Relative Antagonism of Mutants of the CGRP Receptor Extracellular Loop 2 Domain (ECL2) Using a Truncated Competitive Antagonist (CGRP8-37): Evidence for the Dual Involvement of ECL2 in the Two-Domain Binding Model

Biochemistry. 2017 Aug 1;56(30):3877-3880. doi: 10.1021/acs.biochem.7b00077. Epub 2017 Jul 18.

Abstract

The second extracellular loop (ECL2) of the G protein-coupled receptor (GPCR) family is important for ligand interaction and drug discovery. ECL2 of the family B cardioprotective calcitonin gene-related peptide (CGRP) receptor is required for cell signaling. Family B GPCR ligands have two regions; the N-terminus mediates receptor activation, and the remainder confers high-affinity binding. Comparing antagonism of CGRP8-37 at a number of point mutations of ECL2 of the CGRP receptor, we show that the ECL2 potentially facilitates interaction with up to the 18 N-terminal residues of CGRP. This has implications for understanding family B GPCR activation and for drug design at the CGRP receptor.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Substitution
  • Animals
  • Binding Sites
  • Binding, Competitive
  • COS Cells
  • Calcitonin Gene-Related Peptide / chemistry
  • Calcitonin Gene-Related Peptide / genetics
  • Calcitonin Gene-Related Peptide / metabolism
  • Calcitonin Gene-Related Peptide / pharmacology*
  • Calcitonin Receptor-Like Protein / agonists*
  • Calcitonin Receptor-Like Protein / chemistry
  • Calcitonin Receptor-Like Protein / genetics
  • Calcitonin Receptor-Like Protein / metabolism
  • Chlorocebus aethiops
  • Kinetics
  • Ligands
  • Miotics / chemistry
  • Miotics / metabolism
  • Miotics / pharmacology*
  • Models, Molecular*
  • Peptide Fragments / chemistry
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism
  • Peptide Fragments / pharmacology*
  • Point Mutation
  • Protein Conformation
  • Protein Interaction Domains and Motifs
  • Protein Interaction Mapping
  • Protein Multimerization
  • Receptor Activity-Modifying Protein 1 / chemistry
  • Receptor Activity-Modifying Protein 1 / genetics
  • Receptor Activity-Modifying Protein 1 / metabolism*
  • Receptors, Calcitonin Gene-Related Peptide / agonists*
  • Receptors, Calcitonin Gene-Related Peptide / chemistry
  • Receptors, Calcitonin Gene-Related Peptide / genetics
  • Receptors, Calcitonin Gene-Related Peptide / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Recombinant Proteins / pharmacology
  • Signal Transduction / drug effects*
  • Structural Homology, Protein

Substances

  • CALCRL protein, human
  • CRCP protein, human
  • Calcitonin Receptor-Like Protein
  • Ligands
  • Miotics
  • Peptide Fragments
  • RAMP1 protein, human
  • Receptor Activity-Modifying Protein 1
  • Receptors, Calcitonin Gene-Related Peptide
  • Recombinant Proteins
  • calcitonin gene-related peptide (8-37)
  • Calcitonin Gene-Related Peptide