Catalyzes the removal of dipeptides from the N-terminus of oligopeptides. Shows a strict specificity for acidic residues (Asp or Glu) in the P1 position, and has probably a hydrophobic residue preference at the P2 position. Preferentially cleaves the synthetic substrate Leu-Asp-methylcoumaryl-7-amide (Leu-Asp-MCA) as compared to Leu-Glu-MCA. Belongs to the peptidase S46 family.