1
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Shi B, Zhang K, Fleet DJ, McLeod RA, Dwayne Miller RJ, Howe JY. Deep generative priors for biomolecular 3D heterogeneous reconstruction from cryo-EM projections. J Struct Biol 2024; 216:108073. [PMID: 38432598 DOI: 10.1016/j.jsb.2024.108073] [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: 11/08/2023] [Revised: 02/25/2024] [Accepted: 02/25/2024] [Indexed: 03/05/2024]
Abstract
Cryo-electron microscopy has become a powerful tool to determine three-dimensional (3D) structures of rigid biological macromolecules from noisy micrographs with single-particle reconstruction. Recently, deep neural networks, e.g., CryoDRGN, have demonstrated conformational and compositional heterogeneity of complexes. However, the lack of ground-truth conformations poses a challenge to assess the performance of heterogeneity analysis methods. In this work, variational autoencoders (VAE) with three types of deep generative priors were learned for latent variable inference and heterogeneous 3D reconstruction via Bayesian inference. More specifically, VAEs with "Variational Mixture of Posteriors" priors (VampPrior-SPR), non-parametric exemplar-based priors (ExemplarPrior-SPR) and priors from latent score-based generative models (LSGM-SPR) were quantitatively compared with CryoDRGN. We built four simulated datasets composed of hypothetical continuous conformation or discrete states of the hERG K + channel. Empirical and quantitative comparisons of inferred latent representations were performed with affine-transformation-based metrics. These models with more informative priors gave better regularized, interpretable factorized latent representations with better conserved pairwise distances, less deformed latent distributions and lower within-cluster variances. They were also tested on experimental datasets to resolve compositional and conformational heterogeneity (50S ribosome assembly, cowpea chlorotic mottle virus, and pre-catalytic spliceosome) with comparable high resolution. Codes and data are available: https://github.com/benjamin3344/DGP-SPR.
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Affiliation(s)
- Bin Shi
- Department of Materials Science and Engineering, University of Toronto, ON M5S 3H5, Canada
| | - Kevin Zhang
- Department of Materials Science and Engineering, University of Toronto, ON M5S 3H5, Canada
| | - David J Fleet
- Department of Computer Science, University of Toronto, ON M5S 3H5, Canada
| | - Robert A McLeod
- Hitachi High-Technologies Canada, Inc. Based out of Victoria, BC, Canada, British Columbia, Canada
| | - R J Dwayne Miller
- Departments of Chemistry and Physics, University of Toronto, ON M5S 3H6, Canada.
| | - Jane Y Howe
- Department of Materials Science and Engineering, University of Toronto, ON M5S 3H5, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, ON M5S 3E5, Canada
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2
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Gyawali R, Dhakal A, Wang L, Cheng J. CryoSegNet: accurate cryo-EM protein particle picking by integrating the foundational AI image segmentation model and attention-gated U-Net. Brief Bioinform 2024; 25:bbae282. [PMID: 38860738 PMCID: PMC11165428 DOI: 10.1093/bib/bbae282] [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: 03/17/2024] [Revised: 05/15/2024] [Accepted: 05/29/2024] [Indexed: 06/12/2024] Open
Abstract
Picking protein particles in cryo-electron microscopy (cryo-EM) micrographs is a crucial step in the cryo-EM-based structure determination. However, existing methods trained on a limited amount of cryo-EM data still cannot accurately pick protein particles from noisy cryo-EM images. The general foundational artificial intelligence-based image segmentation model such as Meta's Segment Anything Model (SAM) cannot segment protein particles well because their training data do not include cryo-EM images. Here, we present a novel approach (CryoSegNet) of integrating an attention-gated U-shape network (U-Net) specially designed and trained for cryo-EM particle picking and the SAM. The U-Net is first trained on a large cryo-EM image dataset and then used to generate input from original cryo-EM images for SAM to make particle pickings. CryoSegNet shows both high precision and recall in segmenting protein particles from cryo-EM micrographs, irrespective of protein type, shape and size. On several independent datasets of various protein types, CryoSegNet outperforms two top machine learning particle pickers crYOLO and Topaz as well as SAM itself. The average resolution of density maps reconstructed from the particles picked by CryoSegNet is 3.33 Å, 7% better than 3.58 Å of Topaz and 14% better than 3.87 Å of crYOLO. It is publicly available at https://github.com/jianlin-cheng/CryoSegNet.
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Affiliation(s)
- Rajan Gyawali
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO 65211, United States
- NextGen Precision Health, University of Missouri, Columbia, MO 65211, United States
| | - Ashwin Dhakal
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO 65211, United States
- NextGen Precision Health, University of Missouri, Columbia, MO 65211, United States
| | - Liguo Wang
- Laboratory for BioMolecular Structure (LBMS), Brookhaven National Laboratory, Upton, NY 11973, United States
| | - Jianlin Cheng
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO 65211, United States
- NextGen Precision Health, University of Missouri, Columbia, MO 65211, United States
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3
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Lightowler M, Li S, Ou X, Cho J, Liu B, Li A, Hofer G, Xu J, Yang T, Zou X, Lu M, Xu H. Phase Identification and Discovery of an Elusive Polymorph of Drug-Polymer Inclusion Complex Using Automated 3D Electron Diffraction. Angew Chem Int Ed Engl 2024; 63:e202317695. [PMID: 38380831 DOI: 10.1002/anie.202317695] [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: 11/20/2023] [Revised: 02/16/2024] [Accepted: 02/17/2024] [Indexed: 02/22/2024]
Abstract
3D electron diffraction (3D ED) has shown great potential in crystal structure determination in materials, small organic molecules, and macromolecules. In this work, an automated, low-dose and low-bias 3D ED protocol has been implemented to identify six phases from a multiple-phase melt-crystallisation product of an active pharmaceutical ingredient, griseofulvin (GSF). Batch data collection under low-dose conditions using a widely available commercial software was combined with automated data analysis to collect and process over 230 datasets in three days. Accurate unit cell parameters obtained from 3D ED data allowed direct phase identification of GSF Forms III, I and the known GSF inclusion complex (IC) with polyethylene glycol (PEG) (GSF-PEG IC-I), as well as three minor phases, namely GSF Forms II, V and an elusive new phase, GSF-PEG IC-II. Their structures were then directly determined by 3D ED. Furthermore, we reveal how the stabilities of the two GSF-PEG IC polymorphs are closely related to their crystal structures. These results demonstrate the power of automated 3D ED for accurate phase identification and direct structure determination of complex, beam-sensitive crystallisation products, which is significant for drug development where solid form screening is crucial for the overall efficacy of the drug product.
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Affiliation(s)
- Molly Lightowler
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, SE-106 91, Sweden
| | - Shuting Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Xiao Ou
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Jungyoun Cho
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, SE-106 91, Sweden
| | - Binbin Liu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Ao Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Gerhard Hofer
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, SE-106 91, Sweden
| | - Jiaoyan Xu
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, SE-106 91, Sweden
| | - Taimin Yang
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, SE-106 91, Sweden
| | - Xiaodong Zou
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, SE-106 91, Sweden
| | - Ming Lu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Hongyi Xu
- Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, SE-106 91, Sweden
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4
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Bay Y, Venskutonytė R, Frantsen SM, Thorsen TS, Musgaard M, Frydenvang K, Francotte P, Pirotte B, Biggin PC, Kristensen AS, Boesen T, Pickering DS, Gajhede M, Kastrup JS. Small-molecule positive allosteric modulation of homomeric kainate receptors GluK1-3: development of screening assays and insight into GluK3 structure. FEBS J 2024; 291:1506-1529. [PMID: 38145505 DOI: 10.1111/febs.17046] [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: 07/06/2023] [Revised: 10/20/2023] [Accepted: 12/22/2023] [Indexed: 12/27/2023]
Abstract
The kainate receptors GluK1-3 (glutamate receptor ionotropic, kainate receptors 1-3) belong to the family of ionotropic glutamate receptors and are essential for fast excitatory neurotransmission in the brain, and are associated with neurological and psychiatric diseases. How these receptors can be modulated by small-molecule agents is not well understood, especially for GluK3. We show that the positive allosteric modulator BPAM344 can be used to establish robust calcium-sensitive fluorescence-based assays to test agonists, antagonists, and positive allosteric modulators of GluK1-3. The half-maximal effective concentration (EC50) of BPAM344 for potentiating the response of 100 μm kainate was determined to be 26.3 μm for GluK1, 75.4 μm for GluK2, and 639 μm for GluK3. Domoate was found to be a potent agonist for GluK1 and GluK2, with an EC50 of 0.77 and 1.33 μm, respectively, upon co-application of 150 μm BPAM344. At GluK3, domoate acts as a very weak agonist or antagonist with a half-maximal inhibitory concentration (IC50) of 14.5 μm, in presence of 500 μm BPAM344 and 100 μm kainate for competition binding. Using H523A-mutated GluK3, we determined the first dimeric structure of the ligand-binding domain by X-ray crystallography, allowing location of BPAM344, as well as zinc-, sodium-, and chloride-ion binding sites at the dimer interface. Molecular dynamics simulations support the stability of the ion sites as well as the involvement of Asp761, Asp790, and Glu797 in the binding of zinc ions. Using electron microscopy, we show that, in presence of glutamate and BPAM344, full-length GluK3 adopts a dimer-of-dimers arrangement.
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Affiliation(s)
- Yasmin Bay
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Raminta Venskutonytė
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Stine M Frantsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Thor S Thorsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | | | - Karla Frydenvang
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Pierre Francotte
- Department of Medicinal Chemistry, Center for Interdisciplinary Research on Medicines (CIRM), University of Liège, Belgium
| | - Bernard Pirotte
- Department of Medicinal Chemistry, Center for Interdisciplinary Research on Medicines (CIRM), University of Liège, Belgium
| | | | - Anders S Kristensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Thomas Boesen
- Danish Research Institute of Translational Neuroscience-DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Department of Molecular Biology and Genetics, Aarhus University, Denmark
| | - Darryl S Pickering
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Michael Gajhede
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Jette S Kastrup
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
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5
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Gyawali R, Dhakal A, Wang L, Cheng J. Accurate cryo-EM protein particle picking by integrating the foundational AI image segmentation model and specialized U-Net. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.02.560572. [PMID: 37873264 PMCID: PMC10592924 DOI: 10.1101/2023.10.02.560572] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Picking protein particles in cryo-electron microscopy (cryo-EM) micrographs is a crucial step in the cryo-EM-based structure determination. However, existing methods trained on a limited amount of cryo-EM data still cannot accurately pick protein particles from noisy cryo-EM images. The general foundational artificial intelligence (AI)-based image segmentation model such as Meta's Segment Anything Model (SAM) cannot segment protein particles well because their training data do not include cryo-EM images. Here, we present a novel approach (CryoSegNet) of integrating an attention-gated U-shape network (U-Net) specially designed and trained for cryo-EM particle picking and the SAM. The U-Net is first trained on a large cryo-EM image dataset and then used to generate input from original cryo-EM images for SAM to make particle pickings. CryoSegNet shows both high precision and recall in segmenting protein particles from cryo-EM micrographs, irrespective of protein type, shape, and size. On several independent datasets of various protein types, CryoSegNet outperforms two top machine learning particle pickers crYOLO and Topaz as well as SAM itself. The average resolution of density maps reconstructed from the particles picked by CryoSegNet is 3.32 Å, 7% better than 3.57 Å of Topaz and 14% better than 3.85 Å of crYOLO.
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Affiliation(s)
- Rajan Gyawali
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO, 65211, USA
- NextGen Precision Health, University of Missouri, Columbia, MO, 65211, USA
| | - Ashwin Dhakal
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO, 65211, USA
- NextGen Precision Health, University of Missouri, Columbia, MO, 65211, USA
| | - Liguo Wang
- Laboratory for BioMolecular Structure (LBMS), Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Jianlin Cheng
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO, 65211, USA
- NextGen Precision Health, University of Missouri, Columbia, MO, 65211, USA
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6
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Saab C, Stephan J, Akoury E. Structural insights into the binding mechanism of Clr4 methyltransferase to H3K9 methylated nucleosome. Sci Rep 2024; 14:5438. [PMID: 38443490 PMCID: PMC10914790 DOI: 10.1038/s41598-024-56248-2] [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: 11/24/2023] [Accepted: 03/04/2024] [Indexed: 03/07/2024] Open
Abstract
The establishment and maintenance of heterochromatin, a specific chromatin structure essential for genomic stability and regulation, rely on intricate interactions between chromatin-modifying enzymes and nucleosomal histone proteins. However, the precise trigger for these modifications remains unclear, thus highlighting the need for a deeper understanding of how methyltransferases facilitate histone methylation among others. Here, we investigate the molecular mechanisms underlying heterochromatin assembly by studying the interaction between the H3K9 methyltransferase Clr4 and H3K9-methylated nucleosomes. Using a combination of liquid-state nuclear magnetic resonance spectroscopy and cryo-electron microscopy, we elucidate the structural basis of Clr4 binding to H3K9-methylated nucleosomes. Our results reveal that Clr4 engages with nucleosomes through its chromodomain and disordered regions to promote de novo methylation. This study provides crucial insights into the molecular mechanisms governing heterochromatin formation by highlighting the significance of chromatin-modifying enzymes in genome regulation and disease pathology.
