Human hypoxanthine-guanine phosphoribosyltransferase in complex with 9-(2-phosphonoethoxyethyl)hypoxanthine
[HPRT_HUMAN] Defects in HPRT1 are the cause of Lesch-Nyhan syndrome (LNS) [MIM:300322]. LNS is characterized by complete lack of enzymatic activity that results in hyperuricemia, choreoathetosis, mental retardation, and compulsive self-mutilation.          Defects in HPRT1 are the cause of gout HPRT-related (GOUT-HPRT) [MIM:300323]; also known as HPRT-related gout or Kelley-Seegmiller syndrome. Gout is characterized by partial enzyme activity and hyperuricemia.      [:]
[HPRT_HUMAN] Converts guanine to guanosine monophosphate, and hypoxanthine to inosine monophosphate. Transfers the 5-phosphoribosyl group from 5-phosphoribosylpyrophosphate onto the purine. Plays a central role in the generation of purine nucleotides through the purine salvage pathway.
Publication Abstract from PubMed
The purine salvage enzyme hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRT) is essential for purine nucleotide and hence nucleic acid synthesis in the malaria parasite, Plasmodium falciparum. Acyclic nucleoside phosphonates (ANPs) are analogues of the nucleotide product of the reaction, comprising a purine base joined by a linker to a phosphonate moiety. K(i) values for 19 ANPs were determined for Pf HGXPRT and the corresponding human enzyme, HGPRT. Values for Pf HGXPRT were as low as 100 nM, with selectivity for the parasite enzyme of up to 58. Structures of human HGPRT in complex with three ANPs are reported. On binding, a large mobile loop in the free enzyme moves to partly cover the active site. For three ANPs, the IC(50) values for Pf grown in cell culture were 1, 14, and 46 microM, while the cytotoxic concentration for the first compound was 489 microM. These results provide a basis for the design of potent and selective ANP inhibitors of Pf HGXPRT as antimalarial drug leads.
Inhibition of hypoxanthine-guanine phosphoribosyltransferase by acyclic nucleoside phosphonates: a new class of antimalarial therapeutics.,Keough DT, Hockova D, Holy A, Naesens LM, Skinner-Adams TS, Jersey J, Guddat LW J Med Chem. 2009 Jul 23;52(14):4391-9. PMID:19527031
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.