Figure 1.

Losmapimod interacts with MAPK14 and reduces p38 MAPK phosphorylation. (A) Assessment of losmapimod binding to MAPK14 using surface plasmon resonance (SPR). Representative multicycle SPR sensograms for losmapimod showing a dose-dependent concentration series against immobilized MAPK14. K_D, equilibrium dissociation rate constant; K_on (Ms^–1), on-rate constant or association reaction; K_off (s^–1), off-rate constant or dissociation reaction. Experiments were performed in triplicate. (B) Western blot analysis of MAPK14 and p38 MAPK phosphorylation in THP-1 cells with the vehicle control, DMSO, and 1 μM losmapimod for 1 h shows loss of p38 phosphorylation in response to losmapimod. GAPDH serves as a loading control. A representative image of three replicates is shown. Relative mobilities of reference proteins (kDa) are shown on the left of each blot.