ABSTRACT
A novel class of mitogen-activated protein kinase-activated protein kinase 2 (MAPKAP-K2) inhibitors was discovered through screening a kinase-focused library. A homology model of MAPKAP-K2 was generated and used to guide the initial SAR studies and to rationalize the observed selectivity over CDK2. An X-ray crystal structure of a compound from the active series bound to crystalline MAPKAP-K2 confirmed the predicted binding mode. This has enabled the discovery of a series of pyrazolo[1,5-a]pyrimidine derivatives showing good in vitro cellular potency as anti-TNF-α agents and in vivo efficacy in a mouse model of endotoxin shock.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/chemical synthesis , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Protein Serine-Threonine Kinases/antagonists & inhibitors , Pyrazoles/chemical synthesis , Pyrimidines/chemical synthesis , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Cell Line , Crystallography, X-Ray , HSP27 Heat-Shock Proteins/metabolism , Humans , Intracellular Signaling Peptides and Proteins/chemistry , Lipopolysaccharides/pharmacology , Male , Mice , Mice, Inbred C57BL , Models, Molecular , Phosphorylation , Protein Conformation , Protein Serine-Threonine Kinases/chemistry , Pyrazoles/pharmacokinetics , Pyrazoles/pharmacology , Pyrimidines/pharmacokinetics , Pyrimidines/pharmacology , Shock, Septic/metabolism , Small Molecule Libraries , Stereoisomerism , Structure-Activity Relationship , Tumor Necrosis Factor-alpha/biosynthesisABSTRACT
SAR studies were conducted around lead compound 1 using high-throughput parallel solution and solid phase synthesis. Our lead optimization efforts led to the identification of several CCR2b antagonists with potent activity in both binding and functional assays [Compound 71 CCR2b Binding IC(50) 3.2 nM; MCP-1-Induced Chemotaxis IC(50) 0.83 nM; Ca(2+) Flux IC(50) 7.5 nM].
Subject(s)
Chemokine CCL2/metabolism , Chemotaxis/drug effects , Pyrrolidines/pharmacology , Receptors, CCR2/antagonists & inhibitors , Calcium/metabolism , Cells, Cultured , Chromatography, High Pressure Liquid , Fluorescence , Humans , Kidney/cytology , Kidney/drug effects , Kidney/metabolism , Molecular Structure , Monocytes/drug effects , Monocytes/metabolism , Pyrrolidines/chemical synthesis , Receptors, CCR2/metabolism , Structure-Activity Relationship , TransfectionABSTRACT
N,N'-Disubstituted homopiperazine derivatives have been discovered as CC-chemokine receptor 2b (CCR2b) inhibitors with submicromolar activity in the CCR2b binding assay. A 4-substituted benzyl group on one homopiperazine nitrogen was an important moiety for binding affinity to the CCR2b receptor. The SAR for CCR2b binding affinity correlated inversely with the sigma factor of the functional group on this benzyl moiety. Introduction of hydroxy groups to appropriate positions in the 3,3-diphenylpropyl group on the other homopiperazine nitrogen increased CCR2b binding activity. The synthesis of an informer library to search for alternative substructures is also described.
Subject(s)
Piperazines/chemical synthesis , Receptors, Chemokine/antagonists & inhibitors , Cell Line , Chemokine CCL2/metabolism , Combinatorial Chemistry Techniques , Drug Design , Humans , Piperazines/chemistry , Piperazines/pharmacology , Radioligand Assay , Receptors, CCR2 , Structure-Activity RelationshipABSTRACT
Structure-activity relationships (SAR) of a weakly active class of CCR2b inhibitors were utilized to initiate a lead evolution program employing the Drug Discovery Engine. Several alternative structural series have been discovered that display nanomolar activity in the CCR2b binding and CCR2b-mediated chemotaxis assays.
