Dataset Information

Lipoamide channel-binding sulfonamides selectively inhibit mycobacterial lipoamide dehydrogenase.

ABSTRACT: Tuberculosis remains a global health emergency that calls for treatment regimens directed at new targets. Here we explored lipoamide dehydrogenase (Lpd), a metabolic and detoxifying enzyme in Mycobacterium tuberculosis (Mtb) whose deletion drastically impairs Mtb's ability to establish infection in the mouse. Upon screening more than 1.6 million compounds, we identified N-methylpyridine 3-sulfonamides as potent and species-selective inhibitors of Mtb Lpd affording >1000-fold selectivity versus the human homologue. The sulfonamides demonstrated low nanomolar affinity and bound at the lipoamide channel in an Lpd-inhibitor cocrystal. Their selectivity could be attributed, at least partially, to hydrogen bonding of the sulfonamide amide oxygen with the species variant Arg93 in the lipoamide channel. Although potent and selective, the sulfonamides did not enter mycobacteria, as determined by their inability to accumulate in Mtb to effective levels or to produce changes in intracellular metabolites. This work demonstrates that high potency and selectivity can be achieved at the lipoamide-binding site of Mtb Lpd, a site different from the NAD?/NADH pocket targeted by previously reported species-selective triazaspirodimethoxybenzoyl inhibitors.

SUBMITTER: Bryk R

PROVIDER: S-EPMC3894633 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Lipoamide channel-binding sulfonamides selectively inhibit mycobacterial lipoamide dehydrogenase.

Bryk Ruslana R Arango Nancy N Maksymiuk Christina C Balakrishnan Anand A Wu Ying-Ta YT Wong Chi-Huey CH Masquelin Thierry T Hipskind Philip P Lima Christopher D CD Nathan Carl C

Biochemistry 20131126 51

Tuberculosis remains a global health emergency that calls for treatment regimens directed at new targets. Here we explored lipoamide dehydrogenase (Lpd), a metabolic and detoxifying enzyme in Mycobacterium tuberculosis (Mtb) whose deletion drastically impairs Mtb's ability to establish infection in the mouse. Upon screening more than 1.6 million compounds, we identified N-methylpyridine 3-sulfonamides as potent and species-selective inhibitors of Mtb Lpd affording >1000-fold selectivity versus t ...[more]

PMID: 24251446

Similar Datasets

Project description:BackgroundMost normal cells in the presence of oxygen utilize glucose for mitochondrial oxidative phosphorylation. In contrast, many cancer cells rapidly convert glucose to lactate in the cytosol, a process termed aerobic glycolysis. This glycolytic phenotype is enabled by lactate dehydrogenase (LDH), which catalyzes the inter-conversion of pyruvate and lactate. The purpose of this study was to identify and characterize potent and selective inhibitors of LDHA.MethodsHigh throughput screening and lead optimization were used to generate inhibitors of LDHA enzymatic activity. Effects of these inhibitors on metabolism were evaluated using cell-based lactate production, oxygen consumption, and 13C NMR spectroscopy assays. Changes in comprehensive metabolic profile, cell proliferation, and apoptosis were assessed upon compound treatment.Results3-((3-carbamoyl-7-(3,5-dimethylisoxazol-4-yl)-6-methoxyquinolin-4-yl) amino) benzoic acid was identified as an NADH-competitive LDHA inhibitor. Lead optimization yielded molecules with LDHA inhibitory potencies as low as 2 nM and 10 to 80-fold selectivity over LDHB. Molecules in this family rapidly and profoundly inhibited lactate production rates in multiple cancer cell lines including hepatocellular and breast carcinomas. Consistent with selective inhibition of LDHA, the most sensitive breast cancer cell lines to lactate inhibition in hypoxic conditions were cells with low expression of LDHB. Our inhibitors increased rates of oxygen consumption in hepatocellular carcinoma cells at doses up to 3 microM, while higher concentrations directly inhibited mitochondrial function. Analysis of more than 500 metabolites upon LDHA inhibition in Snu398 cells revealed that intracellular concentrations of glycolysis and citric acid cycle intermediates were increased, consistent with enhanced Krebs cycle activity and blockage of cytosolic glycolysis. Treatment with these compounds also potentiated PKM2 activity and promoted apoptosis in Snu398 cells.ConclusionsRapid chemical inhibition of LDHA by these quinoline 3-sulfonamids led to profound metabolic alterations and impaired cell survival in carcinoma cells making it a compelling strategy for treating solid tumors that rely on aerobic glycolysis for survival.

Project description:The erythropoietin-producing hepatocellular (Eph) family of receptor tyrosine kinases regulates a multitude of physiological and pathological processes. Despite the numerous possible research and therapeutic applications of agents capable of modulating Eph receptor function, no small molecule inhibitors targeting the extracellular domain of these receptors have been identified. We have performed a high throughput screen to search for small molecules that inhibit ligand binding to the extracellular domain of the EphA4 receptor. This yielded a 2,5-dimethylpyrrolyl benzoic acid derivative able to inhibit the interaction of EphA4 with a peptide ligand as well as the natural ephrin ligands. Evaluation of a series of analogs identified an isomer with similar inhibitory properties and other less potent compounds. The two isomeric compounds act as competitive inhibitors, suggesting that they target the high affinity ligand-binding pocket of EphA4 and inhibit ephrin-A5 binding to EphA4 with K(i) values of 7 and 9 mum in enzyme-linked immunosorbent assays. Interestingly, despite the ability of each ephrin ligand to promiscuously bind many Eph receptors, the two compounds selectively target EphA4 and the closely related EphA2 receptor. The compounds also inhibit ephrin-induced phosphorylation of EphA4 and EphA2 in cells, without affecting cell viability or the phosphorylation of other receptor tyrosine kinases. Furthermore, the compounds inhibit EphA4-mediated growth cone collapse in retinal explants and EphA2-dependent retraction of the cell periphery in prostate cancer cells. These data demonstrate that the Eph receptor-ephrin interface can be targeted by inhibitory small molecules and suggest that the two compounds identified will be useful to discriminate the activities of EphA4 and EphA2 from those of other co-expressed Eph receptors that are activated by the same ephrin ligands. Furthermore, the newly identified inhibitors represent possible leads for the development of therapies to treat pathologies in which EphA4 and EphA2 are involved, including nerve injuries and cancer.

Dataset Information

Lipoamide channel-binding sulfonamides selectively inhibit mycobacterial lipoamide dehydrogenase.

Publications

Lipoamide channel-binding sulfonamides selectively inhibit mycobacterial lipoamide dehydrogenase.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets