Studies Toward the Synthesis of Inhibitors of Mycobacterium tuberculosis Cell-Wall Biosynthesis: The Assembly of Triazole-Linked 1,6-α-d-Oligomannosides via Click CuAAC

Synlett ◽  
2009 ◽  
Vol 2009 (16) ◽  
pp. 2679-2681 ◽  
Author(s):  
Alberto Marra ◽  
Alessandro Dondoni ◽  
Mauro Lo Conte ◽  
Angela Chambery
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Cell Wall Biosynthesis

1,3-Diarylpyrazolyl-acylsulfonamides as Potent Anti-tuberculosis Agents Targeting Cell Wall Biosynthesis in Mycobacterium tuberculosis

2021 ◽  
Vol 64 (17) ◽  
pp. 12790-12807
Author(s):  
Lutete Peguy Khonde ◽  
Rudolf Müller ◽  
Grant A. Boyle ◽  
Virsinha Reddy ◽  
Aloysius T. Nchinda ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Cell Wall Biosynthesis

scholarly journals Molecular Investigation of Resistance to the Antituberculous Drug Ethionamide in Multidrug-Resistant Clinical Isolates ofMycobacterium tuberculosis

2010 ◽  
Vol 55 (1) ◽  
pp. 355-360 ◽  
Author(s):  
F. Brossier ◽  
N. Veziris ◽  
C. Truffot-Pernot ◽  
V. Jarlier ◽  
W. Sougakoff
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Drug Targets ◽  
Nadh Dehydrogenase ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Cell Wall Biosynthesis ◽  
Molecular Investigation ◽  
Antituberculous Drug ◽  
Resistant Cells

ABSTRACTEthionamide (ETH) needs to be activated by the mono-oxygenase EthA, which is regulated by EthR, in order to be active againstMycobacterium tuberculosis. The activated drug targets the enzyme InhA, which is involved in cell wall biosynthesis. Resistance to ETH has been reported to result from various mechanisms, including mutations altering EthA/EthR, InhA and its promoter, the NADH dehydrogenase encoded byndh, and the MshA enzyme, involved in mycothiol biosynthesis. We searched for such mutations in 87 clinical isolates: 47 ETH-resistant (ETHr) isolates, 24 ETH-susceptible (ETHs) isolates, and 16 isolates susceptible to ETH but displaying an intermediate proportion of resistant cells (ETHSip; defined as ≥1% but <10% resistant cells). In 81% (38/47) of the ETHrisolates, we found mutations inethA,ethR, orinhAor its promoter, which mostly corresponded to new alterations inethAandethR. The 9 ETHrisolates without a mutation in these three genes (9/47, 19%) had no mutation inndh, and a single isolate had a mutation inmshA. Of the 16 ETHSipisolates, 7 had a mutation inethA, 8 had no detectable mutation, and 1 had a mutation inmshA. Finally, of the 24 ETHsisolates, 23 had no mutation in the studied genes and 1 displayed a yet unknown mutation in theinhApromoter. Globally, the mechanism of resistance to ETH remained unknown for 19% of the ETHrisolates, highlighting the complexity of the mechanisms of ETH resistance inM. tuberculosis.

scholarly journals The external PASTA domain of the essential serine/threonine protein kinase PknB regulates mycobacterial growth

Open Biology ◽  
2015 ◽  
Vol 5 (7) ◽  
pp. 150025 ◽  
Author(s):  
Obolbek Turapov ◽  
Jessica Loraine ◽  
Christopher H. Jenkins ◽  
Philippe Barthe ◽  
Daniel McFeely ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Protein Kinase ◽  
Cell Wall Biosynthesis ◽  
Magnesium Ions ◽  
Peptidoglycan Biosynthesis ◽  
Increased Sensitivity ◽  
Mycobacterial Growth ◽  
Pasta Domain ◽  
Cell Wall Architecture

PknB is an essential serine/threonine protein kinase required for mycobacterial cell division and cell-wall biosynthesis. Here we demonstrate that overexpression of the external PknB_PASTA domain in mycobacteria results in delayed regrowth, accumulation of elongated bacteria and increased sensitivity to β-lactam antibiotics. These changes are accompanied by altered production of certain enzymes involved in cell-wall biosynthesis as revealed by proteomics studies. The growth inhibition caused by overexpression of the PknB_PASTA domain is completely abolished by enhanced concentration of magnesium ions, but not muropeptides. Finally, we show that the addition of recombinant PASTA domain could prevent regrowth of Mycobacterium tuberculosis , and therefore offers an alternative opportunity to control replication of this pathogen. These results suggest that the PknB_PASTA domain is involved in regulation of peptidoglycan biosynthesis and maintenance of cell-wall architecture.

