title: Discovery of a compound which acts as a bacterial UMP kinase PyrH inhibitor.
abstract: PyrH is a member of the UMP kinase family that catalyses the conversion of UMP to UDP, an essential step in the pyrimidine metabolic pathway in a variety of bacteria including those causing community-acquired respiratory tract infections (RTIs). In this study, we have developed a luminescence-based kinase assay of PyrH and evaluated the inhibitory activity of PYRH-1 (sodium {3-[4-tert-butyl-3-(9H-xanthen-9-ylacetylamino)phenyl]-1-cyclohexylmethylpropoxycarbonyloxy}acetate). PYRH-1 inhibits PyrH derived from both Streptococcus pneumoniae and Haemophilus influenzae with IC(50)  (concentration of inhibitor giving a 50% decrease in enzyme activity) values of 48 and 75 μM, respectively, whose inhibitory activity against S. pneumoniae PyrH was far higher compared with that of UTP (IC(50)  = 710 μM), an allosteric PyrH inhibitor. The molecular interaction analysis by surface plasmon resonance suggested that PYRH-1 directly interacts with S. pneumoniae PyrH at one-to-one molar ratio. Finally, PYRH-1 was shown to have antimicrobial activity against several different bacteria causing RTIs, such as S. pneumoniae, Staphylococcus aureus, H. influenzae (acrA knockout strain), suggesting that PYRH-1 is a prototype chemical compound that can be harnessed as an antimicrobial drug with a novel mode of action by targeting bacterial PyrH.
authors.affiliation: Biological Research Laboratories IV, Daiichi Sankyo Co., Ltd, Tokyo, Japan. yoshida.tatsuhiko.ej@daiichisankyo.co.jp
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Yoshida
authors.forename: Hatsumi
authors.initials: H
authors.lastname: Nasu
authors.forename: Eiko
authors.initials: E
authors.lastname: Namba
authors.forename: Osamu
authors.initials: O
authors.lastname: Ubukata
authors.forename: Makoto
authors.initials: M
authors.lastname: Yamashita
mesh_terms: D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D006193:Haemophilus influenzae / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D020128:Inhibitory Concentration 50; D008826:Microbial Sensitivity Tests; D009703:Nucleoside-Phosphate Kinase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011485:Protein Binding; D013211:Staphylococcus aureus / Q000187:drug effects; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000201:enzymology*; D020349:Surface Plasmon Resonance; D014530:Uridine Diphosphate / Q000378:metabolism; D014542:Uridine Monophosphate / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D014530:Uridine Diphosphate; D014542:Uridine Monophosphate; C023276:uridine monophosphate kinase; D009703:Nucleoside-Phosphate Kinase