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Affiliation(s)
- Christopher Saab
- Department of Natural Sciences, Lebanese American University, Beirut, 1102-2801, Lebanon
- Department of Chemistry, McGill University, 801 Sherbrooke St. West, Montreal, QC, H3AOB8, Canada
| | - Joseph Stephan
- School of Medicine, Lebanese American University, PO Box 36, Byblos, Lebanon
| | - Elias Akoury
- Department of Natural Sciences, Lebanese American University, Beirut, 1102-2801, Lebanon.
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7
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Carrascosa JL. Characterization of Complexes and Supramolecular Structures by Electron Microscopy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 3234:191-205. [PMID: 38507208 DOI: 10.1007/978-3-031-52193-5_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Recent advancements in cryo-electron microscopy (cryo-TEM) have enabled the determination of structures of macromolecular complexes at near-atomic resolution, establishing it as a pivotal tool in Structural Biology. This high resolution allows for the detection of ligands and substrates under physiological conditions. Enhancements in detectors and imaging devices, like phase plates, improve signal quality, facilitating the reconstruction of even smaller macromolecular complexes. The 100-kDa barrier has been surpassed, presenting new opportunities for pharmacological research and expanding the scope of crystallographic analyses in the pharmaceutical industry. Cryo-TEM produces vast data sets from minimal samples, and refined classification methods can identify different conformational states of macromolecular complexes, offering deeper insights into the functional characteristics of macromolecular systems. Additionally, cryo-TEM is paving the way for time-resolved microscopy, with rapid freezing techniques capturing snapshots of vital structural changes in biological complexes. Finally, in Structural Cell Biology, advanced cryo-TEM, through tomographic procedures, is revealing conformational changes related to the specific subcellular localization of macromolecular systems and their interactions within cells.
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Affiliation(s)
- José L Carrascosa
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología (CNB, CSIC), Madrid, Spain.
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8
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Cuervo A, Losana P, Carrascosa JL. Observation of Bacteriophage Ultrastructure by Cryo-Electron Microscopy. Methods Mol Biol 2024; 2734:13-25. [PMID: 38066360 DOI: 10.1007/978-1-0716-3523-0_2] [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: 12/18/2023]
Abstract
Transmission electron microscopy (TEM) is an ideal method to observe and determine the structure of bacteriophages. From early studies by negative staining to the present atomic structure models derived from cryo-TEM, bacteriophage detection, classification, and structure determination have been mostly done by electron microscopy. Although embedding in metal salts has been a routine method for virus observation for many years, the preservation of bacteriophages in a thin layer of fast frozen buffer has proven to be the most convenient preparation method for obtaining images using cryo-electron microscopy (cryo-EM). In this technique, frozen samples are observed at liquid nitrogen temperature, and the images are acquired using different recording media. The incorporation of direct electron detectors has been a fundamental step in achieving atomic resolution images of a number of viruses. These projection images can be numerically combined using different approaches to render a three-dimensional model of the virus. For those viral components exhibiting any symmetry, averaging can nowadays achieve atomic structures in most cases. Image processing methods have also evolved to improve the resolution in asymmetric viral components or regions showing different types of symmetries (symmetry mismatch).
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Affiliation(s)
- Ana Cuervo
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología, CSIC, Madrid, Spain.
| | - Patricia Losana
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
| | - José L Carrascosa
- Department of Structure of Macromolecules, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
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9
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Fernandez-Gimenez E, Carazo JM, Sorzano COS. Local defocus estimation in single particle analysis in cryo-electron microscopy. J Struct Biol 2023; 215:108030. [PMID: 37758154 DOI: 10.1016/j.jsb.2023.108030] [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: 07/01/2023] [Revised: 08/30/2023] [Accepted: 09/21/2023] [Indexed: 10/02/2023]
Abstract
Single Particle analysis (SPA) aims to determine the three-dimensional structure of proteins and macromolecular complexes. The current state of the art has allowed us to achieve near-atomic and even atomic resolutions. To obtain high-resolution structures, a set of well-defined image processing steps is required. A critical one is the estimation of the Contrast Transfer Function (CTF), which considers the sample defocus and aberrations of the microscope. Defocus is usually globally estimated; in this case, it is the same for all the particles in each micrograph. But proteins are ice-embedded at different heights, suggesting that defocus should be measured in a local (per particle) manner. There are four state-of-the-art programs to estimate local defocus (Gctf, Relion, CryoSPARC, and Xmipp). In this work, we have compared the results of these software packages to check whether the resolution improves. We have used the Scipion framework and developed a specific program to analyze local defocus. The results produced by different programs do not show a clear consensus using the current test datasets in this study.
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Affiliation(s)
- E Fernandez-Gimenez
- Centro Nac. Biotecnologia (CSIC), c/Darwin, 3, 28049 Cantoblanco, Madrid, Spain; Univ. Autonoma de Madrid, 28049 Cantoblanco, Madrid, Spain
| | - J M Carazo
- Centro Nac. Biotecnologia (CSIC), c/Darwin, 3, 28049 Cantoblanco, Madrid, Spain
| | - C O S Sorzano
- Centro Nac. Biotecnologia (CSIC), c/Darwin, 3, 28049 Cantoblanco, Madrid, Spain.
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10
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Fernández-Giménez E, Martínez MM, Marabini R, Strelak D, Sánchez-García R, Carazo JM, Sorzano COS. A new algorithm for particle weighted subtraction to decrease signals from unwanted components in single particle analysis. J Struct Biol 2023; 215:108024. [PMID: 37704013 DOI: 10.1016/j.jsb.2023.108024] [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: 07/04/2023] [Revised: 08/22/2023] [Accepted: 09/04/2023] [Indexed: 09/15/2023]
Abstract
Single particle analysis (SPA) in cryo-electron microscopy (cryo-EM) is highly used to obtain the near-atomic structure of biological macromolecules. The current methods allow users to produce high-resolution maps from many samples. However, there are still challenging cases that require extra processing to obtain high resolution. This is the case when the macromolecule of the sample is composed of different components and we want to focus just on one of them. For example, if the macromolecule is composed of several flexible subunits and we are interested in a specific one, if it is embedded in a viral capsid environment, or if it has additional components to stabilize it, such as nanodiscs. The signal from these components, which in principle we are not interested in, can be removed from the particles using a projection subtraction method. Currently, there are two projection subtraction methods used in practice and both have some limitations. In fact, after evaluating their results, we consider that the problem is still open to new solutions, as they do not fully remove the signal of the components that are not of interest. Our aim is to develop a new and more precise projection subtraction method, improving the performance of state-of-the-art methods. We tested our algorithm with data from public databases and an in-house data set. In this work, we show that the performance of our algorithm improves the results obtained by others, including the localization of small ligands, such as drugs, whose binding location is unknown a priori.
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Affiliation(s)
- E Fernández-Giménez
- Centro Nac. Biotecnología (CSIC), c/Darwin, 3, 28049 Cantoblanco, Madrid, Spain; Univ. Autonoma de Madrid, 28049 Cantoblanco, Madrid, Spain
| | - M M Martínez
- Centro Nac. Biotecnología (CSIC), c/Darwin, 3, 28049 Cantoblanco, Madrid, Spain
| | - R Marabini
- Centro Nac. Biotecnología (CSIC), c/Darwin, 3, 28049 Cantoblanco, Madrid, Spain; Univ. Autonoma de Madrid, 28049 Cantoblanco, Madrid, Spain
| | - D Strelak
- Institute of Computer Science, Masaryk University, Botanická 68a, 60200 Brno, Czech Republic
| | - R Sánchez-García
- Department of Statistics, University of Oxford, 24-29 St Giles', Oxford OX1 3LB, United Kingdom; Astex Pharmaceuticals, 436 Cambridge Science Park, Cambridge CB4 0QA, UK
| | - J M Carazo
- Centro Nac. Biotecnología (CSIC), c/Darwin, 3, 28049 Cantoblanco, Madrid, Spain
| | - C O S Sorzano
- Centro Nac. Biotecnología (CSIC), c/Darwin, 3, 28049 Cantoblanco, Madrid, Spain.
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11
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Guo H, Cho B, Hinton PR, He S, Yu Y, Ramesh AK, Sivaccumar JP, Ku Z, Campo K, Holland S, Sachdeva S, Mensch C, Dawod M, Whitaker A, Eisenhauer P, Falcone A, Honce R, Botten JW, Carroll SF, Keyt BA, Womack AW, Strohl WR, Xu K, Zhang N, An Z, Ha S, Shiver JW, Fu TM. An ACE2 decamer viral trap as a durable intervention solution for current and future SARS-CoV. Emerg Microbes Infect 2023; 12:2275598. [PMID: 38078382 PMCID: PMC10768737 DOI: 10.1080/22221751.2023.2275598] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 10/19/2023] [Indexed: 12/18/2023]
Abstract
The capacity of SARS-CoV-2 to evolve poses challenges to conventional prevention and treatment options such as vaccination and monoclonal antibodies, as they rely on viral receptor binding domain (RBD) sequences from previous strains. Additionally, animal CoVs, especially those of the SARS family, are now appreciated as a constant pandemic threat. We present here a new antiviral approach featuring inhalation delivery of a recombinant viral trap composed of ten copies of angiotensin-converting enzyme 2 (ACE2) fused to the IgM Fc. This ACE2 decamer viral trap is designed to inhibit SARS-CoV-2 entry function, regardless of viral RBD sequence variations as shown by its high neutralization potency against all known SARS-CoV-2 variants, including Omicron BQ.1, BQ.1.1, XBB.1 and XBB.1.5. In addition, it demonstrates potency against SARS-CoV-1, human NL63, as well as bat and pangolin CoVs. The multivalent trap is effective in both prophylactic and therapeutic settings since a single intranasal dosing confers protection in human ACE2 transgenic mice against viral challenges. Lastly, this molecule is stable at ambient temperature for more than twelve weeks and can sustain physical stress from aerosolization. These results demonstrate the potential of a decameric ACE2 viral trap as an inhalation solution for ACE2-dependent coronaviruses of current and future pandemic concerns.
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Affiliation(s)
| | | | | | - Sijia He
- IGM Biosciences, Mountain View, CA, USA
| | | | - Ashwin Kumar Ramesh
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Jwala Priyadarsini Sivaccumar
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Zhiqiang Ku
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | | | | | | | | | | | - Annalis Whitaker
- Cellular, Molecular, and Biomedical Sciences Graduate Program, University of Vermont, Burlington, VT, USA
- Department of Medicine, Division of Pulmonary Disease and Critical Care Medicine, University of Vermont, Burlington, VT, USA
| | - Philip Eisenhauer
- Department of Medicine, Division of Pulmonary Disease and Critical Care Medicine, University of Vermont, Burlington, VT, USA
| | - Allison Falcone
- Department of Medicine, Division of Pulmonary Disease and Critical Care Medicine, University of Vermont, Burlington, VT, USA
| | - Rebekah Honce
- Department of Medicine, Division of Pulmonary Disease and Critical Care Medicine, University of Vermont, Burlington, VT, USA
| | - Jason W. Botten
- Department of Medicine, Division of Pulmonary Disease and Critical Care Medicine, University of Vermont, Burlington, VT, USA
- Department of Microbiology and Molecular Genetics, Robert Larner, M.D. College of Medicine, University of Vermont, Burlington, VT, USA
| | | | | | | | | | - Kai Xu
- Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, USA
| | - Ningyan Zhang
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Zhiqiang An
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Sha Ha
- IGM Biosciences, Mountain View, CA, USA
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12
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Xia Y, Sonneville R, Jenkyn-Bedford M, Ji L, Alabert C, Hong Y, Yeeles JT, Labib KP. DNSN-1 recruits GINS for CMG helicase assembly during DNA replication initiation in Caenorhabditis elegans. Science 2023; 381:eadi4932. [PMID: 37590372 PMCID: PMC7615117 DOI: 10.1126/science.adi4932] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/07/2023] [Indexed: 08/19/2023]
Abstract
Assembly of the CMG (CDC-45-MCM-2-7-GINS) helicase is the key regulated step during eukaryotic DNA replication initiation. Until now, it was unclear whether metazoa require additional factors that are not present in yeast. In this work, we show that Caenorhabditis elegans DNSN-1, the ortholog of human DONSON, functions during helicase assembly in a complex with MUS-101/TOPBP1. DNSN-1 is required to recruit the GINS complex to chromatin, and a cryo-electron microscopy structure indicates that DNSN-1 positions GINS on the MCM-2-7 helicase motor (comprising the six MCM-2 to MCM-7 proteins), by direct binding of DNSN-1 to GINS and MCM-3, using interfaces that we show are important for initiation and essential for viability. These findings identify DNSN-1 as a missing link in our understanding of DNA replication initiation, suggesting that initiation defects underlie the human disease syndrome that results from DONSON mutations.
