Protein & Peptide Letters

Prof. Ben M. Dunn  
Department of Biochemistry and Molecular Biology
University of Florida
College of Medicine
P.O. Box 100245
Gainesville, FL
USA
Email: bdunn@ufl.edu

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Drugs Against Mycobacterium tuberculosis 3-Isopropylmalate Dehydrogenase Can be Developed Using Homologous Enzymes as Surrogate Targets

Author(s): Eva Graczer, Andras Bacso, Denes Konya, Adrian Kazi, Tibor Soos, Laura Molnar, Tamas Szimler, Laszlo Beinrohr, Andras Szilagyi, Peter Zavodszky, Maria Vas.

Graphical Abstract:


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.

Keywords: Enzyme kinetics, expression, isopropylmalate dehydrogenase, inhibition, Mycobacterium tuberculosis, purification, physical-chemical characterization.

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Article Details

VOLUME: 21
ISSUE: 12
Year: 2014
Page: [1295 - 1307]
Pages: 13
DOI: 10.2174/0929866521666140606111019
Price: $58