1. Department of Bionanotechnology, Hanyang University, Ansan 155-88, Korea
2. Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, United States
3. Department of Neuroscience, University of Copenhagen, Copenhagen N DK-2200, Denmark
4. Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, United States
5. Department of Life Sciences, Imperial College London, London SW7 2AZ, U.K.