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Affiliation(s)
- Yisui Xia
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, U.K
| | - Remi Sonneville
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, U.K
| | | | - Liqin Ji
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Constance Alabert
- Division of Molecular, Cell & Developmental Biology, School of Life Sciences, University of Dundee, Dundee, U.K
| | - Ye Hong
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, U.K
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Joseph T.P. Yeeles
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, U.K
| | - Karim P.M. Labib
- The MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, U.K
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13
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Short JM, Palmer CM, Burnley T, Winn MD, Zhang Q, Venkataram Prasad BV, Chen S, Crowther RA, Unwin PNT, Henderson R. MRC2020: improvements to Ximdisp and the MRC image-processing programs. IUCRJ 2023; 10:579-583. [PMID: 37493524 PMCID: PMC10478516 DOI: 10.1107/s2052252523006309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/20/2023] [Indexed: 07/27/2023]
Abstract
The great success of single-particle electron cryo-microscopy (cryoEM) during the last decade has involved the development of powerful new computer programs and packages that guide the user along a recommended processing workflow, in which the wisdom and choices made by the developers help everyone, especially new users, to obtain excellent results. The ability to carry out novel, non-standard or unusual combinations of image-processing steps is sometimes compromised by the convenience of a standard procedure. Some of the older programs were written with great flexibility and are still very valuable. Among these, the original MRC image-processing programs for structure determination by 2D crystal and helical processing alongside general-purpose utility programs such as Ximdisp, label, imedit and twofile are still available. This work describes an updated version of the MRC software package (MRC2020) that is freely available from CCP-EM. It includes new features and improvements such as extensions to the MRC format that retain the versatility of the package and make it particularly useful for testing novel computational procedures in cryoEM.
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Affiliation(s)
- J. M. Short
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - C. M. Palmer
- Science & Technology Facilities Council, Research Complex at Harwell, Harwell, Didcot OX11 0FA, United Kingdom
| | - T. Burnley
- Science & Technology Facilities Council, Research Complex at Harwell, Harwell, Didcot OX11 0FA, United Kingdom
| | - M. D. Winn
- Science & Technology Facilities Council, Research Complex at Harwell, Harwell, Didcot OX11 0FA, United Kingdom
| | - Q. Zhang
- Sun Yat Sen University, School of Life Science, State Key Laboratory of Biocontrol, Guangzhou 510275, People’s Republic of China
| | - B. V. Venkataram Prasad
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA
| | - S. Chen
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - R. A. Crowther
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - P. N. T. Unwin
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - R. Henderson
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
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14
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Cheng H, Zheng L, Liu N, Huang C, Xu J, Lu Y, Cui X, Xu K, Hou Y, Tang J, Zhang Z, Li J, Ni X, Chen Y, Peng H, Wang HW. Dual-Affinity Graphene Sheets for High-Resolution Cryo-Electron Microscopy. J Am Chem Soc 2023; 145:8073-8081. [PMID: 37011903 PMCID: PMC10103130 DOI: 10.1021/jacs.3c00659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
With the development of cryo-electron microscopy (cryo-EM), high-resolution structures of macromolecules can be reconstructed by the single particle method efficiently. However, challenges may still persist during the specimen preparation stage. Specifically, proteins tend to adsorb at the air-water interface and exhibit a preferred orientation in vitreous ice. To overcome these challenges, we have explored dual-affinity graphene (DAG) modified with two different affinity ligands as a supporting material for cryo-EM sample preparation. The ligands can bind to distinct sites on the corresponding tagged particles, which in turn generates various orientation distributions of particles and prevents the adsorption of protein particles onto the air-water interface. As expected, the DAG exhibited high binding specificity and affinity to target macromolecules, resulting in more balanced particle Euler angular distributions compared to single functionalized graphene on two different protein cases, including the SARS -CoV-2 spike glycoprotein. We anticipate that the DAG grids will enable facile and efficient three-dimensional (3D) reconstruction for cryo-EM structural determination, providing a robust and general technique for future studies.
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Affiliation(s)
- Hang Cheng
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- Joint Graduate Program of Peking-Tsinghua-NIBS, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Shuimu BioSciences Ltd., Beijing 102206, China
| | - Liming Zheng
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Nan Liu
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- Beijing Frontier Research Center for Biological Structures, Tsinghua University, Beijing 100084, China
| | - Congyuan Huang
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jie Xu
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Ye Lu
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaoya Cui
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- Beijing Frontier Research Center for Biological Structures, Tsinghua University, Beijing 100084, China
| | - Kui Xu
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yuan Hou
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Junchuan Tang
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Zhong Zhang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Jing Li
- Shuimu BioSciences Ltd., Beijing 102206, China
| | - Xiaodan Ni
- Shuimu BioSciences Ltd., Beijing 102206, China
| | - Yanan Chen
- School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Hailin Peng
- Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
- Beijing Graphene Institute (BGI), Beijing 100095, China
| | - Hong-Wei Wang
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
- Joint Graduate Program of Peking-Tsinghua-NIBS, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Beijing Frontier Research Center for Biological Structures, Tsinghua University, Beijing 100084, China
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15
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Vuillemot R, Mirzaei A, Harastani M, Hamitouche I, Fréchin L, Klaholz BP, Miyashita O, Tama F, Rouiller I, Jonic S. MDSPACE: Extracting Continuous Conformational Landscapes from Cryo-EM Single Particle Datasets Using 3D-to-2D Flexible Fitting based on Molecular Dynamics Simulation. J Mol Biol 2023; 435:167951. [PMID: 36638910 DOI: 10.1016/j.jmb.2023.167951] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 12/08/2022] [Accepted: 01/03/2023] [Indexed: 01/12/2023]
Abstract
This article presents an original approach for extracting atomic-resolution landscapes of continuous conformational variability of biomolecular complexes from cryo electron microscopy (cryo-EM) single particle images. This approach is based on a new 3D-to-2D flexible fitting method, which uses molecular dynamics (MD) simulation and is embedded in an iterative conformational-landscape refinement scheme. This new approach is referred to as MDSPACE, which stands for Molecular Dynamics simulation for Single Particle Analysis of Continuous Conformational hEterogeneity. The article describes the MDSPACE approach and shows its performance using synthetic and experimental datasets.
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Affiliation(s)
- Rémi Vuillemot
- IMPMC-UMR 7590 CNRS, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France; Department of Biochemistry & Pharmacology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia
| | - Alex Mirzaei
- IMPMC-UMR 7590 CNRS, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | - Mohamad Harastani
- IMPMC-UMR 7590 CNRS, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | - Ilyes Hamitouche
- IMPMC-UMR 7590 CNRS, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France
| | - Léo Fréchin
- Centre for Integrative Biology, Department of Integrated Structural Biology, IGBMC-UMR 7104 CNRS, U964 Inserm, Université de Strasbourg, Strasbourg, France
| | - Bruno P Klaholz
- Centre for Integrative Biology, Department of Integrated Structural Biology, IGBMC-UMR 7104 CNRS, U964 Inserm, Université de Strasbourg, Strasbourg, France
| | | | - Florence Tama
- RIKEN Center for Computational Science, Kobe, Japan; Institute of Transformative Biomolecules, Graduate School of Science, Nagoya University, Nagoya, Japan; Department of Physics, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Isabelle Rouiller
- Department of Biochemistry & Pharmacology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia
| | - Slavica Jonic
- IMPMC-UMR 7590 CNRS, Sorbonne Université, Muséum National d'Histoire Naturelle, Paris, France.
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16
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Garcia Condado J, Muñoz-Barrutia A, Sorzano COS. Automatic determination of the handedness of single-particle maps of macromolecules solved by CryoEM. J Struct Biol 2022; 214:107915. [PMID: 36341955 DOI: 10.1016/j.jsb.2022.107915] [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: 04/12/2022] [Revised: 08/29/2022] [Accepted: 10/25/2022] [Indexed: 12/07/2022]
Abstract
Single-Particle Analysis by Cryo-Electron Microscopy is a well-established technique to elucidate the three-dimensional (3D) structure of biological macromolecules. The orientation of the acquired projection images must be initially estimated without any reference to the final structure. In this step, algorithms may find a mirrored version of all the orientations resulting in a mirrored 3D map. It is as compatible with the acquired images as its unmirrored version from the image processing point of view, only that it is not biologically plausible. In this article, we introduce HaPi (Handedness Pipeline), the first method to automatically determine the hand of electron density maps of macromolecules solved by CryoEM. HaPi is built by training two 3D convolutional neural networks. The first determines α-helices in a map, and the second determines whether the α-helix is left-handed or right-handed. A consensus strategy defines the overall map hand. The pipeline is trained on simulated and experimental data. The handedness can be detected only for maps whose resolution is better than 5 Å. HaPi can identify the hand in 89% of new simulated maps correctly. Moreover, we evaluated all the maps deposited at the Electron Microscopy Data Bank and 11 structures uploaded with the incorrect hand were identified.
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Affiliation(s)
- J Garcia Condado
- Biocruces Bizkaia Instituto Investigación Sanitaria, Cruces Plaza, 48903 Barakaldo, Bizkaia, Spain; Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganés, Madrid, Spain; Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - A Muñoz-Barrutia
- Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911 Leganés, Madrid, Spain
| | - C O S Sorzano
- Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain.
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17
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CryoEM structural exploration of catalytically active enzyme pyruvate carboxylase. Nat Commun 2022; 13:6185. [PMID: 36261450 PMCID: PMC9581989 DOI: 10.1038/s41467-022-33987-2] [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: 05/30/2022] [Accepted: 10/04/2022] [Indexed: 12/24/2022] Open
Abstract
Pyruvate carboxylase (PC) is a tetrameric enzyme that contains two active sites per subunit that catalyze two consecutive reactions. A mobile domain with an attached prosthetic biotin links both reactions, an initial biotin carboxylation and the subsequent carboxyl transfer to pyruvate substrate to produce oxaloacetate. Reaction sites are at long distance, and there are several co-factors that play as allosteric regulators. Here, using cryoEM we explore the structure of active PC tetramers focusing on active sites and on the conformational space of the oligomers. The results capture the mobile domain at both active sites and expose catalytic steps of both reactions at high resolution, allowing the identification of substrates and products. The analysis of catalytically active PC tetramers reveals the role of certain motions during enzyme functioning, and the structural changes in the presence of additional cofactors expose the mechanism for allosteric regulation.
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18
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Zhu Z, Deng Z, Wang Q, Wang Y, Zhang D, Xu R, Guo L, Wen H. Simulation and Machine Learning Methods for Ion-Channel Structure Determination, Mechanistic Studies and Drug Design. Front Pharmacol 2022; 13:939555. [PMID: 35837274 PMCID: PMC9275593 DOI: 10.3389/fphar.2022.939555] [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: 05/09/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
Ion channels are expressed in almost all living cells, controlling the in-and-out communications, making them ideal drug targets, especially for central nervous system diseases. However, owing to their dynamic nature and the presence of a membrane environment, ion channels remain difficult targets for the past decades. Recent advancement in cryo-electron microscopy and computational methods has shed light on this issue. An explosion in high-resolution ion channel structures paved way for structure-based rational drug design and the state-of-the-art simulation and machine learning techniques dramatically improved the efficiency and effectiveness of computer-aided drug design. Here we present an overview of how simulation and machine learning-based methods fundamentally changed the ion channel-related drug design at different levels, as well as the emerging trends in the field.
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Affiliation(s)
- Zhengdan Zhu
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Beijing Institute of Big Data Research, Beijing, China
| | - Zhenfeng Deng
- DP Technology, Beijing, China
- School of Pharmaceutical Sciences, Peking University, Beijing, China
| | | | | | - Duo Zhang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- DP Technology, Beijing, China
| | - Ruihan Xu
- DP Technology, Beijing, China
- National Engineering Research Center of Visual Technology, Peking University, Beijing, China
| | | | - Han Wen
- DP Technology, Beijing, China
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19
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Bengtsson VEG, Pacoste L, de la Rosa-Trevin JM, Hofer G, Zou X, Xu H. Scipion-ED: a graphical user interface for batch processing and analysis of 3D ED/MicroED data. J Appl Crystallogr 2022; 55:638-646. [PMID: 35719296 PMCID: PMC9172039 DOI: 10.1107/s1600576722002758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 03/10/2022] [Indexed: 12/03/2022] Open
Abstract
The design and usage of Scipion-ED, a graphical user interface program for processing and analysis of three-dimensional electron diffraction (3D ED)/microcrystal electron diffraction (MicroED) data, are presented. A study of the influence of data merging strategies on the ability to resolve unmodelled features of tetragonal lysozyme is included as an illustration of the advantages of Scipion-ED. Three-dimensional electron diffraction (3D ED)/microcrystal electron diffraction (MicroED) techniques are gaining in popularity. However, the data processing often does not fit existing graphical user interface software, instead requiring the use of the terminal or scripting. Scipion-ED, described in this article, provides a graphical user interface and extendable framework for processing of 3D ED/MicroED data. An illustrative project is described, in which multiple 3D ED/MicroED data sets collected on tetragonal lysozyme were processed with DIALS through the Scipion-ED interface. The ability to resolve unmodelled features in the electrostatic potential map was compared between three strategies for merging data sets.
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20
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Wang X, Lu Y, Lin X. Heterogeneous cryo-EM projection image classification using a two-stage spectral clustering based on novel distance measures. Brief Bioinform 2022; 23:6543485. [PMID: 35255494 DOI: 10.1093/bib/bbac032] [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: 12/22/2021] [Revised: 01/17/2022] [Accepted: 01/23/2022] [Indexed: 11/13/2022] Open
Abstract
Single-particle cryo-electron microscopy (cryo-EM) has become one of the mainstream technologies in the field of structural biology to determine the three-dimensional (3D) structures of biological macromolecules. Heterogeneous cryo-EM projection image classification is an effective way to discover conformational heterogeneity of biological macromolecules in different functional states. However, due to the low signal-to-noise ratio of the projection images, the classification of heterogeneous cryo-EM projection images is a very challenging task. In this paper, two novel distance measures between projection images integrating the reliability of common lines, pixel intensity and class averages are designed, and then a two-stage spectral clustering algorithm based on the two distance measures is proposed for heterogeneous cryo-EM projection image classification. In the first stage, the novel distance measure integrating common lines and pixel intensities of projection images is used to obtain preliminary classification results through spectral clustering. In the second stage, another novel distance measure integrating the first novel distance measure and class averages generated from each group of projection images is used to obtain the final classification results through spectral clustering. The proposed two-stage spectral clustering algorithm is applied on a simulated and a real cryo-EM dataset for heterogeneous reconstruction. Results show that the two novel distance measures can be used to improve the classification performance of spectral clustering, and using the proposed two-stage spectral clustering algorithm can achieve higher classification and reconstruction accuracy than using RELION and XMIPP.
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Affiliation(s)
- Xiangwen Wang
- School of Information Science and Engineering, Lanzhou University, 730000, Lanzhou, China.,College of Computer Science and Engineering, Northwest Normal University, 730070, Lanzhou, China
| | - Yonggang Lu
- School of Information Science and Engineering, Lanzhou University, 730000, Lanzhou, China
| | - Xianghong Lin
- College of Computer Science and Engineering, Northwest Normal University, 730070, Lanzhou, China
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21
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Krakow J, Hammel M, Zhu Y, Hillier BJ, Paolella B, Desmarais A, Wall R, Chen THT, Pei R, Karunatilake C, DuBridge R, Vinogradova M. Structural arrangement of the VH and VL domains in the COBRA™ T-cell engaging single-chain diabody. Antib Ther 2022; 5:1-10. [PMID: 35005430 PMCID: PMC8719580 DOI: 10.1093/abt/tbab028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND COBRA™ (COnditional Bispecific Redirected Activation) T-cell engagers are designed to target solid tumors as a single polypeptide chain prodrug that becomes activated by proteolysis in the tumor microenvironment. One COBRA molecule comprises seven Ig domains: three single-domain antibodies (sdAbs) recognizing a tumor target or human serum albumin (HSA), and CD3ε-binding variable fragment heavy chain (VH) and variable fragment light chain (VL) and their inactivated counterparts, VHi and VLi. Pairing of VH and VL, and VLi and VHi into single-chain variable fragments (Fv) is prevented by shortened inter-domain linkers. Instead, VH and VL are expected to interact with VLi and VHi, respectively, thus making a diabody whose binding to CD3ε on the T-cells is impaired. METHODS We analyzed the structure of an epidermal growth factor receptor (EGFR) COBRA in solution using negative stain electron microscopy (EM) and small-angle X-ray scattering (SAXS). RESULTS We found that this EGFR COBRA forms stable monomers with a very dynamic interdomain arrangement. At most, only five domains at a time appeared ordered, and only one VH-VL pair was found in the Fv orientation. Nonenzymatic posttranslational modifications suggest that the CDR3 loops in the VL-VHi pair are exposed but are buried in the VH-VLi pair. The MMP9 cleavage rate of the prodrug when bound to recombinant EGFR or HSA is not affected, indicating positioning of the MMP9-cleavable linker away from the EGFR and HSA binding sites. CONCLUSION Here, we propose a model for EGFR COBRA where VH and VLi form an Fv, and VL and VHi do not, possibly interacting with other Ig domains. SAXS and MMP9 cleavage analyses suggest that all COBRA molecules tested have a similar structural architecture.
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Affiliation(s)
- Jessica Krakow
- Maverick Therapeutics, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited, Brisbane, CA, USA
| | - Michal Hammel
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Ying Zhu
- Maverick Therapeutics, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited, Brisbane, CA, USA
| | - Brian J Hillier
- Maverick Therapeutics, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited, Brisbane, CA, USA
| | - Bryce Paolella
- Maverick Therapeutics, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited, Brisbane, CA, USA
| | - Austin Desmarais
- Maverick Therapeutics, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited, Brisbane, CA, USA
| | - Rusty Wall
- Maverick Therapeutics, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited, Brisbane, CA, USA
| | - Tseng-Hui T Chen
- Maverick Therapeutics, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited, Brisbane, CA, USA
| | - Rex Pei
- Maverick Therapeutics, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited, Brisbane, CA, USA
| | - Chulani Karunatilake
- Maverick Therapeutics, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited, Brisbane, CA, USA
| | - Robert DuBridge
- Maverick Therapeutics, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited, Brisbane, CA, USA
| | - Maia Vinogradova
- Maverick Therapeutics, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited, Brisbane, CA, USA
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22
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ReconSil: An electron microscopy toolbox to study helicase function at an origin of replication. Methods Enzymol 2022; 672:203-231. [DOI: 10.1016/bs.mie.2022.03.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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23
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Sukeník L, Mukhamedova L, Procházková M, Škubník K, Plevka P, Vácha R. Cargo Release from Nonenveloped Viruses and Virus-like Nanoparticles: Capsid Rupture or Pore Formation. ACS NANO 2021; 15:19233-19243. [PMID: 34881874 DOI: 10.1021/acsnano.1c04814] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Virus-like nanoparticles are protein shells similar to wild-type viruses, and both aim to deliver their content into a cell. Unfortunately, the release mechanism of their cargo/genome remains elusive. Pores on the symmetry axes were proposed to enable the slow release of the viral genome. In contrast, cryo-EM images showed that capsids of nonenveloped RNA viruses can crack open and rapidly release the genome. We combined in vitro cryo-EM observations of the genome release of three viruses with coarse-grained simulations of generic virus-like nanoparticles to investigate the cargo/genome release pathways. Simulations provided details on both slow and rapid release pathways, including the success rates of individual releases. Moreover, the simulated structures from the rapid release pathway were in agreement with the experiment. Slow release occurred when interactions between capsid subunits were long-ranged, and the cargo/genome was noncompact. In contrast, rapid release was preferred when the interaction range was short and/or the cargo/genome was compact. These findings indicate a design strategy of virus-like nanoparticles for drug delivery.
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Affiliation(s)
- Lukáš Sukeník
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
- Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic
| | - Liya Mukhamedova
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Michaela Procházková
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Karel Škubník
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Pavel Plevka
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Robert Vácha
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
- Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
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24
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Jones ML, Baris Y, Taylor MRG, Yeeles JTP. Structure of a human replisome shows the organisation and interactions of a DNA replication machine. EMBO J 2021; 40:e108819. [PMID: 34694004 PMCID: PMC8634136 DOI: 10.15252/embj.2021108819] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 02/01/2023] Open
Abstract
The human replisome is an elaborate arrangement of molecular machines responsible for accurate chromosome replication. At its heart is the CDC45-MCM-GINS (CMG) helicase, which, in addition to unwinding the parental DNA duplex, arranges many proteins including the leading-strand polymerase Pol ε, together with TIMELESS-TIPIN, CLASPIN and AND-1 that have key and varied roles in maintaining smooth replisome progression. How these proteins are coordinated in the human replisome is poorly understood. We have determined a 3.2 Å cryo-EM structure of a human replisome comprising CMG, Pol ε, TIMELESS-TIPIN, CLASPIN and AND-1 bound to replication fork DNA. The structure permits a detailed understanding of how AND-1, TIMELESS-TIPIN and Pol ε engage CMG, reveals how CLASPIN binds to multiple replisome components and identifies the position of the Pol ε catalytic domain. Furthermore, the intricate network of contacts contributed by MCM subunits and TIMELESS-TIPIN with replication fork DNA suggests a mechanism for strand separation.
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25
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Méndez J, Garduño E, Carazo JM, S Sorzano CO. Identification of incorrectly oriented particles in cryo-EM single particle analysis. J Struct Biol 2021; 213:107771. [PMID: 34324977 DOI: 10.1016/j.jsb.2021.107771] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/23/2021] [Accepted: 07/18/2021] [Indexed: 11/24/2022]
Abstract
The quality of a 3D map produced by the single-particle analysis method is highly dependent on an accurate assignment of orientations to the many experimental images. However, the problem's complexity implies the presence of several local minima in the optimized goal functions. Consequently, validation methods to confirm the angular assignment are very useful to yield higher-resolution 3D maps. In this work, we present a graph-signal-processing-based methodology that analyzes the correlation landscape as a function of the orientation, an approach allowing the estimation of the assigned orientations' reliability. Using this method, we may identify low-reliability images that probably incorrectly contribute to the final 3D reconstruction.
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Affiliation(s)
- Jeison Méndez
- Posgrado en Ingeniería Eléctrica, Universidad Nacional Autónoma de México, Cd.Universitaria, C.P.04510, Mexico City, Mexico.
| | - Edgar Garduño
- Department of Computer Science, Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico.
| | - José María Carazo
- National Center of Biotechnology, CSIC, Campus Univ. Autónoma de Madrid, 28049 Cantoblanco, Madrid, Spain.
| | - Carlos Oscar S Sorzano
- Univ. San Pablo CEU, Campus Urb. Montepríncipe s/n, 28668, Boadilla del Monte, Madrid, Spain; National Center of Biotechnology, CSIC, Campus Univ. Autónoma de Madrid, 28049 Cantoblanco, Madrid, Spain.
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26
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Chakraborty R, Dey S, Sil P, Paul SS, Bhattacharyya D, Bhunia A, Sengupta J, Chattopadhyay K. Conformational distortion in a fibril-forming oligomer arrests alpha-Synuclein fibrillation and minimizes its toxic effects. Commun Biol 2021; 4:518. [PMID: 33941845 PMCID: PMC8093279 DOI: 10.1038/s42003-021-02026-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 03/25/2021] [Indexed: 02/06/2023] Open
Abstract
The fibrillation pathway of alpha-Synuclein, the causative protein of Parkinson's disease, encompasses transient, heterogeneous oligomeric forms whose structural understanding and link to toxicity are not yet understood. We report that the addition of the physiologically-available small molecule heme at a sub-stoichiometric ratio to either monomeric or aggregated α-Syn, targets a His50 residue critical for fibril-formation and stabilizes the structurally-heterogeneous populations of aggregates into a minimally-toxic oligomeric state. Cryo-EM 3D reconstruction revealed a 'mace'-shaped structure of this monodisperse population of oligomers, which is comparable to a solid-state NMR Greek key-like motif (where the core residues are arranged in parallel in-register sheets with a Greek key topology at the C terminus) that forms the fundamental unit/kernel of protofilaments. Further structural analyses suggest that heme binding induces a distortion in the Greek key-like architecture of the mace oligomers, which impairs their further appending into protofilaments and fibrils. Additionally, our study reports a novel mechanism of prevention as well as reclamation of amyloid fibril formation by blocking an inter-protofilament His50 residue using a small molecule.
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Affiliation(s)
- Ritobrita Chakraborty
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Sandip Dey
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Pallabi Sil
- Department of Physics, University of Alberta, Edmonton, AB, Canada
| | - Simanta Sarani Paul
- Department of Medicine, Centre for Prion and Protein folding disease, University of Alberta, Edmonton, AB, Canada
| | - Dipita Bhattacharyya
- Department of Biophysics, Bose Institute- Centenary Campus, P-1/12C.I.T. Scheme VII-M, Kolkata, India
| | - Anirban Bhunia
- Department of Biophysics, Bose Institute- Centenary Campus, P-1/12C.I.T. Scheme VII-M, Kolkata, India
| | - Jayati Sengupta
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India.
| | - Krishnananda Chattopadhyay
- Structural Biology and Bioinformatics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India.
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27
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Kyrilis FL, Semchonok DA, Skalidis I, Tüting C, Hamdi F, O'Reilly FJ, Rappsilber J, Kastritis PL. Integrative structure of a 10-megadalton eukaryotic pyruvate dehydrogenase complex from native cell extracts. Cell Rep 2021; 34:108727. [PMID: 33567276 DOI: 10.1016/j.celrep.2021.108727] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 12/02/2020] [Accepted: 01/14/2021] [Indexed: 12/29/2022] Open
Abstract
The pyruvate dehydrogenase complex (PDHc) is a giant enzymatic assembly involved in pyruvate oxidation. PDHc components have been characterized in isolation, but the complex's quaternary structure has remained elusive due to sheer size, heterogeneity, and plasticity. Here, we identify fully assembled Chaetomium thermophilum α-keto acid dehydrogenase complexes in native cell extracts and characterize their domain arrangements utilizing mass spectrometry, activity assays, crosslinking, electron microscopy (EM), and computational modeling. We report the cryo-EM structure of the PDHc core and observe unique features of the previously unknown native state. The asymmetric reconstruction of the 10-MDa PDHc resolves spatial proximity of its components, agrees with stoichiometric data (60 E2p:12 E3BP:∼20 E1p: ≤ 12 E3), and proposes a minimum reaction path among component enzymes. The PDHc shows the presence of a dynamic pyruvate oxidation compartment, organized by core and peripheral protein species. Our data provide a framework for further understanding PDHc and α-keto acid dehydrogenase complex structure and function.
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Affiliation(s)
- Fotis L Kyrilis
- Interdisciplinary Research Center HALOmem, Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3a, Halle/Saale, Germany; Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3, Halle/Saale, Germany
| | - Dmitry A Semchonok
- Interdisciplinary Research Center HALOmem, Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3a, Halle/Saale, Germany
| | - Ioannis Skalidis
- Interdisciplinary Research Center HALOmem, Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3a, Halle/Saale, Germany; Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3, Halle/Saale, Germany
| | - Christian Tüting
- Interdisciplinary Research Center HALOmem, Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3a, Halle/Saale, Germany
| | - Farzad Hamdi
- Interdisciplinary Research Center HALOmem, Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3a, Halle/Saale, Germany
| | - Francis J O'Reilly
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Juri Rappsilber
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany; Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, Scotland, United Kingdom
| | - Panagiotis L Kastritis
- Interdisciplinary Research Center HALOmem, Charles Tanford Protein Center, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3a, Halle/Saale, Germany; Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3, Halle/Saale, Germany; Biozentrum, Martin Luther University Halle-Wittenberg, Weinbergweg 22, Halle/Saale, Germany.
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28
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Zhang B, Zhang W, Pearce R, Zhang Y, Shen HB. Fitting Low-Resolution Protein Structures into Cryo-EM Density Maps by Multiobjective Optimization of Global and Local Correlations. J Phys Chem B 2021; 125:528-538. [PMID: 33397114 DOI: 10.1021/acs.jpcb.0c09903] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The rigid-body fitting of predicted structural models into cryo-electron microscopy (cryo-EM) density maps is a necessary procedure for density map-guided protein structure determination and prediction. We proposed a novel multiobjective optimization protocol, MOFIT, which performs a rigid-body density-map fitting based on particle swarm optimization (PSO). MOFIT was tested on a large set of 292 nonhomologous single-domain proteins. Starting from structural models predicted by I-TASSER, MOFIT achieved an average coordinate root-mean-square deviation of 2.46 Å, which was 1.57, 2.79, and 3.95 Å lower than three leading single-objective function-based methods, where the differences were statistically significant with p-values of 1.65 × 10-6, 6.36 × 10-8, and 6.44 × 10-11 calculated using two-tail Student's t tests. Detailed analyses showed that the major advantages of MOFIT lie in the multiobjective protocol and the extensive PSO search simulations guided by the composite objective functions, which integrates complementary correlation coefficients from the global structure, local fragments, and individual residues with the cryo-EM density maps.
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Affiliation(s)
- Biao Zhang
- Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University, and Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai, China.,Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Wenyi Zhang
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China
| | - Robin Pearce
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Yang Zhang
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Hong-Bin Shen
- Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University, and Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai, China
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29
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Tian JH, Patel N, Haupt R, Zhou H, Weston S, Hammond H, Logue J, Portnoff AD, Norton J, Guebre-Xabier M, Zhou B, Jacobson K, Maciejewski S, Khatoon R, Wisniewska M, Moffitt W, Kluepfel-Stahl S, Ekechukwu B, Papin J, Boddapati S, Jason Wong C, Piedra PA, Frieman MB, Massare MJ, Fries L, Bengtsson KL, Stertman L, Ellingsworth L, Glenn G, Smith G. SARS-CoV-2 spike glycoprotein vaccine candidate NVX-CoV2373 immunogenicity in baboons and protection in mice. Nat Commun 2021; 12:372. [PMID: 33446655 PMCID: PMC7809486 DOI: 10.1038/s41467-020-20653-8] [Citation(s) in RCA: 302] [Impact Index Per Article: 100.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 12/08/2020] [Indexed: 02/08/2023] Open
Abstract
The COVID-19 pandemic continues to spread throughout the world with an urgent need for a safe and protective vaccine to effectuate herd protection and control the spread of SARS-CoV-2. Here, we report the development of a SARS-CoV-2 subunit vaccine (NVX-CoV2373) from the full-length spike (S) protein that is stable in the prefusion conformation. NVX-CoV2373 S form 27.2-nm nanoparticles that are thermostable and bind with high affinity to the human angiotensin-converting enzyme 2 (hACE2) receptor. In mice, low-dose NVX-CoV2373 with saponin-based Matrix-M adjuvant elicit high titer anti-S IgG that blocks hACE2 receptor binding, neutralize virus, and protects against SARS-CoV-2 challenge with no evidence of vaccine-associated enhanced respiratory disease. NVX-CoV2373 also elicits multifunctional CD4+ and CD8+ T cells, CD4+ follicular helper T cells (Tfh), and antigen-specific germinal center (GC) B cells in the spleen. In baboons, low-dose levels of NVX-CoV2373 with Matrix-M was also highly immunogenic and elicited high titer anti-S antibodies and functional antibodies that block S-protein binding to hACE2 and neutralize virus infection and antigen-specific T cells. These results support the ongoing phase 1/2 clinical evaluation of the safety and immunogenicity of NVX-CoV2373 with Matrix-M (NCT04368988).
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Affiliation(s)
- Jing-Hui Tian
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | - Nita Patel
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | - Robert Haupt
- University of Maryland, School of Medicine, 685 West Baltimore St, Baltimore, MD, 21201, USA
| | - Haixia Zhou
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | - Stuart Weston
- University of Maryland, School of Medicine, 685 West Baltimore St, Baltimore, MD, 21201, USA
| | - Holly Hammond
- University of Maryland, School of Medicine, 685 West Baltimore St, Baltimore, MD, 21201, USA
| | - James Logue
- University of Maryland, School of Medicine, 685 West Baltimore St, Baltimore, MD, 21201, USA
| | | | - James Norton
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | | | - Bin Zhou
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | - Kelsey Jacobson
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | | | - Rafia Khatoon
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | | | - Will Moffitt
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | | | - Betty Ekechukwu
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | - James Papin
- Department of Pathology, Division of Comparative Medicine, University of Oklahoma, Health Sciences Center, 940 Stanton L. Young, BMS 203, Oklahoma City, OK, 73104, USA
| | - Sarathi Boddapati
- Catalent Cell & Gene Therapy, 20 Firstfield Road, Gaithersburg, MD, 20874, USA
| | - C Jason Wong
- Catalent Cell & Gene Therapy, 20 Firstfield Road, Gaithersburg, MD, 20874, USA
| | - Pedro A Piedra
- Department of Molecular Virology and Microbiology, and Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Matthew B Frieman
- University of Maryland, School of Medicine, 685 West Baltimore St, Baltimore, MD, 21201, USA
| | | | - Louis Fries
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | | | | | | | - Gregory Glenn
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | - Gale Smith
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA.
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30
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Tian JH, Patel N, Haupt R, Zhou H, Weston S, Hammond H, Logue J, Portnoff AD, Norton J, Guebre-Xabier M, Zhou B, Jacobson K, Maciejewski S, Khatoon R, Wisniewska M, Moffitt W, Kluepfel-Stahl S, Ekechukwu B, Papin J, Boddapati S, Jason Wong C, Piedra PA, Frieman MB, Massare MJ, Fries L, Bengtsson KL, Stertman L, Ellingsworth L, Glenn G, Smith G. SARS-CoV-2 spike glycoprotein vaccine candidate NVX-CoV2373 immunogenicity in baboons and protection in mice. Nat Commun 2021; 12:372. [PMID: 33446655 DOI: 10.1101/2020.06.29.178509] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 12/08/2020] [Indexed: 05/28/2023] Open
Abstract
The COVID-19 pandemic continues to spread throughout the world with an urgent need for a safe and protective vaccine to effectuate herd protection and control the spread of SARS-CoV-2. Here, we report the development of a SARS-CoV-2 subunit vaccine (NVX-CoV2373) from the full-length spike (S) protein that is stable in the prefusion conformation. NVX-CoV2373 S form 27.2-nm nanoparticles that are thermostable and bind with high affinity to the human angiotensin-converting enzyme 2 (hACE2) receptor. In mice, low-dose NVX-CoV2373 with saponin-based Matrix-M adjuvant elicit high titer anti-S IgG that blocks hACE2 receptor binding, neutralize virus, and protects against SARS-CoV-2 challenge with no evidence of vaccine-associated enhanced respiratory disease. NVX-CoV2373 also elicits multifunctional CD4+ and CD8+ T cells, CD4+ follicular helper T cells (Tfh), and antigen-specific germinal center (GC) B cells in the spleen. In baboons, low-dose levels of NVX-CoV2373 with Matrix-M was also highly immunogenic and elicited high titer anti-S antibodies and functional antibodies that block S-protein binding to hACE2 and neutralize virus infection and antigen-specific T cells. These results support the ongoing phase 1/2 clinical evaluation of the safety and immunogenicity of NVX-CoV2373 with Matrix-M (NCT04368988).
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MESH Headings
- Angiotensin-Converting Enzyme 2/genetics
- Angiotensin-Converting Enzyme 2/immunology
- Animals
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/immunology
- COVID-19/genetics
- COVID-19/immunology
- COVID-19/prevention & control
- COVID-19/virology
- COVID-19 Vaccines/administration & dosage
- COVID-19 Vaccines/genetics
- COVID-19 Vaccines/immunology
- Disease Models, Animal
- Female
- Male
- Mice
- Mice, Inbred BALB C
- Papio
- SARS-CoV-2/genetics
- SARS-CoV-2/immunology
- Spike Glycoprotein, Coronavirus/administration & dosage
- Spike Glycoprotein, Coronavirus/genetics
- Spike Glycoprotein, Coronavirus/immunology
- T-Lymphocytes/immunology
- Vaccines, Subunit/administration & dosage
- Vaccines, Subunit/genetics
- Vaccines, Subunit/immunology
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Affiliation(s)
- Jing-Hui Tian
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | - Nita Patel
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | - Robert Haupt
- University of Maryland, School of Medicine, 685 West Baltimore St, Baltimore, MD, 21201, USA
| | - Haixia Zhou
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | - Stuart Weston
- University of Maryland, School of Medicine, 685 West Baltimore St, Baltimore, MD, 21201, USA
| | - Holly Hammond
- University of Maryland, School of Medicine, 685 West Baltimore St, Baltimore, MD, 21201, USA
| | - James Logue
- University of Maryland, School of Medicine, 685 West Baltimore St, Baltimore, MD, 21201, USA
| | | | - James Norton
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | | | - Bin Zhou
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | - Kelsey Jacobson
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | | | - Rafia Khatoon
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | | | - Will Moffitt
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | | | - Betty Ekechukwu
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | - James Papin
- Department of Pathology, Division of Comparative Medicine, University of Oklahoma, Health Sciences Center, 940 Stanton L. Young, BMS 203, Oklahoma City, OK, 73104, USA
| | - Sarathi Boddapati
- Catalent Cell & Gene Therapy, 20 Firstfield Road, Gaithersburg, MD, 20874, USA
| | - C Jason Wong
- Catalent Cell & Gene Therapy, 20 Firstfield Road, Gaithersburg, MD, 20874, USA
| | - Pedro A Piedra
- Department of Molecular Virology and Microbiology, and Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Matthew B Frieman
- University of Maryland, School of Medicine, 685 West Baltimore St, Baltimore, MD, 21201, USA
| | | | - Louis Fries
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | | | | | | | - Gregory Glenn
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA
| | - Gale Smith
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, MD, 20878, USA.
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31
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Krueger S, Curtis JE, Scott DR, Grishaev A, Glenn G, Smith G, Ellingsworth L, Borisov O, Maynard EL. Structural Characterization and Modeling of a Respiratory Syncytial Virus Fusion Glycoprotein Nanoparticle Vaccine in Solution. Mol Pharm 2021; 18:359-376. [PMID: 33322901 PMCID: PMC10467610 DOI: 10.1021/acs.molpharmaceut.0c00986] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The respiratory syncytial virus (RSV) fusion (F) protein/polysorbate 80 (PS80) nanoparticle vaccine is the most clinically advanced vaccine for maternal immunization and protection of newborns against RSV infection. It is composed of a near-full-length RSV F glycoprotein, with an intact membrane domain, formulated into a stable nanoparticle with PS80 detergent. To understand the structural basis for the efficacy of the vaccine, a comprehensive study of its structure and hydrodynamic properties in solution was performed. Small-angle neutron scattering experiments indicate that the nanoparticle contains an average of 350 PS80 molecules, which form a cylindrical micellar core structure and five RSV F trimers that are arranged around the long axis of the PS80 core. All-atom models of full-length RSV F trimers were built from crystal structures of the soluble ectodomain and arranged around the long axis of the PS80 core, allowing for the generation of an ensemble of conformations that agree with small-angle neutron and X-ray scattering data as well as transmission electron microscopy (TEM) images. Furthermore, the hydrodynamic size of the RSV F nanoparticle was found to be modulated by the molar ratio of PS80 to protein, suggesting a mechanism for nanoparticle assembly involving addition of RSV F trimers to and growth along the long axis of the PS80 core. This study provides structural details of antigen presentation and conformation in the RSV F nanoparticle vaccine, helping to explain the induction of broad immunity and observed clinical efficacy. Small-angle scattering methods provide a general strategy to visualize surface glycoproteins from other pathogens and to structurally characterize nanoparticle vaccines.
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Affiliation(s)
- Susan Krueger
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Joseph E Curtis
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Daniel R Scott
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, Maryland 20878, United States
| | - Alexander Grishaev
- Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology, 9600 Gudelsky Drive, Rockville, Maryland 20850, United States
| | - Greg Glenn
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, Maryland 20878, United States
| | - Gale Smith
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, Maryland 20878, United States
| | - Larry Ellingsworth
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, Maryland 20878, United States
| | - Oleg Borisov
- Novavax, Inc., 21 Firstfield Road, Gaithersburg, Maryland 20878, United States
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32
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Raimondi V, Grinzato A. A basic introduction to single particles cryo-electron microscopy. AIMS BIOPHYSICS 2021. [DOI: 10.3934/biophy.2022002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
<abstract>
<p>In the last years, cryogenic-electron microscopy (cryo-EM) underwent the most impressive improvement compared to other techniques used in structural biology, such as X-ray crystallography and NMR. Electron microscopy was invented nearly one century ago but, up to the beginning of the last decades, the 3D maps produced through this technique were poorly detailed, justifying the term “blobbology” to appeal to cryo-EM. Recently, thanks to a new generation of microscopes and detectors, more efficient algorithms, and easier access to computational power, single particles cryo-EM can routinely produce 3D structures at resolutions comparable to those obtained with X-ray crystallography. However, unlike X-ray crystallography, which needs crystallized proteins, cryo-EM exploits purified samples in solution, allowing the study of proteins and protein complexes that are hard or even impossible to crystallize. For these reasons, single-particle cryo-EM is often the first choice of structural biologists today. Nevertheless, before starting a cryo-EM experiment, many drawbacks and limitations must be considered. Moreover, in practice, the process between the purified sample and the final structure could be trickier than initially expected. Based on these observations, this review aims to offer an overview of the principal technical aspects and setups to be considered while planning and performing a cryo-EM experiment.</p>
</abstract>
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33
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Diebolder CA, Dillard RS, Renault L. From Tube to Structure: SPA Cryo-EM Workflow Using Apoferritin as an Example. Methods Mol Biol 2021; 2305:229-256. [PMID: 33950393 DOI: 10.1007/978-1-0716-1406-8_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this chapter, we present an overview of a standard protocol to achieve structure determination at high resolution by Single Particle Analysis cryogenic Electron Microscopy using apoferritin as a standard sample. The purified apoferritin is applied to a glow-discharged support and then flash frozen in liquid ethane. The prepared grids are loaded into the electron microscope and checked for particle spreading and ice thickness. The microscope alignments are performed and the data collection session is setup for an overnight data collection. The collected movies containing two-dimensional images of the apoferritin sample are then processed to obtain a high-resolution three-dimensional reconstruction.
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Affiliation(s)
- Christoph A Diebolder
- The Netherlands Centre for Electron Nanoscopy (NeCEN), Leiden University, Leiden, The Netherlands
| | - Rebecca S Dillard
- The Netherlands Centre for Electron Nanoscopy (NeCEN), Leiden University, Leiden, The Netherlands
| | - Ludovic Renault
- The Netherlands Centre for Electron Nanoscopy (NeCEN), Leiden University, Leiden, The Netherlands.
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34
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Swanson KA, Rainho-Tomko JN, Williams ZP, Lanza L, Peredelchuk M, Kishko M, Pavot V, Alamares-Sapuay J, Adhikarla H, Gupta S, Chivukula S, Gallichan S, Zhang L, Jackson N, Yoon H, Edwards D, Wei CJ, Nabel GJ. A respiratory syncytial virus (RSV) F protein nanoparticle vaccine focuses antibody responses to a conserved neutralization domain. Sci Immunol 2020; 5:5/47/eaba6466. [PMID: 32358170 DOI: 10.1126/sciimmunol.aba6466] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/09/2020] [Indexed: 12/18/2022]
Abstract
A stabilized form of the respiratory syncytial virus (RSV) fusion (F) protein has been explored as a vaccine to prevent viral infection because it presents several potent neutralizing epitopes. Here, we used a structure-based rational design to optimize antigen presentation and focus antibody (Ab) responses to key epitopes on the pre-fusion (pre-F) protein. This protein was fused to ferritin nanoparticles (pre-F-NP) and modified with glycans to mask nonneutralizing or poorly neutralizing epitopes to further focus the Ab response. The multimeric pre-F-NP elicited durable pre-F-specific Abs in nonhuman primates (NHPs) after >150 days and elicited potent neutralizing Ab (NAb) responses in mice and NHPs in vivo, as well as in human cells evaluated in the in vitro MIMIC system. This optimized pre-F-NP stimulated a more potent Ab response than a representative pre-F trimer, DS-Cav1. Collectively, this pre-F vaccine increased the generation of NAbs targeting the desired pre-F conformation, an attribute that facilitates the development of an effective RSV vaccine.
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Affiliation(s)
| | | | - Zachary P Williams
- Sanofi Pasteur VaxDesign, 2501 Discovery Drive, Suite 300, Orlando, FL 32826, USA
| | - Lilibeth Lanza
- Sanofi Pasteur VaxDesign, 2501 Discovery Drive, Suite 300, Orlando, FL 32826, USA
| | - Michael Peredelchuk
- Sanofi Pasteur VaxDesign, 2501 Discovery Drive, Suite 300, Orlando, FL 32826, USA
| | - Michael Kishko
- Sanofi Pasteur, 38 Sidney Street, Cambridge, MA 02139, USA
| | - Vincent Pavot
- Sanofi Pasteur, 1541 Avenue Marcel Mérieux, Marcy l'Etoile, France
| | | | | | - Sankalp Gupta
- Sanofi Pasteur, 38 Sidney Street, Cambridge, MA 02139, USA
| | | | - Scott Gallichan
- Sanofi Pasteur, 95 Willowdale Blvd, Toronto, Ontario, Canada
| | - Linong Zhang
- Sanofi Pasteur, 38 Sidney Street, Cambridge, MA 02139, USA
| | | | - Heesik Yoon
- Sanofi Pasteur VaxDesign, 2501 Discovery Drive, Suite 300, Orlando, FL 32826, USA
| | - Darin Edwards
- Sanofi Pasteur VaxDesign, 2501 Discovery Drive, Suite 300, Orlando, FL 32826, USA
| | | | - Gary J Nabel
- Sanofi, 640 Memorial Drive, Cambridge, MA 02139, USA.
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35
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The Smc5/6 Core Complex Is a Structure-Specific DNA Binding and Compacting Machine. Mol Cell 2020; 80:1025-1038.e5. [PMID: 33301731 DOI: 10.1016/j.molcel.2020.11.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 10/13/2020] [Accepted: 11/04/2020] [Indexed: 01/09/2023]
Abstract
The structural organization of chromosomes is a crucial feature that defines the functional state of genes and genomes. The extent of structural changes experienced by genomes of eukaryotic cells can be dramatic and spans several orders of magnitude. At the core of these changes lies a unique group of ATPases-the SMC proteins-that act as major effectors of chromosome behavior in cells. The Smc5/6 proteins play essential roles in the maintenance of genome stability, yet their mode of action is not fully understood. Here we show that the human Smc5/6 complex recognizes unusual DNA configurations and uses the energy of ATP hydrolysis to promote their compaction. Structural analyses reveal subunit interfaces responsible for the functionality of the Smc5/6 complex and how mutations in these regions may lead to chromosome breakage syndromes in humans. Collectively, our results suggest that the Smc5/6 complex promotes genome stability as a DNA micro-compaction machine.
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36
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Larsen AH, Johansen NT, Gajhede M, Arleth L, Midtgaard SR. Lipid-bound ApoE3 self-assemble into elliptical disc-shaped particles. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183495. [PMID: 33189719 DOI: 10.1016/j.bbamem.2020.183495] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/14/2020] [Accepted: 10/26/2020] [Indexed: 11/29/2022]
Abstract
Apolipoproteins are vital to lipid metabolism and cholesterol transport in the human body. Here we present a structural study of the lipid-bound particles formed by ApoE3 in a full-length and a truncated version. The particles are formed with, respectively, POPC and DMPC and investigated by small-angle X-ray scattering and negative stain electron microscopy. We find that lipid-bound ApoE3 particles are elliptical, disc-shaped particles composed of a central lipid bilayer encircled by two amphipathic ApoE3 proteins. We went on to investigate a truncated form of ApoE3 containing only residue 80 to 255 (ApoE380-255), which is the central helical repeat segment of ApoE3. The lipid-bound ApoE380-255 particles are found to have the same morphology as the particles with full-length ApoE3. However, they are larger, and form more heterogeneous discoidal structures with four proteins per particle. This behavior is in contrast to ApoA1 where the highly similar helical repeat domain determines the size and stoichiometry of the formed particles both in the case of full-length and truncated ApoA1. Our data hence points towards different mechanisms for lipid bilayer structural modulation by ApoA1 and ApoE3 due to different roles of the non-repeat segments.
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Affiliation(s)
- Andreas Haahr Larsen
- University of Copenhagen, Niels Bohr Institute, Copenhagen, Denmark; University of Oxford, Department of Biochemistry, Oxford, United Kingdom.
| | | | - Michael Gajhede
- University of Copenhagen, Department of Drug Design and Pharmacology, Copenhagen, Denmark
| | - Lise Arleth
- University of Copenhagen, Niels Bohr Institute, Copenhagen, Denmark.
| | - Søren Roi Midtgaard
- University of Copenhagen, Niels Bohr Institute, Copenhagen, Denmark; Boston University School of Medicine, Department of Physiology and Biophysics, Boston, USA
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37
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Chung SC, Lin HH, Niu PY, Huang SH, Tu IP, Chang WH. Pre-pro is a fast pre-processor for single-particle cryo-EM by enhancing 2D classification. Commun Biol 2020; 3:508. [PMID: 32917929 PMCID: PMC7486923 DOI: 10.1038/s42003-020-01229-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 07/13/2020] [Indexed: 01/04/2023] Open
Abstract
2D classification plays a pivotal role in analyzing single particle cryo-electron microscopy images. Here, we introduce a simple and loss-less pre-processor that incorporates a fast dimension-reduction (2SDR) de-noiser to enhance 2D classification. By implementing this 2SDR pre-processor prior to a representative classification algorithm like RELION and ISAC, we compare the performances with and without the pre-processor. Tests on multiple cryo-EM experimental datasets show the pre-processor can make classification faster, improve yield of good particles and increase the number of class-average images to generate better initial models. Testing on the nanodisc-embedded TRPV1 dataset with high heterogeneity using a 3D reconstruction workflow with an initial model from class-average images highlights the pre-processor improves the final resolution to 2.82 Å, close to 0.9 Nyquist. Those findings and analyses suggest the 2SDR pre-processor, of minimal cost, is widely applicable for boosting 2D classification, while its generalization to accommodate neural network de-noisers is envisioned.
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Affiliation(s)
- Szu-Chi Chung
- Institute of Statistical Science, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan
| | - Hsin-Hung Lin
- Institute of Chemistry, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan
| | - Po-Yao Niu
- Institute of Statistical Science, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan
| | - Shih-Hsin Huang
- Institute of Chemistry, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan
| | - I-Ping Tu
- Institute of Statistical Science, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan.
| | - Wei-Hau Chang
- Institute of Chemistry, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan.
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38
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Castañeda AF, Didychuk AL, Louder RK, McCollum CO, Davis ZH, Nogales E, Glaunsinger BA. The gammaherpesviral TATA-box-binding protein directly interacts with the CTD of host RNA Pol II to direct late gene transcription. PLoS Pathog 2020; 16:e1008843. [PMID: 32886723 PMCID: PMC7498053 DOI: 10.1371/journal.ppat.1008843] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 09/17/2020] [Accepted: 07/28/2020] [Indexed: 12/11/2022] Open
Abstract
β- and γ-herpesviruses include the oncogenic human viruses Kaposi's sarcoma-associated virus (KSHV) and Epstein-Barr virus (EBV), and human cytomegalovirus (HCMV), which is a significant cause of congenital disease. Near the end of their replication cycle, these viruses transcribe their late genes in a manner distinct from host transcription. Late gene transcription requires six virally encoded proteins, one of which is a functional mimic of host TATA-box-binding protein (TBP) that is also involved in recruitment of RNA polymerase II (Pol II) via unknown mechanisms. Here, we applied biochemical protein interaction studies together with electron microscopy-based imaging of a reconstituted human preinitiation complex to define the mechanism underlying Pol II recruitment. These data revealed that the herpesviral TBP, encoded by ORF24 in KSHV, makes a direct protein-protein contact with the C-terminal domain of host RNA polymerase II (Pol II), which is a unique feature that functionally distinguishes viral from cellular TBP. The interaction is mediated by the N-terminal domain (NTD) of ORF24 through a conserved motif that is shared in its β- and γ-herpesvirus homologs. Thus, these herpesviruses employ an unprecedented strategy in eukaryotic transcription, wherein promoter recognition and polymerase recruitment are facilitated by a single transcriptional activator with functionally distinct domains.
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Affiliation(s)
- Angelica F. Castañeda
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, United States of America
| | - Allison L. Didychuk
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, United States of America
| | - Robert K. Louder
- Molecular Biophysics and Integrative Bio-Imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
- Biophysics Graduate Group, University of California, Berkeley, CA, United States of America
| | - Chloe O. McCollum
- Department of Molecular and Cell Biology, University of California Berkeley, CA, United States of America
| | - Zoe H. Davis
- Division of Infectious Diseases and Immunity, School of Public Health, University of California, Berkeley, CA, United States of America
| | - Eva Nogales
- Molecular Biophysics and Integrative Bio-Imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
- Department of Molecular and Cell Biology, University of California Berkeley, CA, United States of America
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA, United States of America
- Howard Hughes Medical Institute, Berkeley, CA, United States of America
| | - Britt A. Glaunsinger
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, United States of America
- Department of Molecular and Cell Biology, University of California Berkeley, CA, United States of America
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA, United States of America
- Howard Hughes Medical Institute, Berkeley, CA, United States of America
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39
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Zhang B, Zhang X, Pearce R, Shen HB, Zhang Y. A New Protocol for Atomic-Level Protein Structure Modeling and Refinement Using Low-to-Medium Resolution Cryo-EM Density Maps. J Mol Biol 2020; 432:5365-5377. [PMID: 32771523 DOI: 10.1016/j.jmb.2020.07.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 07/14/2020] [Accepted: 07/31/2020] [Indexed: 12/19/2022]
Abstract
The rapid progress of cryo-electron microscopy (cryo-EM) in structural biology has raised an urgent need for robust methods to create and refine atomic-level structural models using low-resolution EM density maps. We propose a new protocol to create initial models using I-TASSER protein structure prediction, followed by EM density map-based rigid-body structure fitting, flexible fragment adjustment and atomic-level structure refinement simulations. The protocol was tested on a large set of 285 non-homologous proteins and generated structural models with correct folds for 260 proteins, where 28% had RMSDs below 2 Å. Compared to other state-of-the-art methods, the major advantage of the proposed pipeline lies in the uniform structure prediction and refinement protocol, as well as the extensive structural re-assembly simulations, which allow for low-to-medium resolution EM density map-guided structure modeling starting from amino acid sequences. Interestingly, the quality of both the image fitting and subsequent structure refinement was found to be strongly correlated with the correctness of the initial I-TASSER models; this is mainly due to the different correlation patterns observed between force field and structural quality for the models with template modeling score (or TM-score, a metric quantifying the similarity of models to the native) above and below a threshold of 0.5. Overall, the results demonstrate a new avenue that is ready to use for large-scale cryo-EM-based structure modeling and atomic-level density map-guided structure refinement.
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Affiliation(s)
- Biao Zhang
- Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University, and Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai, China; Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Xi Zhang
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Robin Pearce
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hong-Bin Shen
- Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University, and Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai, China.
| | - Yang Zhang
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
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40
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Ortiz S, Stanisic L, Rodriguez BA, Rampp M, Hummer G, Cossio P. Validation tests for cryo-EM maps using an independent particle set. J Struct Biol X 2020; 4:100032. [PMID: 32743544 PMCID: PMC7385033 DOI: 10.1016/j.yjsbx.2020.100032] [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] [Indexed: 12/27/2022] Open
Abstract
Cryo-electron microscopy (cryo-EM) has revolutionized structural biology by providing 3D density maps of biomolecules at near-atomic resolution. However, map validation is still an open issue. Despite several efforts from the community, it is possible to overfit 3D maps to noisy data. Here, we develop a novel methodology that uses a small independent particle set (not used during the 3D refinement) to validate the maps. The main idea is to monitor how the map probability evolves over the control set during the 3D refinement. The method is complementary to the gold-standard procedure, which generates two reconstructions at each iteration. We low-pass filter the two reconstructions for different frequency cutoffs, and we calculate the probability of each filtered map given the control set. For high-quality maps, the probability should increase as a function of the frequency cutoff and the refinement iteration. We also compute the similarity between the densities of probability distributions of the two reconstructions. As higher frequencies are included, the distributions become more dissimilar. We optimized the BioEM package to perform these calculations, and tested it over systems ranging from quality data to pure noise. Our results show that with our methodology, it possible to discriminate datasets that are constructed from noise particles. We conclude that validation against a control particle set provides a powerful tool to assess the quality of cryo-EM maps.
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Affiliation(s)
- Sebastian Ortiz
- Biophysics of Tropical Diseases, Max Planck Tandem Group, University of Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Luka Stanisic
- Max Planck Computing and Data Facility, 85748 Garching, Germany
| | - Boris A Rodriguez
- Grupo de Fósica Atómica y Molecular, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
| | - Markus Rampp
- Max Planck Computing and Data Facility, 85748 Garching, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
- Institute of Biophysics, Goethe University, 60438 Frankfurt am Main, Germany
| | - Pilar Cossio
- Biophysics of Tropical Diseases, Max Planck Tandem Group, University of Antioquia UdeA, Calle 70 No. 52-21, Medellín, Colombia
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
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41
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Vogt MR, Fu J, Kose N, Williamson LE, Bombardi R, Setliff I, Georgiev IS, Klose T, Rossmann MG, Bochkov YA, Gern JE, Kuhn RJ, Crowe JE. Human antibodies neutralize enterovirus D68 and protect against infection and paralytic disease. Sci Immunol 2020; 5:5/49/eaba4902. [PMID: 32620559 DOI: 10.1126/sciimmunol.aba4902] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 06/12/2020] [Indexed: 12/17/2022]
Abstract
Enterovirus D68 (EV-D68) causes outbreaks of respiratory illness, and there is increasing evidence that it causes outbreaks of acute flaccid myelitis (AFM). There are no licensed therapies to prevent or treat EV-D68 infection or AFM disease. We isolated a panel of EV-D68-reactive human monoclonal antibodies that recognize diverse antigenic variants from participants with prior infection. One potently neutralizing cross-reactive antibody, EV68-228, protected mice from respiratory and neurologic disease when given either before or after infection. Cryo-electron microscopy studies revealed that EV68-228 and another potently neutralizing antibody (EV68-159) bound around the fivefold or threefold axes of symmetry on virion particles, respectively. The structures suggest diverse mechanisms of action by these antibodies. The high potency and effectiveness observed in vivo suggest that antibodies are a mechanistic correlate of protection against AFM disease and are candidates for clinical use in humans with EV-D68 infection.
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Affiliation(s)
- Matthew R Vogt
- Department of Pediatrics (Infectious Diseases), Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jianing Fu
- Department of Biological Sciences and Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN, USA
| | - Nurgun Kose
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Lauren E Williamson
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Robin Bombardi
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ian Setliff
- Program in Chemical and Physical Biology, Vanderbilt University, Nashville, TN, USA
| | - Ivelin S Georgiev
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Thomas Klose
- Department of Biological Sciences and Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN, USA
| | - Michael G Rossmann
- Department of Biological Sciences and Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN, USA
| | - Yury A Bochkov
- Department of Pediatrics, University of Wisconsin-Madison, Madison, WI, USA
| | - James E Gern
- Department of Pediatrics, University of Wisconsin-Madison, Madison, WI, USA.,Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Richard J Kuhn
- Department of Biological Sciences and Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN, USA
| | - James E Crowe
- Department of Pediatrics (Infectious Diseases), Vanderbilt University Medical Center, Nashville, TN, USA. .,Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.,Program in Chemical and Physical Biology, Vanderbilt University, Nashville, TN, USA
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42
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Baretić D, Jenkyn-Bedford M, Aria V, Cannone G, Skehel M, Yeeles JTP. Cryo-EM Structure of the Fork Protection Complex Bound to CMG at a Replication Fork. Mol Cell 2020; 78:926-940.e13. [PMID: 32369734 PMCID: PMC7276988 DOI: 10.1016/j.molcel.2020.04.012] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 04/09/2020] [Accepted: 04/09/2020] [Indexed: 12/15/2022]
Abstract
The eukaryotic replisome, organized around the Cdc45-MCM-GINS (CMG) helicase, orchestrates chromosome replication. Multiple factors associate directly with CMG, including Ctf4 and the heterotrimeric fork protection complex (Csm3/Tof1 and Mrc1), which has important roles including aiding normal replication rates and stabilizing stalled forks. How these proteins interface with CMG to execute these functions is poorly understood. Here we present 3 to 3.5 Å resolution electron cryomicroscopy (cryo-EM) structures comprising CMG, Ctf4, and the fork protection complex at a replication fork. The structures provide high-resolution views of CMG-DNA interactions, revealing a mechanism for strand separation, and show Csm3/Tof1 “grip” duplex DNA ahead of CMG via a network of interactions important for efficient replication fork pausing. Although Mrc1 was not resolved in our structures, we determine its topology in the replisome by cross-linking mass spectrometry. Collectively, our work reveals how four highly conserved replisome components collaborate with CMG to facilitate replisome progression and maintain genome stability. Cryo-EM structure of Csm3/Tof1 and Ctf4 bound to the eukaryotic CMG helicase Csm3/Tof1 are positioned at the front of the replisome where they grip duplex DNA High-resolution views of CMG-DNA contacts suggest a mechanism for strand separation Mrc1 binds across one side of CMG contacting the front and back of the replisome
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Affiliation(s)
- Domagoj Baretić
- Laboratory of Molecular Biology, Medical Research Council, Cambridge CB2 0QH, UK
| | | | - Valentina Aria
- Laboratory of Molecular Biology, Medical Research Council, Cambridge CB2 0QH, UK
| | - Giuseppe Cannone
- Laboratory of Molecular Biology, Medical Research Council, Cambridge CB2 0QH, UK
| | - Mark Skehel
- Laboratory of Molecular Biology, Medical Research Council, Cambridge CB2 0QH, UK
| | - Joseph T P Yeeles
- Laboratory of Molecular Biology, Medical Research Council, Cambridge CB2 0QH, UK.
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43
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Eldar A, Landa B, Shkolnisky Y. KLT picker: Particle picking using data-driven optimal templates. J Struct Biol 2020; 210:107473. [PMID: 32035993 DOI: 10.1016/j.jsb.2020.107473] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/21/2020] [Accepted: 01/24/2020] [Indexed: 11/15/2022]
Abstract
Particle picking is currently a critical step in the cryo-EM single particle reconstruction pipeline. Despite extensive work on this problem, for many data sets it is still challenging, especially for low SNR micrographs. We present the KLT (Karhunen Loeve Transform) picker, which is fully automatic and requires as an input only the approximated particle size. In particular, it does not require any manual picking. Our method is designed especially to handle low SNR micrographs. It is based on learning a set of optimal templates through the use of multi-variate statistical analysis via the Karhunen Loeve Transform. We evaluate the KLT picker on publicly available data sets and present high-quality results with minimal manual effort.
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Affiliation(s)
- Amitay Eldar
- Department of Applied Mathematics, School of Mathematical Sciences, Tel-Aviv University, Tel-Aviv, Israel.
| | - Boris Landa
- Department of Mathematics, Yale University, 10 Hillhouse Ave, New Haven, USA.
| | - Yoel Shkolnisky
- Department of Applied Mathematics, School of Mathematical Sciences, Tel-Aviv University, Tel-Aviv, Israel.
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44
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Kamp HD, Swanson KA, Wei RR, Dhal PK, Dharanipragada R, Kern A, Sharma B, Sima R, Hajdusek O, Hu LT, Wei CJ, Nabel GJ. Design of a broadly reactive Lyme disease vaccine. NPJ Vaccines 2020; 5:33. [PMID: 32377398 PMCID: PMC7195412 DOI: 10.1038/s41541-020-0183-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 03/31/2020] [Indexed: 02/02/2023] Open
Abstract
A growing global health concern, Lyme disease has become the most common tick-borne disease in the United States and Europe. Caused by the bacterial spirochete Borrelia burgdorferi sensu lato (sl), this disease can be debilitating if not treated promptly. Because diagnosis is challenging, prevention remains a priority; however, a previously licensed vaccine is no longer available to the public. Here, we designed a six component vaccine that elicits antibody (Ab) responses against all Borrelia strains that commonly cause Lyme disease in humans. The outer surface protein A (OspA) of Borrelia was fused to a bacterial ferritin to generate self-assembling nanoparticles. OspA-ferritin nanoparticles elicited durable high titer Ab responses to the seven major serotypes in mice and non-human primates at titers higher than a previously licensed vaccine. This response was durable in rhesus macaques for more than 6 months. Vaccination with adjuvanted OspA-ferritin nanoparticles stimulated protective immunity from both B. burgdorferi and B. afzelii infection in a tick-fed murine challenge model. This multivalent Lyme vaccine offers the potential to limit the spread of Lyme disease.
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Affiliation(s)
| | | | | | | | | | - Aurelie Kern
- Department of Molecular Biology and Microbiology, Tufts University, 136 Harrison Ave, Boston, MA 02111 USA
| | - Bijaya Sharma
- Department of Molecular Biology and Microbiology, Tufts University, 136 Harrison Ave, Boston, MA 02111 USA
| | - Radek Sima
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Ondrej Hajdusek
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Linden T. Hu
- Department of Molecular Biology and Microbiology, Tufts University, 136 Harrison Ave, Boston, MA 02111 USA
| | - Chih-Jen Wei
- Sanofi, 640 Memorial Dr, Cambridge, MA 01239 USA
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45
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Wang CC. Joint Iterative Fast Projection Matching for Fully Automatic Marker-free Alignment of Nano-tomography Reconstructions. Sci Rep 2020; 10:7330. [PMID: 32355164 PMCID: PMC7192921 DOI: 10.1038/s41598-020-62949-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 01/24/2020] [Indexed: 11/21/2022] Open
Abstract
Highly accurate, fully automatic marker-free image alignment plays an important role in nano-tomographic reconstruction, particularly in cases where the spatial resolution of the tomographic system is on the nanometer scale. However, highly accurate marker-free methods such as the projection matching method are computationally complex and time-consuming. Achieving alignment accuracy with reduced computational complexity remains a challenging problem. In this study, we propose an efficient method to achieve marker-free fully automatic alignment. Our method implements three main alignment procedures. First, the frequency-domain common line alignment method is used to correct the in-plane rotational errors of each projection. Second, real-space common line alignment method is used to correct the vertical errors of the projections. Finally, a single layer joint-iterative reconstruction and re-projection method is used to correct the horizontal projection errors. This combined alignment approach significantly reduces the computational complexity of the classical projection matching method, and increases the rate of convergence towards determining the accurate alignment. The total processing time can be reduced by up to 4 orders of magnitude as compared to the classical projection matching method. This suggests that the algorithm can be used to process image alignment of nano-tomographic reconstructions on a conventional personal computer in a reasonable time-frame.
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Affiliation(s)
- Chun-Chieh Wang
- National Synchrotron Radiation Research Center, 30076, Hsinchu, Taiwan.
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46
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Dagbay KB, Treece E, Streich FC, Jackson JW, Faucette RR, Nikiforov A, Lin SC, Boston CJ, Nicholls SB, Capili AD, Carven GJ. Structural basis of specific inhibition of extracellular activation of pro- or latent myostatin by the monoclonal antibody SRK-015. J Biol Chem 2020; 295:5404-5418. [PMID: 32075906 PMCID: PMC7170532 DOI: 10.1074/jbc.ra119.012293] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/05/2020] [Indexed: 12/27/2022] Open
Abstract
Myostatin (or growth/differentiation factor 8 (GDF8)) is a member of the transforming growth factor β superfamily of growth factors and negatively regulates skeletal muscle growth. Its dysregulation is implicated in muscle wasting diseases. SRK-015 is a clinical-stage mAb that prevents extracellular proteolytic activation of pro- and latent myostatin. Here we used integrated structural and biochemical approaches to elucidate the molecular mechanism of antibody-mediated neutralization of pro-myostatin activation. The crystal structure of pro-myostatin in complex with 29H4-16 Fab, a high-affinity variant of SRK-015, at 2.79 Å resolution revealed that the antibody binds to a conformational epitope in the arm region of the prodomain distant from the proteolytic cleavage sites. This epitope is highly sequence-divergent, having only limited similarity to other closely related members of the transforming growth factor β superfamily. Hydrogen/deuterium exchange MS experiments indicated that antibody binding induces conformational changes in pro- and latent myostatin that span the arm region, the loops contiguous to the protease cleavage sites, and the latency-associated structural elements. Moreover, negative-stain EM with full-length antibodies disclosed a stable, ring-like antigen-antibody structure in which the two Fab arms of a single antibody occupy the two arm regions of the prodomain in the pro- and latent myostatin homodimers, suggesting a 1:1 (antibody:myostatin homodimer) binding stoichiometry. These results suggest that SRK-015 binding stabilizes the latent conformation and limits the accessibility of protease cleavage sites within the prodomain. These findings shed light on approaches that specifically block the extracellular activation of growth factors by targeting their precursor forms.
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Affiliation(s)
| | - Erin Treece
- Scholar Rock Inc., Cambridge, Massachusetts 02139
| | | | | | | | | | - Susan C Lin
- Scholar Rock Inc., Cambridge, Massachusetts 02139
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47
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Pathak BK, Das D, Bhakta S, Chakrabarti P, Sengupta J. Resveratrol as a nontoxic excipient stabilizes insulin in a bioactive hexameric form. J Comput Aided Mol Des 2020; 34:915-927. [PMID: 32270361 DOI: 10.1007/s10822-020-00311-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 03/27/2020] [Indexed: 01/14/2023]
Abstract
Insulin aggregation is the leading cause of considerable reduction in the amount of active drug molecules in liquid formulations manufactured for diabetes management. Phenolic compounds, such as phenol and m-cresol, are routinely used to stabilize insulin in a hexameric form during its commercial preparation. However, long term usage of commercial insulin results in various adverse secondary responses, for which toxicity of the phenolic excipients is primarily responsible. In this study we aimed to find out a nontoxic insulin stabilizer. To that end, we have selected resveratrol, a natural polyphenol, as a prospective nontoxic insulin stabilizer because of its structural similarity with commercially used phenolic compounds. Atomic force microscopy visualization of resveratrol-treated human insulin revealed that resveratrol has a unique ability to arrest hINS in a soluble oligomeric form having discrete spherical morphology. Most importantly, resveratrol-treated insulin is nontoxic for HepG2 cells and it effectively maintains low blood glucose in a mouse model. Cryo-electron microscopy revealed 3D morphology of resveratrol-stabilized insulin that strikingly resembles crystal structures of insulin hexamer formulated with m-cresol. Significantly, we found that, in a condition inductive to amyloid fibrillation at physiological pH, resveratrol is capable of stabilizing insulin more efficiently than m-cresol. Thus, this study describes resveratrol as an effective nontoxic natural molecule that can be used for stabilizing insulin in a bioactive oligomeric form during its commercial formulation.
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Affiliation(s)
- Bani Kumar Pathak
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata, 700 032, India
| | - Debajyoti Das
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata, 700 032, India
| | - Sayan Bhakta
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata, 700 032, India
| | - Partha Chakrabarti
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India. .,Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata, 700 032, India.
| | - Jayati Sengupta
- Structural Biology & Bio-Informatics Division, CSIR-Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata, 700 032, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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48
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Carter SD, Hampton CM, Langlois R, Melero R, Farino ZJ, Calderon MJ, Li W, Wallace CT, Tran NH, Grassucci RA, Siegmund SE, Pemberton J, Morgenstern TJ, Eisenman L, Aguilar JI, Greenberg NL, Levy ES, Yi E, Mitchell WG, Rice WJ, Wigge C, Pilli J, George EW, Aslanoglou D, Courel M, Freyberg RJ, Javitch JA, Wills ZP, Area-Gomez E, Shiva S, Bartolini F, Volchuk A, Murray SA, Aridor M, Fish KN, Walter P, Balla T, Fass D, Wolf SG, Watkins SC, Carazo JM, Jensen GJ, Frank J, Freyberg Z. Ribosome-associated vesicles: A dynamic subcompartment of the endoplasmic reticulum in secretory cells. SCIENCE ADVANCES 2020; 6:eaay9572. [PMID: 32270040 PMCID: PMC7112762 DOI: 10.1126/sciadv.aay9572] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 01/13/2020] [Indexed: 05/21/2023]
Abstract
The endoplasmic reticulum (ER) is a highly dynamic network of membranes. Here, we combine live-cell microscopy with in situ cryo-electron tomography to directly visualize ER dynamics in several secretory cell types including pancreatic β-cells and neurons under near-native conditions. Using these imaging approaches, we identify a novel, mobile form of ER, ribosome-associated vesicles (RAVs), found primarily in the cell periphery, which is conserved across different cell types and species. We show that RAVs exist as distinct, highly dynamic structures separate from the intact ER reticular architecture that interact with mitochondria via direct intermembrane contacts. These findings describe a new ER subcompartment within cells.
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Affiliation(s)
- Stephen D. Carter
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Cheri M. Hampton
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Robert Langlois
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Roberto Melero
- Biocomputing Unit, Centro Nacional de Biotecnología–CSIC, Darwin 3, Campus Universidad Autónoma, 28049 Madrid, Spain
| | - Zachary J. Farino
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Michael J. Calderon
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Wen Li
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Callen T. Wallace
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Ngoc Han Tran
- HHMI, Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Robert A. Grassucci
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Stephanie E. Siegmund
- Department of Cellular, Molecular and Biophysical Studies, Columbia University Medical Center, New York, NY 10032, USA
- Department of Neurology, Columbia University, New York, NY 10032, USA
| | - Joshua Pemberton
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Travis J. Morgenstern
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Leanna Eisenman
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jenny I. Aguilar
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Nili L. Greenberg
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Elana S. Levy
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Edward Yi
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - William G. Mitchell
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | | | | | - Jyotsna Pilli
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Emily W. George
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Despoina Aslanoglou
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Maïté Courel
- CNRS-UMR7622, Institut de Biologie Paris-Seine, Université Pierre & Marie Curie, 75252 Paris, France
| | - Robin J. Freyberg
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jonathan A. Javitch
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Zachary P. Wills
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Estela Area-Gomez
- Department of Neurology, Columbia University, New York, NY 10032, USA
| | - Sruti Shiva
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Francesca Bartolini
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Allen Volchuk
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Sandra A. Murray
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Meir Aridor
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Kenneth N. Fish
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Peter Walter
- HHMI, Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Deborah Fass
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Sharon G. Wolf
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Simon C. Watkins
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - José María Carazo
- Biocomputing Unit, Centro Nacional de Biotecnología–CSIC, Darwin 3, Campus Universidad Autónoma, 28049 Madrid, Spain
| | - Grant J. Jensen
- HHMI, Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Joachim Frank
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Zachary Freyberg
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213, USA
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49
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Abstract
Cross-validation is used to determine the validity of a model on unseen data by assessing if the model is overfitted to noise. It is widely used in many fields, from artificial intelligence to structural biology in X-ray crystallography and nuclear magnetic resonance. Although there are concerns of map overfitting in cryo-electron microscopy (cryo-EM), cross-validation is rarely used. The problem is that establishing a performance metric of the maps over unseen data (given by 2D-projection images) is difficult due to the low signal-to-noise ratios in the individual particles. Here, I present recent advances for cryo-EM map reconstruction. I highlight that the gold-standard procedure can fail to detect map overfitting in certain cases, showing the necessity of assessing the map quality on unbiased data. Finally, I describe the challenges and advantages of developing a robust cross-validation methodology for cryo-EM.
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Affiliation(s)
- Pilar Cossio
- Biophysics of Tropical Diseases, Max Planck Tandem Group, University of Antioquia UdeA, Calle 70 No. 52-21, Medellin, Colombia.,Department of Theoretical Biophysics, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
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50
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Portnoff AD, Patel N, Massare MJ, Zhou H, Tian JH, Zhou B, Shinde V, Glenn GM, Smith G. Influenza Hemagglutinin Nanoparticle Vaccine Elicits Broadly Neutralizing Antibodies against Structurally Distinct Domains of H3N2 HA. Vaccines (Basel) 2020; 8:vaccines8010099. [PMID: 32098409 PMCID: PMC7157642 DOI: 10.3390/vaccines8010099] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/17/2020] [Accepted: 02/18/2020] [Indexed: 11/30/2022] Open
Abstract
Influenza vaccine effectiveness varies annually due to the fast evolving seasonal influenza A(H3N2) strain and egg-derived mutations—both of which can cause a mismatch between the vaccine and circulating strains. To address these limitations, we have developed a hemagglutinin (HA)-based protein-detergent nanoparticle influenza vaccine (NIV) with a saponin-based Matrix-M™ adjuvant. In a phase 1 clinical trial of older adults, the vaccine demonstrated broadly cross-reactive A(H3N2) HA antibody responses. Two broadly neutralizing monoclonal antibodies derived from NIV-immunized mice were characterized by transmission electron microscopy (TEM), antibody competition assays, fluorescence-activated cell sorting (FACS) analysis, and protein–protein docking. These antibodies recognize two conserved regions of the head domain, namely the receptor binding site and the vestigial esterase subdomain, thus demonstrating the potential for an HA subunit vaccine to elicit antibodies targeting structurally and antigenically distinct but conserved sites. Antibody competition studies with sera from the phase 1 trial in older adults confirmed that humans also make antibodies to these two head domains and against the highly conserved stem domain. This data supports the potential of an adjuvanted recombinant HA nanoparticle vaccine to induce broadly protective immunity and improved vaccine efficacy.
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