Design and synthesis of novel cell wall inhibitors of Mycobacterium tuberculosis GlmM and GlmU

Li, Yongmeng; Zhou, Yan; Ma, Yufang; Li, Xuebing

doi:10.1016/j.carres.2011.05.024

Cited by 45 publications

(36 citation statements)

References 27 publications

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“…Bioinformatic analyses and kinetic modelling data advocate GlmU Mtb to be a potential target for the development of suitable inhibitors [ 31 ]. In concurrence with these predictions, effective inhibitors have been developed against, the acetyltransferase and uridyltransferase domains of GlmU Mtb [ 32 , 33 ]. However, the precise sites of inhibitor-protein interactions and the efficacy of the inhibitors ex vivo or in vivo have not been investigated.…”

Section: Introductionmentioning

confidence: 99%

Depletion of M. tuberculosis GlmU from Infected Murine Lungs Effects the Clearance of the Pathogen

et al. 2015

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M. tuberculosis N-acetyl-glucosamine-1-phosphate uridyltransferase (GlmUMtb) is a bi-functional enzyme engaged in the synthesis of two metabolic intermediates N-acetylglucosamine-1-phosphate (GlcNAc-1-P) and UDP-GlcNAc, catalyzed by the C- and N-terminal domains respectively. UDP-GlcNAc is a key metabolite essential for the synthesis of peptidoglycan, disaccharide linker, arabinogalactan and mycothiols. While glmU Mtb was predicted to be an essential gene, till date the role of GlmUMtb in modulating the in vitro growth of Mtb or its role in survival of pathogen ex vivo / in vivo have not been deciphered. Here we present the results of a comprehensive study dissecting the role of GlmUMtb in arbitrating the survival of the pathogen both in vitro and in vivo. We find that absence of GlmUMtb leads to extensive perturbation of bacterial morphology and substantial reduction in cell wall thickness under normoxic as well as hypoxic conditions. Complementation studies show that the acetyl- and uridyl- transferase activities of GlmUMtb are independently essential for bacterial survival in vitro, and GlmUMtb is also found to be essential for mycobacterial survival in THP-1 cells as well as in guinea pigs. Depletion of GlmUMtb from infected murine lungs, four weeks post infection, led to significant reduction in the bacillary load. The administration of Oxa33, a novel oxazolidine derivative that specifically inhibits GlmUMtb, to infected mice resulted in significant decrease in the bacillary load. Thus our study establishes GlmUMtb as a strong candidate for intervention measures against established tuberculosis infections.

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Section: Introductionmentioning

confidence: 99%

Depletion of M. tuberculosis GlmU from Infected Murine Lungs Effects the Clearance of the Pathogen

et al. 2015

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“…GlmM is a mutase enzyme that converts Dglucosamine-1-phosphate to D-glucosamine-6-phosphate and has been shown to be an essential gene in M. smegmatis (Li et al 2012). Indeed, the conversion of D-glucosamine-6-phosphate to Dglucosamine-1-phosphate is unique to prokaryotes and is considered a potential drug target (Li et al 2011). GlmU is a bifunctional enzyme that carries out both acetylation and uridylation reactions, ultimately forming UDP-GlcNAc (Jagtap et al 2012(Jagtap et al , 2013.…”

Section: Cytoplasmic Steps Of Peptidoglycan Intermediate Metabolismmentioning

confidence: 99%

The Mycobacterial Cell Wall—Peptidoglycan and Arabinogalactan

Alderwick

Harrison

Lloyd

et al. 2015

Cold Spring Harb Perspect Med

190

156

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The mycobacterial bacillus is encompassed by a remarkably elaborate cell wall structure. The mycolyl-arabinogalactan-peptidoglycan (mAGP) complex is essential for the viability of Mycobacterium tuberculosis and maintains a robust basal structure supporting the upper "myco-membrane." M. tuberculosis peptidoglycan, although appearing to be unexceptional at first glance, contains a number of unique molecular subtleties that become particularly important as the TB-bacilli enters into nonreplicative growth during dormancy. Arabinogalactan, a highly branched polysaccharide, serves to connect peptidoglycan with the outer mycolic acid layer, and a variety of unique glycolsyltransferases are used for its assembly. In this review, we shall explore the microbial chemistry of this unique heteropolysacchride, examine the molecular genetics that underpins its fabrication, and discuss how the essential biosynthetic process might be exploited for the development of future anti-TB chemotherapies. THE MYCOBACTERIAL CELL WALL-PEPTIDOGLYCAN AND ARABINOGALACTAN

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“…the allosteric binding site should be exploited using structure-based approaches so as to design the desired uncompetitive inhibitors. In a more recent study performed on Mtu , an analogue of GlcN1P was found to be an uncompetitive (against E-GlcN1P complex) inhibitor of GlmU rxn-1 albeit with a poor Ki value (18.69mM) [33].…”

Section: Resultsmentioning

confidence: 96%

Kinetic Modelling of GlmU Reactions – Prioritization of Reaction for Therapeutic Application

2012

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Mycobacterium tuberculosis(Mtu), a successful pathogen, has developed resistance against the existing anti-tubercular drugs necessitating discovery of drugs with novel action. Enzymes involved in peptidoglycan biosynthesis are attractive targets for antibacterial drug discovery. The bifunctional enzyme mycobacterial GlmU (Glucosamine 1-phosphate N-acetyltransferase/ N-acetylglucosamine-1-phosphate uridyltransferase) has been a target enzyme for drug discovery. Its C- and N- terminal domains catalyze acetyltransferase (rxn-1) and uridyltransferase (rxn-2) activities respectively and the final product is involved in peptidoglycan synthesis. However, the bifunctional nature of GlmU poses difficulty in deciding which function to be intervened for therapeutic advantage. Genetic analysis showed this as an essential gene but it is still unclear whether any one or both of the activities are critical for cell survival. Often enzymatic activity with suitable high-throughput assay is chosen for random screening, which may not be the appropriate biological function inhibited for maximal effect. Prediction of rate-limiting function by dynamic network analysis of reactions could be an option to identify the appropriate function. With a view to provide insights into biochemical assays with appropriate activity for inhibitor screening, kinetic modelling studies on GlmU were undertaken. Kinetic model of Mtu GlmU-catalyzed reactions was built based on the available kinetic data on Mtu and deduction from Escherichia coli data. Several model variants were constructed including coupled/decoupled, varying metabolite concentrations and presence/absence of product inhibitions. This study demonstrates that in coupled model at low metabolite concentrations, inhibition of either of the GlmU reactions cause significant decrement in the overall GlmU rate. However at higher metabolite concentrations, rxn-2 showed higher decrement. Moreover, with available intracellular concentration of the metabolites and in vivo variant of model, uncompetitive inhibition of rxn-2 caused highest decrement. Thus, at physiologically relevant metabolite concentrations, targeting uridyltranferase activity of Mtu GlmU would be a better choice for therapeutic intervention.

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Design and synthesis of novel cell wall inhibitors of Mycobacterium tuberculosis GlmM and GlmU

Cited by 45 publications

References 27 publications

Depletion of M. tuberculosis GlmU from Infected Murine Lungs Effects the Clearance of the Pathogen

Depletion of M. tuberculosis GlmU from Infected Murine Lungs Effects the Clearance of the Pathogen

The Mycobacterial Cell Wall—Peptidoglycan and Arabinogalactan

Kinetic Modelling of GlmU Reactions – Prioritization of Reaction for Therapeutic Application

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