6a7c
Human dihydrofolate reductase complexed with NADPH and BT1
Structural highlights
DiseaseDYR_HUMAN Defects in DHFR are the cause of megaloblastic anemia due to dihydrofolate reductase deficiency (DHFRD) [MIM:613839. DHFRD is an inborn error of metabolism, characterized by megaloblastic anemia and/or pancytopenia, severe cerebral folate deficiency, and cerebral tetrahydrobiopterin deficiency. Clinical features include variable neurologic symptoms, ranging from severe developmental delay and generalized seizures in infancy, to childhood absence epilepsy with learning difficulties, to lack of symptoms.[1] [2] FunctionDYR_HUMAN Key enzyme in folate metabolism. Contributes to the de novo mitochondrial thymidylate biosynthesis pathway. Catalyzes an essential reaction for de novo glycine and purine synthesis, and for DNA precursor synthesis. Binds its own mRNA and that of DHFRL1.[3] [4] Publication Abstract from PubMedThe S108N mutation of dihydrofolate reductase (DHFR) renders Plasmodium falciparum malaria parasites resistant to pyrimethamine through steric clash with the rigid side chain of the inhibitor. Inhibitors with flexible side chains can avoid this clash and retain effectiveness against the mutant. However, other mutations such as N108S reversion confer resistance to flexible inhibitors. We designed and synthesized hybrid inhibitors with two structural types in a single molecule, which are effective against both wild-type and multiple mutants of P. falciparum through their selective target binding, as demonstrated by X-ray crystallography. Furthermore, the hybrid inhibitors can forestall the emergence of new resistant mutants, as shown by selection of mutants resistant to hybrid compound BT1 from a diverse PfDHFR random mutant library expressed in a surrogate bacterial system. These results show that it is possible to develop effective antifolate antimalarials to which the range of parasite resistance mutations is greatly reduced. Hybrid Inhibitors of Malarial Dihydrofolate Reductase with Dual Binding Modes That Can Forestall Resistance.,Tarnchompoo B, Chitnumsub P, Jaruwat A, Shaw PJ, Vanichtanankul J, Poen S, Rattanajak R, Wongsombat C, Tonsomboon A, Decharuangsilp S, Anukunwithaya T, Arwon U, Kamchonwongpaisan S, Yuthavong Y ACS Med Chem Lett. 2018 Nov 7;9(12):1235-1240. doi:, 10.1021/acsmedchemlett.8b00389. eCollection 2018 Dec 13. PMID:30613332[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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