1
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Zhang DY, Xu Z, Li JY, Mao S, Wang H. Graphene-Assisted Electron-Based Imaging of Individual Organic and Biological Macromolecules: Structure and Transient Dynamics. ACS NANO 2025; 19:120-151. [PMID: 39723464 DOI: 10.1021/acsnano.4c12083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2024]
Abstract
Characterizing the structures, interactions, and dynamics of molecules in their native liquid state is a long-existing challenge in chemistry, molecular science, and biophysics with profound scientific significance. Advanced transmission electron microscopy (TEM)-based imaging techniques with the use of graphene emerged as promising tools, mainly due to their performance on spatial and temporal resolution. This review focuses on the various approaches to achieving high-resolution imaging of individual molecules and their transient interactions. We highlight the crucial role of graphene grids in cryogenic electron microscopy for achieving Ångstrom-level resolution for resolving molecular structures and the importance of graphene liquid cells in liquid-phase TEM for directly observing dynamics with subnanometer resolution at a frame rate of several frames per second, as well as the cross-talks of the two imaging modes. To understand the chemistry and physics encoded in these molecular movies, incorporating machine learning algorithms for image analysis provides a promising approach that further bolsters the resolution adventure. Besides reviewing the recent advances and methodologies in TEM imaging of individual molecules using graphene, this review also outlines future directions to improve these techniques and envision problems in molecular science, chemistry, and biology that could benefit from these experiments.
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Affiliation(s)
- De-Yi Zhang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Key Laboratory of Polymer Chemistry & Physics, National Biomedical Imaging Center, Peking University, Beijing 100871, People's Republic of China
| | - Zhipeng Xu
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Key Laboratory of Polymer Chemistry & Physics, National Biomedical Imaging Center, Peking University, Beijing 100871, People's Republic of China
| | - Jia-Ye Li
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Key Laboratory of Polymer Chemistry & Physics, National Biomedical Imaging Center, Peking University, Beijing 100871, People's Republic of China
| | - Sheng Mao
- College of Engineering, Peking University, Beijing 100871, People's Republic of China
| | - Huan Wang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Key Laboratory of Polymer Chemistry & Physics, National Biomedical Imaging Center, Peking University, Beijing 100871, People's Republic of China
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2
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Harley I, Mazzotta F, Shaulli X, Scheffold F, Landfester K, Lieberwirth I. Practical considerations for plunge freezing samples over 40 °C for Cryo-EM. Micron 2025; 188:103745. [PMID: 39549637 DOI: 10.1016/j.micron.2024.103745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2024] [Revised: 11/11/2024] [Accepted: 11/12/2024] [Indexed: 11/18/2024]
Abstract
Cryo-EM is now an established tool for examining samples in their native, hydrated states-a leap made possible by vitrification. Utilising this sample preparation method to directly visualise temperature-responsive samples allows for deeper insights into their structural behaviours under functional conditions. This requires samples to be plunge-frozen at elevated temperatures and presents additional challenges, including condensation within the blotting chamber and difficulties in maintaining a stable sample temperatures. Here, we address these challenges and suggest practical strategies to minimise condensation and reduce temperature fluctuations during the plunge-freezing of samples at elevated temperatures (>40 °C). By preheating equipment and reducing chamber humidity and blotting times, we can improve sample preservation and grid reproducibility. These considerations are then demonstrated on poly(N-isopropylacrylamide) microgels, which exhibit a volume phase transition due to temperature changes.
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Affiliation(s)
- Iain Harley
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
| | - Francesca Mazzotta
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
| | - Xhorxhina Shaulli
- Department of Physics, University of Fribourg, Chemin du Musée 3, Fribourg 1700, Switzerland
| | - Frank Scheffold
- Department of Physics, University of Fribourg, Chemin du Musée 3, Fribourg 1700, Switzerland
| | - Katharina Landfester
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
| | - Ingo Lieberwirth
- Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany.
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3
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Lee M, Jeon Y, Kim S, Jung I, Kang S, Jeong SH, Park J. Unravelling complex mechanisms in materials processes with cryogenic electron microscopy. Chem Sci 2024:d4sc05188b. [PMID: 39697416 PMCID: PMC11651391 DOI: 10.1039/d4sc05188b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2024] [Accepted: 12/02/2024] [Indexed: 12/20/2024] Open
Abstract
Investigating nanoscale structural variations, including heterogeneities, defects, and interfacial characteristics, is crucial for gaining insight into material properties and functionalities. Cryogenic electron microscopy (cryo-EM) is developing as a powerful tool in materials science particularly for non-invasively understanding nanoscale structures of materials. These advancements bring us closer to the ultimate goal of correlating nanoscale structures to bulk functional outcomes. However, while understanding mechanisms from structural information requires analysis that closely mimics operation conditions, current challenges in cryo-EM imaging and sample preparation hinder the extraction of detailed mechanistic insights. In this Perspective, we discuss the innovative strategies and the potential for using cryo-EM for revealing mechanisms in materials science, with examples from high-resolution imaging, correlative elemental analysis, and three-dimensional and time-resolved analysis. Furthermore, we propose improvements in cryo-sample preparation, optimized instrumentation setup for imaging, and data interpretation techniques to enable the wider use of cryo-EM and achieve deeper context into materials to bridge structural observations with mechanistic understanding.
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Affiliation(s)
- Minyoung Lee
- Department of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University Seoul 08826 Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS) Seoul 08826 Republic of Korea
| | - Yonggoon Jeon
- Department of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University Seoul 08826 Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS) Seoul 08826 Republic of Korea
- Department of Physics and Chemistry, Korea Military Academy (KMA) Seoul 01805 Republic of Korea
| | - Sungin Kim
- Department of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University Seoul 08826 Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS) Seoul 08826 Republic of Korea
- Department of Chemistry and Chemical Biology, Cornell University Ithaca NY 14853 USA
| | - Ihnkyung Jung
- Department of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University Seoul 08826 Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS) Seoul 08826 Republic of Korea
| | - Sungsu Kang
- Department of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University Seoul 08826 Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS) Seoul 08826 Republic of Korea
- Department of Chemistry, University of Chicago Chicago IL 60637 USA
| | - Seol-Ha Jeong
- Department of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University Seoul 08826 Republic of Korea
| | - Jungwon Park
- Department of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University Seoul 08826 Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS) Seoul 08826 Republic of Korea
- Institute of Engineering Research, Seoul National University Seoul 08826 Republic of Korea
- Advanced Institute of Convergence Technology, Seoul National University Suwon 16229 Republic of Korea
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4
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Garg P, Feng X, De S, Frank J. Passage through micro-sprayer increases functional activity - implications for activity assays in time-resolved cryo-EM. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.12.01.624867. [PMID: 39677783 PMCID: PMC11642776 DOI: 10.1101/2024.12.01.624867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2024]
Abstract
This study examines the validity of an assay that is used to report on the retainment of functional competence by ribosomes as they pass a micro-sprayer. We find a reproducible increase , rather than the expected decrease in GFP production as monitored by fluorescence, which suggests heterogeneity or partial aggregation of ribosomes in solution. An even larger increase in functional activity is observed when sonication is used, pointing to mechanical agitation as the decisive factor in both scenarios. The results have a bearing on the design and interpretation of validation experiments in time-resolved cryo-EM based on microfluidic chips.
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5
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Henderikx RJM, Schotman MJG, Shahzad S, Fromm SA, Mann D, Hennies J, Heidler TV, Ashtiani D, Hagen WJH, Jeurissen RJM, Mattei S, Peters PJ, Sachse C, Beulen BWAMM. Ice thickness control and measurement in the VitroJet for time-efficient single particle structure determination. J Struct Biol 2024; 216:108139. [PMID: 39433138 DOI: 10.1016/j.jsb.2024.108139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 08/30/2024] [Accepted: 10/18/2024] [Indexed: 10/23/2024]
Abstract
Embedding biomolecules in vitreous ice of optimal thickness is critical for structure determination by cryo-electron microscopy. Ice thickness assessment and selection of suitable holes for data collection are currently part of time-consuming preparatory routines performed on expensive electron microscopes. To address this challenge, a routine has been developed to measure ice thickness during sample preparation using an optical camera integrated in the VitroJet. This method allows to estimate the ice thickness with an error below ±20 nm for ice layers in the range of 0-70 nm. Additionally, we characterized the influence of pin printing parameters and found that the median ice thickness can be reproduced with a standard deviation below ±11 nm for thicknesses up to 75 nm. Therefore, the ice thickness of buffer-suspended holes on an EM grid can be tuned and measured within the working range relevant for single particle cryo-EM. Single particle structures of apoferritin were determined at two distinct thicknesses of 30 nm and 70 nm. These reconstructions demonstrate the importance of ice thickness for time-efficient cryo-EM structure determination.
