The isocitrate lyases (ICL1/2) are essential enzymes of (), the causative agent of tuberculosis. At present, no ICL1/2 inhibitors have progressed to clinical evaluation, despite extensive drug discovery efforts. Herein, we surveyed succinate analogs against ICL1 and found that dicarboxylic acids constrained in their conformations, such as maleic acid, comprise uncompetitive inhibitors of ICL1 and inhibit more potently than their -isomers. From this, we identified -2,3 epoxysuccinic acid (-EpS) as a selective, irreversible covalent inactivator of ICL1 (/= (5.0 ± 1.4) × 10 M s; = 200 ± 50 nM), the most potent inactivator of ICL1 yet characterized. Crystallographic and mass spectrometric analysis demonstrated that Cys of ICL1 was S-malylated by -EpS, and a crystallographic "snapshot" of inactivation lent insight into the chemical mechanism of this inactivation. Proteomic analysis of lysates showed that -EpS selectively labeled plasmid-expressed ICL1. Consistently, -EpS, but not its -isomer, inhibited the growth of under conditions in which ICL function is essential. These findings encourage the development of analogs of -2,3-epoxysuccinate as antituberculosis agents.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acschembio.0c00740 | DOI Listing |
J Am Chem Soc
October 2021
The Ferrier Research Institute, Victoria University of Wellington, Wellington 5046, New Zealand.
The isocitrate lyase paralogs of (ICL1 and 2) are essential for mycobacterial persistence and constitute targets for the development of antituberculosis agents. We report that (2,3)-2-hydroxy-3-(nitromethyl)succinic acid (5-NIC) undergoes apparent retro-aldol cleavage as catalyzed by ICL1 to produce glyoxylate and 3-nitropropionic acid (3-NP), the latter of which is a covalent-inactivating agent of ICL1. Kinetic analysis of this reaction identified that 5-NIC serves as a robust and efficient mechanism-based inactivator of ICL1 (/ = (1.
View Article and Find Full Text PDFACS Chem Biol
March 2021
Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States.
The isocitrate lyases (ICL1/2) are essential enzymes of (), the causative agent of tuberculosis. At present, no ICL1/2 inhibitors have progressed to clinical evaluation, despite extensive drug discovery efforts. Herein, we surveyed succinate analogs against ICL1 and found that dicarboxylic acids constrained in their conformations, such as maleic acid, comprise uncompetitive inhibitors of ICL1 and inhibit more potently than their -isomers.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 2017
Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843;
Isocitrate lyase (ICL, types 1 and 2) is the first enzyme of the glyoxylate shunt, an essential pathway for () during the persistent phase of human TB infection. Here, we report 2-vinyl-d-isocitrate (2-VIC) as a mechanism-based inactivator of ICL1 and ICL2. The enzyme-catalyzed retro-aldol cleavage of 2-VIC unmasks a Michael substrate, 2-vinylglyoxylate, which then forms a slowly reversible, covalent adduct with the thiolate form of active-site Cys 2-VIC displayed kinetic properties consistent with covalent, mechanism-based inactivation of ICL1 and ICL2 with high efficiency (partition ratio, <1).
View Article and Find Full Text PDFJundishapur J Microbiol
September 2016
Infectomics Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Malaysia.
Background: A major characteristic of biofilm cells that differentiates them from free-floating cells is their high tolerance to antifungal drugs. This high resistance is attributed to particular biofilm properties, including the accumulation of extrapolymeric substances, morphogenetic switching, and metabolic flexibility.
Objectives: This study evaluated the roles of metabolic processes (in particular the glyoxylate cycle) on biofilm formation, antifungal drug resistance, morphology, and cell wall components.
mBio
December 2012
School of Medical Sciences, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom.
Microbes must assimilate carbon to grow and colonize their niches. Transcript profiling has suggested that Candida albicans, a major pathogen of humans, regulates its carbon assimilation in an analogous fashion to the model yeast Saccharomyces cerevisiae, repressing metabolic pathways required for the use of alterative nonpreferred carbon sources when sugars are available. However, we show that there is significant dislocation between the proteome and transcriptome in C.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!