title: Identification of novel irreversible inhibitors of UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) from Haemophilus influenzae.
abstract: Uridinediphospho-N-acetylglucosamine enolpyruvyl transferase (MurA, E.C. 2.5.1.7) is an essential bacterial enzyme that catalyzes the first step of the cell wall biosynthetic pathway, which involves the transfer of an enolpyruvyl group from phosphoenolpyruvate to uridinediphospho-Nacetylglucosamine. In this study, novel inhibitors of Haemophilus influenzae MurA (Hi MurA) were identified using high-throughput screening of a chemical library from the Korea Chemical Bank. The identified compounds contain a quinoline moiety and have much lower effective inhibitory concentrations (IC(50)) than fosfomycin, a wellknown inhibitor of MurA. These inhibitors appear to covalently modify the sulfhydryl group of the active site cysteine (C117), since the C117D mutant Hi MurA was not inhibited by these compounds and excess dithiothreitol abolished their inhibitory activities. The increased mass value of Hi MurA after treatment with the identified inhibitor further confirmed that the active-site cysteine residue of Hi MurA is covalently modified by the inhibitor.
authors: Department of Chemistry, Kookmin University, Seoul 136-702, Korea.
authors: Seong-Gu
authors: SG
authors: Han
authors: Won-Kyu
authors: WK
authors: Lee
authors: Bong-Suk
authors: BS
authors: Jin
authors: Ki-In
authors: KI
authors: Lee
authors: Hyeong Ho
authors: HH
authors: Lee
authors: Yeon Gyu
authors: YG
authors: Yu
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000037:antagonists & inhibitors*; D003545:Cysteine / Q000378:metabolism; D004353:Drug Evaluation, Preclinical; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D006193:Haemophilus influenzae / Q000201:enzymology*; D057166:High-Throughput Screening Assays; D020128:Inhibitory Concentration 50; D007723:Korea; D054852:Small Molecule Libraries; D013439:Sulfhydryl Reagents / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D054852:Small Molecule Libraries; D013439:Sulfhydryl Reagents; D019883:Alkyl and Aryl Transferases; C022566:UDP-N-acetylglucosamine 1-carboxyvinyltransferase; D003545:Cysteine