Proline-Based Allosteric Inhibitors of Zika and Dengue Virus NS2B/NS3 Proteases

The NS2B/NS3 serine proteases of the Zika and Dengue flaviviruses are attractive targets for the development of antiviral drugs. We report the synthesis and evaluation of a new, proline-based compound class that displays allosteric inhibition of both proteases. The structural features relevant for protease binding and inhibition were determined to establish them as new lead compounds for flaviviral inhibitors. Based on our structure-activity relationship studies, the molecules were further optimized, leading to inhibitors with submicromolar IC50 values and improved lipophilic ligand efficiency. The allosteric binding site in the proteases was probed using mutagenesis and covalent modificati…