title: High-throughput screening for small-molecule inhibitors of plasmodium falciparum glucose-6-phosphate dehydrogenase 6-phosphogluconolactonase.
abstract: Plasmodium falciparum causes severe malaria infections in millions of people every year. The parasite is developing resistance to the most common antimalarial drugs, which creates an urgent need for new therapeutics. A promising and attractive target for antimalarial drug design is the bifunctional enzyme glucose-6-phosphate dehydrogenase-6-phosphogluconolactonase (PfGluPho) of P. falciparum, which catalyzes the key step in the parasites' pentose phosphate pathway. In this study, we describe the development of a high-throughput screening assay to identify small-molecule inhibitors of recombinant PfGluPho. The optimized assay was used to screen three small-molecule compound libraries-namely, LOPAC (Sigma-Aldrich, 1280 compounds), Spectrum (MicroSource Discovery Systems, 1969 compounds), and DIVERSet (ChemBridge, 49 971 compounds). These pilot screens identified 899 compounds that inhibited PfGluPho activity by at least 50%. Selected compounds were further studied to determine IC(50) values in an orthogonal assay, the type of inhibition and reversibility, and effects on P. falciparum growth. Screening results and follow-up studies for selected PfGluPho inhibitors are presented. Our high-throughput screening assay may provide the basis to identify novel and urgently needed antimalarial drugs.
authors.affiliation: Department of Pediatrics, University of California, San Diego, CA, USA.
authors.forename: Janina
authors.initials: J
authors.lastname: Preuss
authors.forename: Michael
authors.initials: M
authors.lastname: Hedrick
authors.forename: Eduard
authors.initials: E
authors.lastname: Sergienko
authors.forename: Anthony
authors.initials: A
authors.lastname: Pinkerton
authors.forename: Arianna
authors.initials: A
authors.lastname: Mangravita-Novo
authors.forename: Layton
authors.initials: L
authors.lastname: Smith
authors.forename: Carolin
authors.initials: C
authors.lastname: Marx
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Fischer
authors.forename: Esther
authors.initials: E
authors.lastname: Jortzik
authors.forename: Stefan
authors.initials: S
authors.lastname: Rahlfs
authors.forename: Katja
authors.initials: K
authors.lastname: Becker
authors.forename: Lars
authors.initials: L
authors.lastname: Bode
mesh_terms: D000962:Antimalarials / Q000494:pharmacology*; D002265:Carboxylic Ester Hydrolases / Q000037:antagonists & inhibitors*; D002478:Cells, Cultured; D004353:Drug Evaluation, Preclinical / Q000379:methods; D005954:Glucosephosphate Dehydrogenase / Q000037:antagonists & inhibitors*; D022781:Hepatocytes; D057166:High-Throughput Screening Assays; D006801:Humans; D020128:Inhibitory Concentration 50; D016778:Malaria, Falciparum / Q000188:drug therapy; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors*; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000201:enzymology; D054852:Small Molecule Libraries / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D000962:Antimalarials; D009097:Multienzyme Complexes; D054852:Small Molecule Libraries; C560097:glucose-6-phosphate dehydrogenase-6-phosphogluconolactonase, Plasmodium falciparum; D005954:Glucosephosphate Dehydrogenase; D002265:Carboxylic Ester Hydrolases