Tags: Enzyme.
Prolyl isomerase (also known as peptidylprolyl isomerase or PPIase) is an enzyme (EC 5.2.1.8) found in both prokaryotes and eukaryotes that interconverts the cis and trans isomers of peptide bonds with the amino acid proline. Proline has an unusually conformationally restrained peptide bond due to its cyclic structure with its side chain bonded to its secondary amine nitrogen.