Journal
BIOCHEMISTRY
Volume 48, Issue 23, Pages 5303-5312Publisher
AMER CHEMICAL SOC
DOI: 10.1021/bi9004705
Keywords
-
Categories
Funding
- National Institutes of Health [DK32878]
- Fiterman Foundation
- Mayo Clinic
Ask authors/readers for more resources
G protein-coupled receptors represent the largest family of receptors and the major target of current drug development efforts. Understanding of the mechanisms of ligand binding and activation of these receptors remains limited, despite recent advances in structural determination of family members. This work focuses oil the use of photoaffinity labeling and molecular modeling to elucidate the structural basis of binding a natural peptide ligand to a family A G protein-coupled receptor, the type I cholecystokinin receptor. Two photolabile cholecystokinin analogues were developed and characterized as representing high-affinity, fully biologically active probes with sites of covalent attachment at positions 28 and 31. The sites of receptor labeling were identified by purification, proteolytic peptide mapping, and radiochemical sequencing of labeled wild-type and mutant cholecystokinin receptors. The position 28 probe labeled second extracellular loop residue Phe(107). Along with five additional spatial approximation constraints coming from previous photoaffinity labeling studies and 12 distance restraints from fluorescence resonance energy transfer studies, these were built into two homology models of the cholecystokinin receptor, based on the recent crystal structures of the beta 2-adrenergic receptor and A2a-adenosine receptor. The resultant agonist ligand-occupied receptor models fully accommodate all existing experimental data and represent the best refined models of a peptide hormone receptor in this important family.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available