1
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Hirst IJ, Thomas WJR, Davies RA, Muench SP. CryoEM grid preparation: a closer look at advancements and impact of preparation mode and new approaches. Biochem Soc Trans 2024; 52:1529-1537. [PMID: 38864435 DOI: 10.1042/bst20231553] [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: 04/25/2024] [Revised: 05/30/2024] [Accepted: 06/03/2024] [Indexed: 06/13/2024]
Abstract
Sample preparation can present a significant hurdle within single particle cryo-electron microscopy (cryoEM), resulting in issues with reproducibility, data quality or an inability to visualise the sample. There are several factors which can influence this, including sample or buffer composition, grid type, route of sample preparation and interactions with the air-water interface (AWI). Here, we review some of the current routes for sample preparation and the associated challenges. We discuss a range of approaches for overcoming these challenges, such as minimising the grid preparation time, surfactants, grid type and biochemical approaches such as nanomagnetic beads. Finally, we discuss how a set of commercially available protein samples may serve as a benchmark suite for future technologies. This provides a route to compare techniques' abilities not just to generate high-resolution structures but also to overcome the challenges traditionally associated with cryoEM. As the field continues to produce new approaches to sample preparation and we start to better understand the underlying principles behind the behaviour of proteins within a thin film and in response to different environments, especially grid composition, it is hoped that more universal solutions can be provided that make the intractable systems tractable, improve resolution and, importantly, speed up data collection and reduce the currently required dataset sizes.
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Affiliation(s)
- Isobel J Hirst
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, U.K
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K
| | - William J R Thomas
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, U.K
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K
| | - Rhiannon A Davies
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, U.K
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K
| | - Stephen P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, U.K
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K
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2
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Liu N, Wang HW. Graphene in cryo-EM specimen optimization. Curr Opin Struct Biol 2024; 86:102823. [PMID: 38688075 DOI: 10.1016/j.sbi.2024.102823] [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: 02/03/2024] [Revised: 03/16/2024] [Accepted: 04/06/2024] [Indexed: 05/02/2024]
Abstract
Specimen preparation is a critical but challenging step in high-resolution cryogenic electron microscopy (cryo-EM) structural analysis of macromolecules. In the past decade, graphene has gained much recognition as the supporting substrate to optimize cryo-EM specimen preparation. It improves macromolecule embedding in ice, reduces beam-induced motion, while imposing negligible background noise. Various types of graphene-coated cryo-EM grids were implemented to improve the robustness and efficiency of specimen preparation. Graphene functionalization by different means has been proved specifically useful in addressing challenges related to the air-water interface (AWI), such as preferential orientation and sample denaturation. Graphene sandwich specimen preparation sets a new direction to explore in cryo-EM analysis of biological specimens. In this review, we discuss the current challenges and future prospects of graphene application in cryo-EM analysis of macromolecules.
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Affiliation(s)
- Nan Liu
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Hong-Wei Wang
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China.
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3
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Gizardin-Fredon H, Santo PE, Chagot ME, Charpentier B, Bandeiras TM, Manival X, Hernandez-Alba O, Cianférani S. Denaturing mass photometry for rapid optimization of chemical protein-protein cross-linking reactions. Nat Commun 2024; 15:3516. [PMID: 38664367 PMCID: PMC11045720 DOI: 10.1038/s41467-024-47732-4] [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: 01/22/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
Chemical cross-linking reactions (XL) are an important strategy for studying protein-protein interactions (PPIs), including low abundant sub-complexes, in structural biology. However, choosing XL reagents and conditions is laborious and mostly limited to analysis of protein assemblies that can be resolved using SDS-PAGE. To overcome these limitations, we develop here a denaturing mass photometry (dMP) method for fast, reliable and user-friendly optimization and monitoring of chemical XL reactions. The dMP is a robust 2-step protocol that ensures 95% of irreversible denaturation within only 5 min. We show that dMP provides accurate mass identification across a broad mass range (30 kDa-5 MDa) along with direct label-free relative quantification of all coexisting XL species (sub-complexes and aggregates). We compare dMP with SDS-PAGE and observe that, unlike the benchmark, dMP is time-efficient (3 min/triplicate), requires significantly less material (20-100×) and affords single molecule sensitivity. To illustrate its utility for routine structural biology applications, we show that dMP affords screening of 20 XL conditions in 1 h, accurately identifying and quantifying all coexisting species. Taken together, we anticipate that dMP will have an impact on ability to structurally characterize more PPIs and macromolecular assemblies, expected final complexes but also sub-complexes that form en route.
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Affiliation(s)
- Hugo Gizardin-Fredon
- Laboratoire de Spectrométrie de Masse BioOrganique, IPHC UMR 7178, Université de Strasbourg, CNRS, Strasbourg, France
- Infrastructure Nationale de Protéomique ProFI - FR2048, Strasbourg, France
| | - Paulo E Santo
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | | | | | - Tiago M Bandeiras
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | | | - Oscar Hernandez-Alba
- Laboratoire de Spectrométrie de Masse BioOrganique, IPHC UMR 7178, Université de Strasbourg, CNRS, Strasbourg, France
- Infrastructure Nationale de Protéomique ProFI - FR2048, Strasbourg, France
| | - Sarah Cianférani
- Laboratoire de Spectrométrie de Masse BioOrganique, IPHC UMR 7178, Université de Strasbourg, CNRS, Strasbourg, France.
- Infrastructure Nationale de Protéomique ProFI - FR2048, Strasbourg, France.
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4
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Liu YT, Fan H, Hu JJ, Zhou ZH. Overcoming the preferred orientation problem in cryoEM with self-supervised deep-learning. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.11.588921. [PMID: 38645074 PMCID: PMC11030451 DOI: 10.1101/2024.04.11.588921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
While advances in single-particle cryoEM have enabled the structural determination of macromolecular complexes at atomic resolution, particle orientation bias (the so-called "preferred" orientation problem) remains a complication for most specimens. Existing solutions have relied on biochemical and physical strategies applied to the specimen and are often complex and challenging. Here, we develop spIsoNet, an end-to-end self-supervised deep-learning-based software to address the preferred orientation problem. Using preferred-orientation views to recover molecular information in under-sampled views, spIsoNet improves both angular isotropy and particle alignment accuracy during 3D reconstruction. We demonstrate spIsoNet's capability of generating near-isotropic reconstructions from representative biological systems with limited views, including ribosomes, β-galactosidases, and a previously intractable hemagglutinin trimer dataset. spIsoNet can also be generalized to improve map isotropy and particle alignment of preferentially oriented molecules in subtomogram averaging. Therefore, without additional specimen-preparation procedures, spIsoNet provides a general computational solution to the preferred orientation problem.
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Affiliation(s)
- Yun-Tao Liu
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Hongcheng Fan
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Jason J. Hu
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
- Current address: Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Z. Hong Zhou
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
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5
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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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6
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Wang L, Zimanyi CM. Cryo-EM sample preparation for high-resolution structure studies. Acta Crystallogr F Struct Biol Commun 2024; 80:74-81. [PMID: 38530656 PMCID: PMC11058511 DOI: 10.1107/s2053230x24002553] [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: 01/13/2024] [Accepted: 03/18/2024] [Indexed: 03/28/2024] Open
Abstract
High-resolution structures of biomolecules can be obtained using single-particle cryo-electron microscopy (SPA cryo-EM), and the rapidly growing number of structures solved by this method is encouraging more researchers to utilize this technique. As with other structural biology methods, sample preparation for an SPA cryo-EM data collection requires some expertise and an understanding of the strengths and limitations of the technique in order to make sensible decisions in the sample-preparation process. In this article, common strategies and pitfalls are described and practical advice is given to increase the chances of success when starting an SPA cryo-EM project.
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Affiliation(s)
- Liguo Wang
- Laboratory for BioMolecular Structure, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Christina M. Zimanyi
- National Center for CryoEM Access and Training, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
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7
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Cebi E, Lee J, Subramani VK, Bak N, Oh C, Kim KK. Cryo-electron microscopy-based drug design. Front Mol Biosci 2024; 11:1342179. [PMID: 38501110 PMCID: PMC10945328 DOI: 10.3389/fmolb.2024.1342179] [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: 11/21/2023] [Accepted: 01/31/2024] [Indexed: 03/20/2024] Open
Abstract
Structure-based drug design (SBDD) has gained popularity owing to its ability to develop more potent drugs compared to conventional drug-discovery methods. The success of SBDD relies heavily on obtaining the three-dimensional structures of drug targets. X-ray crystallography is the primary method used for solving structures and aiding the SBDD workflow; however, it is not suitable for all targets. With the resolution revolution, enabling routine high-resolution reconstruction of structures, cryogenic electron microscopy (cryo-EM) has emerged as a promising alternative and has attracted increasing attention in SBDD. Cryo-EM offers various advantages over X-ray crystallography and can potentially replace X-ray crystallography in SBDD. To fully utilize cryo-EM in drug discovery, understanding the strengths and weaknesses of this technique and noting the key advancements in the field are crucial. This review provides an overview of the general workflow of cryo-EM in SBDD and highlights technical innovations that enable its application in drug design. Furthermore, the most recent achievements in the cryo-EM methodology for drug discovery are discussed, demonstrating the potential of this technique for advancing drug development. By understanding the capabilities and advancements of cryo-EM, researchers can leverage the benefits of designing more effective drugs. This review concludes with a discussion of the future perspectives of cryo-EM-based SBDD, emphasizing the role of this technique in driving innovations in drug discovery and development. The integration of cryo-EM into the drug design process holds great promise for accelerating the discovery of new and improved therapeutic agents to combat various diseases.
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Affiliation(s)
| | | | | | | | - Changsuk Oh
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Kyeong Kyu Kim
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
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8
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Esser TK, Böhning J, Önür A, Chinthapalli DK, Eriksson L, Grabarics M, Fremdling P, Konijnenberg A, Makarov A, Botman A, Peter C, Benesch JLP, Robinson CV, Gault J, Baker L, Bharat TAM, Rauschenbach S. Cryo-EM of soft-landed β-galactosidase: Gas-phase and native structures are remarkably similar. SCIENCE ADVANCES 2024; 10:eadl4628. [PMID: 38354247 PMCID: PMC10866560 DOI: 10.1126/sciadv.adl4628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/11/2024] [Indexed: 02/16/2024]
Abstract
Native mass spectrometry (MS) has become widely accepted in structural biology, providing information on stoichiometry, interactions, homogeneity, and shape of protein complexes. Yet, the fundamental assumption that proteins inside the mass spectrometer retain a structure faithful to native proteins in solution remains a matter of intense debate. Here, we reveal the gas-phase structure of β-galactosidase using single-particle cryo-electron microscopy (cryo-EM) down to 2.6-Å resolution, enabled by soft landing of mass-selected protein complexes onto cold transmission electron microscopy (TEM) grids followed by in situ ice coating. We find that large parts of the secondary and tertiary structure are retained from the solution. Dehydration-driven subunit reorientation leads to consistent compaction in the gas phase. By providing a direct link between high-resolution imaging and the capability to handle and select protein complexes that behave problematically in conventional sample preparation, the approach has the potential to expand the scope of both native mass spectrometry and cryo-EM.
