title: Imaging proteins at the single-molecule level.
abstract: Imaging single proteins has been a long-standing ambition for advancing various fields in natural science, as for instance structural biology, biophysics, and molecular nanotechnology. In particular, revealing the distinct conformations of an individual protein is of utmost importance. Here, we show the imaging of individual proteins and protein complexes by low-energy electron holography. Samples of individual proteins and protein complexes on ultraclean freestanding graphene were prepared by soft-landing electrospray ion beam deposition, which allows chemical- and conformational-specific selection and gentle deposition. Low-energy electrons do not induce radiation damage, which enables acquiring subnanometer resolution images of individual proteins (cytochrome C and BSA) as well as of protein complexes (hemoglobin), which are not the result of an averaging process.
authors.affiliation: Physics Department of the University of Zurich, CH-8057 Zurich, Switzerland; longchamp@physik.uzh.ch k.kern@fkf.mpg.de hwfink@physik.uzh.ch.
authors.forename: Jean-Nicolas
authors.initials: JN
authors.lastname: Longchamp
authors.affiliation: Max Planck Institute for Solid State Research, DE-70569 Stuttgart, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Rauschenbach
authors.affiliation: Max Planck Institute for Solid State Research, DE-70569 Stuttgart, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Abb
authors.affiliation: Physics Department of the University of Zurich, CH-8057 Zurich, Switzerland.
authors.forename: Conrad
authors.initials: C
authors.lastname: Escher
authors.affiliation: Physics Department of the University of Zurich, CH-8057 Zurich, Switzerland.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Latychevskaia
authors.affiliation: Max Planck Institute for Solid State Research, DE-70569 Stuttgart, Germany; longchamp@physik.uzh.ch k.kern@fkf.mpg.de hwfink@physik.uzh.ch.|Institut de Physique, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Klaus
authors.initials: K
authors.lastname: Kern
authors.affiliation: Physics Department of the University of Zurich, CH-8057 Zurich, Switzerland; longchamp@physik.uzh.ch k.kern@fkf.mpg.de hwfink@physik.uzh.ch.
authors.forename: Hans-Werner
authors.initials: HW
authors.lastname: Fink
mesh_terms: D000818:Animals; D002417:Cattle; D045304:Cytochromes c / Q000648:ultrastructure; D004583:Electrons; D006108:Graphite; D006454:Hemoglobins / Q000648:ultrastructure; D006696:Holography / Q000295:instrumentation / Q000379:methods*; D011506:Proteins / Q000648:ultrastructure*; D012710:Serum Albumin, Bovine / Q000648:ultrastructure; D000072760:Single Molecule Imaging / Q000295:instrumentation / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D055672:Static Electricity; D014618:Vacuum
chemical_list: D006454:Hemoglobins; D011506:Proteins; D012710:Serum Albumin, Bovine; D006108:Graphite; D045304:Cytochromes c
keywords: low-energy electron holography; microscopy; preparative mass spectrometry; single protein imaging; structural biology