Molecular cloning of cDNA for Sarcophaga prolyl endopeptidase and characterization of the recombinant enzyme produced by an E. coli expression system.

A cDNA for prolyl endopeptidase (PEP) of Sarcophaga peregrina (flesh fly) was cloned and its sequence determined. The overall amino acid sequence identity between Sarcophaga and mammalian PEPs was 53%, indicating that these enzymes are structurally very similar. Northern blot hybridization revealed that the Sarcophaga PEP gene was activated significantly at the eversion stage of imaginal disc differentiation. We obtained recombinant PEP by expressing the cDNA in Escherichia coli. The recombinant and authentic enzymes showed almost identical characteristics, in terms of substrate specificities and sensitivities to inhibitors.