EC 3.4.21.26; other names: prolyl endopeptidase; post-proline cleaving enzyme; post-proline endopeptidase. An enzyme that catalyses the hydrolysis of Pro-|-Xaa >> Ala-|-Xaa in oligopeptides. It is a cytoplasmic (in eukaryotes) serine endopeptidase, also found in some bacteria.