High Throughput Screening to Identify Selective and Nonpeptidomimetic Proteasome Inhibitors As Antimalarials.

Area of Science:

• Biochemistry
• Parasitology
• Drug Discovery

Background:

• The Ubiquitin Proteasome System is crucial for cellular processes in eukaryotes.
• The Plasmodium falciparum proteasome is a validated antimalarial target, necessitating selective inhibitors to minimize human cytotoxicity.
• Developing selective inhibitors is key for effective antimalarial drug discovery.

Purpose of the Study:

• To identify selective inhibitors of the Plasmodium falciparum proteasome.
• To discover novel chemical scaffolds with antimalarial potential.
• To validate target engagement and assess parasite growth inhibition.

Main Methods:

• High-throughput screening of approximately 550000 compounds using a Proteasome-GLO luminescence assay.
• Orthogonal confirmation of hits using Rho110-labeled peptide assays.
• Selectivity assessment against human proteasome and characterization in parasite growth inhibition assays.

Main Results:

• Identification of four distinct nonpeptidomimetic chemical families exhibiting selectivity for the P. falciparum proteasome.
• Characterization of identified hits against chymotrypsin-like, trypsin, and caspase proteasome activities.
• Validation of target engagement and demonstration of parasite growth inhibition by selected compounds.

Conclusions:

• The identified compounds represent promising starting points for developing new antimalarial drugs.
• These compounds can serve as valuable tools for further research into Plasmodium falciparum proteasome function.
• The study validates a screening approach for discovering selective proteasome inhibitors with therapeutic potential.