The proteasome as a target for protozoan parasites

04 Nov 2019

Stanley C. Xie, Lawrence R. Dick, Alexandra Gould, Stephen Brand, Leann Tilley

Expert Opinion on Therapeutic Targets

Doi: 10.1080/14728222.2019.1685981

Photo: Freedom Studio/



The proteasome is a multi-subunit enzyme complex responsible for the turnover of shortlived, abnormal or damaged proteins in eukaryotic cells. As organisms that undergo rapid growth and cell division, protozoan parasites exist on the knife-edge of proteotoxic catastrophe and thus rely heavily on their protein quality control machinery for survival. Because of this, the proteasome has recently emerged as a desirable drug target.


This review focuses on efforts to identify protozoan parasite-specific proteasome inhibitors using substrate profiling, library screening, and in vitro evolution of resistance approaches to inform medicinal chemistry. Targeting the parasite’s 20S proteasome chymotrypsin-like (β5) activity and selectively inhibiting protein turnover in parasites compared to human cells are critical properties of potent, selective inhibitors.


Proteasome inhibitors have the potential for rapid action against all stages, all species and all strains of plasmodium and kinetoplastid parasites. Given the high level of conservation of proteasome active sites in eukaryotes, an important challenge is achieving inhibitors that show sufficient selectivity while maintaining properties consistent with drug development.

Read the full article on Taylor & Francis Online