1. R. MacKinnon and A. Kuo, Laboratory of Molecular Neurobiology and Biophysics and the Howard Hughes Medical Institute, Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
2. S. L. Cohen and B. T. Chait, Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
3. A. Lee, Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.