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Affiliation(s)
- Tim K. Esser
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
- Thermo Fisher Scientific, 1 Boundary Park, Hemel Hempstead, Hertfordshire HP2 7GE, UK
| | - Jan Böhning
- Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Alpcan Önür
- Department of Chemistry, University of Konstanz, Konstanz 78457, Germany
| | - Dinesh K. Chinthapalli
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
| | - Lukas Eriksson
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
| | - Marko Grabarics
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
| | - Paul Fremdling
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | | | - Alexander Makarov
- Thermo Fisher Scientific, Bremen 28199, Germany
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Centre for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
| | - Aurelien Botman
- Thermo Fisher Scientific, 5350 NE Dawson Creek Drive, Hillsboro, OR 97124, USA
| | - Christine Peter
- Department of Chemistry, University of Konstanz, Konstanz 78457, Germany
| | - Justin L. P. Benesch
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
| | - Carol V. Robinson
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
| | - Joseph Gault
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Lindsay Baker
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Tanmay A. M. Bharat
- Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Stephan Rauschenbach
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Kavli Institute for NanoScience Discovery, Dorothy Crowfoot Hodgkin Building, Oxford OX1 3QU, UK
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9
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Marie Haynes R, Myers J, López CS, Evans J, Davulcu O, Yoshioka C. A strategic approach for efficient cryo-EM grid optimization using design of experiments. J Struct Biol 2024:108068. [PMID: 38364988 DOI: 10.1016/j.jsb.2024.108068] [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: 11/13/2023] [Revised: 01/26/2024] [Accepted: 02/13/2024] [Indexed: 02/18/2024]
Abstract
In recent years, cryo-electron microscopy (cryo-EM) has become a practical and effective method of determining structures at previously unattainable resolutions due to advances in detection, automation, and data processing. However, sample preparation remains a major bottleneck in the cryo-EM workflow. Even after the arduous process of biochemical sample optimization, it often takes several iterations of grid vitrification and screening to determine the optimal grid freezing parameters that yield suitable ice thickness and particle distribution for data collection. Since a high-quality sample is imperative for high-resolution structure determination, grid optimization is a vital step. For researchers who rely on cryo-EM facilities for grid screening, each iteration of this optimization process may delay research progress by a matter of months. Therefore, a more strategic and efficient approach should be taken to ensure that the grid optimization process can be completed in as few iterations as possible. Here, we present an implementation of Design of Experiments (DOE) to expedite and strategize the grid optimization process. A Fractional Factorial Design (FFD) guides the determination of a limited set of experimental conditions which can model the full parameter space of interest. Grids are frozen with these conditions and screened for particle distribution and ice thickness. Quantitative scores are assigned to each of these grid characteristics based on a qualitative rubric. Input conditions and response scores are used to generate a least-squares regression model of the parameter space in JMP, which is used to determine the conditions which should, in theory, yield optimal grids. Upon testing this approach on apoferritin and L-glutamate dehydrogenase on both the Vitrobot Mark IV and the Leica GP2 plunge freezers, the resulting grid conditions reliably yielded grids with high-quality ice and particle distribution that were suitable for collecting large overnight datasets on a Krios. We conclude that a DOE-based approach is a cost-effective and time-saving tool for cryo-EM grid preparation.
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Affiliation(s)
- Rose Marie Haynes
- Pacific Northwest Center for Cryo-Electron Microscopy, Oregon Health & Science University, Portland, OR 97201, USA; Pacific Northwest National Laboratory, Richland, WA 99354, USA.
| | - Janette Myers
- Pacific Northwest Center for Cryo-Electron Microscopy, Oregon Health & Science University, Portland, OR 97201, USA
| | - Claudia S López
- Pacific Northwest Center for Cryo-Electron Microscopy, Oregon Health & Science University, Portland, OR 97201, USA
| | - James Evans
- Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | - Omar Davulcu
- Pacific Northwest Center for Cryo-Electron Microscopy, Oregon Health & Science University, Portland, OR 97201, USA
| | - Craig Yoshioka
- Pacific Northwest Center for Cryo-Electron Microscopy, Oregon Health & Science University, Portland, OR 97201, USA
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10
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Xu Y, Qin Y, Wang L, Zhang Y, Wang Y, Dang S. Metallo-supramolecular branched polymer protects particles from air-water interface in single-particle cryo-electron microscopy. Commun Biol 2024; 7:65. [PMID: 38195919 PMCID: PMC10776832 DOI: 10.1038/s42003-023-05752-8] [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: 07/26/2023] [Accepted: 12/28/2023] [Indexed: 01/11/2024] Open
Abstract
Recent technological breakthroughs in single-particle cryo-electron microscopy (cryo-EM) enable rapid atomic structure determination of biological macromolecules. A major bottleneck in the current single particle cryo-EM pipeline is the preparation of good quality frozen cryo-EM grids, which is mostly a trial-and-error process. Among many issues, preferred particle orientation and sample damage by air-water interface (AWI) are common practical problems. Here we report a method of applying metallo-supramolecular branched polymer (MSBP) in the cryo-sample preparation for high-resolution single-particle cryo-EM. Our data shows that MSBP keeps a majority of particles away from air-water interface and mitigates preferred orientation as verified by the analyses of apoferritin, hemagglutinin) trimer and various sample proteins. The use of MSBP is a simple method to improve particle distribution for high-resolution structure determination in single-particle cryo-EM.
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Affiliation(s)
- Yixin Xu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Yuqi Qin
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Lang Wang
- Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Yingyi Zhang
- Biological Cryo-EM Center, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Yufeng Wang
- Department of Chemistry, The University of Hong Kong, Hong Kong, China.
| | - Shangyu Dang
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China.
- HKUST-Shenzhen Research Institute, Nanshan, Shenzhen, China.
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11
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Orris B, Sung MW, Bhat S, Xu Y, Huynh KW, Han S, Johnson DC, Bosbach B, Shields DJ, Stivers JT. Guanine-containing ssDNA and RNA induce dimeric and tetrameric structural forms of SAMHD1. Nucleic Acids Res 2023; 51:12443-12458. [PMID: 37930833 PMCID: PMC10711556 DOI: 10.1093/nar/gkad971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/19/2023] [Accepted: 10/14/2023] [Indexed: 11/08/2023] Open
Abstract
The dNTPase activity of tetrameric SAM and HD domain containing deoxynucleoside triphosphate triphosphohydrolase 1 (SAMHD1) plays a critical role in cellular dNTP regulation. SAMHD1 also associates with stalled DNA replication forks, DNA repair foci, ssRNA and telomeres. The above functions require nucleic acid binding by SAMHD1, which may be modulated by its oligomeric state. Here we establish in cryo-EM and biochemical studies that the guanine-specific A1 activator site of each SAMHD1 monomer is used to target the enzyme to guanine nucleotides within single-stranded (ss) DNA and RNA. Remarkably, nucleic acid strands containing a single guanine base induce dimeric SAMHD1, while two or more guanines with ∼20 nucleotide spacing induce a tetrameric form. A cryo-EM structure of ssRNA-bound tetrameric SAMHD1 shows how ssRNA strands bridge two SAMHD1 dimers and stabilize the structure. This ssRNA-bound tetramer is inactive with respect to dNTPase and RNase activity.
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Affiliation(s)
- Benjamin Orris
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205, USA
| | | | - Shridhar Bhat
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205, USA
| | - Yingrong Xu
- Medicine Design, Pfizer, Groton, CT 06340, USA
| | | | - Seungil Han
- Medicine Design, Pfizer, Groton, CT 06340, USA
| | - Darren C Johnson
- Centers for Therapeutic Innovation (CTI), Pfizer, New York, NY 10016, USA
| | - Benedikt Bosbach
- Centers for Therapeutic Innovation (CTI), Pfizer, New York, NY 10016, USA
| | - David J Shields
- Centers for Therapeutic Innovation (CTI), Pfizer, New York, NY 10016, USA
| | - James T Stivers
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205, USA
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12
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Westphall MS, Lee KW, Salome AZ, Coon JJ, Grant T. Mass spectrometers as cryoEM grid preparation instruments. Curr Opin Struct Biol 2023; 83:102699. [PMID: 37703606 PMCID: PMC11019453 DOI: 10.1016/j.sbi.2023.102699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 07/18/2023] [Accepted: 08/15/2023] [Indexed: 09/15/2023]
Abstract
Structure determination by single-particle cryoEM has matured into a core structural biology technique. Despite many methodological advancements, most cryoEM grids are still prepared using the plunge-freezing method developed ∼40 years ago. Embedding samples in thin films and exposing them to the air-water interface often leads to sample damage and preferential orientation of the particles. Using native mass spectrometry to create cryoEM samples, potentially avoids these problems and allows the use of mass spectrometry sample isolation techniques during EM grid creation. We review the recent publications that have demonstrated protein complexes can be ionized, flown through the mass spectrometer, gently landed onto EM grids, imaged, and reconstructed in 3D. Although many uncertainties and challenges remain, the combination of cryoEM and MS has great potential.
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Affiliation(s)
- Michael S Westphall
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Kenneth W Lee
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Austin Z Salome
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Joshua J Coon
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI 53706, United States; Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, United States; Morgridge Institute for Research, 330 N Orchard Street, Madison, WI 53706, United States.
| | - Timothy Grant
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States; Morgridge Institute for Research, 330 N Orchard Street, Madison, WI 53706, United States.
