The interactions of proteins with other proteins (or ligands) and the regulation of protein activity by conformational changes are fundamental aspects of how a wide range of enzymes, signaling proteins, and ion channels function. Volgraf et al. describe the design of a channel that can be turned on (at 380 nm) and off (at 500 nm) by light. Using structure-based design, the authors covalently linked to the ligand-binding domain of the ionotropic glutamate receptor a light-sensitive azobenzene derivative with an appended agonist. Photoisomerization (from trans to cis) brings the agonist within striking distance of the ligand-binding site and triggers a conformational change that closes the channel within milliseconds. This approach can be used in future designs of light-operated switches incorporated into a variety of proteins either in electrophysiological settings or in nanodevices. -- SMH
Nat. Chem. Biol. 10.1038/nchembio756 (2005).
