Fig. 1. Structure-based drug design yields a lead candidate MAPK13 inhibitor (NuP-4).

A, Screening funnel steps for chemical compound library (n=520) using chemical properties, MAPK13-14 enzyme assays, trans-epithelial electrical resistance (TEER) for human tracheobronchial epithelial cell (hTEC) monolayer integrity for cell toxicity, and additional MAPK13 assays. B, Enzyme inhibition activities for NuP-4 based on MAPK13 and MAPK14 phosphorylation of kinase substrate. C, Heat map for enzyme inhibition activities for NuP-4 based on a 425-kinase panel. D, Values for K_D derived from biolayer interferometry (BLI) analysis of NuP-4 binding for MAPK13 versus MAPK12 or MAPK14.