The puromycin-sensitive aminopeptidase (ApPS) is a zinc metallopeptidase involved in the degradation of neuropeptides. Putative catalytic residues of the enzyme, Cys146, Glu338, and Lys396 were mutated, and the resultant mutant enzymes characterized. ApPS C146S exhibited normal catalytic activity, ApPS E338A exhibited decreased substrate binding, and ApPS K396I exhibited decreases in both substrate binding and catalysis. ApPS K396I and ApPS Y394F were analyzed with respect to transition state inhibitor binding. No effect was seen with the K396I mutation, but ApPS Y394F exhibited a 3.3-fold lower affinity for RB-3014, a transition state inhibitor, indicating that Tyr394 is involved in transition state stabilization.
|Number of pages||7|
|State||Published - Sep 2003|
Bibliographical noteFunding Information:
This work was supported by grants DA-05736 (M.W.T.) and DA-02243 (L.B.H.) from the National Institute on Drug Abuse. The inhibitor RB-3014 was kindly provided by Dr. Marie-Claude Fournie-Zaluski (Laboratoire de Pharmacochimie Moléculaire et Structurale, INSERM, Paris, France).
- Catalytic residues
- Substrate binding
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience