Multiple unbiased approaches identify oxidosqualene cyclase as the molecular target of a promising anti-leishmanial

Luciana S. Paradela, Richard J. Wall, Sandra Carvalho, Giulia Chemi, Victoriano Corpas-Lopez, Eoin Moynihan, Davide Bello, Stephen Patterson, Maria Lucia S. Guther, Alan H. Fairlamb, Michael A. J. Ferguson, Fabio Zuccotto, Julio Martin, Ian H. Gilbert, Susan Wyllie (Lead / Corresponding author)

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)
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Phenotypic screening identified a benzothiophene compound with activity against Leishmania donovani, the causative agent of visceral leishmaniasis. Using multiple orthogonal approaches, oxidosqualene cyclase (OSC), a key enzyme of sterol biosynthesis, was identified as the target of this racemic compound and its enantiomers. Whole genome sequencing and screening of a genome-wide overexpression library confirmed that OSC gene amplification is associated with resistance to compound 1. Introduction of an ectopic copy of the OSC gene into wild-type cells reduced susceptibility to these compounds confirming the role of this enzyme in resistance. Biochemical analyses demonstrated the accumulation of the substrate of OSC and depletion of its product in compound (S)-1-treated-promastigotes and cell-free membrane preparations, respectively. Thermal proteome profiling confirmed that compound (S)-1 binds directly to OSC. Finally, modeling and docking studies identified key interactions between compound (S)-1 and the LdOSC active site. Strategies to improve the potency for this promising anti-leishmanial are proposed.

Original languageEnglish
Pages (from-to)711-721.e8
Number of pages20
JournalCell Chemical Biology
Issue number5
Early online date9 Mar 2021
Publication statusPublished - 20 May 2021


  • oxidosqualene cyclase
  • Leishmania donovani
  • drug target
  • mechanism of action
  • lanosterol
  • neglected tropical diseases
  • visceral leishmaniasis
  • drug discovery
  • neglected tropical disease

ASJC Scopus subject areas

  • Drug Discovery
  • Molecular Medicine
  • Molecular Biology
  • Biochemistry
  • Clinical Biochemistry
  • Pharmacology


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