A first subnanomolar and in vivo active inhibitor of aminopeptidase A (EC 3.4.11.7)

Aminopeptidase A is a zinc metallopeptidase which specifically cleaves the N-terminal aspartate or glutamate of peptides. Thus, it is involved in the in vivo metabolism of CCK8 [1] and angiotensin II [2]. Previous studies [3] of the catalytic site of APA had led to the first selective inhibitor of this enzyme, i.e. the -aminothiol EC33 which presents a negatively charged residue in position and a thiol for an optimal chelation of the zinc ion. However, to further investigate the physiological role of APA, some new and more potent inhibitors of the general formula I were designed (Fig. 1) by exploration of the and subsites.