Gift from Nature: Cyclomarin A Kills Mycobacteria and Malaria Parasites by Distinct Modes of Action

Chembiochem. 2015 Nov;16(17):2433-6. doi: 10.1002/cbic.201500472. Epub 2015 Oct 16.


Malaria continues to be one of the most devastating human diseases despite many efforts to limit its spread by prevention of infection or by pharmaceutical treatment of patients. We have conducted a screen for antiplasmodial compounds by using a natural product library. Here we report on cyclomarin A as a potent growth inhibitor of Plasmodium falciparum and the identification of its molecular target, diadenosine triphosphate hydrolase (PfAp3Aase), by chemical proteomics. Using a biochemical assay, we could show that cyclomarin A is a specific inhibitor of the plasmodial enzyme but not of the closest human homologue hFHIT. Co-crystallisation experiments demonstrate a unique binding mode of the inhibitor. One molecule of cyclomarin A binds a dimeric PfAp3Aase and prevents the formation of the enzyme⋅substrate complex. These results validate PfAp3Aase as a new drug target for the treatment of malaria. We have previously elucidated the structurally unrelated regulatory subunit ClpC1 of the ClpP protease as the molecular target of cyclomarin A in Mycobacterium tuberculosis. Thus, cyclomarin A is a rare example of a natural product with two distinct and specific modes of action.

Keywords: antiprotozoal agents; cyclomarin; diadenosine triphosphate; malaria; natural products.

MeSH terms

  • Acid Anhydride Hydrolases / antagonists & inhibitors
  • Acid Anhydride Hydrolases / metabolism
  • Antimalarials / chemistry
  • Antimalarials / metabolism
  • Antimalarials / pharmacology
  • Bacterial Proteins / antagonists & inhibitors
  • Bacterial Proteins / metabolism
  • Binding Sites
  • Biological Products / chemistry*
  • Biological Products / metabolism
  • Biological Products / pharmacology
  • Endopeptidase Clp / antagonists & inhibitors
  • Endopeptidase Clp / metabolism
  • Humans
  • Inhibitory Concentration 50
  • Molecular Dynamics Simulation
  • Mycobacterium tuberculosis / drug effects
  • Mycobacterium tuberculosis / enzymology
  • Neoplasm Proteins / antagonists & inhibitors
  • Neoplasm Proteins / metabolism
  • Oligopeptides / chemistry*
  • Oligopeptides / metabolism
  • Oligopeptides / pharmacology
  • Plasmodium falciparum / drug effects
  • Plasmodium falciparum / enzymology
  • Plasmodium falciparum / growth & development
  • Protein Binding
  • Protein Structure, Tertiary


  • Antimalarials
  • Bacterial Proteins
  • Biological Products
  • Neoplasm Proteins
  • Oligopeptides
  • cyclomarin A
  • fragile histidine triad protein
  • Endopeptidase Clp
  • Acid Anhydride Hydrolases