Understanding Biased Signaling and Small-Molecule Binding for Treatment of Type 2 Diabetes Mellitus and Obesity at the Glucagon-Like Peptide-1 Receptor (GLP-1R) Based on Molecular Dynamics Simulations.

Glucagon-like peptide-1 receptor (GLP-1R) is a class B1 G protein-coupled receptor expressed in multiple tissues and is a major therapeutic target for type 2 diabetes mellitus and obesity. Here, we investigate the mechanisms of GLP-1R binding and activation using molecular dynamics (MD) simulations of semaglutide, tirzepatide, danuglipron, and CHU-128bound GLP-1R-Gs complexes. We analyze these simulations as a function of temperature, ligand class (peptide vs. small molecule), and signaling profile (biased vs. non-biased) to assess how these factors affect GLP-1R interactions and conformational dynamics. Our results reveal distinct interaction patterns and structural features associated with each factor which persist over the MD trajectories. Together, these findings deepen our mechanistic understanding of GLP-1R agonism and further aid in the design of effective, orally available GLP-1R agonists with reduced side effects.