Mitogen-Activated Protein Kinase-Activated Protein Kinase 2 (MAPKAP-K2) as an Antiinflammatory Target: Discovery and in Vivo Activity of Selective Pyrazolo[1,5-a]pyrimidine Inhibitors Using a Focused Library and Structure-Based Optimization Approach

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.

Crystal structure of human cyclin-dependent kinase-2 complex with MK2 inhibitor TEI-I01800: insight into the selectivity

“…The purified CDK2 was concentrated to 5-10 mg ml À1 and crystallization experiments of apo-CDK2 were performed using the sitting-drop vapourdiffusion method under the conditions of 0.1 M HEPES pH 7.4, 10-15% PEG 3350 and 50 mM ammonium acetate. After the crystals were grown for 2-3 d, TEI-I01800, which was synthesized by Kosugi et al (2012), was added to the crystallization drop at a final concentration of 2 mM and soaked for 12-24 h. X-ray diffraction data were collected on beamline BL32B2 at SPring-8 at 100 K using 25% glycerol as cryoprotectant. The CDK2-TEI-I01800 complex crystals diffracted to 2.0 Å resolution and belonged to space group P2 1 2 1 2 1 with unit-cell parameters a = 53.64, b = 72.10 and c = 72.61 Å .…”

“…Statistics of the data collection and final structure are summarized in Table 1. Methods for measurement of MK2 and CDK2 enzyme assay were described in our previous paper (Kosugi et al, 2012). Structure minimization of the protein-ligand complex with OPLS 2005 force field was performed using the Protein Preparation Wizard.…”

“…Kinases are particularly prominent in signal transduction and coordination of complex functions. In particular, cyclin-dependent kinase 2 (CDK2), which is also a member of the Ser/Thr kinase family, plays a central role in the control of the cell cycle (Tsai et al, 1991) and interference with the cell cycle via inhibition likely to be an undesirable feature in anti-inflammatory drugs used chronically such as MK2 inhibitor; in fact, the improvement of selectivity over CDK2 has been published (Anderson et al, 2009a,b;Kosugi et al, 2012). MK2 and CDK2 complex structures with the same inhibitor which has only 29-fold selectivity against MK2 are reported and the interaction mode is observed to look similar (Anderson et al, 2009a).…”

Synthesis of Novel 5-(N-Boc-N-Benzyl-2-aminoethyl)-7-oxo- 4,7-dihydropyrazolo[1,5-a]pyrimidin-3-carboxamides and Their Inhibition of Cathepsins B and K

“…For 2016 alone, 74 references can be found for a term "pyrazolo [1,5-a]pyrimidines". Among bioactive pyrazolo [1,5-a]pyrimidines there are hepatitis C virus inhibitors, 6 antagonists of serotonin 5-HT6 receptors, 7 kinase inhibitors, [8][9][10] PET tumor imaging agents, 11 and inhibitors of amyloid β-peptide aggregation. 12 Sedative agents zaleplon and indiplon and the anxiolytic agent ocinaplon are approved drugs containing a pyrazolo [1,5-a]pyrimidine core ( Figure 1).…”

Asymmetric synthesis of N-protected 3-methylpiperidin-2-one and its diastereoisomer

“…Piperidin-2-one is a versatile building block for the synthesis of piperidine and piperidone derivatives (Bailey et al, 1998;Baussanne et al, 1998), a large variety of bioactive moieties (Kosugi et al, 2012;Wang et al, 2013;Jadav et al, 2014;Zarate et al, 2014) as well as medicines to treat diseases like inflammatory bowel disease (Old et al, 2005) and neurodegenerative diseases (Cohen and Patel, 2014). 5-substituted 1-methyl-2-pyridones, which are one kind of piperidone derivative, have been evaluated as active agents against benign prostatic hyperplasia (BPH) and prostate cancer (Hartmann et al, 1994).…”