Structure-based design of novel small-molecule inhibitors of Plasmodium falciparum

J Chem Inf Model. 2010 May 24;50(5):840-9. doi: 10.1021/ci100039k.

Abstract

Malaria is endemic in most developing countries, with nearly 500 million cases estimated to occur each year. The need to design a new generation of antimalarial drugs that can combat the most drug-resistant forms of the malarial parasite is well recognized. In this study, we wanted to develop inhibitors of key proteins that form the invasion machinery of the malarial parasite. A critical feature of host-cell invasion by apicomplexan parasites is the interaction between the carboxy terminal tail of myosin A (MyoA) and the myosin tail interacting protein (MTIP). Using the cocrystal structure of the Plasmodium knowlesi MTIP and the MyoA tail peptide as input to the hybrid structure-based virtual screening approach, we identified a series of small molecules as having the potential to inhibit MTIP-MyoA interactions. Of the initial 15 compounds tested, a pyrazole-urea compound inhibited P. falciparum growth with an EC(50) value of 145 nM. We screened an additional 51 compounds belonging to the same chemical class and identified 8 compounds with EC(50) values less than 400 nM. Interestingly, the compounds appeared to act at several stages of the parasite's life cycle to block growth and development. The pyrazole-urea compounds identified in this study could be effective antimalarial agents because they competitively inhibit a key protein-protein interaction between MTIP and MyoA responsible for the gliding motility and the invasive features of the malarial parasite.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antimalarials / chemistry*
  • Antimalarials / pharmacology*
  • Crystallography, X-Ray
  • Drug Design
  • Humans
  • Malaria, Falciparum / drug therapy*
  • Models, Molecular
  • Nonmuscle Myosin Type IIA / antagonists & inhibitors
  • Nonmuscle Myosin Type IIA / chemistry
  • Nonmuscle Myosin Type IIA / metabolism
  • Parasitic Sensitivity Tests
  • Plasmodium falciparum / drug effects*
  • Protozoan Proteins / antagonists & inhibitors*
  • Protozoan Proteins / chemistry
  • Protozoan Proteins / metabolism
  • Pyrazoles / chemistry
  • Pyrazoles / pharmacology
  • Small Molecule Libraries / chemistry*
  • Small Molecule Libraries / pharmacology*
  • Urea / chemistry
  • Urea / pharmacology

Substances

  • Antimalarials
  • Protozoan Proteins
  • Pyrazoles
  • Small Molecule Libraries
  • pyrazole
  • Urea
  • Nonmuscle Myosin Type IIA