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13
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Basanta B, Chen W, Pride DE, Lander GC. Fabrication of Monolayer Graphene-Coated Grids for Cryoelectron Microscopy. J Vis Exp 2023:10.3791/65702. [PMID: 37747197 PMCID: PMC11141527 DOI: 10.3791/65702] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/26/2023] Open
Abstract
Cryogenic electron microscopy (cryoEM) has emerged as a powerful technique for probing the atomic structure of macromolecular complexes. Sample preparation for cryoEM requires preserving specimens in a thin layer of vitreous ice, typically suspended within the holes of a fenestrated support film. However, all commonly used sample preparation approaches for cryoEM studies expose the specimen to the air-water interface, introducing a strong hydrophobic effect on the specimen that often results in denaturation, aggregation, and complex dissociation. Further, preferred hydrophobic interactions between regions of the specimen and the air-water interface impact the orientations adopted by the macromolecules, resulting in 3D reconstructions with anisotropic directional resolution. Adsorption of cryoEM specimens to a monolayer of graphene has been shown to help mitigate interactions with the air-water interface while minimizing the introduction of background noise. Graphene supports also offer the benefit of substantially lowering the required concentration of proteins required for cryoEM imaging. Despite the advantages of these supports, graphene-coated grids are not widely used by the cryoEM community due to the prohibitive expense of commercial options and the challenges associated with large-scale in-house production. This paper describes an efficient method for preparing batches of cryoEM grids that have nearly full coverage of monolayer graphene.
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Affiliation(s)
- Benjamin Basanta
- Department of Structural and Computational Biology, Scripps Research
| | - Wenqian Chen
- Department of Structural and Computational Biology, Scripps Research
| | - Daniel E Pride
- Department of Structural and Computational Biology, Scripps Research
| | - Gabriel C Lander
- Department of Structural and Computational Biology, Scripps Research;
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14
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Rehan S, Tranter D, Sharp PP, Craven GB, Lowe E, Anderl JL, Muchamuel T, Abrishami V, Kuivanen S, Wenzell NA, Jennings A, Kalyanaraman C, Strandin T, Javanainen M, Vapalahti O, Jacobson MP, McMinn D, Kirk CJ, Huiskonen JT, Taunton J, Paavilainen VO. Signal peptide mimicry primes Sec61 for client-selective inhibition. Nat Chem Biol 2023; 19:1054-1062. [PMID: 37169961 PMCID: PMC10449633 DOI: 10.1038/s41589-023-01326-1] [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: 06/03/2022] [Accepted: 04/06/2023] [Indexed: 05/13/2023]
Abstract
Preventing the biogenesis of disease-relevant proteins is an attractive therapeutic strategy, but attempts to target essential protein biogenesis factors have been hampered by excessive toxicity. Here we describe KZR-8445, a cyclic depsipeptide that targets the Sec61 translocon and selectively disrupts secretory and membrane protein biogenesis in a signal peptide-dependent manner. KZR-8445 potently inhibits the secretion of pro-inflammatory cytokines in primary immune cells and is highly efficacious in a mouse model of rheumatoid arthritis. A cryogenic electron microscopy structure reveals that KZR-8445 occupies the fully opened Se61 lateral gate and blocks access to the lumenal plug domain. KZR-8445 binding stabilizes the lateral gate helices in a manner that traps select signal peptides in the Sec61 channel and prevents their movement into the lipid bilayer. Our results establish a framework for the structure-guided discovery of novel therapeutics that selectively modulate Sec61-mediated protein biogenesis.
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Affiliation(s)
- Shahid Rehan
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Dale Tranter
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Phillip P Sharp
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | - Gregory B Craven
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | - Eric Lowe
- Kezar Life Sciences, South San Francisco, CA, USA
| | | | | | - Vahid Abrishami
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Suvi Kuivanen
- Institute of Virology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Nicole A Wenzell
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA
| | | | - Chakrapani Kalyanaraman
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of California, San Francisco, CA, USA
| | - Tomas Strandin
- Department of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Matti Javanainen
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Olli Vapalahti
- Department of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Matthew P Jacobson
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of California, San Francisco, CA, USA
| | | | | | - Juha T Huiskonen
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Jack Taunton
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA.
| | - Ville O Paavilainen
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland.
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15
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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: 8] [Impact Index Per Article: 8.0] [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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16
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Grassetti AV, May MB, Davis JH. Application of monolayer graphene to cryo-electron microscopy grids for high-resolution structure determination. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.28.550908. [PMID: 37546934 PMCID: PMC10402136 DOI: 10.1101/2023.07.28.550908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
In cryogenic electron microscopy (cryo-EM), purified macromolecules are typically applied to a grid bearing a holey carbon foil, blotted to remove excess liquid and rapidly frozen in a roughly 20-100 nm thick layer of vitreous ice that is suspended across roughly 1 μm-wide foil holes. The resulting sample is then imaged using cryogenic transmission electron microscopy and, after substantial image processing, near-atomic resolution structures can be determined. Despite cryo-EM's widespread adoption, sample preparation remains a severe bottleneck in cryo-EM workflows, with users often encountering challenges related to samples behaving poorly in the suspended vitreous ice. Recently, methods have been developed to modify cryo-EM grids with a single continuous layer of graphene, which acts as a support surface that often increases particle density in the imaged area and can reduce interactions between particles and the air-water interface. Here, we provide detailed protocols for the application of graphene to cryo-EM grids, and for rapidly assessing the relative hydrophilicity of the resulting grids. Additionally, we describe an EM-based method to confirm the presence of graphene by visualizing its characteristic diffraction pattern. Finally, we demonstrate the utility of these graphene supports by rapidly reconstructing a 2.7 Å resolution density map of an exemplar Cas9 complex using a highly pure sample at a relatively low concentration.
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Affiliation(s)
- Andrew V. Grassetti
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Mira B. May
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Joseph H. Davis
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
- Program in Computational and Systems Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
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17
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Su CC, Lyu M, Zhang Z, Miyagi M, Huang W, Taylor DJ, Yu EW. High-resolution structural-omics of human liver enzymes. Cell Rep 2023; 42:112609. [PMID: 37289586 PMCID: PMC10592444 DOI: 10.1016/j.celrep.2023.112609] [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: 12/26/2022] [Revised: 03/28/2023] [Accepted: 05/20/2023] [Indexed: 06/10/2023] Open
Abstract
We applied raw human liver microsome lysate to a holey carbon grid and used cryo-electron microscopy (cryo-EM) to define its composition. From this sample we identified and simultaneously determined high-resolution structural information for ten unique human liver enzymes involved in diverse cellular processes. Notably, we determined the structure of the endoplasmic bifunctional protein H6PD, where the N- and C-terminal domains independently possess glucose-6-phosphate dehydrogenase and 6-phosphogluconolactonase enzymatic activity, respectively. We also obtained the structure of heterodimeric human GANAB, an ER glycoprotein quality-control machinery that contains a catalytic α subunit and a noncatalytic β subunit. In addition, we observed a decameric peroxidase, PRDX4, which directly contacts a disulfide isomerase-related protein, ERp46. Structural data suggest that several glycosylations, bound endogenous compounds, and ions associate with these human liver enzymes. These results highlight the importance of cryo-EM in facilitating the elucidation of human organ proteomics at the atomic level.
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Affiliation(s)
- Chih-Chia Su
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Meinan Lyu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Zhemin Zhang
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Masaru Miyagi
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Wei Huang
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Derek J Taylor
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Edward W Yu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
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18
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Orris B, Sung MW, Bhat S, Xu Y, Huynh KW, Han S, Johnson DC, Bosbach B, Shields DJ, Stivers JT. Guanine-containing ssDNA and RNA induce dimeric and tetrameric SAMHD1 in cryo-EM and binding studies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.15.544806. [PMID: 37398126 PMCID: PMC10312740 DOI: 10.1101/2023.06.15.544806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
The dNTPase activity of tetrameric SAM and HD domain containing deoxynucleoside triphosphate triphosphohydrolase 1 (SAMHD1) plays a critical role in cellular dNTP regulation. SAMHD1 also associates with stalled DNA replication forks, DNA repair foci, ssRNA, and telomeres. The above functions require nucleic acid binding by SAMHD1, which may be modulated by its oligomeric state. Here we establish that the guanine-specific A1 activator site of each SAMHD1 monomer is used to target the enzyme to guanine nucleotides within single-stranded (ss) DNA and RNA. Remarkably, nucleic acid strands containing a single guanine base induce dimeric SAMHD1, while two or more guanines with ~20 nucleotide spacing induce a tetrameric form. A cryo-EM structure of ssRNA-bound tetrameric SAMHD1 shows how ssRNA strands bridge two SAMHD1 dimers and stabilize the structure. This ssRNA-bound tetramer is inactive with respect to dNTPase and RNase activity.
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Affiliation(s)
- Benjamin Orris
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205
| | | | - Shridhar Bhat
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205
| | | | | | | | - Darren C. Johnson
- Centers for Therapeutic Innovation (CTI), Pfizer, New York, NY 10016
| | - Benedikt Bosbach
- Centers for Therapeutic Innovation (CTI), Pfizer, New York, NY 10016
| | - David J. Shields
- Centers for Therapeutic Innovation (CTI), Pfizer, New York, NY 10016
| | - James T. Stivers
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205
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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: 0] [Impact Index Per Article: 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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Ahn E, Kim B, Park S, Erwin AL, Sung SH, Hovden R, Mosalaganti S, Cho US. Batch Production of High-Quality Graphene Grids for Cryo-EM: Cryo-EM Structure of Methylococcus capsulatus Soluble Methane Monooxygenase Hydroxylase. ACS NANO 2023; 17:6011-6022. [PMID: 36926824 PMCID: PMC10062032 DOI: 10.1021/acsnano.3c00463] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/13/2023] [Indexed: 06/18/2023]
Abstract
Cryogenic electron microscopy (cryo-EM) has become a widely used tool for determining the protein structure. Despite recent technical advances, sample preparation remains a major bottleneck for several reasons, including protein denaturation at the air-water interface, the presence of preferred orientations, nonuniform ice layers, etc. Graphene, a two-dimensional allotrope of carbon consisting of a single atomic layer, has recently gained attention as a near-ideal support film for cryo-EM that can overcome these challenges because of its superior properties, including mechanical strength and electrical conductivity. Here, we introduce a reliable, easily implemented, and reproducible method to produce 36 graphene-coated grids within 1.5 days. To demonstrate their practical application, we determined the cryo-EM structure of Methylococcus capsulatus soluble methane monooxygenase hydroxylase (sMMOH) at resolutions of 2.9 and 2.5 Å using Quantifoil and graphene-coated grids, respectively. We found that the graphene-coated grid has several advantages, including a smaller amount of protein required and avoiding protein denaturation at the air-water interface. By comparing the cryo-EM structure of sMMOH with its crystal structure, we identified subtle yet significant geometrical changes at the nonheme diiron center, which may better indicate the active site configuration of sMMOH in the resting/oxidized state.
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Affiliation(s)
- Eungjin Ahn
- Department
of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Byungchul Kim
- Department
of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Soyoung Park
- Department
of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department
of Fine Chemistry, Seoul National University
of Science and Technology, Seoul 139-743, Korea
| | - Amanda L. Erwin
- Department
of Cell and Developmental Biology, University
of Michigan, Ann Arbor, Michigan 48109, United
States
- Life
Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Suk Hyun Sung
- Department
of Materials Science and Engineering, University
of Michigan, Ann Arbor, Michigan 48105, United
States
| | - Robert Hovden
- Department
of Materials Science and Engineering, University
of Michigan, Ann Arbor, Michigan 48105, United
States
- Applied
Physics Program, University of Michigan, Ann Arbor, Michigan 48105, United States
| | - Shyamal Mosalaganti
- Department
of Cell and Developmental Biology, University
of Michigan, Ann Arbor, Michigan 48109, United
States
- Life
Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Uhn-Soo Cho
- Department
of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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21
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Le‐Trilling VTK, Banchenko S, Paydar D, Leipe PM, Binting L, Lauer S, Graziadei A, Klingen R, Gotthold C, Bürger J, Bracht T, Sitek B, Jan Lebbink R, Malyshkina A, Mielke T, Rappsilber J, Spahn CMT, Voigt S, Trilling M, Schwefel D. Structural mechanism of CRL4-instructed STAT2 degradation via a novel cytomegaloviral DCAF receptor. EMBO J 2023; 42:e112351. [PMID: 36762436 PMCID: PMC9975947 DOI: 10.15252/embj.2022112351] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 12/15/2022] [Accepted: 12/21/2022] [Indexed: 02/11/2023] Open
Abstract
Human cytomegalovirus (CMV) is a ubiquitously distributed pathogen whose rodent counterparts such as mouse and rat CMV serve as common infection models. Here, we conducted global proteome profiling of rat CMV-infected cells and uncovered a pronounced loss of the transcription factor STAT2, which is crucial for antiviral interferon signalling. Via deletion mutagenesis, we found that the viral protein E27 is required for CMV-induced STAT2 depletion. Cellular and in vitro analyses showed that E27 exploits host-cell Cullin4-RING ubiquitin ligase (CRL4) complexes to induce poly-ubiquitylation and proteasomal degradation of STAT2. Cryo-electron microscopy revealed how E27 mimics molecular surface properties of cellular CRL4 substrate receptors called DCAFs (DDB1- and Cullin4-associated factors), thereby displacing them from the catalytic core of CRL4. Moreover, structural analyses showed that E27 recruits STAT2 through a bipartite binding interface, which partially overlaps with the IRF9 binding site. Structure-based mutations in M27, the murine CMV homologue of E27, impair the interferon-suppressing capacity and virus replication in mouse models, supporting the conserved importance of DCAF mimicry for CMV immune evasion.
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Affiliation(s)
| | - Sofia Banchenko
- Institute of Medical Physics and BiophysicsCharité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt‐Universität zu BerlinBerlinGermany
| | - Darius Paydar
- Institute for VirologyUniversity Hospital Essen, University of Duisburg‐EssenEssenGermany
- Zentrum für KinderpsychiatrieUniversitätsklinik ZürichZürichSwitzerland
| | - Pia Madeleine Leipe
- Institute for VirologyUniversity Hospital Essen, University of Duisburg‐EssenEssenGermany
| | - Lukas Binting
- Institute of Medical Physics and BiophysicsCharité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt‐Universität zu BerlinBerlinGermany
| | - Simon Lauer
- Institute of Medical Physics and BiophysicsCharité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt‐Universität zu BerlinBerlinGermany
| | - Andrea Graziadei
- Bioanalytics Unit, Institute of BiotechnologyTechnische Universität BerlinBerlinGermany
| | - Robin Klingen
- Institute for VirologyUniversity Hospital Essen, University of Duisburg‐EssenEssenGermany
| | - Christine Gotthold
- Institute of Medical Physics and BiophysicsCharité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt‐Universität zu BerlinBerlinGermany
| | - Jörg Bürger
- Institute of Medical Physics and BiophysicsCharité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt‐Universität zu BerlinBerlinGermany
- Microscopy and Cryo‐Electron Microscopy Service GroupMax‐Planck‐Institute for Molecular GeneticsBerlinGermany
| | - Thilo Bracht
- Medizinisches Proteom‐CenterRuhr‐University BochumBochumGermany
- Department of Anesthesia, Intensive Care Medicine and Pain TherapyUniversity Hospital Knappschaftskrankenhaus BochumBochumGermany
| | - Barbara Sitek
- Medizinisches Proteom‐CenterRuhr‐University BochumBochumGermany
- Department of Anesthesia, Intensive Care Medicine and Pain TherapyUniversity Hospital Knappschaftskrankenhaus BochumBochumGermany
| | - Robert Jan Lebbink
- Department of Medical MicrobiologyUniversity Medical Center UtrechtUtrechtthe Netherlands
| | - Anna Malyshkina
- Institute for VirologyUniversity Hospital Essen, University of Duisburg‐EssenEssenGermany
| | - Thorsten Mielke
- Microscopy and Cryo‐Electron Microscopy Service GroupMax‐Planck‐Institute for Molecular GeneticsBerlinGermany
| | - Juri Rappsilber
- Bioanalytics Unit, Institute of BiotechnologyTechnische Universität BerlinBerlinGermany
- Wellcome Centre for Cell BiologyUniversity of EdinburghEdinburghUK
| | - Christian MT Spahn
- Institute of Medical Physics and BiophysicsCharité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt‐Universität zu BerlinBerlinGermany
| | - Sebastian Voigt
- Institute for VirologyUniversity Hospital Essen, University of Duisburg‐EssenEssenGermany
| | - Mirko Trilling
- Institute for VirologyUniversity Hospital Essen, University of Duisburg‐EssenEssenGermany
| | - David Schwefel
- Institute of Medical Physics and BiophysicsCharité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt‐Universität zu BerlinBerlinGermany
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22
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Fujita J, Makino F, Asahara H, Moriguchi M, Kumano S, Anzai I, Kishikawa JI, Matsuura Y, Kato T, Namba K, Inoue T. Epoxidized graphene grid for highly efficient high-resolution cryoEM structural analysis. Sci Rep 2023; 13:2279. [PMID: 36755111 PMCID: PMC9908306 DOI: 10.1038/s41598-023-29396-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 02/03/2023] [Indexed: 02/10/2023] Open
Abstract
Functionalization of graphene is one of the most important fundamental technologies in a wide variety of fields including industry and biochemistry. We have successfully achieved a novel oxidative modification of graphene using photoactivated ClO2· as a mild oxidant and confirmed the oxidized graphene grid is storable with its functionality for at least three months under N2 atmosphere. Subsequent chemical functionalization enabled us to develop an epoxidized graphene grid (EG-grid™), which effectively adsorbs protein particles for electron cryomicroscopy (cryoEM) image analysis. The EG-grid dramatically improved the particle density and orientation distribution. The density maps of GroEL and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) were reconstructed at 1.99 and 2.16 Å resolution from only 504 and 241 micrographs, respectively. A sample solution of 0.1 mg ml-1 was sufficient to reconstruct a 3.10 Å resolution map of SARS-CoV-2 spike protein from 1163 micrographs. The map resolutions of β-galactosidase and apoferritin easily reached 1.81 Å and 1.29 Å resolution, respectively, indicating its atomic-resolution imaging capability. Thus, the EG-grid will be an extremely powerful tool for highly efficient high-resolution cryoEM structural analysis of biological macromolecules.
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Affiliation(s)
- Junso Fujita
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan.,JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Fumiaki Makino
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan.,JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan.,JEOL Ltd, 3-2-1 Musashino, Akishima, Tokyo, 196-8558, Japan
| | - Haruyasu Asahara
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Open and Transdisciplinary Research Initiatives, Osaka University, 2-8 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Maiko Moriguchi
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Shota Kumano
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Itsuki Anzai
- Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Jun-Ichi Kishikawa
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Department of Molecular Biosciences, Kyoto Sangyo University, Motoyama Kamigamo, Kita-ku, Kyoto, 603-8555, Japan
| | - Yoshiharu Matsuura
- Center for Infectious Disease Education and Research, Osaka University, 2-8 Yamadaoka, Suita, Osaka, 565-0871, Japan.,Laboratory of Virus Control, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Takayuki Kato
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Keiichi Namba
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,RIKEN Center for Biosystems Dynamics Research and SPring-8 Center, 1-3 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Tsuyoshi Inoue
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,Open and Transdisciplinary Research Initiatives, Osaka University, 2-8 Yamadaoka, Suita, Osaka, 565-0871, Japan. .,dotAqua Inc., 2-1 Yamadaoka, Suita, Osaka, Japan.
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23
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Hillen HS. Cryo-EM for Structure Determination of Mitochondrial Ribosome Samples. Methods Mol Biol 2023; 2661:89-100. [PMID: 37166633 DOI: 10.1007/978-1-0716-3171-3_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Single-particle cryoelectron microscopy (cryo-EM) allows structure determination of large macromolecular complexes from conformationally and compositionally heterogeneous mixtures of particles. This technique has been used to reveal the architecture of the mitochondrial ribosome and to visualize transient states that occur during the translation cycle or during mitoribosome biogenesis. Here, we outline an exemplary workflow for the analysis of single-particle cryo-EM data of human mitoribosome samples. In addition, we provide an example dataset which can be used for training purposes alongside the protocol.
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Affiliation(s)
- Hauke S Hillen
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany.
- Research Group Structure and Function of Molecular Machines, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
- Cluster of Excellence 'Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells' (MBExC), University of Göttingen, Göttingen, Germany.
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24
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Wang H, Hayer-Hartl M. Phase Separation of Rubisco by the Folded SSUL Domains of CcmM in Beta-Carboxysome Biogenesis. Methods Mol Biol 2023; 2563:269-296. [PMID: 36227479 DOI: 10.1007/978-1-0716-2663-4_14] [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: 06/16/2023]
Abstract
Carboxysomes are large, cytosolic bodies present in all cyanobacteria and many proteobacteria that function as the sites of photosynthetic CO2 fixation by the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). The carboxysome lumen is enriched with Rubisco and carbonic anhydrase (CA). The polyhedral proteinaceous shell allows the passage of HCO3- ions into the carboxysome, where they are converted to CO2 by CA. Thus, the carboxysome functions as a CO2-concentrating mechanism (CCM), enhancing the efficiency of Rubisco in CO2 fixation. In β-cyanobacteria, carboxysome biogenesis first involves the aggregation of Rubisco by CcmM, a scaffolding protein that exists in two isoforms. Both isoforms contain a minimum of three Rubisco small subunit-like (SSUL) domains, connected by flexible linkers. Multivalent interaction between these linked SSUL domains with Rubisco results in phase separation and condensate formation. Here, we use Rubisco and the short isoform of CcmM (M35) of the β-cyanobacterium Synechococcus elongatus PCC7942 to describe the methods used for in vitro analysis of the mechanism of condensate formation driven by the SSUL domains. The methods include turbidity assays, bright-field and fluorescence microscopy, as well as transmission electron microscopy (TEM) in both negative staining and cryo-conditions.
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Affiliation(s)
- Huping Wang
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
- Membrane Protein Biosynthesis and Quality Control, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany.
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25
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Shenkarev ZO, Chesnokov YM, Zaigraev MM, Chugunov AO, Kulbatskii DS, Kocharovskaya MV, Paramonov AS, Bychkov ML, Shulepko MA, Nolde DE, Kamyshinsky RA, Yablokov EO, Ivanov AS, Kirpichnikov MP, Lyukmanova EN. Membrane-mediated interaction of non-conventional snake three-finger toxins with nicotinic acetylcholine receptors. Commun Biol 2022; 5:1344. [PMID: 36477694 PMCID: PMC9729238 DOI: 10.1038/s42003-022-04308-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
Nicotinic acetylcholine receptor of α7 type (α7-nAChR) presented in the nervous and immune systems and epithelium is a promising therapeutic target for cognitive disfunctions and cancer treatment. Weak toxin from Naja kaouthia venom (WTX) is a non-conventional three-finger neurotoxin, targeting α7-nAChR with weak affinity. There are no data on interaction mode of non-conventional neurotoxins with nAChRs. Using α-bungarotoxin (classical three-finger neurotoxin with high affinity to α7-nAChR), we showed applicability of cryo-EM to study complexes of α7-nAChR extracellular ligand-binding domain (α7-ECD) with toxins. Using cryo-EM structure of the α7-ECD/WTX complex, together with NMR data on membrane active site in the WTX molecule and mutagenesis data, we reconstruct the structure of α7-nAChR/WTX complex in the membrane environment. WTX interacts at the entrance to the orthosteric site located at the receptor intersubunit interface and simultaneously forms the contacts with the membrane surface. WTX interaction mode with α7-nAChR significantly differs from α-bungarotoxin's one, which does not contact the membrane. Our study reveals the important role of the membrane for interaction of non-conventional neurotoxins with the nicotinic receptors.
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Affiliation(s)
- Zakhar O. Shenkarev
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.18763.3b0000000092721542Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Institutsky Lane 9, Dolgoprudny, Moscow, 141701 Russia
| | - Yuri M. Chesnokov
- grid.18919.380000000406204151National Research Center “Kurchatov Institute”, Academic Kurchatov Sq. 1, Moscow, 123182 Russia ,grid.435159.f0000 0001 1941 7461Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” of Russian Academy of Sciences, Leninsky Prospect 59, Moscow, 119333 Russia
| | - Maxim M. Zaigraev
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.18763.3b0000000092721542Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Institutsky Lane 9, Dolgoprudny, Moscow, 141701 Russia
| | - Anton O. Chugunov
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.18763.3b0000000092721542Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Institutsky Lane 9, Dolgoprudny, Moscow, 141701 Russia ,grid.410682.90000 0004 0578 2005National Research University Higher School of Economics, Myasnitskaya Str. 20, Moscow, 101000 Russia
| | - Dmitrii S. Kulbatskii
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia
| | - Milita V. Kocharovskaya
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.18763.3b0000000092721542Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Institutsky Lane 9, Dolgoprudny, Moscow, 141701 Russia
| | - Alexander S. Paramonov
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia
| | - Maxim L. Bychkov
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia
| | - Mikhail A. Shulepko
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia
| | - Dmitry E. Nolde
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.410682.90000 0004 0578 2005National Research University Higher School of Economics, Myasnitskaya Str. 20, Moscow, 101000 Russia
| | - Roman A. Kamyshinsky
- grid.18919.380000000406204151National Research Center “Kurchatov Institute”, Academic Kurchatov Sq. 1, Moscow, 123182 Russia ,grid.435159.f0000 0001 1941 7461Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” of Russian Academy of Sciences, Leninsky Prospect 59, Moscow, 119333 Russia
| | - Evgeniy O. Yablokov
- grid.418846.70000 0000 8607 342XInstitute of Biomedical Chemistry, Pogodinskaya 10k8, Moscow, 119121 Russia
| | - Alexey S. Ivanov
- grid.418846.70000 0000 8607 342XInstitute of Biomedical Chemistry, Pogodinskaya 10k8, Moscow, 119121 Russia
| | - Mikhail P. Kirpichnikov
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.14476.300000 0001 2342 9668Interdisciplinary Scientific and Educational School of Moscow University “Molecular Technologies of the Living Systems and Synthetic Biology”, Faculty of Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow, 119234 Russia
| | - Ekaterina N. Lyukmanova
- grid.418853.30000 0004 0440 1573Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, Moscow, 117997 Russia ,grid.18763.3b0000000092721542Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Institutsky Lane 9, Dolgoprudny, Moscow, 141701 Russia ,grid.14476.300000 0001 2342 9668Interdisciplinary Scientific and Educational School of Moscow University “Molecular Technologies of the Living Systems and Synthetic Biology”, Faculty of Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow, 119234 Russia
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26
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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. [DOI: 10.1107/s2059798322009299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [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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27
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Bromberg R, Cai K, Guo Y, Plymire D, Emde T, Puzio M, Borek D, Otwinowski Z. The His-tag as a decoy modulating preferred orientation in cryoEM. Front Mol Biosci 2022; 9:912072. [PMID: 36325274 PMCID: PMC9619061 DOI: 10.3389/fmolb.2022.912072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 08/19/2022] [Indexed: 12/02/2022] Open
Abstract
The His-tag is a widely used affinity tag that facilitates purification by means of affinity chromatography of recombinant proteins for functional and structural studies. We show here that His-tag presence affects how coproheme decarboxylase interacts with the air-water interface during grid preparation for cryoEM. Depending on His-tag presence or absence, we observe significant changes in patterns of preferred orientation. Our analysis of particle orientations suggests that His-tag presence can mask the hydrophobic and hydrophilic patches on a protein’s surface that mediate the interactions with the air-water interface, while the hydrophobic linker between a His-tag and the coding sequence of the protein may enhance other interactions with the air-water interface. Our observations suggest that tagging, including rational design of the linkers between an affinity tag and a protein of interest, offer a promising approach to modulating interactions with the air-water interface.
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Affiliation(s)
- Raquel Bromberg
- Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
- Ligo Analytics, Dallas, TX, United States
| | - Kai Cai
- Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Yirui Guo
- Ligo Analytics, Dallas, TX, United States
| | - Daniel Plymire
- Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
- Ligo Analytics, Dallas, TX, United States
| | - Tabitha Emde
- Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Maciej Puzio
- Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Dominika Borek
- Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX, United States
- Center for Structural Genomics of Infectious Diseases, Dallas, TX, United States
- *Correspondence: Dominika Borek, ; Zbyszek Otwinowski,
| | - Zbyszek Otwinowski
- Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX, United States
- Center for Structural Genomics of Infectious Diseases, Dallas, TX, United States
- *Correspondence: Dominika Borek, ; Zbyszek Otwinowski,
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28
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Fremdling P, Esser TK, Saha B, Makarov AA, Fort KL, Reinhardt-Szyba M, Gault J, Rauschenbach S. A Preparative Mass Spectrometer to Deposit Intact Large Native Protein Complexes. ACS NANO 2022; 16:14443-14455. [PMID: 36037396 PMCID: PMC9527803 DOI: 10.1021/acsnano.2c04831] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 08/12/2022] [Indexed: 06/15/2023]
Abstract
Electrospray ion-beam deposition (ES-IBD) is a versatile tool to study the structure and reactivity of molecules from small metal clusters to large protein assemblies. It brings molecules gently into the gas phase, where they can be accurately manipulated and purified, followed by controlled deposition onto various substrates. In combination with imaging techniques, direct structural information on well-defined molecules can be obtained, which is essential to test and interpret results from indirect mass spectrometry techniques. To date, ion-beam deposition experiments are limited to a small number of custom instruments worldwide, and there are no commercial alternatives. Here we present a module that adds ion-beam deposition capabilities to a popular commercial MS platform (Thermo Scientific Q Exactive UHMR mass spectrometer). This combination significantly reduces the overhead associated with custom instruments, while benefiting from established high performance and reliability. We present current performance characteristics including beam intensity, landing-energy control, and deposition spot size for a broad range of molecules. In combination with atomic force microscopy (AFM) and transmission electron microscopy (TEM), we distinguish near-native from unfolded proteins and show retention of the native shape of protein assemblies after dehydration and deposition. Further, we use an enzymatic assay to quantify the activity of a noncovalent protein complex after deposition on a dry surface. Together, these results not only indicate a great potential of ES-IBD for applications in structural biology, but also outline the challenges that need to be solved for it to reach its full potential.
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Affiliation(s)
- Paul Fremdling
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Tim K. Esser
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Bodhisattwa Saha
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Alexander A. Makarov
- Thermo
Fisher Scientific, Bremen 28199, Germany
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584
CH Utrecht, The Netherlands
| | | | | | - Joseph Gault
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Stephan Rauschenbach
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
- Max
Planck Institute for Solid State Research, Heisenbergstrasse 1, Stuttgart 70569, Germany
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29
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Structural insight and characterization of human Twinkle helicase in mitochondrial disease. Proc Natl Acad Sci U S A 2022; 119:e2207459119. [PMID: 35914129 PMCID: PMC9371709 DOI: 10.1073/pnas.2207459119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Twinkle is the mammalian helicase vital for replication and integrity of mitochondrial DNA. Over 90 Twinkle helicase disease variants have been linked to progressive external ophthalmoplegia and ataxia neuropathies among other mitochondrial diseases. Despite the biological and clinical importance, Twinkle represents the only remaining component of the human minimal mitochondrial replisome that has yet to be structurally characterized. Here, we present 3-dimensional structures of human Twinkle W315L. Employing cryo-electron microscopy (cryo-EM), we characterize the oligomeric assemblies of human full-length Twinkle W315L, define its multimeric interface, and map clinical variants associated with Twinkle in inherited mitochondrial disease. Cryo-EM, crosslinking-mass spectrometry, and molecular dynamics simulations provide insight into the dynamic movement and molecular consequences of the W315L clinical variant. Collectively, this ensemble of structures outlines a framework for studying Twinkle function in mitochondrial DNA replication and associated disease states.
