title: Drugs against Mycobacterium tuberculosis 3-isopropylmalate dehydrogenase can be developed using homologous enzymes as surrogate targets.
abstract: 3-Isopropylmalate dehydrogenase (IPMDH) from Mycobacterium tuberculosis (Mtb) may be a target for specific drugs against this pathogenic bacterium. We have expressed and purified Mtb IPMDH and determined its physicalchemical and enzymological properties. Size-exclusion chromatography and dynamic light scattering measurements (DLS) suggest a tetrameric structure for Mtb IPMDH, in contrast to the dimeric structure of most IPMDHs. The kinetic properties (kcat and Km values) of Mtb IPMDH and the pH-dependence of kcat are very similar to both Escherichia coli (Ec) and Thermus thermophilus (Tt) IPMDHs. The stability of Mtb IPMDH in 8 M urea is close to that of the mesophilic counterpart, Ec IPMDH, both of them being much less stable than the thermophilic (Tt) enzyme. Two known IPMDH inhibitors, O-methyl oxalohydroxamate and 3-methylmercaptomalate, have been synthesised. Their inhibitory effects were found to be independent of the origin of IPMDHs. Thus, experiments with either Ec or Tt IPMDH would be equally relevant for designing specific inhibitory drugs against Mtb IPMDH.
authors.forename: Eva
authors.initials: E
authors.lastname: Graczer
authors.forename: Andras
authors.initials: A
authors.lastname: Bacso
authors.forename: Denes
authors.initials: D
authors.lastname: Konya
authors.forename: Adrian
authors.initials: A
authors.lastname: Kazi
authors.forename: Tibor
authors.initials: T
authors.lastname: Soos
authors.forename: Laura
authors.initials: L
authors.lastname: Molnar
authors.forename: Tamas
authors.initials: T
authors.lastname: Szimler
authors.forename: Laszlo
authors.initials: L
authors.lastname: Beinrohr
authors.forename: Andras
authors.initials: A
authors.lastname: Szilagyi
authors.forename: Peter
authors.initials: P
authors.lastname: Zavodszky
authors.affiliation: Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, H- 1117 Budapest, Magyar tudósok korutja 2., Hungary; H-1519 Budapest, P. O. Box 286., Hungary. vas.maria@ttk.mta.hu.
authors.forename: Maria
authors.initials: M
authors.lastname: Vas
mesh_terms: D050539:3-Isopropylmalate Dehydrogenase / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D000995:Antitubercular Agents / Q000378:metabolism* / Q000494:pharmacology; D001426:Bacterial Proteins / Q000737:chemistry / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D055808:Drug Discovery; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008958:Models, Molecular; D009169:Mycobacterium tuberculosis / Q000201:enzymology* / Q000235:genetics; D058849:Protein Refolding
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; D050539:3-Isopropylmalate Dehydrogenase