ABSTRACT
In this communication we describe the design, synthesis, and evaluation of novel sultam hydroxamates 4 as MMP-2, -9, and -13 inhibitors. Compound 26 was found to be an active inhibitor (MMP-2 IC(50) = 1 nM) with 1000-fold selectivity over MMP-1 and good oral bioavailability (F = 43%) in mouse. An X-ray crystal structure of 26 in MMP-13 confirms the key hydrogen bonds and prime side binding in the active site.
Subject(s)
Hydroxamic Acids/chemical synthesis , Matrix Metalloproteinase Inhibitors , Sulfonamides/chemical synthesis , Administration, Oral , Animals , Biological Availability , Crystallography, X-Ray , Hydroxamic Acids/chemistry , Hydroxamic Acids/pharmacology , Matrix Metalloproteinase 13 , Mice , Models, Molecular , Structure-Activity Relationship , Sulfonamides/chemistry , Sulfonamides/pharmacologyABSTRACT
Elevated levels of tumor necrosis factor-alpha (TNF-alpha) have been associated with several inflammatory diseases, and therefore, strategies for its suppression have become important targets in drug discovery. Our efforts to suppress TNF-alpha have centered on the inhibition of TNF-alpha converting enzyme (TACE) through the use of hydroxamate inhibitors. Starting from broad-spectrum matrix metalloproteinase (MMP) inhibitors, we have designed and synthesized novel benzothiadiazepines as potent and selective TACE inhibitors. The benzothiadiazepines were synthesized with variation in P1 and P1' in order to effect potency and selectivity. The inhibitors were evaluated versus porcine TACE (pTACE), and the initial selectivity was assessed with counterscreens of MMP-1, -2, and -9. Several potent and selective inhibitors were discovered with compound 41 being the most active against pTACE (K(i) = 5 nM) while still maintaining good selectivity versus the MMP's (at least 75-fold). Most compounds were assessed in the human peripheral blood mononuclear cell assay (PBMC) and the human whole blood assay (WBA) to determine their ability to suppress TNF-alpha. Compound 32 was the most potent compound in the PBMC assay (IC(50) = 0.35 microM), while compound 62 was the most active in the WBA (IC(50) = 1.4 microM).
Subject(s)
Benzodiazepinones/chemical synthesis , Enzyme Inhibitors/chemical synthesis , Hydroxamic Acids/chemical synthesis , Metalloendopeptidases/antagonists & inhibitors , Thiazepines/chemical synthesis , Tumor Necrosis Factor-alpha/antagonists & inhibitors , ADAM Proteins , ADAM17 Protein , Animals , Benzodiazepinones/chemistry , Benzodiazepinones/pharmacology , Blood Proteins/metabolism , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Humans , Hydroxamic Acids/chemistry , Hydroxamic Acids/pharmacology , Leukocytes, Mononuclear/drug effects , Matrix Metalloproteinase Inhibitors , Models, Molecular , Protein Binding , Structure-Activity Relationship , Swine , Thiazepines/chemistry , Thiazepines/pharmacology , Tumor Necrosis Factor-alpha/biosynthesisABSTRACT
Inhibition of tumor necrosis factor-alpha converting enzyme (TACE) is a widespread objective in the search for disease modifying agents to combat rheumatoid arthritis and other autoimmune diseases. Until recently, most of the inhibitors in the literature have shown concomitant activity against the related matrix metalloproteinases (MMPs), producing undesired side effects. Here we describe the successful search for a TACE selectivity mechanism. We built a homology model based on the crystal structure of the related snake venom protein atrolysin. Comparison of the model with crystal structures of MMPs suggested a uniquely shaped S1' pocket that might be exploited for selectivity. A novel gamma-lactam scaffold was used to explore the activity profile of P1' sidechains, resulting in highly selective compounds consistent with this hypothesis. Transferability of the hypothesis was then demonstrated with five other distinct scaffolds.
Subject(s)
Metalloendopeptidases/antagonists & inhibitors , Metalloendopeptidases/chemistry , Models, Chemical , Models, Molecular , ADAM Proteins , ADAM17 Protein , Amino Acid Sequence , Catalytic Domain , Crystallography, X-Ray , Drug Design , Enzyme Inhibitors/chemistry , Lactams/chemistry , Matrix Metalloproteinases/chemistry , Molecular Sequence Data , Molecular Structure , Sequence Homology, Amino Acid , Snake Venoms/chemistry , Tumor Necrosis Factor-alpha/chemistryABSTRACT
New gamma-lactam TACE inhibitors were designed from known MMP inhibitors. A homology model of TACE was built and examined to identify the S1' site as the key area for TACE selectivity over MMPs. Rational exploration of the P1'-S1' interactions resulted in the discovery of the 3,5-disubstituted benzyl ether as a TACE-selective P1' group. Further optimization led to the discovery of IK682 as a selective and orally bioavailable TACE inhibitor.
