Structure-guided development of selective caseinolytic protease P agonists as antistaphylococcal agents.

Methicillin-resistant Staphylococcus aureus is a ubiquitous pathogen, posing a serious threat to human health worldwide. Thus, there is a high demand for antibiotics with distinct targets. Caseinolytic protease P (ClpP) is a promising target for combating staphylococcal infections; however, selectively activating S. aureus ClpP (SaClpP) rather than Homo sapiens ClpP (HsClpP) remains challenging. Herein, we rationally design and identify ZG297 by structure-based strategy. It binds and activates SaClpP instead of HsClpP. This is due to differentiated ligand binding attributed to crossed "tyrosine/histidine" amino acid pairs. ZG297 substantially inhibits the growth of a broad panel of S. aureus strains in vitro, outperforming the selective (R)-ZG197 agonist. ZG297 also functions as a potent antibiotic against multidrug-resistant S. aureus infections in Galleria mellonella larvae, zebrafish, murine skin, and thigh infection models. Collectively, we demonstrate that ZG297 is a safer and more potent antistaphylococcal agent than acyldepsipeptide 4 and (R)-ZG197.