Abstract
The efficiency of covalent labeling of a receptor by a photolabile analogue of its natural ligand is dependent on the spatial approximation of the probe and its target. Systematic application of intrinsic photoaffinity labeling to the secretin receptor, a prototypic Family B G protein-coupled receptor, demonstrated reduced efficiency of labeling for amino-terminal and mid-region sites of labeling relative to carboxyl-terminal sites. Reduction of pH from 7.4 to 5.5 and reduction of temperature from 25 °C to 4 °C improved the efficiency of covalent labeling of the receptor with these probes. This correlated with sites of labeling at the interface between the receptor amino terminus and the receptor core, a region containing histidine residues that have their ionization affected in this pH range. Application to the calcitonin receptor, another Family B G protein-coupled receptor, yielded analogous results. These results support the consistent mode of docking peptide ligands to this group of receptors.
Original language | English (US) |
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Pages (from-to) | 110-115 |
Number of pages | 6 |
Journal | Regulatory Peptides |
Volume | 158 |
Issue number | 1-3 |
DOIs | |
State | Published - Nov 27 2009 |
Keywords
- Calcitonin receptor
- G protein-coupled receptors
- Photoaffinity labeling
- Secretin receptor
ASJC Scopus subject areas
- Biochemistry
- Physiology
- Endocrinology
- Clinical Biochemistry
- Cellular and Molecular Neuroscience