Identification of potent and reversible piperidine carboxamides that are species-selective orally active proteasome inhibitors to treat malaria.
Lawong, A., Gahalawat, S., Ray, S., Ho, N., Han, Y., Ward, K.E., Deng, X., Chen, Z., Kumar, A., Xing, C., Hosangadi, V., Fairhurst, K.J., Tashiro, K., Liszczak, G., Shackleford, D.M., Katneni, K., Chen, G., Saunders, J., Crighton, E., Casas, A., Robinson, J.J., Imlay, L.S., Zhang, X., Lemoff, A., Zhao, Z., Angulo-Barturen, I., Jimenez-Diaz, M.B., Wittlin, S., Campbell, S.F., Fidock, D.A., Laleu, B., Charman, S.A., Ready, J.M., Phillips, M.A.(2024) Cell Chem Biol 31: 1503
- PubMed: 39084225 
- DOI: https://doi.org/10.1016/j.chembiol.2024.07.001
- Primary Citation of Related Structures:  
8W2F - PubMed Abstract: 
Malaria remains a global health concern as drug resistance threatens treatment programs. We identified a piperidine carboxamide (SW042) with anti-malarial activity by phenotypic screening. Selection of SW042-resistant Plasmodium falciparum (Pf) parasites revealed point mutations in the Pf_proteasome β5 active-site (Pfβ5). A potent analog (SW584) showed efficacy in a mouse model of human malaria after oral dosing. SW584 had a low propensity to generate resistance (minimum inoculum for resistance [MIR] >10 9 ) and was synergistic with dihydroartemisinin. Pf_proteasome purification was facilitated by His 8 -tag introduction onto β7. Inhibition of Pfβ5 correlated with parasite killing, without inhibiting human proteasome isoforms or showing cytotoxicity. The Pf_proteasome_SW584 cryoelectron microscopy (cryo-EM) structure showed that SW584 bound non-covalently distal from the catalytic threonine, in an unexplored pocket at the β5/β6/β3 subunit interface that has species differences between Pf and human proteasomes. Identification of a reversible, species selective, orally active series with low resistance propensity provides a path for drugging this essential target.
Organizational Affiliation: 
Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA.