Development of an antibody fragment that stabilizes GPCR/G-protein complexes.
Maeda, S., Koehl, A., Matile, H., Hu, H., Hilger, D., Schertler, G.F.X., Manglik, A., Skiniotis, G., Dawson, R.J.P., Kobilka, B.K.(2018) Nat Commun 9: 3712-3712
- PubMed: 30213947 
- DOI: https://doi.org/10.1038/s41467-018-06002-w
- Primary Citation of Related Structures:  
6CRK - PubMed Abstract: 
Single-particle cryo-electron microscopy (cryo-EM) has recently enabled high-resolution structure determination of numerous biological macromolecular complexes. Despite this progress, the application of high-resolution cryo-EM to G protein coupled receptors (GPCRs) in complex with heterotrimeric G proteins remains challenging, owning to both the relative small size and the limited stability of these assemblies. Here we describe the development of antibody fragments that bind and stabilize GPCR-G protein complexes for the application of high-resolution cryo-EM. One antibody in particular, mAb16, stabilizes GPCR/G-protein complexes by recognizing an interface between Gα and Gβγ subunits in the heterotrimer, and confers resistance to GTPγS-triggered dissociation. The unique recognition mode of this antibody makes it possible to transfer its binding and stabilizing effect to other G-protein subtypes through minimal protein engineering. This antibody fragment is thus a broadly applicable tool for structural studies of GPCR/G-protein complexes.
Organizational Affiliation: 
Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA, 94305, USA.