Inhibitors selective for mycobacterial versus human proteasomes

Area of Science:

• Biochemistry
• Microbiology
• Drug Discovery

Background:

• Most anti-infectives target bacterial protein synthesis or kill replicating pathogens.
• Few drugs target bacterial protein degradation or non-replicating pathogens.
• Selective proteasome inhibitors are needed for novel anti-infective strategies.

Purpose of the Study:

• To identify selective inhibitors of the Mycobacterium tuberculosis proteasome.
• To explore alternative anti-infective approaches targeting protein degradation.

Main Methods:

• Screening of oxathiazol-2-one compounds for proteasome inhibition.
• Investigating the mechanism of inhibition of the M. tuberculosis proteasome.
• Comparing the potency of inhibitors against M. tuberculosis and human proteasomes.

Main Results:

• Certain oxathiazol-2-one compounds selectively inhibit the M. tuberculosis proteasome.
• These compounds act as suicide-substrate inhibitors, irreversibly blocking the proteasome.
• Inhibitor potency is linked to non-conserved residues outside the M. tuberculosis proteasome active site, sparing the human homologue.

Conclusions:

• Oxathiazol-2-one compounds represent a promising new class of anti-tubercular agents.
• Selective proteasome inhibition offers a viable strategy against non-replicating Mycobacterium tuberculosis.
• Targeting conserved yet non-conserved regions of essential enzymes can yield selective therapeutics.