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30
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Esser TK, Böhning J, Fremdling P, Agasid MT, Costin A, Fort K, Konijnenberg A, Gilbert JD, Bahm A, Makarov A, Robinson CV, Benesch JLP, Baker L, Bharat TAM, Gault J, Rauschenbach S. Mass-selective and ice-free electron cryomicroscopy protein sample preparation via native electrospray ion-beam deposition. PNAS NEXUS 2022; 1:pgac153. [PMID: 36714824 PMCID: PMC9802471 DOI: 10.1093/pnasnexus/pgac153] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 08/03/2022] [Indexed: 02/01/2023]
Abstract
Despite tremendous advances in sample preparation and classification algorithms for electron cryomicroscopy (cryo-EM) and single-particle analysis (SPA), sample heterogeneity remains a major challenge and can prevent access to high-resolution structures. In addition, optimization of preparation conditions for a given sample can be time-consuming. In the current work, it is demonstrated that native electrospray ion-beam deposition (native ES-IBD) is an alternative, reliable approach for the preparation of extremely high-purity samples, based on mass selection in vacuum. Folded protein ions are generated by native electrospray ionization, separated from other proteins, contaminants, aggregates, and fragments, gently deposited on cryo-EM grids, frozen in liquid nitrogen, and subsequently imaged by cryo-EM. We demonstrate homogeneous coverage of ice-free cryo-EM grids with mass-selected protein complexes. SPA reveals that the complexes remain folded and assembled, but variations in secondary and tertiary structures are currently limiting information in 2D classes and 3D EM density maps. We identify and discuss challenges that need to be addressed to obtain a resolution comparable to that of the established cryo-EM workflow. Our results show the potential of native ES-IBD to increase the scope and throughput of cryo-EM for protein structure determination and provide an essential link between gas-phase and solution-phase protein structures.
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Affiliation(s)
| | - Jan Böhning
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Paul Fremdling
- Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | | | | | - Kyle Fort
- Thermo Fisher Scientific, Hanna-Kunath-Straße 11, 28199 Bremen, Germany
| | - Albert Konijnenberg
- Thermo Fisher Scientific, Zwaanstraat 31G/H, 5651 CA Eindhoven, The Netherlands
| | - Joshua D Gilbert
- Thermo Fisher Scientific, 5350 NE Dawson Creek Drive, Hillsboro, OR 97124, USA
| | - Alan Bahm
- Thermo Fisher Scientific, 5350 NE Dawson Creek Drive, Hillsboro, OR 97124, USA
| | - Alexander Makarov
- Thermo Fisher Scientific, Hanna-Kunath-Straße 11, 28199 Bremen, Germany,Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Carol V Robinson
- Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | - Justin L P Benesch
- Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
| | | | - Tanmay A M Bharat
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK,Structural Studies Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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31
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Klebl DP, Wang Y, Sobott F, Thompson RF, Muench SP. It started with a Cys: Spontaneous cysteine modification during cryo-EM grid preparation. Front Mol Biosci 2022; 9:945772. [PMID: 35992264 PMCID: PMC9389043 DOI: 10.3389/fmolb.2022.945772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 06/27/2022] [Indexed: 12/31/2022] Open
Abstract
Advances in single particle cryo-EM data collection and processing have seen a significant rise in its use. However, the influences of the environment generated through grid preparation, by for example interactions of proteins with the air-water interface are poorly understood and can be a major hurdle in structure determination by cryo-EM. Initial interactions of proteins with the air-water interface occur quickly and proteins can adopt preferred orientation or partially unfold within hundreds of milliseconds. It has also been shown previously that thin-film layers create hydroxyl radicals. To investigate the potential this might have in cryo-EM sample preparation, we studied two proteins, HSPD1, and beta-galactosidase, and show that cysteine residues are modified in a time-dependent manner. In the case of both HSPD1 and beta-galactosidase, this putative oxidation is linked to partial protein unfolding, as well as more subtle structural changes. We show these modifications can be alleviated through increasing the speed of grid preparation, the addition of DTT, or by sequestering away from the AWI using continuous support films. We speculate that the modification is oxidation by reactive oxygen species which are formed and act at the air-water interface. Finally, we show grid preparation on a millisecond timescale outruns cysteine modification, showing that the reaction timescale is in the range of 100s to 1,000s milliseconds and offering an alternative approach to prevent spontaneous cysteine modification and its consequences during cryo-EM grid 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, United Kingdom
| | - Yiheng Wang
- School of Biomedical Sciences, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Frank Sobott
- School of Molecular and Cellular Biology, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Rebecca F. Thompson
- School of Molecular and Cellular Biology, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, United Kingdom
- *Correspondence: Rebecca F. Thompson, ; Stephen P. Muench,
| | - Stephen P. Muench
- School of Biomedical Sciences, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, United Kingdom
- *Correspondence: Rebecca F. Thompson, ; Stephen P. Muench,
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32
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Piper SJ, Johnson RM, Wootten D, Sexton PM. Membranes under the Magnetic Lens: A Dive into the Diverse World of Membrane Protein Structures Using Cryo-EM. Chem Rev 2022; 122:13989-14017. [PMID: 35849490 DOI: 10.1021/acs.chemrev.1c00837] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Membrane proteins are highly diverse in both structure and function and can, therefore, present different challenges for structure determination. They are biologically important for cells and organisms as gatekeepers for information and molecule transfer across membranes, but each class of membrane proteins can present unique obstacles to structure determination. Historically, many membrane protein structures have been investigated using highly engineered constructs or using larger fusion proteins to improve solubility and/or increase particle size. Other strategies included the deconstruction of the full-length protein to target smaller soluble domains. These manipulations were often required for crystal formation to support X-ray crystallography or to circumvent lower resolution due to high noise and dynamic motions of protein subdomains. However, recent revolutions in membrane protein biochemistry and cryo-electron microscopy now provide an opportunity to solve high resolution structures of both large, >1 megadalton (MDa), and small, <100 kDa (kDa), drug targets in near-native conditions, routinely reaching resolutions around or below 3 Å. This review provides insights into how the recent advances in membrane biology and biochemistry, as well as technical advances in cryo-electron microscopy, help us to solve structures of a large variety of membrane protein groups, from small receptors to large transporters and more complex machineries.
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Affiliation(s)
- Sarah J Piper
- Drug Discovery Biology theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Rachel M Johnson
- Drug Discovery Biology theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Denise Wootten
- Drug Discovery Biology theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Patrick M Sexton
- Drug Discovery Biology theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
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Fan H, Sun F. Developing Graphene Grids for Cryoelectron Microscopy. Front Mol Biosci 2022; 9:937253. [PMID: 35911962 PMCID: PMC9326159 DOI: 10.3389/fmolb.2022.937253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 05/31/2022] [Indexed: 11/13/2022] Open
Abstract
Cryogenic electron microscopy (cryo-EM) single particle analysis has become one of the major techniques used to study high-resolution 3D structures of biological macromolecules. Specimens are generally prepared in a thin layer of vitrified ice using a holey carbon grid. However, the sample quality using this type of grid is not always ideal for high-resolution imaging even when the specimens in the test tube behave ideally. Various problems occur during a vitrification procedure, including poor/nonuniform distribution of particles, preferred orientation of particles, specimen denaturation/degradation, high background from thick ice, and beam-induced motion, which have become important bottlenecks in high-resolution structural studies using cryo-EM in many projects. In recent years, grids with support films made of graphene and its derivatives have been developed to efficiently solve these problems. Here, the various advantages of graphene grids over conventional holey carbon film grids, functionalization of graphene support films, production methods of graphene grids, and origins of pristine graphene contamination are reviewed and discussed.
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Affiliation(s)
- Hongcheng Fan
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Fei Sun
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Bioland Laboratory, Guangzhou, China
- *Correspondence: Fei Sun,
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34
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Xu Y, Dang S. Recent Technical Advances in Sample Preparation for Single-Particle Cryo-EM. Front Mol Biosci 2022; 9:892459. [PMID: 35813814 PMCID: PMC9263182 DOI: 10.3389/fmolb.2022.892459] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/12/2022] [Indexed: 11/25/2022] Open
Abstract
Cryo-sample preparation is a vital step in the process of obtaining high-resolution structures of macromolecules by using the single-particle cryo–electron microscopy (cryo-EM) method; however, cryo-sample preparation is commonly hampered by high uncertainty and low reproducibility. Specifically, the existence of air-water interfaces during the sample vitrification process could cause protein denaturation and aggregation, complex disassembly, adoption of preferred orientations, and other serious problems affecting the protein particles, thereby making it challenging to pursue high-resolution 3D reconstruction. Therefore, sample preparation has emerged as a critical research topic, and several new methods for application at various preparation stages have been proposed to overcome the aforementioned hurdles. Here, we summarize the methods developed for enhancing the quality of cryo-samples at distinct stages of sample preparation, and we offer insights for developing future strategies based on diverse viewpoints. We anticipate that cryo-sample preparation will no longer be a limiting step in the single-particle cryo-EM field as increasing numbers of methods are developed in the near future, which will ultimately benefit the entire research community.
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Affiliation(s)
- Yixin Xu
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China
| | - Shangyu Dang
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China
- *Correspondence: Shangyu Dang,
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35
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Niebling S, Veith K, Vollmer B, Lizarrondo J, Burastero O, Schiller J, Struve García A, Lewe P, Seuring C, Witt S, García-Alai M. Biophysical Screening Pipeline for Cryo-EM Grid Preparation of Membrane Proteins. Front Mol Biosci 2022; 9:882288. [PMID: 35813810 PMCID: PMC9259969 DOI: 10.3389/fmolb.2022.882288] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 05/04/2022] [Indexed: 11/13/2022] Open
Abstract
Successful sample preparation is the foundation to any structural biology technique. Membrane proteins are of particular interest as these are important targets for drug design, but also notoriously difficult to work with. For electron cryo-microscopy (cryo-EM), the biophysical characterization of sample purity, homogeneity, and integrity as well as biochemical activity is the prerequisite for the preparation of good quality cryo-EM grids as these factors impact the result of the computational reconstruction. Here, we present a quality control pipeline prior to single particle cryo-EM grid preparation using a combination of biophysical techniques to address the integrity, purity, and oligomeric states of membrane proteins and its complexes to enable reproducible conditions for sample vitrification. Differential scanning fluorimetry following the intrinsic protein fluorescence (nDSF) is used for optimizing buffer and detergent conditions, whereas mass photometry and dynamic light scattering are used to assess aggregation behavior, reconstitution efficiency, and oligomerization. The data collected on nDSF and mass photometry instruments can be analyzed with web servers publicly available at spc.embl-hamburg.de. Case studies to optimize conditions prior to cryo-EM sample preparation of membrane proteins present an example quality assessment to corroborate the usefulness of our pipeline.
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Affiliation(s)
- Stephan Niebling
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Katharina Veith
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
| | - Benjamin Vollmer
- Centre for Structural Systems Biology (CSSB), Leibniz Institute of Virology (LIV), Hamburg, Germany
| | | | - Osvaldo Burastero
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Janina Schiller
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
| | - Angelica Struve García
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
| | - Philipp Lewe
- Centre for Structural Systems Biology (CSSB), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carolin Seuring
- Centre for Structural Systems Biology (CSSB), Department of Chemistry, University of Hamburg, Hamburg, Germany
| | - Susanne Witt
- Centre for Structural Systems Biology (CSSB), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - María García-Alai
- European Molecular Biology Laboratory Hamburg, Hamburg, Germany
- Centre for Structural Systems Biology (CSSB), Hamburg, Germany
- *Correspondence: María García-Alai,
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36
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Levitz TS, Weckener M, Fong I, Naismith JH, Drennan CL, Brignole EJ, Clare DK, Darrow MC. Approaches to Using the Chameleon: Robust, Automated, Fast-Plunge cryoEM Specimen Preparation. Front Mol Biosci 2022; 9:903148. [PMID: 35813832 PMCID: PMC9260054 DOI: 10.3389/fmolb.2022.903148] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/31/2022] [Indexed: 01/21/2023] Open
Abstract
The specimen preparation process is a key determinant in the success of any cryo electron microscopy (cryoEM) structural study and until recently had remained largely unchanged from the initial designs of Jacques Dubochet and others in the 1980s. The process has transformed structural biology, but it is largely manual and can require extensive optimisation for each protein sample. The chameleon instrument with its self-wicking grids and fast-plunge freezing represents a shift towards a robust, automated, and highly controllable future for specimen preparation. However, these new technologies require new workflows and an understanding of their limitations and strengths. As early adopters of the chameleon technology, we report on our experiences and lessons learned through case studies. We use these to make recommendations for the benefit of future users of the chameleon system and the field of cryoEM specimen preparation generally.
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Affiliation(s)
- Talya S. Levitz
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Miriam Weckener
- Structural Biology, The Rosalind Franklin Institute, Harwell Science Campus, Didcot, United Kingdom,Division of Structural Biology, The Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Ivan Fong
- SPT Labtech, Melbourn, United Kingdom
| | - James H. Naismith
- Structural Biology, The Rosalind Franklin Institute, Harwell Science Campus, Didcot, United Kingdom,Division of Structural Biology, The Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Catherine L. Drennan
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States,Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, United States,Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Edward J. Brignole
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States,MIT.nano, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Daniel K. Clare
- Diamond Light Source Ltd., Harwell Science Campus, Didcot, United Kingdom
| | - Michele C. Darrow
- SPT Labtech, Melbourn, United Kingdom,Artificial Intelligence and Informatics, The Rosalind Franklin Institute, Harwell Science Campus, Didcot, United Kingdom,*Correspondence: Michele C. Darrow,
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Huntington B, Zhao L, Bron P, Shahul Hameed UF, Arold ST, Qureshi BM. Thicker Ice Improves the Integrity and Angular Distribution of CDC48A Hexamers on Cryo-EM Grids. Front Mol Biosci 2022; 9:890390. [PMID: 35782862 PMCID: PMC9247313 DOI: 10.3389/fmolb.2022.890390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 05/26/2022] [Indexed: 11/21/2022] Open
Abstract
Many cryogenic electron microscopy (cryo-EM) single particle analyses are constrained by the sample preparation step upon which aggregation, dissociation, and/or preferential orientation of particles can be introduced. Here, we report how we solved these problems in the case of CDC48A, a hexameric AAA ATPase from Arabidopsis thaliana. CDC48A hexamers are well preserved under negative staining conditions but disassemble during grid freezing using the classical blotting method. Vitrification of grids using the blot-free Chameleon method preserved the integrity of particles but resulted in their strong preferential orientation. We then used a strategy where we improved in parallel the purification of CDC48A and the conditions for cryo-EM data acquisition. Indeed, we noted that images taken from thicker ice presented an even distribution of intact particles with random orientations, but resulted in a lower image resolution. Consequently, in our case, distribution, orientation, image resolution, and the integrity of particles were tightly correlated with ice thickness. By combining the more homogeneous and stable CDC48A hexamers resulting from our improved purification protocol with an iterative search across different ice thicknesses, we identified an intermediate thickness that retained sufficiently high-resolution structural information while maintaining a complete distribution of particle orientations. Our approach may provide a simple, fast, and generally applicable strategy to record data of sufficient quality under standard laboratory and microscope settings. This method may be of particular value when time and resources are limited.
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Affiliation(s)
- Brandon Huntington
- Bioscience Program, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Computational Biology Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Lingyun Zhao
- Imaging and Characterization Core Lab, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Patrick Bron
- Centre de Biologie Structurale (CBS), INSERM, CNRS, Université de Montpellier, Montpellier, France
| | - Umar F. Shahul Hameed
- Bioscience Program, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Computational Biology Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- *Correspondence: Umar F. Shahul Hameed, ; Stefan T. Arold, ; Bilal M. Qureshi,
| | - Stefan T. Arold
- Bioscience Program, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Computational Biology Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Centre de Biologie Structurale (CBS), INSERM, CNRS, Université de Montpellier, Montpellier, France
- *Correspondence: Umar F. Shahul Hameed, ; Stefan T. Arold, ; Bilal M. Qureshi,
| | - Bilal M. Qureshi
- Bioscience Program, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Computational Biology Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Division of Structural Biology (Strubi), University of Oxford, Oxford, United Kingdom
- Scientific Center of Optical and Electron Microscopy (ScopeM), ETH Zurich, Zurich, Switzerland
- *Correspondence: Umar F. Shahul Hameed, ; Stefan T. Arold, ; Bilal M. Qureshi,
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38
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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: 1.5] [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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39
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Olek M, Cowtan K, Webb D, Chaban Y, Zhang P. IceBreaker: Software for high-resolution single-particle cryo-EM with non-uniform ice. Structure 2022; 30:522-531.e4. [PMID: 35150604 PMCID: PMC9033277 DOI: 10.1016/j.str.2022.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 12/01/2021] [Accepted: 01/18/2022] [Indexed: 12/23/2022]
Abstract
Despite the abundance of available software tools, optimal particle selection is still a vital issue in single-particle cryoelectron microscopy (cryo-EM). Regardless of the method used, most pickers struggle when ice thickness varies on a micrograph. IceBreaker allows users to estimate the relative ice gradient and flatten it by equalizing the local contrast. It allows the differentiation of particles from the background and improves overall particle picking performance. Furthermore, we introduce an additional parameter corresponding to local ice thickness for each particle. Particles with a defined ice thickness can be grouped and filtered based on this parameter during processing. These functionalities are especially valuable for on-the-fly processing to automatically pick as many particles as possible from each micrograph and to select optimal regions for data collection. Finally, estimated ice gradient distributions can be stored separately and used to inspect the quality of prepared samples.
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Affiliation(s)
- Mateusz Olek
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; Department of Chemistry, University of York, York, UK
| | - Kevin Cowtan
- Department of Chemistry, University of York, York, UK
| | - Donovan Webb
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Yuriy Chaban
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK.
| | - Peijun Zhang
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK; Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK; Chinese Academy of Medical Sciences Oxford Institute, University of Oxford, Oxford OX3 7BN, UK.
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40
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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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41
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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: 5.5] [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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42
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Ong Q, Mao T, Iranpour Anaraki N, Richter Ł, Malinverni C, Xu X, Olgiati F, Silva PHJ, Murello A, Neels A, Demurtas D, Shimizu S, Stellacci F. Cryogenic electron tomography to determine thermodynamic quantities for nanoparticle dispersions. MATERIALS HORIZONS 2022; 9:303-311. [PMID: 34739025 PMCID: PMC8725794 DOI: 10.1039/d1mh01461g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/15/2021] [Indexed: 05/24/2023]
Abstract
Here we present a method to extract thermodynamic quantities for nanoparticle dispersions in solvents. The method is based on the study of tomograms obtained from cryogenic electron tomography (cryoET). The approach is demonstrated for gold nanoparticles (diameter < 5 nm). Tomograms are reconstructed from tilt-series 2D images. Once the three-dimensional (3D) coordinates for the centres of mass of all of the particles in the sample are determined, we calculate the pair distribution function g(r) and the potential of mean force U(r) without any assumption. Importantly, we show that further quantitative information from 3D tomograms is readily available as the spatial fluctuation in the particles' position can be efficiently determined. This in turn allows for the prompt derivation of the Kirkwood-Buff integrals with all their associated quantities such as the second virial coefficient. Finally, the structure factor and the agglomeration states of the particles are evaluated directly. These thermodynamic quantities provide key insights into the dispersion properties of the particles. The method works well both for dispersed systems containing isolated particles and for systems with varying degrees of agglomerations.
