Targeting the Plasmodium falciparum IspE Enzyme

The enzyme IspE in Plasmodium falciparum is considered an attractive drug target, as it is essential for\nparasite survival and is absent\nin the human proteome. Yet it still has not been addressed\nby a small-molecule inhibitor. In this study, we conducted\na high-throughput screening campaign against the <i>Pf</i>IspE enzyme. Our approach toward a <i>Pf</i>IspE inhibitor\ncomprises <i>in vitro</i> screening, structure–activity\nrelationship studies, examining the docking position using an AlphaFold\nmodel, and finally target verification through probe binding and sodium\ndodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis.\nThe newly synthesized probe containing a diazirine and an alkyne moiety\n(<b>23</b>) allowed us to demonstrate its binding to IspE in\nthe presence of a lysate of human cells (HEK293 cells) and to get\nevidence that both probe <b>23</b> and the best inhibitor of\nthe series (<b>19</b>) compete for the same IspE binding site.