scholarly journals Synthetic Lethality Reveals Mechanisms of Mycobacterium tuberculosis Resistance to β-Lactams

mBio ◽  
2014 ◽  
Vol 5 (5) ◽  
Author(s):  
Shichun Lun ◽  
David Miranda ◽  
Andre Kubler ◽  
Haidan Guo ◽  
Mariama C. Maiga ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Synthetic Lethality ◽  
Multidrug Resistant ◽  
Cell Wall Biosynthesis ◽  
Drug Resistant ◽  
Content Type ◽  
Innate Resistance ◽  
Extensively Drug Resistant

ABSTRACT Most β-lactam antibiotics are ineffective against Mycobacterium tuberculosis due to the microbe’s innate resistance. The emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains has prompted interest to repurpose this class of drugs. To identify the genetic determinants of innate β-lactam resistance, we carried out a synthetic lethality screen on a transposon mutant library for susceptibility to imipenem, a carbapenem β-lactam antibiotic. Mutations in 74 unique genes demonstrated synthetic lethality. The majority of mutations were in genes associated with cell wall biosynthesis. A second quantitative real-time PCR (qPCR)-based synthetic lethality screen of randomly selected mutants confirmed the role of cell wall biosynthesis in β-lactam resistance. The global transcriptional response of the bacterium to β-lactams was investigated, and changes in levels of expression of cell wall biosynthetic genes were identified. Finally, we validated these screens in vivo using the MT1616 transposon mutant, which lacks a functional acyl-transferase gene. Mice infected with the mutant responded to β-lactam treatment with a 100-fold decrease in bacillary lung burden over 4 weeks, while the numbers of organisms in the lungs of mice infected with wild-type bacilli proliferated. These findings reveal a road map of genes required for β-lactam resistance and validate synthetic lethality screening as a promising tool for repurposing existing classes of licensed, safe, well-characterized antimicrobials against tuberculosis. IMPORTANCE The global emergence of multidrug-resistant and extensively drug-resistant M. tuberculosis strains has threatened public health worldwide, yet the pipeline of new tuberculosis drugs under development remains limited. One strategy to cope with the urgent need for new antituberculosis agents is to repurpose existing, approved antibiotics. The carbapenem class of β-lactam antibiotics has been proposed as one such class of drugs. Our study identifies molecular determinants of innate resistance to β-lactam drugs in M. tuberculosis, and we demonstrate that functional loss of one of these genes enables successful treatment of M. tuberculosis with β-lactams in the mouse model.

scholarly journals InhA inhibitors have activity against non-replicating Mycobacterium tuberculosis

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0239354
Author(s):  
Lindsay Flint ◽  
Aaron Korkegian ◽  
Tanya Parish
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Nutrient Starvation ◽  
Cell Wall Biosynthesis

We previously identified a diazaborine series with potential for development as a new tuberculosis drug. This series has activity in vitro and in vivo and targets cell wall biosynthesis via inhibition of InhA. The overall aim of this study was to determine whether InhA inhibitors have activity against non-replicating Mycobacterium tuberculosis. We tested the ability of two molecules of the diazaborine series to kill non-replicating M. tuberculosis in the nutrient starvation model; both molecules were bactericidal, reducing viability by >3 logs in 21 days. Activity showed similar kill rates to other InhA inhibitors (isoniazid and NITD-916). We conclude that inhibition of InhA is bactericidal against nutrient-starved non-replicating M. tuberculosis.

Identification of inhibitors targeting Mycobacterium tuberculosis cell wall biosynthesis via dynamic combinatorial chemistry

2017 ◽  
Vol 53 (77) ◽  
pp. 10632-10635 ◽  
Author(s):  
Jian Fu ◽  
Huixiao Fu ◽  
Marc Dieu ◽  
Iman Halloum ◽  
Laurent Kremer ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Combinatorial Chemistry ◽  
Cell Wall Biosynthesis ◽  
Combinatorial Approach ◽  
Dynamic Combinatorial Chemistry ◽  
Mycobacterial Cell ◽  
Essential Enzyme ◽  
Mycobacterial Cell Wall

In this study, we report a dynamic combinatorial approach along with highly efficient in situ screening to identify inhibitors of UDP-galactopyranose mutase (UGM), an essential enzyme involved in mycobacterial cell wall biosynthesis.

scholarly journals Impact of LytR-CpsA-Psr Proteins on Cell Wall Biosynthesis in Corynebacterium glutamicum

2016 ◽  
Vol 198 (22) ◽  
pp. 3045-3059 ◽  
Author(s):  
Meike Baumgart ◽  
Karin Schubert ◽  
Marc Bramkamp ◽  
Julia Frunzke
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Corynebacterium Glutamicum ◽  
Morphological Changes ◽  
Cell Wall Biosynthesis ◽  
Special Focus ◽  
Content Type ◽  
Cell Wall Biogenesis ◽  
Exact Function ◽  
The Impact

