Study on a prolyl endopeptidase from the skeletal muscle of common carp (Cyprinus carpio)

► A novel prolyl endopeptidase (PEP) was purified to homogeneity from common carp. ► PEP prefers to hydrolyze MCA substrates containing proline residue. ► Peptide mass fingerprinting analysis testified the enzyme is PEP. ► PEP may function in fish collagen metabolism and protein decomposition.