Proline

Proline (Pro or P) is an amino acid present in proteins.

Structure of proline

Proline has a rather specific structure and it is the only cyclical amino acid. Its side chain is composed of two CH₂ and attaches to the NH involved in the peptide bond.

Function of proline

Proline is a non-essential amino acid produced by the body.

Its specific structure introduces a bend into protein chains and links the helices α and sheets β. However, it can create specific helices, proline helices, such as those found in collagen.