Ligand-induced extramembrane conformation switch controlling alamethicin assembly and the channel current.
In this review, we describe our approach to creating artificial receptor-channel proteins or sensor systems, using an extramembrane segment conformationally switchable by external stimuli. Alamethicin is known to self-assemble in membranes to form ion channels with various open states. Employment of an alpha-helical leucine-zipper segment resulted in the effective modulation of the association states of alamethicin to produce a single predominant channel-open state. A decrease in the helical content of the extramembrane segments was found to induce a channel-current increase. Therefore, conformational changes in the extramembrane segments induced by the interaction with ligands can be reflected in the current levels.
Futaki
Shiroh
S
Institute for Chemical Research, Kyoto University, Uji, Kyoto, Japan. futaki@scl.kyoto-u.ac.jp
Asami
Koji
K
D000408:Alamethicin / Q000737:chemistry*; D007473:Ion Channels / Q000737:chemistry*; D008024:Ligands; D011487:Protein Conformation
D007473:Ion Channels; D008024:Ligands; D000408:Alamethicin