Mycobacterial Epoxide Hydrolase EphD Is Inhibited by Urea and Thiourea Derivatives

Abstract

The genome of the human intracellular pathogen Mycobacterium tuberculosis encodes an unusually large number of epoxide hydrolases, which are thought to be involved in lipid metabolism and detoxification reactions needed to endure the hostile environment of host macrophages. These enzymes therefore represent suitable targets for compounds such as urea derivatives, which are known inhibitors of soluble epoxide hydrolases. In this work, we studied in vitro the effect of the thiourea drug isoxyl on six epoxide hydrolases of M. tuberculosis using a fatty acid substrate. We show that one of the proteins inhibited by isoxyl is EphD, an enzyme involved in the metabolism of mycolic acids, key components of the mycobacterial cell wall. By analyzing mycolic acid profiles, we demonstrate the inhibition of EphD epoxide hydrolase activity by isoxyl and two other urea-based inhibitors, thiacetazone and AU1235, inside the mycobacterial cell.

Impact of the elderly lung mucosa onMycobacterium tuberculosismetabolic adaptation during infection of alveolar epithelial cells

“…In addition, epoxide hydrolases, sigma factors, and WhiB proteins are all characterized as additional M.tb detoxifying strategies to withstand adverse conditions (51–53). Our findings indicate that during infection E-ALF-exposed M.tb downregulates some epoxide hydrolases genes ( ephA , ephB, and ephC ) ( Fig.…”

Uncovering the Roles ofMycobacterium tuberculosis melHin Redox and Bioenergetic Homeostasis: Implications for Antitubercular Therapy

“…Because electron transfer reactions are the main function of NAD (20), we next determined whether the lower intracellular NAD + and NADH levels in the mutant might be due to increased proton conductance and resulting membrane depolarization, as seen with classical uncouplers. We used the fluorescent dye 3,3′-diethyloxacarbocyanine iodide (3) to measure the membrane potential of Mm cells. Δ melH showed no changes in membrane potential compared to WT under the tested carbon source conditions, although, as expected, the membrane uncoupler carbonyl cyanide m -chlorophenyl hydrazone (CCCP) did reduce the membrane potential compared to untreated mycobacteria (Figure 4B).…”

“…The Mtb H37Rv strain has at least six potential epoxide hydrolases (EHs), which belong to the virulence, detoxification, and adaptation functional category (3). EHs convert epoxides to trans -dihydrodiols and play a role in detoxification of xenobiotics and biotransformation of endogenous epoxides, and in signaling-molecule regulation (4).…”

EphH, a unique epoxide hydrolase encoded by Rv3338 is involved in the survival of Mycobacterium tuberculosis under in vitro stress and vacuolar pH-induced changes

“…Another EH, EphD, is involved in the processing of epoxy mycolates. Overproduction of EphD leads to an accumulation of mycolic acids and a concomitant decrease in epoxy mycolates ( El-Etr et al, 2004 ; Madacki et al, 2021 ). EphG is known to be involved in detoxification following oxidative damage to lipids ( Madacki et al, 2021 ).…”

“…Overproduction of EphD leads to an accumulation of mycolic acids and a concomitant decrease in epoxy mycolates ( El-Etr et al, 2004 ; Madacki et al, 2021 ). EphG is known to be involved in detoxification following oxidative damage to lipids ( Madacki et al, 2021 ). Studies conducted with MesT showed it is essential for the optimal growth of Mtb in the presence of styrene oxide ( Chownk et al, 2017 ).…”