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Affiliation(s)
- Rene J M Henderikx
- CryoSol-World, Weert, the Netherlands; Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, the Netherlands.
| | | | - Saba Shahzad
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C-3): Structural Biology, Forschungszentrum Jülich, Jülich, Germany; Institute of Biological Information Processing (IBI-6): Structural Cell Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Simon A Fromm
- European Molecular Biology Laboratory, EMBL Imaging Centre, Heidelberg, Germany
| | - Daniel Mann
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C-3): Structural Biology, Forschungszentrum Jülich, Jülich, Germany; Institute of Biological Information Processing (IBI-6): Structural Cell Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Julian Hennies
- European Molecular Biology Laboratory, EMBL Imaging Centre, Heidelberg, Germany
| | - Thomas V Heidler
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C-3): Structural Biology, Forschungszentrum Jülich, Jülich, Germany; Institute of Biological Information Processing (IBI-6): Structural Cell Biology, Forschungszentrum Jülich, Jülich, Germany
| | | | - Wim J H Hagen
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany
| | - Roger J M Jeurissen
- ACFD Consultancy, Heel, the Netherlands; Physics of Fluids group, University of Twente, Enschede, the Netherlands
| | - Simone Mattei
- European Molecular Biology Laboratory, EMBL Imaging Centre, Heidelberg, Germany; European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg, Germany
| | - Peter J Peters
- Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, the Netherlands
| | - Carsten Sachse
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C-3): Structural Biology, Forschungszentrum Jülich, Jülich, Germany; Institute of Biological Information Processing (IBI-6): Structural Cell Biology, Forschungszentrum Jülich, Jülich, Germany; Department of Biology, Heinrich-Heine-University, Düsseldorf
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6
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MacDonald CRM, Draper ER. Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels. Beilstein J Org Chem 2024; 20:2608-2634. [PMID: 39445219 PMCID: PMC11496719 DOI: 10.3762/bjoc.20.220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 09/26/2024] [Indexed: 10/25/2024] Open
Abstract
When evaluating soft self-assembling materials for use in any application, the structural or morphological characterisation is highly important. We know that the hierarchal molecular self-assembly of these materials into larger structures directly influences behaviours such as performance and stability. It is therefore imperative that these materials are characterised effectively over multiple length scales. Two effective methods of achieving this are small angle scattering (SAS) and imaging. Scattering giving us indirect information about the systems, whereas imaging is often looking at the material directly. In this review, we discuss the benefits, caveats and power of using both these techniques separately and together for the characterisation of supramolecular gels.
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Affiliation(s)
| | - Emily R Draper
- School of Chemistry, University of Glasgow, Glasgow, Scotland, G12 8QQ, UK
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7
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Yang JE, Mitchell JM, Bingman CA, Mosher DF, Wright ER. In situ crystalline structure of the human eosinophil major basic protein-1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.10.09.617336. [PMID: 39416224 PMCID: PMC11483036 DOI: 10.1101/2024.10.09.617336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/19/2024]
Abstract
Eosinophils are white blood cells that participate in innate immune responses and have an essential role in the pathogenesis of inflammatory and neoplastic disorders. Upon activation, eosinophils release cytotoxic proteins such as major basic protein-1 (MBP-1) from cytoplasmic secretory granules (SGr) wherein MBP-1 is stored as nanocrystals. How the MBP-1 nanocrystalline core is formed, stabilized, and subsequently mobilized remains unknown. Here, we report the in-situ structure of crystalline MBP-1 within SGrs of human eosinophils. The structure reveals a mechanism for intragranular crystal packing and stabilization of MBP-1 via a structurally conserved loop region that is associated with calcium-dependent carbohydrate binding in other C-type lectin (CTL) proteins. Single-cell and single-SGr profiling correlating real-space three-dimensional information from cellular montage cryo-electron tomography (cryo-ET) and microcrystal electron diffraction (MicroED) data obtained from non-activated and IL33-activated eosinophils revealed activation-dependent crystal expansion and extrusion of expanded crystals from SGr. These results suggest that MBP-1 crystals play a dynamic role in the release of SGr contents. Collectively, this research demonstrates the importance of in-situ macromolecular structure determination.
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Affiliation(s)
- Jie E Yang
- Department of Biochemistry, University of Wisconsin, Madison, WI USA
- Cryo-Electron Microscopy Research Center, Department of Biochemistry, University of Wisconsin, Madison, WI USA
- Midwest Center for Cryo-Electron Tomography, Department of Biochemistry, University of Wisconsin, Madison, WI USA
| | - Joshua M Mitchell
- Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, WI USA
| | - Craig A Bingman
- Department of Biochemistry, University of Wisconsin, Madison, WI USA
- Collaborative Crystallography Core, University of Wisconsin, Madison, WI USA
| | - Deane F Mosher
- Departments of Biomolecular Chemistry and Medicine, University of Wisconsin, Madison, WI USA
- Morgridge Institute for Research, Madison, WI, USA
| | - Elizabeth R Wright
- Department of Biochemistry, University of Wisconsin, Madison, WI USA
- Cryo-Electron Microscopy Research Center, Department of Biochemistry, University of Wisconsin, Madison, WI USA
- Midwest Center for Cryo-Electron Tomography, Department of Biochemistry, University of Wisconsin, Madison, WI USA
- Morgridge Institute for Research, Madison, WI, USA
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8
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Rizvi A, Favetta B, Jaber N, Lee YK, Jiang J, Idris NS, Schuster BS, Dai W, Patterson JP. Revealing nanoscale structure and interfaces of protein and polymer condensates via cryo-electron microscopy. NANOSCALE 2024; 16:16706-16717. [PMID: 39171763 PMCID: PMC11392623 DOI: 10.1039/d4nr01877j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
Liquid-liquid phase separation (LLPS) is a ubiquitous demixing phenomenon observed in various molecular solutions, including in polymer and protein solutions. Demixing of solutions results in condensed, phase separated droplets which exhibit a range of liquid-like properties driven by transient intermolecular interactions. Understanding the organization within these condensates is crucial for deciphering their material properties and functions. This study explores the distinct nanoscale networks and interfaces in the condensate samples using a modified cryo-electron microscopy (cryo-EM) method. The method involves initiating condensate formation on electron microscopy grids to limit droplet growth as large droplet sizes are not ideal for cryo-EM imaging. The versatility of this method is demonstrated by imaging three different classes of condensates. We further investigate the condensate structures using cryo-electron tomography which provides 3D reconstructions, uncovering porous internal structures, unique core-shell morphologies, and inhomogeneities within the nanoscale organization of protein condensates. Comparison with dry-state transmission electron microscopy emphasizes the importance of preserving the hydrated structure of condensates for accurate structural analysis. We correlate the internal structure of protein condensates with their amino acid sequences and material properties by performing viscosity measurements that support that more viscous condensates exhibit denser internal assemblies. Our findings contribute to a comprehensive understanding of nanoscale condensate structure and its material properties. Our approach here provides a versatile tool for exploring various phase-separated systems and their nanoscale structures for future studies.
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Affiliation(s)
- Aoon Rizvi
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, USA.
| | - Bruna Favetta
- Department of Biomedical Engineering, Rutgers, the State University of New Jersey, Piscataway, NJ 08854, USA
| | - Nora Jaber
- Department of Cell Biology and Neuroscience & Institute for Quantitative Biomedicine, Rutgers, the State University of New Jersey, Piscataway, NJ 08854, USA
| | - Yun-Kyung Lee
- Department of Cell Biology and Neuroscience & Institute for Quantitative Biomedicine, Rutgers, the State University of New Jersey, Piscataway, NJ 08854, USA
| | - Jennifer Jiang
- Department of Cell Biology and Neuroscience & Institute for Quantitative Biomedicine, Rutgers, the State University of New Jersey, Piscataway, NJ 08854, USA
| | - Nehal S Idris
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, USA.
| | - Benjamin S Schuster
- Department of Chemical and Biochemical Engineering, Rutgers, the State University of New Jersey, Piscataway, NJ 08854, USA
| | - Wei Dai
- Department of Cell Biology and Neuroscience & Institute for Quantitative Biomedicine, Rutgers, the State University of New Jersey, Piscataway, NJ 08854, USA
| | - Joseph P Patterson
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, USA.
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA 92697-2025, USA
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9
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Held RG, Liang J, Brunger AT. Nanoscale architecture of synaptic vesicles and scaffolding complexes revealed by cryo-electron tomography. Proc Natl Acad Sci U S A 2024; 121:e2403136121. [PMID: 38923992 PMCID: PMC11228483 DOI: 10.1073/pnas.2403136121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Accepted: 05/16/2024] [Indexed: 06/28/2024] Open
Abstract
The spatial distribution of proteins and their arrangement within the cellular ultrastructure regulates the opening of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in response to glutamate release at the synapse. Fluorescence microscopy imaging revealed that the postsynaptic density (PSD) and scaffolding proteins in the presynaptic active zone (AZ) align across the synapse to form a trans-synaptic "nanocolumn," but the relation to synaptic vesicle release sites is uncertain. Here, we employ focused-ion beam (FIB) milling and cryoelectron tomography to image synapses under near-native conditions. Improved image contrast, enabled by FIB milling, allows simultaneous visualization of supramolecular nanoclusters within the AZ and PSD and synaptic vesicles. Surprisingly, membrane-proximal synaptic vesicles, which fuse to release glutamate, are not preferentially aligned with AZ or PSD nanoclusters. These synaptic vesicles are linked to the membrane by peripheral protein densities, often consistent in size and shape with Munc13, as well as globular densities bridging the synaptic vesicle and plasma membrane, consistent with prefusion complexes of SNAREs, synaptotagmins, and complexin. Monte Carlo simulations of synaptic transmission events using biorealistic models guided by our tomograms predict that clustering AMPARs within PSD nanoclusters increases the variability of the postsynaptic response but not its average amplitude. Together, our data support a model in which synaptic strength is tuned at the level of single vesicles by the spatial relationship between scaffolding nanoclusters and single synaptic vesicle fusion sites.
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Affiliation(s)
- Richard G. Held
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA94305
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA94305
- Department of Structural Biology, Stanford University, Stanford, CA94305
- Department of Photon Science, Stanford University, Stanford, CA94305
- HHMI, Stanford University, Stanford, CA94305
| | - Jiahao Liang
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA94305
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA94305
- Department of Structural Biology, Stanford University, Stanford, CA94305
- Department of Photon Science, Stanford University, Stanford, CA94305
- HHMI, Stanford University, Stanford, CA94305
| | - Axel T. Brunger
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA94305
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA94305
- Department of Structural Biology, Stanford University, Stanford, CA94305
- Department of Photon Science, Stanford University, Stanford, CA94305
- HHMI, Stanford University, Stanford, CA94305
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10
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Yang Z, Fan J, Wang J, Fan X, Ouyang Z, Wang HW, Zhou X. Electrospray-assisted cryo-EM sample preparation to mitigate interfacial effects. Nat Methods 2024; 21:1023-1032. [PMID: 38664529 PMCID: PMC11166575 DOI: 10.1038/s41592-024-02247-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 03/17/2024] [Indexed: 06/13/2024]
Abstract
Addressing interfacial effects during specimen preparation in cryogenic electron microscopy remains challenging. Here we introduce ESI-cryoPrep, a specimen preparation method based on electrospray ionization in native mass spectrometry, designed to alleviate issues associated with protein denaturation or preferred orientation induced by macromolecule adsorption at interfaces. Through fine-tuning spraying parameters, we optimized protein integrity preservation and achieved the desired ice thickness for analyzing target macromolecules. With ESI-cryoPrep, we prepared high-quality cryo-specimens of five proteins and obtained three-dimensional reconstructions at near-atomic resolution. Our findings demonstrate that ESI-cryoPrep effectively confines macromolecules within the middle of the thin layer of amorphous ice, facilitating the preparation of blotting-free vitreous samples. The protective mechanism, characterized by the uneven distribution of charged biomolecules of varying sizes within charged droplets, prevents the adsorption of target biomolecules at air-water or graphene-water interfaces, thereby avoiding structural damage to the protein particles or the introduction of dominant orientation issues.
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Affiliation(s)
- Zi Yang
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center of Biological Structures, School of Life Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, China
| | - Jingjin Fan
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, China
| | - Jia Wang
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center of Biological Structures, School of Life Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, China
| | - Xiao Fan
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center of Biological Structures, School of Life Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, China
| | - Zheng Ouyang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, China.
| | - Hong-Wei Wang
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center of Biological Structures, School of Life Sciences, Tsinghua University, Beijing, China.
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, China.
| | - Xiaoyu Zhou
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, China.
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11
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Henderikx RJM, Mann D, Domanska A, Dong J, Shahzad S, Lak B, Filopoulou A, Ludig D, Grininger M, Momoh J, Laanto E, Oksanen HM, Bisikalo K, Williams PA, Butcher SJ, Peters PJ, Beulen BWAMM. VitroJet: new features and case studies. Acta Crystallogr D Struct Biol 2024; 80:232-246. [PMID: 38488730 PMCID: PMC10994172 DOI: 10.1107/s2059798324001852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 02/26/2024] [Indexed: 04/05/2024] Open
Abstract
Single-particle cryo-electron microscopy has become a widely adopted method in structural biology due to many recent technological advances in microscopes, detectors and image processing. Before being able to inspect a biological sample in an electron microscope, it needs to be deposited in a thin layer on a grid and rapidly frozen. The VitroJet was designed with this aim, as well as avoiding the delicate manual handling and transfer steps that occur during the conventional grid-preparation process. Since its creation, numerous technical developments have resulted in a device that is now widely utilized in multiple laboratories worldwide. It features plasma treatment, low-volume sample deposition through pin printing, optical ice-thickness measurement and cryofixation of pre-clipped Autogrids through jet vitrification. This paper presents recent technical improvements to the VitroJet and the benefits that it brings to the cryo-EM workflow. A wide variety of applications are shown: membrane proteins, nucleosomes, fatty-acid synthase, Tobacco mosaic virus, lipid nanoparticles, tick-borne encephalitis viruses and bacteriophages. These case studies illustrate the advancement of the VitroJet into an instrument that enables accurate control and reproducibility, demonstrating its suitability for time-efficient cryo-EM structure determination.
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Affiliation(s)
- Rene J. M. Henderikx
- CryoSol-World, Weert, The Netherlands
- Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, The Netherlands
| | - Daniel Mann
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C-3): Structural Biology, Forschungszentrum Jülich, Jülich, Germany
- Institute of Biological Information Processing (IBI-6): Structural Cell Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Aušra Domanska
- Molecular and Integrative Bioscience Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
- Helsinki Life Science Institute–Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
| | - Jing Dong
- Astex Pharmaceuticals, 436 Cambridge Science Park, Milton Road, Cambridge CB4 0QA, United Kingdom
| | - Saba Shahzad
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C-3): Structural Biology, Forschungszentrum Jülich, Jülich, Germany
- Institute of Biological Information Processing (IBI-6): Structural Cell Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Behnam Lak
- Molecular and Integrative Bioscience Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
- Helsinki Life Science Institute–Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
| | - Aikaterini Filopoulou
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C-3): Structural Biology, Forschungszentrum Jülich, Jülich, Germany
- Institute of Biological Information Processing (IBI-6): Structural Cell Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Damian Ludig
- Institute of Organic Chemistry and Chemical Biology, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Martin Grininger
- Institute of Organic Chemistry and Chemical Biology, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Jeffrey Momoh
- Department of Nanomedicine and Theranostics, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany
| | - Elina Laanto
- Department of Biological and Environmental Science, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Hanna M. Oksanen
- Molecular and Integrative Bioscience Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
| | - Kyrylo Bisikalo
- Molecular and Integrative Bioscience Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
- Helsinki Life Science Institute–Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
| | - Pamela A. Williams
- Astex Pharmaceuticals, 436 Cambridge Science Park, Milton Road, Cambridge CB4 0QA, United Kingdom
| | - Sarah J. Butcher
- Molecular and Integrative Bioscience Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
- Helsinki Life Science Institute–Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
| | - Peter J. Peters
- Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, The Netherlands
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12
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Gobet A, Moissonnier L, Chaptal V. CryoEM Data Analysis of Membrane Proteins. Practical Considerations on Amphipathic Belts, Ligands, and Variability Analysis. Methods Mol Biol 2024; 2715:471-483. [PMID: 37930545 DOI: 10.1007/978-1-0716-3445-5_28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2023]
Abstract
Membrane proteins data analysis by cryoEM shows some specificities, as can be found in other typical investigations such as biochemistry, biophysics, or X-ray crystallography. Membrane proteins are typically surrounded by an amphipathic belt that will have some degree of influence on the 3D reconstruction and analysis. In this chapter, we review our experience with the ABC transporter BmrA, as well as our statistical analysis of amphipathic belts around membrane proteins, to bring awareness on some particular features of membrane protein investigations by cryoEM.
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Affiliation(s)
- Alexia Gobet
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS University Lyon 1, Lyon, France
| | - Loïck Moissonnier
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS University Lyon 1, Lyon, France
| | - Vincent Chaptal
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS University Lyon 1, Lyon, France.
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13
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Kim JY, Yang JE, Mitchell JW, English LA, Yang SZ, Tenpas T, Dent EW, Wildonger J, Wright ER. Handling Difficult Cryo-ET Samples: A Study with Primary Neurons from Drosophila melanogaster. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:2127-2148. [PMID: 37966978 PMCID: PMC11168236 DOI: 10.1093/micmic/ozad125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 10/01/2023] [Accepted: 10/18/2023] [Indexed: 11/17/2023]
Abstract
Cellular neurobiology has benefited from recent advances in the field of cryo-electron tomography (cryo-ET). Numerous structural and ultrastructural insights have been obtained from plunge-frozen primary neurons cultured on electron microscopy grids. With most primary neurons having been derived from rodent sources, we sought to expand the breadth of sample availability by using primary neurons derived from 3rd instar Drosophila melanogaster larval brains. Ultrastructural abnormalities were encountered while establishing this model system for cryo-ET, which were exemplified by excessive membrane blebbing and cellular fragmentation. To optimize neuronal samples, we integrated substrate selection, micropatterning, montage data collection, and chemical fixation. Efforts to address difficulties in establishing Drosophila neurons for future cryo-ET studies in cellular neurobiology also provided insights that future practitioners can use when attempting to establish other cell-based model systems.
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Affiliation(s)
- Joseph Y. Kim
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Jie E. Yang
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Cryo-Electron Microscopy Research Center, University of Wisconsin-Madison, Madison, WI 53706, USA
- Midwest Center for Cryo-Electron Tomography, Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Josephine W. Mitchell
- Department of Chemistry and Biochemistry, Kalamazoo College, Kalamazoo, MI 49006, USA
| | - Lauren A. English
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Sihui Z. Yang
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Tanner Tenpas
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Erik W. Dent
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Jill Wildonger
- Departments of Pediatrics and Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Elizabeth R. Wright
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Cryo-Electron Microscopy Research Center, University of Wisconsin-Madison, Madison, WI 53706, USA
- Midwest Center for Cryo-Electron Tomography, Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, WI 53715, USA
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14
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Vénien-Bryan C, Fernandes CAH. Overview of Membrane Protein Sample Preparation for Single-Particle Cryo-Electron Microscopy Analysis. Int J Mol Sci 2023; 24:14785. [PMID: 37834233 PMCID: PMC10573263 DOI: 10.3390/ijms241914785] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 09/21/2023] [Accepted: 09/28/2023] [Indexed: 10/15/2023] Open
Abstract
Single-particle cryo-electron microscopy (cryo-EM SPA) has recently emerged as an exceptionally well-suited technique for determining the structure of membrane proteins (MPs). Indeed, in recent years, huge increase in the number of MPs solved via cryo-EM SPA at a resolution better than 3.0 Å in the Protein Data Bank (PDB) has been observed. However, sample preparation remains a significant challenge in the field. Here, we evaluated the MPs solved using cryo-EM SPA deposited in the PDB in the last two years at a resolution below 3.0 Å. The most critical parameters for sample preparation are as follows: (i) the surfactant used for protein extraction from the membrane, (ii) the surfactant, amphiphiles, nanodiscs or other molecules present in the vitrification step, (iii) the vitrification method employed, and (iv) the type of grids used. The aim is not to provide a definitive answer on the optimal sample conditions for cryo-EM SPA of MPs but rather assess the current trends in the MP structural biology community towards obtaining high-resolution cryo-EM structures.
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Affiliation(s)
| | - Carlos A. H. Fernandes
- Unité Mixte de Recherche (UMR) 7590, Centre National de la Recherche Scientifique (CNRS), Muséum National d’Histoire Naturelle, Institut de Recherche pour le Développement (IRD), Institut de Minéralogie, Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Université, 75005 Paris, France;
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15
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Lee D, Lee H, Lee J, Roh SH, Ha NC. Copper Oxide Spike Grids for Enhanced Solution Transfer in Cryogenic Electron Microscopy. Mol Cells 2023; 46:538-544. [PMID: 37528647 PMCID: PMC10495688 DOI: 10.14348/molcells.2023.0058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/27/2023] [Accepted: 06/27/2023] [Indexed: 08/03/2023] Open
Abstract
The formation of uniform vitreous ice is a crucial step in the preparation of samples for cryogenic electron microscopy (cryo-EM). Despite the rapid technological progress in EM, controlling the thickness of vitreous ice on sample grids with reproducibility remains a major obstacle to obtaining high-quality data in cryo-EM imaging. The commonly employed classical blotting process faces the problem of excess water that cannot be absorbed by the filter paper, resulting in the formation of thick and heterogeneous ice. In this study, we propose a novel approach that combines the recently developed nanowire self-wicking technique with the classical blotting method to effectively control the thickness and homogeneity of vitrified ice. With simple procedures, we generated a copper oxide spike (COS) grid by inducing COSs on commercially available copper grids, which can effectively remove excess water during the blotting procedure without damaging the holey carbon membrane. The ice thickness could be controlled with good reproducibility compared to non-oxidized grids. Incorporated into other EM techniques, our new modification method is an effective option for obtaining high-quality data during cryo-EM imaging.
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Affiliation(s)
- Dukwon Lee
- Research Institute of Agriculture and Life Sciences, Center for Food and Bioconvergence, Department of Agricultural Biotechnology, Interdisciplinary Programs in Agricultural Genomics, College of Agriculture and Life Sciences (CALS), Seoul National University, Seoul 08826, Korea
| | - Hansol Lee
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Korea
| | - Jinwook Lee
- Research Institute of Agriculture and Life Sciences, Center for Food and Bioconvergence, Department of Agricultural Biotechnology, Interdisciplinary Programs in Agricultural Genomics, College of Agriculture and Life Sciences (CALS), Seoul National University, Seoul 08826, Korea
| | - Soung-Hun Roh
- School of Biological Sciences, Seoul National University, Seoul 08826, Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Korea
| | - Nam-Chul Ha
- Research Institute of Agriculture and Life Sciences, Center for Food and Bioconvergence, Department of Agricultural Biotechnology, Interdisciplinary Programs in Agricultural Genomics, College of Agriculture and Life Sciences (CALS), Seoul National University, Seoul 08826, Korea
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16
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Han BG, Avila-Sakar A, Remis J, Glaeser RM. Challenges in making ideal cryo-EM samples. Curr Opin Struct Biol 2023; 81:102646. [PMID: 37392555 DOI: 10.1016/j.sbi.2023.102646] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 06/02/2023] [Accepted: 06/02/2023] [Indexed: 07/03/2023]
Abstract
Recognizing that interaction with the air-water interface (AWI) is a major challenge for cryo-EM, we first review current approaches designed to avoid it. Of these, immobilizing particles on affinity grids is arguably the most promising. In addition, we review efforts to gain more reliable control of the sample thicknesses, not the least important reason being to prevent immobilized particles from coming in contact with the AWI of the remaining buffer. It is emphasized that avoiding such a contact is as important for cryo-ET as for single-particle cryo-EM. Finally, looking to the future, it is proposed that immobilized samples might be used to perform time-resolved biochemical experiments directly on EM grids rather than just in test tubes or cuvettes.
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Affiliation(s)
- Bong-Gyoon Han
- Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720, USA
| | - Agustin Avila-Sakar
- Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720, USA
| | - Jonathan Remis
- Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Robert M Glaeser
- Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720, USA.
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17
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Kim JY, Yang JE, Mitchell JW, English LA, Yang SZ, Tenpas T, Dent EW, Wildonger J, Wright ER. Handling difficult cryo-ET samples: A study with primary neurons from Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.10.548468. [PMID: 37502991 PMCID: PMC10369871 DOI: 10.1101/2023.07.10.548468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Cellular neurobiology has benefited from recent advances in the field of cryo-electron tomography (cryo-ET). Numerous structural and ultrastructural insights have been obtained from plunge-frozen primary neurons cultured on electron microscopy grids. With most primary neurons been derived from rodent sources, we sought to expand the breadth of sample availability by using primary neurons derived from 3rd instar Drosophila melanogaster larval brains. Ultrastructural abnormalities were encountered while establishing this model system for cryo-ET, which were exemplified by excessive membrane blebbing and cellular fragmentation. To optimize neuronal samples, we integrated substrate selection, micropatterning, montage data collection, and chemical fixation. Efforts to address difficulties in establishing Drosophila neurons for future cryo-ET studies in cellular neurobiology also provided insights that future practitioners can use when attempting to establish other cell-based model systems.
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Affiliation(s)
- Joseph Y. Kim
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Jie E. Yang
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Cryo-Electron Microscopy Research Center, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Midwest Center for Cryo-Electron Tomography, Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Josephine W. Mitchell
- Department of Chemistry and Biochemistry, Kalamazoo College, Kalamazoo, MI, 49006, USA
| | - Lauren A. English
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Sihui Z. Yang
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Tanner Tenpas
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Erik W. Dent
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Jill Wildonger
- Departments of Pediatrics and Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Elizabeth R. Wright
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Cryo-Electron Microscopy Research Center, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Midwest Center for Cryo-Electron Tomography, Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, WI, 53715, USA
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18
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Wong CF, Leow CY, Grüber G. Cryo-EM structure of the Mycobacterium abscessus F 1-ATPase. Biochem Biophys Res Commun 2023; 671:140-145. [PMID: 37302287 DOI: 10.1016/j.bbrc.2023.05.095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 05/14/2023] [Accepted: 05/24/2023] [Indexed: 06/13/2023]
Abstract
The cases of lung disease caused by non-tuberculous mycobacterium Mycobacterium abscessus (Mab) are increasing and not reliably curable. Repurposing of anti-tuberculosis inhibitors brought the oxidative phosphorylation pathway with its final product ATP, formed by the essential F1FO-ATP synthase (subunits α3:β3:γ:δ:ε:a:b:b':c9), into focus as an attractive inhibitor target against Mab. Because of the pharmacological attractiveness of this enzyme, we generated and purified a recombinant and enzymatically active Mab F1-ATPase complex, including subunits α3:β3:γ:δ:ε (MabF1-αβγδε) to achieve mechanistic, regulatory, and structural insights. The high purity of the complex enabled the first cryo-electron microscopy structure determination of the Mab F1-ATPase complex to 7.3 Å resolution. The enzyme showed low ATP hydrolysis activity, which was stimulated by trypsin treatment. No effect was observed in the presence of the detergent lauryldimethylamine oxide.
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Affiliation(s)
- Chui-Fann Wong
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore
| | - Chen-Yen Leow
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore
| | - Gerhard Grüber
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore.
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19
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Michon B, López-Sánchez U, Degrouard J, Nury H, Leforestier A, Rio E, Salonen A, Zoonens M. Role of surfactants in electron cryo-microscopy film preparation. Biophys J 2023; 122:1846-1857. [PMID: 37077048 PMCID: PMC10209149 DOI: 10.1016/j.bpj.2023.04.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 01/01/2023] [Accepted: 04/13/2023] [Indexed: 04/21/2023] Open
Abstract
Single-particle electron cryo-microscopy (cryo-EM) has become an effective and straightforward approach to determine the structure of membrane proteins. However, obtaining cryo-EM grids of sufficient quality for high-resolution structural analysis remains a major bottleneck. One of the difficulties arises from the presence of detergents, which often leads to a lack of control of the ice thickness. Amphipathic polymers such as amphipols (APols) are detergent substitutes, which have proven to be valuable tools for cryo-EM studies. In this work, we investigate the physico-chemical behavior of APol- and detergent-containing solutions and show a correlation with the properties of vitreous thin films in cryo-EM grids. This study provides new insight on the potential of APols, allowing a better control of ice thickness while limiting protein adsorption at the air-water interface, as shown with the full-length mouse serotonin 5-HT3A receptor whose structure has been solved in APol. These findings may speed up the process of grid optimization to obtain high-resolution structures of membrane proteins.
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Affiliation(s)
- Baptiste Michon
- Université Paris Cité, Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, UMR 7099, Paris, France; Institut de Biologie Physico-Chimique, Fondation Edmond de Rothschild pour le développement de la recherche scientifique, Paris, France
| | | | - Jéril Degrouard
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay, France
| | - Hugues Nury
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
| | - Amélie Leforestier
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay, France.
| | - Emmanuelle Rio
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay, France
| | - Anniina Salonen
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, Orsay, France
| | - Manuela Zoonens
- Université Paris Cité, Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, CNRS, UMR 7099, Paris, France; Institut de Biologie Physico-Chimique, Fondation Edmond de Rothschild pour le développement de la recherche scientifique, Paris, France.
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20
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Tollervey F, Zhang X, Bose M, Sachweh J, Woodruff JB, Franzmann TM, Mahamid J. Cryo-Electron Tomography of Reconstituted Biomolecular Condensates. Methods Mol Biol 2023; 2563:297-324. [PMID: 36227480 DOI: 10.1007/978-1-0716-2663-4_15] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The assembly of membraneless compartments by phase separation has recently been recognized as a mechanism for spatial and temporal organization of biomolecules within the cell. The functions of such mesoscale assemblies, termed biomolecular condensates, depend on networks of multivalent interactions between proteins, their structured and disordered domains, and commonly also include nucleic acids. Cryo-electron tomography is an ideal tool to investigate the three-dimensional architecture of such pleomorphic interaction networks at nanometer resolution and thus form inferences about function. However, preparation of suitable cryo-electron microscopy samples of condensates may be prone to protein denaturation, low retention of material on the sample carrier, and contamination associated with cryo-sample preparation and transfers. Here, we describe a series of protocols designed to obtain high-quality cryo-electron tomography data of biomolecular condensates reconstituted in vitro. These include critical screening by light microscopy, cryo-fixation by plunge freezing, sample loading into an electron microscope operated at liquid nitrogen temperature, data collection, processing of the data into three-dimensional tomograms, and their interpretation.
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Affiliation(s)
- Fergus Tollervey
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Collaboration for Joint PhD Between EMBL and Heidelberg University Faculty of Biosciences, Heidelberg, Germany
| | - Xiaojie Zhang
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Mainak Bose
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Jenny Sachweh
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Jeffrey B Woodruff
- Department of Cell Biology, Department of Biophysics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Titus M Franzmann
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Dresden, Germany
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
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21
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Zheng L, Liu N, Gao X, Zhu W, Liu K, Wu C, Yan R, Zhang J, Gao X, Yao Y, Deng B, Xu J, Lu Y, Liu Z, Li M, Wei X, Wang HW, Peng H. Uniform thin ice on ultraflat graphene for high-resolution cryo-EM. Nat Methods 2023; 20:123-130. [PMID: 36522503 PMCID: PMC9834055 DOI: 10.1038/s41592-022-01693-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 10/20/2022] [Indexed: 12/23/2022]
Abstract
Cryo-electron microscopy (cryo-EM) visualizes the atomic structure of macromolecules that are embedded in vitrified thin ice at their close-to-native state. However, the homogeneity of ice thickness, a key factor to ensure high image quality, is poorly controlled during specimen preparation and has become one of the main challenges for high-resolution cryo-EM. Here we found that the uniformity of thin ice relies on the surface flatness of the supporting film, and developed a method to use ultraflat graphene (UFG) as the support for cryo-EM specimen preparation to achieve better control of vitreous ice thickness. We show that the uniform thin ice on UFG improves the image quality of vitrified specimens. Using such a method we successfully determined the three-dimensional structures of hemoglobin (64 kDa), α-fetoprotein (67 kDa) with no symmetry, and streptavidin (52 kDa) at a resolution of 3.5 Å, 2.6 Å and 2.2 Å, respectively. Furthermore, our results demonstrate the potential of UFG for the fields of cryo-electron tomography and structure-based drug discovery.
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Affiliation(s)
- Liming Zheng
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Beijing Graphene Institute (BGI), Beijing, China
| | - Nan Liu
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structures, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.
| | - Xiaoyin Gao
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Wenqing Zhu
- State Key Laboratory for Turbulence and Complex System, Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing, China
| | - Kun Liu
- Hainan Provincial Key Laboratory of Carcinogenesis and Intervention, Hainan Medical College, Haikou, China
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Cang Wu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Rui Yan
- Beijing Graphene Institute (BGI), Beijing, China
| | - Jincan Zhang
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Xin Gao
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Yating Yao
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Bing Deng
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | - Jie Xu
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structures, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, China
| | - Ye Lu
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structures, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, China
| | - Zhongmin Liu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Mengsen Li
- Hainan Provincial Key Laboratory of Carcinogenesis and Intervention, Hainan Medical College, Haikou, China
| | - Xiaoding Wei
- State Key Laboratory for Turbulence and Complex System, Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing, China.
- Beijing Innovation Center for Engineering Science and Advanced Technology, Peking University, Beijing, China.
- Peking University Nanchang Innovation Institute, Nanchang, China.
| | - Hong-Wei Wang
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structures, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China.
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, China.
| | - Hailin Peng
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
- Beijing Graphene Institute (BGI), Beijing, China.
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
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22
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Rima L, Zimmermann M, Fränkl A, Clairfeuille T, Lauer M, Engel A, Engel HA, Braun T. cryoWriter: a blotting free cryo-EM preparation system with a climate jet and cover-slip injector. Faraday Discuss 2022; 240:55-66. [PMID: 35924676 PMCID: PMC9641993 DOI: 10.1039/d2fd00066k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Electron microscopy (EM) introduced a fast and lasting change to structural and cellular biology. However, the sample preparation is still the bottleneck in the cryogenic electron microscopy (cryo-EM) workflow. Classical specimen preparation methods employ a harsh paper-blotting step, and the protein particles are exposed to a damaging air-water interface. Therefore, improved preparation strategies are urgently needed. Here, we present an amended microfluidic sample preparation method, which entirely avoids paper blotting and allows the passivation of the air-water interface during the preparation process. First, a climate jet excludes oxygen from the sample environment and controls the preparation temperature by varying the relative humidity of the grid environment. Second, the integrated "coverslip injector" allows the modulation of the air-water interface of the thin sample layer with effector molecules. We will briefly discuss the climate jet's effect on the stability and dynamics of the sample thin films. Furthermore, we will address the coverslip injector and demonstrate significant improvement in the sample quality.
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Affiliation(s)
- Luca Rima
- Biozentrum, University of BaselSpitalstrasse 414056 BaselSwitzerland+41 79 7337269
| | - Michael Zimmermann
- Biozentrum, University of BaselSpitalstrasse 414056 BaselSwitzerland+41 79 7337269
| | - Andri Fränkl
- Swiss Nanoscience Institute, University of Basel4056 BaselSwitzerland
| | - Thomas Clairfeuille
- Roche Pharma Research and Early Development, Therapeutic Modalities, Lead Discovery, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd.Grenzacherstrasse 1244070 BaselSwitzerland
| | - Matthias Lauer
- Roche Pharma Research and Early Development, Therapeutic Modalities, Lead Discovery, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd.Grenzacherstrasse 1244070 BaselSwitzerland
| | - Andreas Engel
- cryoWrite Ltd.Klingelbergstrasse 504056 BaselSwitzerland
| | | | - Thomas Braun
- Biozentrum, University of BaselSpitalstrasse 414056 BaselSwitzerland+41 79 7337269
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23
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Reynolds MJ, Hachicho C, Carl AG, Gong R, Alushin GM. Bending forces and nucleotide state jointly regulate F-actin structure. Nature 2022; 611:380-386. [PMID: 36289330 PMCID: PMC9646526 DOI: 10.1038/s41586-022-05366-w] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 09/20/2022] [Indexed: 02/05/2023]
Abstract
ATP-hydrolysis-coupled actin polymerization is a fundamental mechanism of cellular force generation1-3. In turn, force4,5 and actin filament (F-actin) nucleotide state6 regulate actin dynamics by tuning F-actin's engagement of actin-binding proteins through mechanisms that are unclear. Here we show that the nucleotide state of actin modulates F-actin structural transitions evoked by bending forces. Cryo-electron microscopy structures of ADP-F-actin and ADP-Pi-F-actin with sufficient resolution to visualize bound solvent reveal intersubunit interfaces bridged by water molecules that could mediate filament lattice flexibility. Despite extensive ordered solvent differences in the nucleotide cleft, these structures feature nearly identical lattices and essentially indistinguishable protein backbone conformations that are unlikely to be discriminable by actin-binding proteins. We next introduce a machine-learning-enabled pipeline for reconstructing bent filaments, enabling us to visualize both continuous structural variability and side-chain-level detail. Bent F-actin structures reveal rearrangements at intersubunit interfaces characterized by substantial alterations of helical twist and deformations in individual protomers, transitions that are distinct in ADP-F-actin and ADP-Pi-F-actin. This suggests that phosphate rigidifies actin subunits to alter the bending structural landscape of F-actin. As bending forces evoke nucleotide-state dependent conformational transitions of sufficient magnitude to be detected by actin-binding proteins, we propose that actin nucleotide state can serve as a co-regulator of F-actin mechanical regulation.
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Affiliation(s)
- Matthew J Reynolds
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
| | - Carla Hachicho
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
| | - Ayala G Carl
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
- Tri-Institutional Program in Chemical Biology, The Rockefeller University, New York, NY, USA
| | - Rui Gong
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA
| | - Gregory M Alushin
- Laboratory of Structural Biophysics and Mechanobiology, The Rockefeller University, New York, NY, USA.
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24
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Hrebík D, Gondová M, Valentová L, Füzik T, Přidal A, Nováček J, Plevka P. Polyelectrolyte coating of cryo-EM grids improves lateral distribution and prevents aggregation of macromolecules. Acta Crystallogr D Struct Biol 2022; 78:1337-1346. [PMID: 36322417 PMCID: PMC9629489 DOI: 10.1107/s2059798322009299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 09/21/2022] [Indexed: 11/06/2022] Open
Abstract
Cryo-electron microscopy (cryo-EM) is one of the primary methods used to determine the structures of macromolecules and their complexes. With the increased availability of cryo-electron microscopes, the preparation of high-quality samples has become a bottleneck in the cryo-EM structure-determination pipeline. Macromolecules can be damaged during the purification or preparation of vitrified samples for cryo-EM, making them prone to binding to the grid support, to aggregation or to the adoption of preferential orientations at the air-water interface. Here, it is shown that coating cryo-EM grids with a negatively charged polyelectrolyte, such as single-stranded DNA, before applying the sample reduces the aggregation of macromolecules and improves their distribution. The single-stranded DNA-coated grids enabled the determination of high-resolution structures from samples that aggregated on conventional grids. The polyelectrolyte coating reduces the diffusion of macromolecules and thus may limit the negative effects of the contact of macromolecules with the grid support and blotting paper, as well as of the shear forces on macromolecules during grid blotting. Coating grids with polyelectrolytes can readily be employed in any laboratory dealing with cryo-EM sample preparation, since it is fast, simple, inexpensive and does not require specialized equipment.
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Affiliation(s)
- Dominik Hrebík
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Mária Gondová
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Lucie Valentová
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Tibor Füzik
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Antonín Přidal
- Faculty of Agronomy, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic
| | - Jiří Nováček
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Pavel Plevka
- Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
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25
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Chua EYD, Mendez JH, Rapp M, Ilca SL, Tan YZ, Maruthi K, Kuang H, Zimanyi CM, Cheng A, Eng ET, Noble AJ, Potter CS, Carragher B. Better, Faster, Cheaper: Recent Advances in Cryo-Electron Microscopy. Annu Rev Biochem 2022; 91:1-32. [PMID: 35320683 PMCID: PMC10393189 DOI: 10.1146/annurev-biochem-032620-110705] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cryo-electron microscopy (cryo-EM) continues its remarkable growth as a method for visualizing biological objects, which has been driven by advances across the entire pipeline. Developments in both single-particle analysis and in situ tomography have enabled more structures to be imaged and determined to better resolutions, at faster speeds, and with more scientists having improved access. This review highlights recent advances at each stageof the cryo-EM pipeline and provides examples of how these techniques have been used to investigate real-world problems, including antibody development against the SARS-CoV-2 spike during the recent COVID-19 pandemic.
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Affiliation(s)
- Eugene Y D Chua
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Center for CryoEM Access and Training, New York, NY, USA
| | - Joshua H Mendez
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Center for CryoEM Access and Training, New York, NY, USA
| | - Micah Rapp
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
| | - Serban L Ilca
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
| | - Yong Zi Tan
- Department of Biological Sciences, National University of Singapore, Singapore;
- Disease Intervention Technology Laboratory, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Kashyap Maruthi
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Resource for Automated Molecular Microscopy, New York, NY, USA
| | - Huihui Kuang
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Resource for Automated Molecular Microscopy, New York, NY, USA
| | - Christina M Zimanyi
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Center for CryoEM Access and Training, New York, NY, USA
| | - Anchi Cheng
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Resource for Automated Molecular Microscopy, New York, NY, USA
| | - Edward T Eng
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Center for CryoEM Access and Training, New York, NY, USA
| | - Alex J Noble
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Resource for Automated Molecular Microscopy, New York, NY, USA
- National Center for In-Situ Tomographic Ultramicroscopy, New York, NY, USA
- Simons Machine Learning Center, New York, NY, USA
| | - Clinton S Potter
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Center for CryoEM Access and Training, New York, NY, USA
- National Resource for Automated Molecular Microscopy, New York, NY, USA
- National Center for In-Situ Tomographic Ultramicroscopy, New York, NY, USA
- Simons Machine Learning Center, New York, NY, USA
| | - Bridget Carragher
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Center for CryoEM Access and Training, New York, NY, USA
- National Resource for Automated Molecular Microscopy, New York, NY, USA
- National Center for In-Situ Tomographic Ultramicroscopy, New York, NY, USA
- Simons Machine Learning Center, New York, NY, USA
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26
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Han BG, Armstrong M, Fletcher DA, Glaeser RM. Perspective: Biochemical and Physical Constraints Associated With Preparing Thin Specimens for Single-Particle Cryo-EM. Front Mol Biosci 2022; 9:864829. [PMID: 35573724 PMCID: PMC9100935 DOI: 10.3389/fmolb.2022.864829] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/25/2022] [Indexed: 11/13/2022] Open
Abstract
While many aspects of single-particle electron cryo-microscopy (cryo-EM) of biological macromolecules have reached a sophisticated level of development, this is not yet the case when it comes to preparing thin samples on specimen grids. As a result, there currently is considerable interest in achieving better control of both the sample thickness and the amount of area that is useful, but this is only one aspect in which improvement is needed. This Perspective addresses the further need to prevent the macromolecular particles from making contact with the air-water interface, something that can result in preferential orientation and even structural disruption of macromolecular particles. This unwanted contact can occur either as the result of free diffusion of particles during the interval between application, thinning and vitrification of the remaining buffer, or-when particles have been immobilized-by the film of buffer becoming too thin prior to vitrification. An opportunity now exists to apply theoretical and practical insights from the fields of thin-film physical chemistry and interfacial science, in an effort to bring cryo-EM sample preparation to a level of sophistication that is comparable to that of current data collection and analysis.
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Affiliation(s)
- Bong-Gyoon Han
- Lawrence Berkeley National Laboratory, University of California, Berkeley, Berkeley, CA, United States
| | - Max Armstrong
- Lawrence Berkeley National Laboratory, University of California, Berkeley, Berkeley, CA, United States,Department of Bioengineering, University of California, Berkeley, Berkeley, CA, United States
| | - Daniel A. Fletcher
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, United States,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, Berkeley, CA, United States,Chan Zuckerberg Biohub, San Francisco, CA, United States
| | - Robert M. Glaeser
- Lawrence Berkeley National Laboratory, University of California, Berkeley, Berkeley, CA, United States,*Correspondence: Robert M. Glaeser,
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27
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Ahn E, Tang T, Kim B, Lee HJ, Cho US. Development of an atmospheric plasma jet device for versatile treatment of electron microscope sample grids. J Biol Chem 2022; 298:101793. [PMID: 35248533 PMCID: PMC8980800 DOI: 10.1016/j.jbc.2022.101793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 11/26/2022] Open
Abstract
Atmospheric-pressure plasmas have been widely applied for surface modification and biomedical treatment because of their ability to generate highly reactive radicals and charged particles. In negative-stain electron microscopy (Neg-EM) and cryogenic electron microscopy (cryo-EM), plasmas have been used to generate hydrophilic surfaces and eliminate surface contaminants to embed specimens onto grids. In addition, plasma treatment is a prerequisite for negative-stain and Quantifoil grids, whose surfaces are coated with hydrophobic amorphous carbon. Although the conventional glow discharge system has been used successfully in this purpose, there has been no further effort to take an advantage from the recent progress in the plasma field. Here, we developed a nonthermal atmospheric plasma jet system as an alternative tool for treatment of surfaces. The low-temperature plasma is a nonequilibrium system that has been widely used in biomedical area. Unlike conventional glow discharge systems, the plasma jet system successfully cleans and introduces hydrophilicity on the grid surface in the ambient environment without a vacuum. Therefore, we anticipate that the plasma jet system will have numerous benefits, such as convenience and versatility, as well as having potential applications in surface modification for both negative-stain and cryo-EM grid treatment.
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Affiliation(s)
- Eungjin Ahn
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Tianyu Tang
- Department of Electrical and Computer Engineering, Pusan National University, Busan 46241, South Korea
| | - Byungchul Kim
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Hae June Lee
- Department of Electrical and Computer Engineering, Pusan National University, Busan 46241, South Korea
| | - Uhn-Soo Cho
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
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28
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Huber ST, Sarajlic E, Huijink R, Weis F, Evers WH, Jakobi AJ. Nanofluidic chips for cryo-EM structure determination from picoliter sample volumes. eLife 2022; 11:72629. [PMID: 35060902 PMCID: PMC8786315 DOI: 10.7554/elife.72629] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 12/07/2021] [Indexed: 01/25/2023] Open
Abstract
Cryogenic electron microscopy has become an essential tool for structure determination of biological macromolecules. In practice, the difficulty to reliably prepare samples with uniform ice thickness still represents a barrier for routine high-resolution imaging and limits the current throughput of the technique. We show that a nanofluidic sample support with well-defined geometry can be used to prepare cryo-EM specimens with reproducible ice thickness from picoliter sample volumes. The sample solution is contained in electron-transparent nanochannels that provide uniform thickness gradients without further optimisation and eliminate the potentially destructive air-water interface. We demonstrate the possibility to perform high-resolution structure determination with three standard protein specimens. Nanofabricated sample supports bear potential to automate the cryo-EM workflow, and to explore new frontiers for cryo-EM applications such as time-resolved imaging and high-throughput screening.
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Affiliation(s)
- Stefan T Huber
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology
| | | | | | - Felix Weis
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL)
| | - Wiel H Evers
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology
| | - Arjen J Jakobi
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology
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29
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Levitz TS, Brignole EJ, Fong I, Darrow MC, Drennan CL. Effects of chameleon dispense-to-plunge speed on particle concentration, complex formation, and final resolution: A case study using the Neisseria gonorrhoeae ribonucleotide reductase inactive complex. J Struct Biol 2021; 214:107825. [PMID: 34906669 PMCID: PMC8994553 DOI: 10.1016/j.jsb.2021.107825] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 11/11/2021] [Accepted: 12/06/2021] [Indexed: 12/16/2022]
Abstract
Ribonucleotide reductase (RNR) is an essential enzyme that converts ribonucleotides to deoxyribonucleotides and is a promising antibiotic target, but few RNRs have been structurally characterized. We present the use of the chameleon, a commercially-available piezoelectric cryogenic electron microscopy plunger, to address complex denaturation in the Neisseria gonorrhoeae class Ia RNR. Here, we characterize the extent of denaturation of the ring-shaped complex following grid preparation using a traditional plunger and using a chameleon with varying dispense-to-plunge times. We also characterize how dispense-to-plunge time influences the amount of protein sample required for grid preparation and preferred orientation of the sample. We demonstrate that the fastest dispense-to-plunge time of 54 ms is sufficient for generation of a data set that produces a high quality structure, and that a traditional plunging technique or slow chameleon dispense-to-plunge times generate data sets limited in resolution by complex denaturation. The 4.3 Å resolution structure of Neisseria gonorrhoeae class Ia RNR in the inactive α4β4 oligomeric state solved using the chameleon with a fast dispense-to-plunge time yields molecular information regarding similarities and differences to the well studied Escherichia coli class Ia RNR α4β4 ring.
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Affiliation(s)
- Talya S Levitz
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA
| | - Edward J Brignole
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA; MIT.nano, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA
| | - Ivan Fong
- SPT Labtech Melbourn Science Park, Cambridge Rd, Melbourn SG8 6HB, United Kingdom
| | - Michele C Darrow
- SPT Labtech Melbourn Science Park, Cambridge Rd, Melbourn SG8 6HB, United Kingdom.
| | - Catherine L Drennan
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA; Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA.
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30
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Grundler J, Shin K, Suh HW, Zhong M, Saltzman WM. Surface Topography of Polyethylene Glycol Shell Nanoparticles Formed from Bottlebrush Block Copolymers Controls Interactions with Proteins and Cells. ACS NANO 2021; 15:16118-16129. [PMID: 34633171 PMCID: PMC8919421 DOI: 10.1021/acsnano.1c04835] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Although poly(ethylene glycol) (PEG) is commonly used in nanoparticle design, the impact of surface topography on nanoparticle performance in biomedical applications has received little attention, despite showing significant promise in the study of inorganic nanoparticles. Control of the surface topography of polymeric nanoparticles is a formidable challenge due to the limited conformational control of linear polymers that form the nanoparticle surface. In this work, we establish a straightforward method to precisely tailor the surface topography of PEGylated polymeric nanoparticles based on tuning the architecture of shape-persistent amphiphilic bottlebrush block copolymer (BBCP) building blocks. We demonstrate that nanoparticle formation and surface topography can be controlled by systematically changing the structural parameters of BBCP architecture. Furthermore, we reveal that the surface topography of PEGylated nanoparticles significantly affects their performance. In particular, the adsorption of a model protein and the uptake into HeLa cells were closely correlated to surface roughness and BBCP terminal PEG block brush width. Overall, our work elucidates the importance of surface topography in nanoparticle research as well as provides an approach to improve the performance of PEGylated nanoparticles.
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Affiliation(s)
- Julian Grundler
- Department of Chemistry, Yale University, New Haven, CT 06511 (USA)
- Department of Biomedical Engineering, Yale University, New Haven, CT 06511 (USA)
| | - Kwangsoo Shin
- Department of Biomedical Engineering, Yale University, New Haven, CT 06511 (USA)
| | - Hee-Won Suh
- Department of Biomedical Engineering, Yale University, New Haven, CT 06511 (USA)
| | - Mingjiang Zhong
- Department of Chemistry, Yale University, New Haven, CT 06511 (USA)
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06511 (USA)
| | - W. Mark Saltzman
- Department of Biomedical Engineering, Yale University, New Haven, CT 06511 (USA)
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31
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Abstract
In the recent years, the protein databank has been fueled by the exponential growth of high-resolution electron cryo-microscopy (cryo-EM) structures. This trend will be further accelerated through the continuous software and method developments and the increasing availability of imaging centers, which will open cryo-EM to a wide array of researchers with their diverse scientific goals and questions. Especially for structural biology of membrane proteins, cryo-EM offers significant advantages as it can overcome multiple limitations of classical methods. Most importantly, in cryo-EM, the sample is prepared as a vitrified suspension, which abolishes the need for crystallization, reduces the required sample amount and allows usage of a wide arsenal of hydrophobic environments. Despite recent improvements, high-resolution cryo-EM still poses some significant challenges, and standardized procedures, especially for the characterization of membrane proteins, are missing. While there can be no ultimate recipe toward a high-resolution cryo-EM structure for every membrane protein, certain factors seem to be universally relevant. Here, we share the protocols that have been successfully used in our laboratory. We hope that this may be a useful resource to other researchers in the field and may increase their chances of success.
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Affiliation(s)
- Dovile Januliene
- Max-Planck Institute of Biophysics, Frankfurt, Germany.,Department of Structural Biology, University of Osnabrück, Osnabrück, Germany
| | - Arne Moeller
- Max-Planck Institute of Biophysics, Frankfurt, Germany. .,Department of Structural Biology, University of Osnabrück, Osnabrück, Germany.
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32
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Zielinski M, Röder C, Schröder GF. Challenges in sample preparation and structure determination of amyloids by cryo-EM. J Biol Chem 2021; 297:100938. [PMID: 34224730 PMCID: PMC8335658 DOI: 10.1016/j.jbc.2021.100938] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 01/12/2023] Open
Abstract
Amyloids share a common architecture but play disparate biological roles in processes ranging from bacterial defense mechanisms to protein misfolding diseases. Their structures are highly polymorphic, which makes them difficult to study by X-ray diffraction or NMR spectroscopy. Our understanding of amyloid structures is due in large part to recent advances in the field of cryo-EM, which allows for determining the polymorphs separately. In this review, we highlight the main stepping stones leading to the substantial number of high-resolution amyloid fibril structures known today as well as recent developments regarding automation and software in cryo-EM. We discuss that sample preparation should move closer to physiological conditions to understand how amyloid aggregation and disease are linked. We further highlight new approaches to address heterogeneity and polymorphism of amyloid fibrils in EM image processing and give an outlook to the upcoming challenges in researching the structural biology of amyloids.
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Affiliation(s)
- Mara Zielinski
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7) and JuStruct, Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Christine Röder
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7) and JuStruct, Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany; Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Gunnar F Schröder
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7) and JuStruct, Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany; Physics Department, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
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33
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Januliene D, Moeller A. Cryo-EM of ABC transporters: an ice-cold solution to everything? FEBS Lett 2021; 594:3776-3789. [PMID: 33156959 DOI: 10.1002/1873-3468.13989] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/28/2020] [Accepted: 10/27/2020] [Indexed: 01/10/2023]
Abstract
High-resolution cryo-EM has revolutionized how we look at ABC transporters and membrane proteins in general. An ever-increasing number of software tools and faster processing now allow dissecting the molecular details of nanomachines at atomic precision. Considering the further benefits of significantly reduced sample demands and increased speed, cryo-EM will dominate the structure determination of membrane proteins in the near future without compromising on data quality or detail. Moreover, improved and new algorithms make it now possible to resolve the conformational spectrum of macromolecular machines under turnover conditions and to analyze heterogeneous samples at high resolution. The future of cryo-EM is, therefore, bright, and the growing number of imaging facilities and groups active in this field will amplify this trend even further. Nevertheless, expectations have to be managed, as cryo-EM alone cannot provide an ultimate answer to all scientific questions. In this review, we discuss the capabilities and limitations of cryo-EM together with possible solutions for studies of ABC transporters.
