Synthesis of mammalian prolylendopeptidase in Escherichia coli and analysis of the recombinant protein.

Prolylendopeptidase is a cytoplasmic serine proteinase which hydrolyses peptide bonds at the C-terminal side of prolines. Here, the expression in Escherichia coli of the cDNA coding for the enzyme from porcine brain is reported. Furthermore, the purification of active prolylendopeptidase from the extract of recombinant bacterial cells is described. The large amounts of protein obtained were used to gain insight in the substrate specificity of recombinant prolylendopeptidase, by using internally quenched fluorescent substrates.