an amino acid that is found in many proteins (especially collagen)
"The lab technician noted that proline was abundant in the extracted collagen sample, confirming its structural role in the protein."
A nonessential amino acid C₅H₉NO₂ found in most animal proteins, especially collagen; its cyclic structure leads to kinks in the peptide chain of proteins.
"Proline's unique cyclic structure creates a sharp kink in the triple helix of collagen, which is why it appears so frequently in this structural protein."