Design, Synthesis, and Application of Fluorescent Ligands Targeting the Intracellular Allosteric Binding Site of the CXC Chemokine Receptor 2

Casella, Bianca Maria; Farmer, James P.; Nesheva, Desislava N.; Williams, Huw E.L.; Charlton, Steven J.; Holliday, Nicholas D.; Laughton, Charles A.; Mistry, Shailesh N.

Abstract

The inhibition of CXC chemokine receptor 2 (CXCR2), a key inflammatory mediator, is a potential strategy in the treatment of several pulmonary diseases and cancers. The complexity of endogenous chemokine interaction with the orthosteric binding site has led to the development of CXCR2 negative allosteric modulators (NAMs) targeting an intracellular pocket near the G protein binding site. Our understanding of NAM binding and mode of action has been limited by the availability of suitable tracer ligands for competition studies, allowing direct ligand binding measurements. Here, we report the rational design, synthesis, and pharmacological evaluation of a series of fluorescent NAMs, based on navarixin (2), which display high affinity and preferential binding for CXCR2 over CXCR1. We demonstrate their application in fluorescence imaging and NanoBRET binding assays, in whole cells or membranes, capable of kinetic and equilibrium analysis of NAM binding, providing a platform to screen for alternative chemophores targeting these receptors.

• Journal Article Type: Article
• Acceptance Date: Jul 20, 2023
• Online Publication Date: Jul 31, 2023
• Publication Date: Jul 31, 2023
• Deposit Date: Aug 1, 2023
• Publicly Available Date: Aug 1, 2023
• Journal: Journal of Medicinal Chemistry
• Print ISSN: 0022-2623
• Electronic ISSN: 1520-4804
• Publisher: American Chemical Society (ACS)
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1021/acs.jmedchem.3c00849
• Keywords: Drug Discovery; Molecular Medicine
• Public URL: https://nottingham-repository.worktribe.com/output/23646999
• Publisher URL: https://pubs.acs.org/doi/10.1021/acs.jmedchem.3c00849