Structural insight into antibody-mediated antagonism of the Glucagon-like peptide-1 Receptor

TY - JOUR

T1 - Structural insight into antibody-mediated antagonism of the Glucagon-like peptide-1 Receptor

AU - Hennen, Stephanie

AU - Kodra, János T

AU - Soroka, Vladyslav

AU - Krogh, Berit O

AU - Wu, Xiaoai

AU - Kaastrup, Peter

AU - Ørskov, Cathrine

AU - Rønn, Sif G.

AU - Schluckebier, Gerd

AU - Barbateskovic, Silvia

AU - Gandhi, Prafull S.

AU - Reedtz-Runge, Steffen

PY - 2016/5/19

Y1 - 2016/5/19

N2 - The Glucagon-like peptide-1 receptor (GLP-1R) is a member of the class B G protein-coupled receptor (GPCR) family and a well-established target for the treatment of type 2 diabetes. The N-terminal extracellular domain (ECD) of GLP-1R is important for GLP-1 binding and the crystal structure of the GLP-1/ECD complex was reported previously. The first structure of a class B GPCR transmembrane (TM) domain was solved recently, but the full length receptor structure is still not well understood. Here we describe the molecular details of antibody-mediated antagonism of the GLP-1R using both in vitro pharmacology and x-ray crystallography. We showed that the antibody Fab fragment (Fab 3F52) blocked the GLP-1 binding site of the ECD directly and thereby acts as a competitive antagonist of native GLP-1. Interestingly, Fab 3F52 also blocked a short peptide agonist believed to engage primarily the transmembrane and extracellular loop region of GLP-1R, whereas functionality of an allosteric small-molecule agonist was not inhibited. This study has implications for the structural understanding of the GLP-1R and related class B GPCRs, which is important for the development of new and improved therapeutics targeting these receptors.

AB - The Glucagon-like peptide-1 receptor (GLP-1R) is a member of the class B G protein-coupled receptor (GPCR) family and a well-established target for the treatment of type 2 diabetes. The N-terminal extracellular domain (ECD) of GLP-1R is important for GLP-1 binding and the crystal structure of the GLP-1/ECD complex was reported previously. The first structure of a class B GPCR transmembrane (TM) domain was solved recently, but the full length receptor structure is still not well understood. Here we describe the molecular details of antibody-mediated antagonism of the GLP-1R using both in vitro pharmacology and x-ray crystallography. We showed that the antibody Fab fragment (Fab 3F52) blocked the GLP-1 binding site of the ECD directly and thereby acts as a competitive antagonist of native GLP-1. Interestingly, Fab 3F52 also blocked a short peptide agonist believed to engage primarily the transmembrane and extracellular loop region of GLP-1R, whereas functionality of an allosteric small-molecule agonist was not inhibited. This study has implications for the structural understanding of the GLP-1R and related class B GPCRs, which is important for the development of new and improved therapeutics targeting these receptors.

U2 - 10.1038/srep26236

DO - 10.1038/srep26236

M3 - Journal article

C2 - 27196125

SN - 2045-2322

VL - 6

JO - Scientific Reports

JF - Scientific Reports

M1 - 26236

ER -