Library of MedicineBiochemistry, Essential Amino AcidsChecked 2026-09-05
  2. NIH National Library of MedicineBiochemistry, Protein CatabolismChecked 2026-09-05
  3. NIH National Library of MedicineBiochemistry, Primary Protein StructureChecked 2026-09-05
  4. NIH National Library of MedicineBiochemistry, Collagen SynthesisChecked 2026-09-05