Affiliation: | 1. Contributed equally to this work.;2. Biomolecular Mass Spectrometry Laboratory, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne (Switzerland), Fax: (+41)?121‐693‐9700;3. Current address: Proteomics Core Facility, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne (Switzerland);4. Laboratory of Physical Chemistry of Polymers and Membranes, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne (Switzerland) |