3dga
Wild-type Plasmodium falciparum dihydrofolate reductase-thymidylate synthase (PfDHFR-TS) complexed with RJF01302, NADPH, and dUMPWild-type Plasmodium falciparum dihydrofolate reductase-thymidylate synthase (PfDHFR-TS) complexed with RJF01302, NADPH, and dUMP
Structural highlights
FunctionDRTS_PLAFK Bifunctional enzyme. Involved in de novo dTMP biosynthesis. Key enzyme in folate metabolism. Catalyzes an essential reaction for de novo glycine and purine synthesis, DNA precursor synthesis, and for the conversion of dUMP to dTMP.[HAMAP-Rule:MF_00008] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPlasmodium falciparum thymidylate synthase-dihydrofolate reductase (TS-DHFR) is an essential enzyme in folate biosynthesis and a major malarial drug target. This bifunctional enzyme thus presents different design approaches for developing novel inhibitors against drug-resistant mutants. We performed a high-throughput in silico screen of a database of diverse, drug-like molecules against a non-active-site pocket of TS-DHFR. The top compounds from this virtual screen were evaluated by in vitro enzymatic and cellular culture studies. Three compounds active to 20 microM IC(50)'s in both wildtype and antifolate-resistant P. falciparum parasites were identified; moreover, no inhibition of human DHFR enzyme was observed, indicating that the inhibitory effects appeared to be parasite-specific. Notably, all three compounds had a biguanide scaffold. However, relative free energy of binding calculations suggested that the compounds might preferentially interact with the active site over the screened non-active-site region. To resolve the two possible modes of binding, co-crystallization studies of the compounds complexed with TS-DHFR enzyme were performed. Surprisingly, the structural analysis revealed that these novel, biguanide compounds do indeed bind at the active site of DHFR and additionally revealed the molecular basis by which they overcome drug resistance. To our knowledge, these are the first co-crystal structures of novel, biguanide, non-WR99210 compounds that are active against folate-resistant malaria parasites in cell culture. Exploiting structural analysis, in silico screening, and serendipity to identify novel inhibitors of drug-resistant falciparum malaria.,Dasgupta T, Chitnumsub P, Kamchonwongpaisan S, Maneeruttanarungroj C, Nichols SE, Lyons TM, Tirado-Rives J, Jorgensen WL, Yuthavong Y, Anderson KS ACS Chem Biol. 2009 Jan 16;4(1):29-40. PMID:19146480[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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