ABSTRACT Proteins of the LCP (LytR, CpsA, Psr) family have been shown to inherit important roles in bacterial cell wall biosynthesis. However, their exact function in the formation of the complex cell wall structures of the Corynebacteriales , including the prominent pathogens Mycobacterium tuberculosis and Corynebacterium diphtheriae , remains unclear. Here, we analyzed the role of the LCP proteins LcpA and LcpB of Corynebacterium glutamicum , both of which localize at regions of nascent cell wall biosynthesis. A strain lacking lcpB did not show any growth-related or morphological phenotype under the tested conditions. In contrast, conditional silencing of the essential lcpA gene resulted in severe growth defects and drastic morphological changes. Compared to the wild-type cell wall, the cell wall of this mutant contained significantly less mycolic acids and a reduced amount of arabinogalactan. In particular, rhamnose, a specific sugar component of the linker that connects arabinogalactan and peptidoglycan, was decreased. Complementation studies of the lcpA -silencing strain with several mutated and truncated LcpA variants suggested that both periplasmic domains are essential for function whereas the cytoplasmic N-terminal part is dispensable. Successful complementation experiments with proteins of M. tuberculosis and C. diphtheriae revealed a conserved function of LCP proteins in these species. Finally, pyrophosphatase activity of LcpA was shown in an in vitro assay. Taken together, our results suggest that LCP proteins are responsible for the transfer of arabinogalactan onto peptidoglycan in actinobacterial species and support a crucial function of a so-far-uncharacterized C-terminal domain (LytR_C domain) which is frequently found at the C terminus of the LCP domain in this prokaryotic phylum. IMPORTANCE About one-third of the world's population is infected with Mycobacterium tuberculosis , and multiple-antibiotic resistance provokes the demand for novel antibiotics. The special cell wall architecture of Corynebacteriales is critical for treatments because it is either a direct target or a barrier that the drug has to cross. Here, we present the analysis of LcpA and LcpB of the closely related Corynebacterium glutamicum , the first of which is an essential protein involved in cell wall biogenesis. Our work provides a comprehensive characterization of the impact of LCP proteins on cell wall biogenesis in this medically and biotechnologically important class of bacteria. Special focus is set on the two periplasmic LcpA domains and their contributions to physiological function.

scholarly journals Inhibition of Mycobacterium tuberculosis Glutamine Synthetase as a Novel Antibiotic Strategy against Tuberculosis: Demonstration of Efficacy In Vivo

2003 ◽  
Vol 71 (1) ◽  
pp. 456-464 ◽  
Author(s):  
Günter Harth ◽  
Marcus A. Horwitz
Keyword(s):  
Weight Loss ◽  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Glutamine Synthetase ◽  
Secretory Proteins ◽  
Cell Wall Biosynthesis ◽  
Conventional Antibiotics ◽  
Guinea Pig Model ◽  
Highly Virulent

ABSTRACT Tuberculosis remains one of humankind's greatest killers, and new therapeutic strategies are needed to combat the causative agent, Mycobacterium tuberculosis, which is rapidly developing resistance to conventional antibiotics. Using the highly demanding guinea pig model of pulmonary tuberculosis, we have investigated the feasibility of inhibiting M. tuberculosis glutamine synthetase (GS), an enzyme that plays a key role in both nitrogen metabolism and cell wall biosynthesis, as a novel antibiotic strategy. In guinea pigs challenged by aerosol with the highly virulent Erdman strain of M. tuberculosis, the GS inhibitor l-methionine-SR-sulfoximine (MSO) protected the animals against weight loss, a hallmark of tuberculosis, and against the growth of M. tuberculosis in the lungs and spleen; MSO reduced the CFU of M. tuberculosis at 10 weeks after challenge by ∼0.7 log unit compared with that in control animals. MSO acted synergistically with isoniazid in protecting animals against weight loss and bacterial growth, reducing the CFU in the lungs and spleen by ∼1.5 log units below the level seen with isoniazid alone. In the presence of ascorbate, which allows treatment with a higher dose, MSO was highly efficacious, reducing the CFU in the lungs and spleen by 2.5 log units compared with that in control animals. This study demonstrates that inhibition of M. tuberculosis GS is a feasible therapeutic strategy against this pathogen and supports the concept that M. tuberculosis enzymes involved in cell wall biosynthesis, including major secretory proteins, have potential as antibiotic targets.

scholarly journals InhA inhibitors have activity against non-replicating Mycobacterium tuberculosis

2020 ◽  
Author(s):  
Lindsay Flint ◽  
Aaron Korkegian ◽  
Tanya Parish
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Nutrient Starvation ◽  
Cell Wall Biosynthesis

AbstractWe previously identified a diazaborine series with potential for development as a new tuberculosis drug. This series has activity in vitro and in vivo and targets cell wall biosynthesis via inhibition of InhA. We tested the ability of two molecules of the diazaborine series to kill non-replicating Mycobacterium tuberculosis in the nutrient starvation model; both molecules were bactericidal, reducing viability by >3 logs in 21 days. Activity was not inoculum-dependent and showed similar kill rates to other InhA inhibitors (isoniazid and NITD-916). We conclude that inhibition of InhA is bactericidal against nutrient-starved non-replicating M. tuberculosis.

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