The effects of allosteric and competitive inhibitors on ZIKV protease conformational dynamics explored through smFRET, nanoDSF, DSF, and F NMR.

Zika and dengue viruses cause mosquito-borne diseases of high epidemic relevance. The viral NS2B-NS3 proteases play crucial roles in the pathogen replication cycle and are validated drug targets. They can adopt at least two conformations depending on the position of the NS2B cofactor. Recently, we reported ligand-induced conformational changes of dengue virus NS2B-NS3 protease by single-molecule Förster resonance energy transfer (smFRET). Here, we investigated the conformational dynamics of the homologous Zika virus protease through an integrated methodological approach combining smFRET, thermal shift assays (DSF and nanoDSF) and F NMR spectroscopy. Our results show that allosteric inhibitors favor the open conformation and competitive inhibitors stabilize the closed conformation of the Zika virus protease.