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Affiliation(s)
- Dovile Januliene
- University of Osnabrück, Germany.,Max-Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Arne Moeller
- University of Osnabrück, Germany.,Max-Planck Institute of Biophysics, Frankfurt am Main, Germany
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34
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Weissenberger G, Henderikx RJM, Peters PJ. Understanding the invisible hands of sample preparation for cryo-EM. Nat Methods 2021; 18:463-471. [PMID: 33963356 DOI: 10.1038/s41592-021-01130-6] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 03/30/2021] [Indexed: 02/03/2023]
Abstract
Cryo-electron microscopy (cryo-EM) is rapidly becoming an attractive method in the field of structural biology. With the exploding popularity of cryo-EM, sample preparation must evolve to prevent congestion in the workflow. The dire need for improved microscopy samples has led to a diversification of methods. This Review aims to categorize and explain the principles behind various techniques in the preparation of vitrified samples for the electron microscope. Various aspects and challenges in the workflow are discussed, from sample optimization and carriers to deposition and vitrification. Reliable and versatile specimen preparation remains a challenge, and we hope to give guidelines and posit future directions for improvement.
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Affiliation(s)
- Giulia Weissenberger
- CryoSol-World, Maastricht, the Netherlands.,Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, the Netherlands
| | - Rene J M Henderikx
- CryoSol-World, Maastricht, the Netherlands.,Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, the Netherlands
| | - Peter J Peters
- Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, the Netherlands.
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35
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Efremov RG, Stroobants A. Coma-corrected rapid single-particle cryo-EM data collection on the CRYO ARM 300. Acta Crystallogr D Struct Biol 2021; 77:555-564. [PMID: 33950012 PMCID: PMC8098478 DOI: 10.1107/s2059798321002151] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 02/23/2021] [Indexed: 01/22/2023] Open
Abstract
Single-particle cryogenic electron microscopy has recently become a major method for determining the structures of proteins and protein complexes. This has markedly increased the demand for throughput of high-resolution electron microscopes, which are required to produce high-resolution images at high rates. An increase in data-collection throughput can be achieved by using large beam-image shifts combined with off-axis coma correction, enabling the acquisition of multiple images from a large area of the EM grid without moving the microscope stage. Here, the optical properties of the JEOL CRYO ARM 300 electron microscope equipped with a K3 camera were characterized under off-axis illumination conditions. It is shown that efficient coma correction can be achieved for beam-image shifts with an amplitude of at least 10 µm, enabling a routine throughput for data collection of between 6000 and 9000 images per day. Use of the benchmark for the rapid data-collection procedure (with beam-image shifts of up to 7 µm) on apoferritin resulted in a reconstruction at a resolution of 1.7 Å. This demonstrates that the rapid automated acquisition of high-resolution micrographs is possible using a CRYO ARM 300.
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Affiliation(s)
- Rouslan G. Efremov
- Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050 Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Annelore Stroobants
- Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050 Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
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36
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Amphipathic environments for determining the structure of membrane proteins by single-particle electron cryo-microscopy. Q Rev Biophys 2021; 54:e6. [PMID: 33785082 DOI: 10.1017/s0033583521000044] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Over the past decade, the structural biology of membrane proteins (MPs) has taken a new turn thanks to epoch-making technical progress in single-particle electron cryo-microscopy (cryo-EM) as well as to improvements in sample preparation. The present analysis provides an overview of the extent and modes of usage of the various types of surfactants for cryo-EM studies. Digitonin, dodecylmaltoside, protein-based nanodiscs, lauryl maltoside-neopentyl glycol, glyco-diosgenin, and amphipols (APols) are the most popular surfactants at the vitrification step. Surfactant exchange is frequently used between MP purification and grid preparation, requiring extensive optimization each time the study of a new MP is undertaken. The variety of both the surfactants and experimental approaches used over the past few years bears witness to the need to continue developing innovative surfactants and optimizing conditions for sample preparation. The possibilities offered by novel APols for EM applications are discussed.
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Abstract
CryoEM has become the method of choice for determining the structure of large macromolecular complexes in multiple conformations, at resolutions where unambiguous atomic models can be built. Two effects that have limited progress in single-particle cryoEM are (i) beam-induced movement during image acquisition and (ii) protein adsorption and denaturation at the air-water interface during specimen preparation. While beam-induced movement now appears to have been resolved by all-gold specimen support grids with very small holes, surface effects at the air-water interface are a persistent problem. Strategies to overcome these effects include the use of alternative support films and new techniques for specimen deposition. We examine the future potential of recording perfect images of biological samples for routine structure determination at atomic resolution.
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38
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Glaeser RM. Preparing Better Samples for Cryo-Electron Microscopy: Biochemical Challenges Do Not End with Isolation and Purification. Annu Rev Biochem 2021; 90:451-474. [PMID: 33556280 DOI: 10.1146/annurev-biochem-072020-020231] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The preparation of extremely thin samples, which are required for high-resolution electron microscopy, poses extreme risk of damaging biological macromolecules due to interactions with the air-water interface. Although the rapid increase in the number of published structures initially gave little indication that this was a problem, the search for methods that substantially mitigate this hazard is now intensifying. The two main approaches under investigation are (a) immobilizing particles onto structure-friendly support films and (b) reducing the length of time during which such interactions may occur. While there is little possibility of outrunning diffusion to the interface, intentional passivation of the interface may slow the process of adsorption and denaturation. In addition, growing attention is being given to gaining more effective control of the thickness of the sample prior to vitrification.
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Affiliation(s)
- Robert M Glaeser
- Department of Molecular and Cell Biology and Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA;
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Klebl DP, Gravett MSC, Kontziampasis D, Wright DJ, Bon RS, Monteiro DCF, Trebbin M, Sobott F, White HD, Darrow MC, Thompson RF, Muench SP. Need for Speed: Examining Protein Behavior during CryoEM Grid Preparation at Different Timescales. Structure 2020; 28:1238-1248.e4. [PMID: 32814033 PMCID: PMC7652391 DOI: 10.1016/j.str.2020.07.018] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/15/2020] [Accepted: 07/29/2020] [Indexed: 12/18/2022]
Abstract
A host of new technologies are under development to improve the quality and reproducibility of cryoelectron microscopy (cryoEM) grid preparation. Here we have systematically investigated the preparation of three macromolecular complexes using three different vitrification devices (Vitrobot, chameleon, and a time-resolved cryoEM device) on various timescales, including grids made within 6 ms (the fastest reported to date), to interrogate particle behavior at the air-water interface for different timepoints. Results demonstrate that different macromolecular complexes can respond to the thin-film environment formed during cryoEM sample preparation in highly variable ways, shedding light on why cryoEM sample preparation can be difficult to optimize. We demonstrate that reducing time between sample application and vitrification is just one tool to improve cryoEM grid quality, but that it is unlikely to be a generic "silver bullet" for improving the quality of every cryoEM sample preparation.
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Affiliation(s)
- David P Klebl
- School of Biomedical Sciences, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Molly S C Gravett
- School of Molecular and Cellular Biology, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Dimitrios Kontziampasis
- School of Biomedical Sciences, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK; School of Chemical and Process Engineering, Faculty of Engineering and Physical Sciences, University of Leeds, Leeds LS2 9JT, UK; Institute of Business, Industry & Leadership, University of Cumbria, Carlisle CA1 2HH, UK
| | - David J Wright
- School of Medicine, Faculty of Medicine and Health & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
| | - Robin S Bon
- School of Medicine, Faculty of Medicine and Health & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
| | | | - Martin Trebbin
- Hauptman-Woodward Medical Research Institute, Buffalo, NY, USA; Department of Chemistry, State University of New York at Buffalo, Buffalo, NY, USA
| | - Frank Sobott
- School of Molecular and Cellular Biology, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK; Department of Chemistry, Biomolecular & Analytical Mass Spectrometry Group, University of Antwerp, Antwerp, Belgium
| | - Howard D White
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA, USA
| | | | - Rebecca F Thompson
- School of Molecular and Cellular Biology, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
| | - Stephen P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
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Tan YZ, Rubinstein JL. Through-grid wicking enables high-speed cryoEM specimen preparation. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2020; 76:1092-1103. [PMID: 33135680 DOI: 10.1107/s2059798320012474] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 09/10/2020] [Indexed: 01/23/2023]
Abstract
Blotting times for conventional cryoEM specimen preparation complicate time-resolved studies and lead to some specimens adopting preferred orientations or denaturing at the air-water interface. Here, it is shown that solution sprayed onto one side of a holey cryoEM grid can be wicked through the grid by a glass-fiber filter held against the opposite side, often called the `back', of the grid, producing a film suitable for vitrification. This process can be completed in tens of milliseconds. Ultrasonic specimen application and through-grid wicking were combined in a high-speed specimen-preparation device that was named `Back-it-up' or BIU. The high liquid-absorption capacity of the glass fiber compared with self-wicking grids makes the method relatively insensitive to the amount of sample applied. Consequently, through-grid wicking produces large areas of ice that are suitable for cryoEM for both soluble and detergent-solubilized protein complexes. The speed of the device increases the number of views for a specimen that suffers from preferred orientations.
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Affiliation(s)
- Yong Zi Tan
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - John L Rubinstein
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, Ontario, Canada
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Cryo-EM: Ice Is Nice, but Good Ice Can Be Hard to Find. Biophys J 2020; 118:1238-1239. [PMID: 32061273 DOI: 10.1016/j.bpj.2020.01.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 01/27/2020] [Indexed: 11/23/2022] Open
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