Discovery of a compound which acts as a bacterial UMP kinase PyrH inhibitor

• Published in: FEMS microbiology letters Vol. 330; no. 2; pp. 121 - 126
• Main Authors: Yoshida, Tatsuhiko, Nasu, Hatsumi, Namba, Eiko, Ubukata, Osamu, Yamashita, Makoto
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-05-2012; Wiley-Blackwell; Oxford University Press
• Subjects: Acetic acid; Allosteric properties; Antiinfectives and antibacterials; Antimicrobial activity; Antimicrobial agents; Bacteria; Bacteriology; Biological and medical sciences; Chemical compounds; Enzymatic activity; Enzyme activity; Enzyme inhibitors; Enzyme Inhibitors - isolation & purification; Enzyme Inhibitors - metabolism; Fundamental and applied biological sciences. Psychology; Haemophilus influenzae; Haemophilus influenzae - drug effects; Haemophilus influenzae - enzymology; Humans; Inhibitors; Inhibitory Concentration 50; Kinases; Metabolic pathways; Microbial Sensitivity Tests; Microbiology; Miscellaneous; Mode of action; Molecular interactions; Nucleoside-Phosphate Kinase - antagonists & inhibitors; Nucleoside-Phosphate Kinase - metabolism; Organic chemistry; Protein Binding; Respiratory tract; Respiratory tract diseases; Sodium; Staphylococcus aureus - drug effects; Streptococcus infections; Streptococcus pneumoniae; Streptococcus pneumoniae - drug effects; Streptococcus pneumoniae - enzymology; Surface Plasmon Resonance; UMP kinase; Uridine Diphosphate - metabolism; Uridine Monophosphate - metabolism; UMP kinase; Pasteurellaceae; Streptococcaceae; Enzyme; Kinase; Transferases; Micrococcales; Bacteria; Haemophilus influenzae; Streptococcus pneumoniae
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2012.02546.x

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 IC50 (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 (IC50 = 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.