ABSTRACT
The specificity of the immune response relies on processing of foreign proteins and presentation of antigenic peptides at the cell surface. Inhibition of antigen presentation, and the subsequent activation of T-cells, should, in theory, modulate the immune response. The cysteine protease Cathepsin S performs a fundamental step in antigen presentation and therefore represents an attractive target for inhibition. Herein, we report a series of potent and reversible Cathepsin S inhibitors based on dipeptide nitriles. These inhibitors show nanomolar inhibition of the target enzyme as well as cellular potency in a human B cell line. The first X-ray crystal structure of a reversible inhibitor cocrystallized with Cathepsin S is also reported.
Subject(s)
Cathepsins/chemical synthesis , Dipeptides/chemical synthesis , Enzyme Inhibitors/chemical synthesis , Nitriles/chemical synthesis , B-Lymphocytes/drug effects , Binding, Competitive , Cathepsins/chemistry , Cathepsins/pharmacology , Cell Line , Crystallography, X-Ray , Dipeptides/chemistry , Dipeptides/pharmacology , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Humans , Kinetics , Models, Molecular , Nitriles/chemistry , Nitriles/pharmacology , Stereoisomerism , Structure-Activity RelationshipABSTRACT
Synthesis and structure-activity relationship (SAR) of a series of nonsteroidal glucocorticoid receptor (GR) agonists are described. These compounds contain "diazaindole" moieties and display different transcriptional regulatory profiles in vitro and are considered "dissociated" between gene transrepression and transactivation. The lead optimization effort described in this article focused in particular on limiting the transactivation of genes which result in bone side effects and these were assessed in vitro in MG-63 osteosarcoma cells, leading to the identification of (R)-18 and (R)-21. These compounds maintained anti-inflammatory activity in vivo in collagen induced arthritis studies in mouse but had reduced effects on bone relevant parameters compared to the widely used synthetic glucocorticoid prednisolone 2 in vivo. To our knowledge, we are the first to report on selective glucocorticoid ligands with reduced bone loss in a preclinical in vivo model.
Subject(s)
Bone and Bones/drug effects , Receptors, Glucocorticoid/agonists , Animals , Cell Line, Tumor , Female , Humans , Magnetic Resonance Spectroscopy , Mice , Structure-Activity RelationshipABSTRACT
The discovery of a series of potent, carboline-based MK2 inhibitors is described. These compounds inhibit MK2 with IC50s as low as 10 nM, as measured in a DELFIA assay. An X-ray crystal structure reveals that they bind in a region near the p-loop and the hinge region of MK2a.
Subject(s)
Carbolines/chemistry , Carbolines/pharmacology , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Protein Serine-Threonine Kinases/antagonists & inhibitors , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Models, Molecular , Molecular Structure , Structure-Activity RelationshipABSTRACT
The synthesis and in vitro activities of a series of succinyl-nitrile-based inhibitors of Cathepsin S are described. Several members of this class show nanomolar inhibition of the target enzyme as well as cellular potency. The inhibitors displaying the greatest potency contain N-alkyl substituted piperidine and pyrrolidine rings spiro-fused to the alpha-carbon of the P1 residue.