Fragment-Based Development of Small Molecule Inhibitors Targeting Mycobacterium tuberculosis Cholesterol Metabolism

Area of Science:

• Medicinal Chemistry
• Microbiology
• Drug Discovery

Background:

• Tuberculosis remains a leading infectious killer, necessitating new treatments against multidrug-resistant strains.
• Mycobacterium tuberculosis (Mtb) relies on host cholesterol for survival, presenting a potential therapeutic target.
• CYP125 and CYP142 enzymes are critical for Mtb's cholesterol metabolism pathway.

Purpose of the Study:

• To develop a novel class of antitubercular compounds targeting Mtb CYP125 and CYP142.
• To identify and optimize inhibitors of Mtb cholesterol metabolism for potential new tuberculosis therapies.

Main Methods:

• Employed fragment screening and structure-based drug design to identify lead compounds.
• Synthetically optimized a dual CYP125/142 ligand, designated compound 5m.
• Assessed enzyme inhibition in vitro and antimycobacterial activity in extracellular and intracellular assays.

Main Results:

• Identified compound 5m as a potent dual inhibitor of Mtb CYP125 and CYP142 (K_D 40-160 nM, K_I < 100 nM).
• Compound 5m demonstrated significant inhibition of Mtb growth in vitro (MIC_99 0.4-1.5 μM) and intracellular assays (IC_50 1.7 μM).
• Structural data and lead compounds provide a foundation for further research into Mtb cholesterol metabolism.

Conclusions:

• Novel antitubercular compounds targeting Mtb cholesterol metabolism have been successfully developed.
• Compound 5m shows promising potency against multidrug-resistant Mtb strains.
• This research offers a new avenue for developing urgently needed antibiotics against tuberculosis.