Abstract
The
enzymes isocitrate lyase (ICL) isoforms 1 and 2 are essential for
Mycobacterium tuberculosis survival
within macrophages during latent tuberculosis (TB).
1 As such; ICLs
are attractive therapeutic targets for the treatment of tuberculosis. However,
there are few biophysical assays that are available for accurate kinetic and
inhibition studies of ICL
in vitro. Here
we report the development of a combined NMR spectroscopy and thermal shift
assay to study ICL inhibitors for both screening and inhibition constant (IC
50)
measurement. Operating this new assay in tandem with virtual high-throughput
screening has led to the discovery of several new ICL1 inhibitors.
2
Furthermore, the crystal structure of the ICL2 isoform is reported, which has
been poorly understood until now. It is shown that ICL2 plays a pivotal role
regulating carbon flux between the TCA, glyoxylate and methylcitrate cycles at
high lipid concentrations, a mechanism essential for bacterial growth and
virulence.
3 1. Bhusal, R. P. et al. Drug Discov. Today 2017,
22, 1008–1016.
2. Bhusal, R. P.
et al. Med. Chem. Commun. 2017, 8, 2155–2163.
3. Bhusal, R. P.
et al. Nature Commun. 2019, 10,
4639.
