Publications (3)5.25 Total impact
Article: Inhibitors of tripeptidyl peptidase II. 3. Derivation of butabindide by successive structure optimizations leading to a potential general approach to designing exopeptidase inhibitors.[show abstract] [hide abstract]
ABSTRACT: The cholecystokinin-8 (CCK-8)-inactivating peptidase is a serine peptidase that has been shown to be a membrane-bound isoform of tripeptidyl peptidase II (EC 18.104.22.168). It cleaves the neurotransmitter CCK-8 sulfate at the Met-Gly bond to give Asp-Tyr(SO3H)-Met-OH + Gly-Trp-Met-Asp-Phe-NH2. Starting from Val-Pro-NHBu, a dipeptide of submicromolar affinity that had previously been generated to serve as a lead, successive optimization at P3, P1, and then P2 gave Abu-Pro-NHBu (18, Ki = 80 nM). Further transformation (by making a benzologue) gave the indoline analogue, butabindide (33) as a reversible inhibitor having nanomolar affinity (Ki = 7 nM). Retrospective analysis suggested the possibility of a general approach to designing exopeptidase inhibitors starting from the structure of the first hydrolysis product. Application of this approach to CCK-8 led to Abu-Phe-NHBu (37), but this only had Ki = 9.4 microM. Molecular modeling, to determine the minimum energy conformations and explain the 1000-fold better affinity of butabindide, indicated that 37 cannot access the likely active conformation of butabindide.Journal of Medicinal Chemistry 12/2005; 48(23):7333-42. · 5.25 Impact Factor
Article: Inhibitors of Tripeptidyl Peptidase II. 2. Generation of the First Novel Lead Inhibitor of Cholecystokinin-8-Inactivating Peptidase: A Strategy for the Design of Peptidase Inhibitors‡[show abstract] [hide abstract]
ABSTRACT: The cholecystokinin-8 (CCK-8)-inactivating peptidase is a serine peptidase which has been shown to be a membrane-bound isoform of tripeptidyl peptidase II (EC 22.214.171.124). It cleaves the neurotransmitter CCK-8 sulfate at the Met−Gly bond to give Asp-Tyr(SO3H)-Met-OH + Gly-Trp-Met-Asp-Phe-NH2. In seeking a reversible inhibitor of this peptidase, the enzymatic binding subsites were characterized using a fluorimetric assay based on the hydrolysis of the artificial substrate Ala-Ala-Phe-amidomethylcoumarin. A series of di- and tripeptides having various alkyl or aryl side chains was studied to determine the accessible volume for binding and to probe the potential for hydrophobic interactions. From this initial study the tripeptides Ile-Pro-Ile-OH (Ki = 1 μM) and Ala-Pro-Ala-OH (Ki = 3 μM) and dipeptide amide Val-Nvl-NHBu (Ki = 3 μM) emerged as leads. Comparison of these structures led to the synthesis of Val-Pro-NHBu (Ki = 0.57 μM) which served for later optimization in the design of butabindide, a potent reversible competitive and selective inhibitor of the CCK-8-inactivating peptidase. The strategy for this work is explicitly described since it illustrates a possible general approach for peptidase inhibitor design.02/2000;
[show abstract] [hide abstract]
ABSTRACT: A cholecystokinin (CCK)-inactivating peptidase was purified and identified as a membrane-bound isoform of tripeptidyl peptidase II (EC 126.96.36.199), a cytosolic subtilisin-like peptidase of previously unknown functions. The peptidase was found in neurons responding to cholecystokinin, as well as in non-neuronal cells. Butabindide, a potent and specific inhibitor, was designed and shown to protect endogenous cholecystokinin from inactivation and to display pro-satiating effects mediated by the CCKA receptor.04/1996; 380(6573):403-409.