Mechanism-Based Inactivation of Mycobacterium tuberculosis Isocitrate Lyase 1 by (2R,3S)-2-Hydroxy-3-(nitromethyl)succinic acid.
J Am Chem Soc
; 143(42): 17666-17676, 2021 10 27.
Article
in En
| MEDLINE
| ID: mdl-34664502
ABSTRACT
The isocitrate lyase paralogs of Mycobacterium tuberculosis (ICL1 and 2) are essential for mycobacterial persistence and constitute targets for the development of antituberculosis agents. We report that (2R,3S)-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 (kinact/KI = (1.3 ± 0.1) × 103 M-1 s-1) with a partition ratio <1. Using enzyme kinetics, mass spectrometry, and X-ray crystallography, we identified that the reaction of the 5-NIC-derived 3-NP with the Cys191 thiolate of ICL1 results in formation of an ICL1-thiohydroxamate adduct as predicted. One aspect of the design of 5-NIC was to lower its overall charge compared to isocitrate to assist with cell permeability. Accordingly, the absence of the third carboxylate group will simplify the synthesis of pro-drug forms of 5-NIC for characterization in cell-infection models of M. tuberculosis.
Full text:
1
Database:
MEDLINE
Main subject:
Succinates
/
Enzyme Inhibitors
/
Isocitrate Lyase
/
Mycobacterium tuberculosis
Type of study:
Prognostic_studies
Language:
En
Year:
2021
Type:
Article