Modifies a noun

• residue: In these cases, we find that the proline residue almost always occurs on the solvent exposed face of each helix.

• metabolism: We found that the patient had a disorder of proline metabolism.

• accumulation: Effects of free proline accumulation in petunias under drought stress.

Noun used with modifier

• amino: Our initial studies focused on the amino acid proline.

• acid: Our initial studies focused on the amino acid proline.