Cryo-EM structure of the dual incretin receptor agonist, peptide-19, in complex with the glucagon-like peptide-1 receptor.
Johnson, R.M., Zhang, X., Piper, S.J., Nettleton, T.J., Vandekolk, T.H., Langmead, C.J., Danev, R., Sexton, P.M., Wootten, D.(2021) Biochem Biophys Res Commun 578: 84-90
- PubMed: 34547628 
- DOI: https://doi.org/10.1016/j.bbrc.2021.09.016
- Primary Citation of Related Structures:  
7RTB - PubMed Abstract: 
Dual agonists that can activate both the glucagon-like peptide-1 receptor (GLP-1R) and the gastric inhibitory polypeptide receptor (GIPR) have demonstrated high efficacy for the treatment of metabolic disease. Peptide-19 is a prototypical dual agonist that has high potency at both GLP-1R and GIPR but has a distinct signalling profile relative to the native peptides at the cognate receptors. In this study, we solved the structure of peptide-19 bound to the GLP-1R in complex with Gs protein, and compared the structure and dynamics of this complex to that of published structures of GLP-1R:Gs in complex with other receptor agonists. Unlike other peptide-bound receptor complexes, peptide-19:GLP-1R:Gs demonstrated a more open binding pocket where transmembrane domain (TM) 6, TM7 and the interconnecting extracellular loop 3 (ECL3) were located away from the peptide, with no interactions between peptide-19 and TM6/ECL3. Analysis of conformational variance of the complex revealed that peptide-19 was highly dynamic and underwent binding and unbinding motions facilitated by the more open TM binding pocket. Both the consensus structure of the GLP-1R complex with peptide-19 and the dynamics of this complex were distinct from previously described GLP-1R structures providing unique insights into the mode of GLP-1R activation by this dual agonist.
Organizational Affiliation: 
Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Victoria, Australia.