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Samsudin F, Zuzic L, Marzinek JK, Bond PJ. Mechanisms of allostery at the viral surface through the eyes of molecular simulation. Curr Opin Struct Biol 2024; 84:102761. [PMID: 38142635 DOI: 10.1016/j.sbi.2023.102761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/13/2023] [Accepted: 12/04/2023] [Indexed: 12/26/2023]
Abstract
The outermost surface layer of any virus is formed by either a capsid shell or envelope. Such layers have traditionally been thought of as immovable structures, but it is becoming apparent that they cannot be viewed exclusively as static architectures protecting the viral genome. A limited number of proteins on the virion surface must perform a multitude of functions in order to orchestrate the viral life cycle, and allostery can regulate their structures at multiple levels of organization, spanning individual molecules, protomers, large oligomeric assemblies, or entire viral surfaces. Here, we review recent contributions from the molecular simulation field to viral surface allostery, with a particular focus on the trimeric spike glycoprotein emerging from the coronavirus surface, and the icosahedral flaviviral envelope complex. As emerging viral pathogens continue to pose a global threat, an improved understanding of viral dynamics and allosteric regulation will prove crucial in developing novel therapeutic strategies.
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Affiliation(s)
- Firdaus Samsudin
- Bioinformatics Institute (A∗STAR), 30 Biopolis Street, 07-01 Matrix, 138671, Singapore
| | - Lorena Zuzic
- Department of Chemistry, Langelandsgade 140, Aarhus University, Aarhus 8000, Denmark
| | - Jan K Marzinek
- Bioinformatics Institute (A∗STAR), 30 Biopolis Street, 07-01 Matrix, 138671, Singapore
| | - Peter J Bond
- Bioinformatics Institute (A∗STAR), 30 Biopolis Street, 07-01 Matrix, 138671, Singapore; Department of Biological Sciences, 16 Science Drive 4, National University of Singapore, 117558, Singapore.
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2
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Bavnhøj L, Driller JH, Zuzic L, Stange AD, Schiøtt B, Pedersen BP. Structure and sucrose binding mechanism of the plant SUC1 sucrose transporter. Nat Plants 2023; 9:938-950. [PMID: 37188854 PMCID: PMC10281868 DOI: 10.1038/s41477-023-01421-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 04/19/2023] [Indexed: 05/17/2023]
Abstract
Sucrose import from photosynthetic tissues into the phloem is mediated by transporters from the low-affinity sucrose transporter family (SUC/SUT family). Furthermore, sucrose redistribution to other tissues is driven by phloem sap movement, the product of high turgor pressure created by this import activity. Additionally, sink organs such as fruits, cereals and seeds that accumulate high concentrations of sugar also depend on this active transport of sucrose. Here we present the structure of the sucrose-proton symporter, Arabidopsis thaliana SUC1, in an outward open conformation at 2.7 Å resolution, together with molecular dynamics simulations and biochemical characterization. We identify the key acidic residue required for proton-driven sucrose uptake and describe how protonation and sucrose binding are strongly coupled. Sucrose binding is a two-step process, with initial recognition mediated by the glucosyl moiety binding directly to the key acidic residue in a stringent pH-dependent manner. Our results explain how low-affinity sucrose transport is achieved in plants, and pinpoint a range of SUC binders that help define selectivity. Our data demonstrate a new mode for proton-driven symport with links to cation-driven symport and provide a broad model for general low-affinity transport in highly enriched substrate environments.
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Affiliation(s)
- Laust Bavnhøj
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jan Heiner Driller
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Lorena Zuzic
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | | | - Birgit Schiøtt
- Department of Chemistry, