Using Unbiased Chemical Proteomics Approaches to Explore the Target Landscape of the Resistance Refractory 7-Azaindole MMV022224 in Plasmodium falciparum

  • ACS Infect Dis. 2026 Jul 10;12(7):2332-2344. doi: 10.1021/acsinfecdis.6c00276.
Aisha J Syed  1 ,  Rachel Milne  1 ,  Victoriano Corpas-Lopez  1 ,  Gourav Dey  1 ,  Nonlawat Boonyalai  2 ,  Richard J Wall  1 ,  Natalie Wiedemar  1 ,  Lukas Montejo  3 ,  Flore Nardella  3 ,  Kathryn J Wicht  4 ,  Charisse Flerida A Pasaje  5 ,  John Okombo  6  7 ,  Jacquin C Niles  5 ,  David A Fidock  6  7 ,  Marcus C S Lee  2 ,  Debopam Chakrabarti  3 ,  Stephen Patterson  1 ,  Susan Wyllie  1
Affiliations
  • 1. Drug Discovery Unit, Division of Drug Discovery, Faculty of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom.
  • 2. Division of Biological Chemistry and Drug Discovery, Faculty of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, United Kingdom.
  • 3. Division of Molecular Microbiology, Burnett School of Biomedical Sciences, University of Central Florida, 12722 Research Parkway, Orlando, Florida 32826, United States.
  • 4. Holistic Drug Discovery and Development (H3D) Centre, Department of Chemistry and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa.
  • 5. Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
  • 6. Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, New York 10032, United States.
  • 7. Center for Malaria Therapeutics and Antimicrobial Resistance, Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, New York 10032, United States.
PMID: 42345078 DOI: 10.1021/acsinfecdis.6c00276
Abstract

Current standard of care, artemisinin-based therapies for malaria, are threatened by emerging drug resistance. Developing antimalarials with novel mechanisms of action and low propensity for resistance is of the highest priority. Here, we explore the target landscape of MMV022224, a promising antimalarial that is active against multiple stages of Plasmodium falciparum and refractory to resistance generation. Using two orthogonal chemical proteomics approaches, chemical pulldown and thermal proteome profiling, we demonstrate that MMV022224 binds selectively and with high affinity to the genetically essential P. falciparum protein kinase 6 (PfPK6), as well as to several additional Plasmodium kinases. Enzymatic studies verify that MMV022224 inhibits PfPK6; however, PfPK6 knockdown does not affect Parasite compound susceptibility, confirming that PfPK6 inhibition is not the sole driver of antimalarial activity and that MMV022224 may act through broader, kinase-focused polypharmacology. Employing the same chemical proteomics strategies, we demonstrate that the structurally related azaindole, TCMDC-135051, is a selective inhibitor of the cyclin-dependent kinase PfCLK3. Collectively, these studies demonstrate the value of chemical proteomics for antimalarial drug target deconvolution.

Keywords
Plasmodium; antimalarial drug discovery; chemical biology; chemical pulldown; isothermal TPP; target deconvolution.
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