Photoaffinity scanning in the mapping of the peptide receptor interface of class II G protein-coupled receptors.

The family of G protein-coupled receptors constitutes about 50% of the therapeutic drug targets used in clinical medicine today, although the mechanisms of ligand binding, activation and signal transduction for G protein-coupled receptors are not yet well defined. This review discusses ongoing research using the photoaffinity scanning method to map the bimolecular interface between class II G protein-coupled receptors and their ligands. Furthermore the available computer model of class II peptide ligand docking into the receptor, based on the positional constraints imposed by the photoaffinity scanning analyses, will be discussed briefly. The ultimate goal of these efforts is to understand the molecular basis of receptor binding and therefore to generate a template for rational drug design.