Poststatin, a new inhibitor of prolyl endopeptidase. V. Endopeptidase inhibitory activity of poststatin analogues

Article abstract of DOI:10.7164/antibiotics.49.890

Thirty analogues of poststatin were synthesized, and their inhibitory activities against prolyl endopeptidase, human leukocyte elastase and cathepsin B were measured. The α-ketone was essential and the S configuration was preferable to the R configuration in the β-substituted-β-amino-α-oxopropionic acid moiety of poststatin analogues for endopeptidase inhibitory activity. The analogue in which the D-leucine residue of poststatin was replaced by L-leucine showed strong inhibitory activity to cathepsin B. Introduction of an aromatic group into the P₄ position and proline into the P₂ position increased inhibitory activity to elastase. Benzyloxycarbonyl-L-homophenylalanyl-(RS)-3-amino-2-oxovaleryl-D- leucyl-L-valine was about 6 times more active to prolyl endopeptidase than natural poststatin.