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Direct electron detector and phase plate for cryo-transmission electron microscopy of biological samples

English title Direct electron detector and phase plate for cryo-transmission electron microscopy of biological samples
Applicant Fotiadis Dimitrios
Number 157704
Funding scheme R'EQUIP
Research institution Institut für Biochemie und Molekulare Medizin Universität Bern
Institution of higher education University of Berne - BE
Main discipline Biophysics
Start/End 01.12.2014 - 30.11.2015
Approved amount 420'000.00
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All Disciplines (2)

Discipline
Biophysics
Biochemistry

Keywords (6)

membrane protein; cryo-electro tomography; structure; proteoliposome; 2D crystal; transmission electron microscopy

Lay Summary (German)

Lead
Die Kryo-Elektronenmikroskopie von biologischen Proben hat in den letzten Jahren eine bedeutende Entwicklung erfahren. Hochempfindliche Kameras (DED Kameras), die Elektronen direkt detektieren, liefern heutzutage noch nie da gewesene Auflösungen von Biomolekülen und biologischen Strukturen. Ziel dieses Projektes ist es die Strukturen von verschiedenen biologisch und medizinisch relevanten Biomolekülen mittels Kryo-Elektronenmikroskopie und der bahnbrechenden DED Technologie aufzuklären. Diese Strukturen werden fundamentale Informationen zum Aufbau von Biomolekülen liefern und für das Verständnis von bestimmten menschlichen und tierischen Krankheiten grundlegend sein.
Lay summary

Die Kryo-Elektronenmikroskopie (Kryo-EM) ermöglicht die Visualisierung von biologischen Proben unter nahe physiologischen Bedingungen. Dreidimensionale (3D) Strukturen von biologischen Molekülen, z.B., Eiweissen, bei hoher Auflösung können bestimmt und dynamische Vorgänge visualisiert werden. Um Auflösungen im Ångström (1:10'000'000'000 Meter) Bereich zu erreichen, sind in der heutigen modernen Kryo-EM direkte Elektronendetektor-Kameras, auf englisch “Direct Electron Detection“ (DED)-Kameras, unentbehrlich. DED-Kameras sind hochempfindliche, rauscharmen Detektoren, die maximale Empfindlichkeiten aufweisen.

Im gegenwärtigen Projekt werden Berner Forscher aus den Biowissenschaften und der Medizin verschiedene biologische Proben mittels Kryo-EM und der vom Schweizerischen Nationalfonds finanzierten DED-Kamera visualisieren können. Die ermittelten Strukturen werden wichtige Aussagen über den Aufbau und die Funktionsweise von verschiedenen medizinisch und biologisch relevanten Biomolekülen ermöglichen. Diese Informationen werden auch für das Verständnis von menschlichen und tierischen Krankheiten fundamental sein.     

 

Direct link to Lay Summary Last update: 09.12.2014

Responsible applicant and co-applicants

Publications

Publication
Design and assembly of a chemically switchable and fluorescently traceable light-driven proton pump system for bionanotechnological applications
Hirschi S., Fischer N., Kalbermatter D., Laskowski P. R., Ucurum Z., Müller D. J., Fotiadis D. (2019), Design and assembly of a chemically switchable and fluorescently traceable light-driven proton pump system for bionanotechnological applications, in Scientific Reports, 9(1), 1046-1046.
Volta Phase Plate Cryo-EM Structure of the Human Heterodimeric Amino Acid Transporter 4F2hc-LAT2
Jeckelmann Jean-Marc, Fotiadis Dimitrios (2019), Volta Phase Plate Cryo-EM Structure of the Human Heterodimeric Amino Acid Transporter 4F2hc-LAT2, in International Journal of Molecular Sciences, 20(4), 931-931.
Protein-enriched outer membrane vesicles as a native platform for outer membrane protein studies
Thoma Johannes, Manioglu Selen, Kalbermatter David, Bosshart Patrick D., Fotiadis Dimitrios, Müller Daniel J. (2018), Protein-enriched outer membrane vesicles as a native platform for outer membrane protein studies, in Communications Biology, 1(1), 23-23.
Fusion Domains Guide the Oriented Insertion of Light-Driven Proton Pumps into Liposomes
Ritzmann Noah, Thoma Johannes, Hirschi Stephan, Kalbermatter David, Fotiadis Dimitrios, Müller Daniel J. (2017), Fusion Domains Guide the Oriented Insertion of Light-Driven Proton Pumps into Liposomes, in Biophysical Journal, 113(6), 1181-1186.

