Proline Iminopeptidase v Proline Aminopeptidase
There are two related enzymes that cleave an N-terminal residue. Enzyme 3.4.11.9 cleaves any residue from a peptide when the next residue is proline. Enzyme 3.4.11.5 cleaves an N-terminal proline from a peptide. Unfortunately, it appears that both are sometimes referred to as proline aminopeptidase. However, only 3.4.11.5 is referred to as proline iminopeptidase.

The vendor should certainly specify which enzyme they are offering.