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Affiliation(s)
- Quy Ong
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Ting Mao
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Neda Iranpour Anaraki
- Center for X-ray Analytics, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, St. Gallen, 9014, Switzerland
- Laboratory of Particles-Biology Interactions, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, St. Gallen, 9014, Switzerland
- Department of Chemistry, University of Fribourg, Chemin du Musée 9, Fribourg, 1700, Switzerland
| | - Łukasz Richter
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Carla Malinverni
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Xufeng Xu
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Francesca Olgiati
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | | | - Anna Murello
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Antonia Neels
- Center for X-ray Analytics, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, St. Gallen, 9014, Switzerland
- Department of Chemistry, University of Fribourg, Chemin du Musée 9, Fribourg, 1700, Switzerland
| | - Davide Demurtas
- Interdisciplinary Centre for Electron Microscopy (CIME), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Seishi Shimizu
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Francesco Stellacci
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
- Bioengineering Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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43
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Li N, Rao G, Li Z, Yin J, Chong T, Tian K, Fu Y, Cao S. Cryo-EM structure of glycoprotein C from Crimean-Congo hemorrhagic fever virus. Virol Sin 2022; 37:127-137. [PMID: 35234630 PMCID: PMC8922431 DOI: 10.1016/j.virs.2022.01.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 11/12/2021] [Indexed: 01/09/2023] Open
Abstract
Crimean-Congo hemorrhagic fever virus (CCHFV) is a causative agent of serious hemorrhagic diseases in humans with high mortality rates. CCHFV glycoprotein Gc plays critical roles in mediating virus-host membrane fusion and has been studied extensively as an immunogen. However, the molecular mechanisms involved in membrane fusion and Gc-specific antibody-antigen interactions remain unresolved largely because structural information of this glycoprotein is missing. We designed a trimeric protein including most of the ectodomain region of Gc from the prototype CCHFV strain, IbAr10200, which enabled the cryo-electron microscopy structure to be solved at a resolution of 2.8 Å. The structure confirms that CCHFV Gc is a class II fusion protein. Unexpectedly, structural comparisons with other solved Gc trimers in the postfusion conformation revealed that CCHFV Gc adopted hybrid architectural features of the fusion loops from hantaviruses and domain III from phenuiviruses, suggesting a complex evolutionary pathway among these bunyaviruses. Antigenic sites on CCHFV Gc that protective neutralizing antibodies target were mapped onto the CCHFV Gc structure, providing valuable information that improved our understanding of potential neutralization mechanisms of various antibodies. Cryo-EM structure of the ectodomain of CCHFV Gc in the postfusion conformation was determined at atomic-resolution. CCHFV Gc is a class II fusion protein and adopts hybrid architectural features of hantaviruses and phenuiviruses. Structural mapping of Gc epitope residues targeted by neutralizing antibodies would facilitate future vaccine development.
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Tsai MD, Wu WJ, Ho MC. Enzymology and Dynamics by Cryogenic Electron Microscopy. Annu Rev Biophys 2021; 51:19-38. [PMID: 34932913 DOI: 10.1146/annurev-biophys-100121-075228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cryogenic electron microscopy (cryo-EM) has revolutionized the field of structural biology, particularly in solving the structures of large protein complexes or cellular machineries that play important biological functions. This review focuses on the contribution and future potential of cryo-EM in related emerging applications-enzymatic mechanisms and dynamic processes. Work on these subjects can benefit greatly from the capability of cryo-EM to solve the structures of specific protein complexes in multiple conditions, including variations in the buffer condition, ligands, and temperature, and to capture multiple conformational states, conformational change intermediates, and reaction intermediates. These studies can expand the structural landscape of specific proteins or protein complexes in multiple dimensions and drive new advances in the fields of enzymology and dynamic processes. The advantages and complementarity of cryo-EM relative to X-ray crystallography and nuclear magnetic resonance with regard to these applications are also addressed. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Ming-Daw Tsai
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; .,Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Wen-Jin Wu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan;
| | - Meng-Chiao Ho
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; .,Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
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Wood DM, Dobson RC, Horne CR. Using cryo-EM to uncover mechanisms of bacterial transcriptional regulation. Biochem Soc Trans 2021; 49:2711-2726. [PMID: 34854920 PMCID: PMC8786299 DOI: 10.1042/bst20210674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/10/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022]
Abstract
Transcription is the principal control point for bacterial gene expression, and it enables a global cellular response to an intracellular or environmental trigger. Transcriptional regulation is orchestrated by transcription factors, which activate or repress transcription of target genes by modulating the activity of RNA polymerase. Dissecting the nature and precise choreography of these interactions is essential for developing a molecular understanding of transcriptional regulation. While the contribution of X-ray crystallography has been invaluable, the 'resolution revolution' of cryo-electron microscopy has transformed our structural investigations, enabling large, dynamic and often transient transcription complexes to be resolved that in many cases had resisted crystallisation. In this review, we highlight the impact cryo-electron microscopy has had in gaining a deeper understanding of transcriptional regulation in bacteria. We also provide readers working within the field with an overview of the recent innovations available for cryo-electron microscopy sample preparation and image reconstruction of transcription complexes.
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Affiliation(s)
- David M. Wood
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Renwick C.J. Dobson
- Biomolecular Interaction Centre and School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- Bio21 Molecular Science and Biotechnology Institute, Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC, Australia
| | - Christopher R. Horne
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC 3052, Australia
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46
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Fan H, Wang B, Zhang Y, Zhu Y, Song B, Xu H, Zhai Y, Qiao M, Sun F. A cryo-electron microscopy support film formed by 2D crystals of hydrophobin HFBI. Nat Commun 2021; 12:7257. [PMID: 34907237 PMCID: PMC8671466 DOI: 10.1038/s41467-021-27596-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/30/2021] [Indexed: 01/27/2023] Open
Abstract
Cryo-electron microscopy (cryo-EM) has become a powerful tool to resolve high-resolution structures of biomacromolecules in solution. However, air-water interface induced preferred orientations, dissociation or denaturation of biomacromolecules during cryo-vitrification remains a limiting factor for many specimens. To solve this bottleneck, we developed a cryo-EM support film using 2D crystals of hydrophobin HFBI. The hydrophilic side of the HFBI film adsorbs protein particles via electrostatic interactions and sequesters them from the air-water interface, allowing the formation of sufficiently thin ice for high-quality data collection. The particle orientation distribution can be regulated by adjusting the buffer pH. Using this support, we determined the cryo-EM structures of catalase (2.29 Å) and influenza haemagglutinin trimer (2.56 Å), which exhibited strong preferred orientations using a conventional cryo-vitrification protocol. We further show that the HFBI film is suitable to obtain high-resolution structures of small proteins, including aldolase (150 kDa, 3.28 Å) and haemoglobin (64 kDa, 3.6 Å). Our work suggests that HFBI films may have broad future applications in increasing the success rate and efficiency of cryo-EM.
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Affiliation(s)
- Hongcheng Fan
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Bo Wang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, 300071, Tianjin, China
| | - Yan Zhang
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Yun Zhu
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Bo Song
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, 300071, Tianjin, China
| | - Haijin Xu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, 300071, Tianjin, China
| | - Yujia Zhai
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Mingqiang Qiao
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, 300071, Tianjin, China.
- School of Life Science, Shanxi University, Shanxi, China.
| | - Fei Sun
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
- Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China.
- Physical Science Laboratory, Huairou National Comprehensive Science Center, No. 5 Yanqi East Second Street, 101400, Beijing, China.
- Bioland Laboratory, 510005, Guangzhou, Guangdong Province, China.
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47
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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: 4.3] [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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48
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Han BG, Glaeser RM. Simple assay for adsorption of proteins to the air-water interface. J Struct Biol 2021; 213:107798. [PMID: 34534654 DOI: 10.1016/j.jsb.2021.107798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 09/05/2021] [Accepted: 09/09/2021] [Indexed: 11/27/2022]
Abstract
A rapid assay is described, based upon the Marangoni effect, which detects the formation of a denatured-protein film at the air-water interface (AWI) of aqueous samples. This assay requires no more than a 20 µL aliquot of sample, at a protein concentration of no more than1 mg/ml, and it can be performed with any buffer that is used to prepare grids for electron cryo-microscopy (cryo-EM). In addition, this assay provides an easy way to estimate the rate at which a given protein forms such a film at the AWI. Use of this assay is suggested as a way to pre-screen the effect of various additives and chemical modifications that one might use to optimize the preparation of grids, although the final proof of optimization still requires further screening of grids in the electron microscope. In those cases when the assay establishes that a given protein does form a sacrificial, denatured-protein monolayer, it is suggested that subsequent optimization strategies might focus on discovering how to improve the adsorption of native proteins onto that monolayer, rather than to prevent its formation. A second alternative might be to bind such proteins to the surface of rationally designed affinity grids, in order to prevent their diffusion to, and unwanted interaction with, the AWI.
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Affiliation(s)
- Bong-Gyoon Han
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, United States
| | - Robert M Glaeser
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, United States.
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49
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Exploring the Effect of Structure-Based Scaffold Hopping on the Inhibition of Coxsackievirus A24v Transduction by Pentavalent N-Acetylneuraminic Acid Conjugates. Int J Mol Sci 2021; 22:ijms22168418. [PMID: 34445134 PMCID: PMC8395083 DOI: 10.3390/ijms22168418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 07/26/2021] [Accepted: 07/31/2021] [Indexed: 11/17/2022] Open
Abstract
Coxsackievirus A24 variant (CVA24v) is the primary causative agent of the highly contagious eye infection designated acute hemorrhagic conjunctivitis (AHC). It is solely responsible for two pandemics and several recurring outbreaks of the disease over the last decades, thus affecting millions of individuals throughout the world. To date, no antiviral agents or vaccines are available for combating this disease, and treatment is mainly supportive. CVA24v utilizes Neu5Ac-containing glycans as attachment receptors facilitating entry into host cells. We have previously reported that pentavalent Neu5Ac conjugates based on a glucose-scaffold inhibit CVA24v infection of human corneal epithelial cells. In this study, we report on the design and synthesis of scaffold-replaced pentavalent Neu5Ac conjugates and their effect on CVA24v cell transduction and the use of cryogenic electron microscopy (cryo-EM) to study the binding of these multivalent conjugates to CVA24v. The results presented here provide insights into the development of Neu5Ac-based inhibitors of CVA24v and, most significantly, the first application of cryo-EM to study the binding of a multivalent ligand to a lectin.
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50
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Rizvi A, Mulvey JT, Carpenter BP, Talosig R, Patterson JP. A Close Look at Molecular Self-Assembly with the Transmission Electron Microscope. Chem Rev 2021; 121:14232-14280. [PMID: 34329552 DOI: 10.1021/acs.chemrev.1c00189] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Molecular self-assembly is pervasive in the formation of living and synthetic materials. Knowledge gained from research into the principles of molecular self-assembly drives innovation in the biological, chemical, and materials sciences. Self-assembly processes span a wide range of temporal and spatial domains and are often unintuitive and complex. Studying such complex processes requires an arsenal of analytical and computational tools. Within this arsenal, the transmission electron microscope stands out for its unique ability to visualize and quantify self-assembly structures and processes. This review describes the contribution that the transmission electron microscope has made to the field of molecular self-assembly. An emphasis is placed on which TEM methods are applicable to different structures and processes and how TEM can be used in combination with other experimental or computational methods. Finally, we provide an outlook on the current challenges to, and opportunities for, increasing the impact that the transmission electron microscope can have on molecular self-assembly.
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Affiliation(s)
- Aoon Rizvi
- Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Justin T Mulvey
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Brooke P Carpenter
- Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Rain Talosig
- Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Joseph P Patterson
- Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
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