A Chemical Biology Toolbox Targeting the Intracellular Binding Site of CCR9: Fluorescent Ligands, New Drug Leads and PROTACs. Issue 12 (27th January 2022)

• Record Type: Journal Article
• Authors: Huber, Max E.; Toy, Lara; Schmidt, Maximilian F.; Vogt, Hannah; Budzinski, Julian; Wiefhoff, Martin F. J.; Merten, Nicole; Kostenis, Evi; Weikert, Dorothee; Schiedel, Matthias
• Is Part Of: Angewandte Chemie international edition. Volume 61:Issue 12(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-01-27
• Subjects: CCR9 -- Drug Design -- Fluorescent Probes -- PROTAC -- Receptors; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202116782
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: A conserved intracellular allosteric binding site (IABS) has recently been identified at several G protein‐coupled receptors (GPCRs). Starting from vercirnon, an intracellular C−C chemokine receptor type 9 (CCR9) antagonist and previous phase III clinical candidate for the treatment of Crohn's disease, we developed a chemical biology toolbox targeting the IABS of CCR9. We first synthesized a fluorescent ligand enabling equilibrium and kinetic binding studies via NanoBRET as well as fluorescence microscopy. Applying this molecular tool in a membrane‐based setup and in living cells, we discovered a 4‐aminopyrimidine analogue as a new intracellular CCR9 antagonist with improved affinity. To chemically induce CCR9 degradation, we then developed the first PROTAC targeting the IABS of GPCRs. In a proof‐of‐principle study, we succeeded in showing that our CCR9‐PROTAC is able to reduce CCR9 levels, thereby offering an unprecedented approach to modulate GPCR activity. Abstract : Based on the intracellular CCR9 antagonist vercirnon, we developed the first small‐molecule‐based fluorescent ligand targeting the intracellular allosteric binding site (IABS) of a GPCR. This tool enabled binding studies via NanoBRET, fluorescence microscopy, and the discovery of a new intracellular CCR9 antagonist with improved affinity. To induce CCR9 degradation, we developed the first PROTAC targeting the IABS of GPCRs.