Abstract
The beta2-adrenergic receptor (beta2AR) is a well-studied prototype for heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs) that respond to diffusible hormones and neurotransmitters. To overcome the structural flexibility of the beta2AR and to facilitate its crystallization, we engineered a beta2AR fusion protein in which T4 lysozyme (T4L) replaces most of the third intracellular loop of the GPCR ("beta2AR-T4L") and showed that this protein retains near-native pharmacologic properties. Analysis of adrenergic receptor ligand-binding mutants within the context of the reported high-resolution structure of beta2AR-T4L provides insights into inverse-agonist binding and the structural changes required to accommodate catecholamine agonists. Amino acids known to regulate receptor function are linked through packing interactions and a network of hydrogen bonds, suggesting a conformational pathway from the ligand-binding pocket to regions that interact with G proteins.
| Original language | English |
|---|---|
| Journal | Science (New York, N.Y.) |
| Volume | 318 |
| Issue number | 5854 |
| Pages (from-to) | 1266-73 |
| Number of pages | 8 |
| ISSN | 0036-8075 |
| DOIs | |
| Publication status | Published - 23 Nov 2007 |
Keywords
- Adrenergic beta-Agonists
- Adrenergic beta-Antagonists
- Amino Acid Sequence
- Bacteriophage T4
- Binding Sites
- Cell Line
- Cell Membrane
- Crystallization
- Crystallography, X-Ray
- Drug Inverse Agonism
- Humans
- Immunoglobulin Fab Fragments
- Ligands
- Models, Molecular
- Molecular Sequence Data
- Muramidase
- Propanolamines
- Protein Conformation
- Protein Structure, Secondary
- Protein Structure, Tertiary
- Receptors, Adrenergic, beta-2
- Recombinant Fusion Proteins