Molecular Dynamics Reveals Distinct GLP-1R Binding and Activation Mechanisms for Semaglutide, Tirzepatide, Danuglipron, and CHU-128

The glucagon-like peptide-1 receptor (GLP-1R) is a critical class B1 G protein-coupled receptor (GPCR) and a primary therapeutic target for Type 2 Diabetes Mellitus and obesity. Current treatments, while effective, often face challenges with oral bioavailability and side effects. Understanding the precise molecular mechanisms of GLP-1R binding and activation by different agonists, especially small molecules, is crucial for designing novel, orally available compounds with improved efficacy and tolerability. This study addresses the gap in detailed mechanistic insight into how various ligand classes and signaling profiles influence GLP-1R conformational dynamics.

Researchers employed molecular dynamics (MD) simulations to investigate the mechanisms of GLP-1R binding and activation. The study modeled GLP-1R-Gs complexes bound to four distinct agonists: the peptide-based semaglutide and tirzepatide, and the small-molecule danuglipron and CHU-128. Simulations analyzed these complexes across varying conditions, specifically examining the influence of temperature, ligand class (peptide vs. small molecule), and signaling profile (biased vs. non-biased agonism). The primary endpoint was to assess how these factors affect GLP-1R interactions and conformational dynamics, providing a detailed computational model of receptor activation.