In vitro activity: BMS-582949 is found to inhibit p38 activation in cells, as measured by phosphorylation of p38. BMS-582949 treatment of cells in which p38 has been activated by LPS rapidly reversed p38 activation as shown by loss of phosphorylation of p38. BMS-582949 is therefore a dual action p38 kinase inhibitor, inhibiting both p38 kinase activity and p38 activation in cells. BMS-582949 binding to p38a results in a conformational change of the activation loop which is phosphorylated by upstream kinases, therefore it inhibits phosphorylation of p38 by upstream MKK by inducing a less accessible conformation of the activation loop.

Kinase Assay: BMS-582949 was found to be 450-fold selective over Jnk2, a MAP kinase involved in inflammation, and 190-fold selective against Raf. Moreover, the binding mode of BMS-582949 with p38R was further demonstrated by X-ray crystallographic analyses.

Cell Assay: BMS-582949 inhibits both p38 kinase activity and activation of p38. BMS-582949 is found to inhibit p38 activation in cells, as measured by phosphorylation of p38. BMS-582949 treatment of cells in which p38 has been activated by LPS rapidly reversed p38 activation as shown by loss of phosphorylation of p38.