Abstract: The present invention provides isolated polypeptides, dipeptidylpeptidases, active analogs, active fragments, or active modifications thereof, having amidolytic activity for cleavage of a peptide bond between the second and third amino acids from the N-terminal end of a target polypeptide, wherein the target polypeptide has an aliphatic or an aromatic residue as a substituent on the ?-carbon atom of the second amino acid from the N-terminal end of the peptide. Isolated nucleic acids encoding dipeptidylpeptidases are also provided, as are methods of reducing growth of a bacterium by inhibiting a dipeptidylpeptidase.

Abstract: The present invention provides isolated polypeptides, dipeptidylpeptidases, active analogs, active fragments, or active modifications thereof, having amidolytic activity for cleavage of a peptide bond between the second and third amino acids from the N-terminal end of a target polypeptide, wherein the target polypeptide has an aliphatic or an aromatic residue as a substituent on the &agr;-carbon atom of the second amino acid from the N-terminal end of the peptide. Isolated nucleic acids encoding dipeptidylpeptidases are also provided, as are methods of reducing growth of a bacterium by inhibiting a dipeptidylpeptidase.