Collaboration

Group / person Country
Types of collaboration
Microscopy Imaging Center Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
- Industry/business/other use-inspired collaboration

Associated projects

Number Title Start Funding scheme
156419 The role of CRALBP in the chemistry of vision 01.11.2014 Project funding (Div. I-III)
136222 Elucidating the biological function of FUS and its role in neurodegeneration 01.09.2011 Sinergia
140691 Pathogen-host cell interactions during the liver stage of Plasmodium parasites 01.08.2012 Project funding (Div. I-III)
184980 Structures of solute carrier membrane transport proteins 01.07.2019 Project funding (Div. I-III)
144168 Structure and supramolecular organization of membrane transport proteins 01.11.2012 Project funding (Div. I-III)
153281 Unraveling Paramyxovirus Cell Entry 01.05.2014 Project funding (Div. I-III)
143717 Quality control of gene expression: towards understanding mechanism and physiological role of nonsense-mediated mRNA decay (NMD) 01.10.2012 Project funding (Div. I-III)
183481 Morbillivirus cell entry machinery: mechanisms, structures and antiviral drug discovery 01.04.2019 Sinergia
125762 NCCR TransCure: From transport physiology to identification of therapeutic targets (phase I) 01.11.2010 National Centres of Competence in Research (NCCRs)
153351 Novel technologies for the functional investigation of membrane proteins 01.09.2014 Project funding (Div. I-III)
139098 Time-resolved structural study of calcium-dependent membrane fusion 01.07.2012 SNSF Professorships
143388 Molecular insight into ribosome functions and translation regulation 01.01.2013 Project funding (Div. I-III)

Abstract

Low electron-dose imaging of biological samples by cryo-transmission electron microscopy (cryo-TEM) has experienced a major revolution in the last year. Cameras based on a groundbreaking new technology directly detect electrons. This is in contrast to conventional CCD cameras, which convert electrons to light with a scintillator before read-out. The new cameras, termed direct electron detector devices (DDDs), have unprecedented high sensitivity and signal-to-noise ratio. Due to the much improved sensitivity of DDDs, recording of ’movies’ and subsequent correction of electron beam-induced drift are possible. The drift correction together with the high signal-to-noise ratio of DDDs dramatically improves contrast and resolution of electron micrographs making possible the determination of macromolecule structures at near-atomic resolution by cryo-TEM and single particle 3D reconstruction. An additional important improvement of contrast will be achieved by the requested first commercial phase plate that will be made available to the cryo-TEM community by the FEI company at the end of 2014. The phase plate technology is particularly attractive for single particle analysis of relatively small macromolecules and for cryo-electron tomography.The applicants are established and internationally recognized experts in the fields of transmission electron microscopy (TEM) and cryo-electron tomography of biological samples. For them and the University of Bern, the here requested DDD camera and phase plate are essential in order to stay at the forefront in the field of TEM and competitive at the international level. Nine research groups from the Medical, Life and Natural Sciences, and Veterinary Medical Faculties of the University of Bern will directly benefit from these new technologies. The requested equipment will be mounted on the FEI Tecnai F20 field emission gun electron microscope. This high-end electron microscope is located at the Institute of Anatomy, which is the leading house of the interfaculty Microscopy Imaging Centre (MIC) of the University of Bern. Through the MIC, users from the University of Bern as well as external users from other public and private research institutions will have the possibility to access and benefit from this state-of-the art equipment.
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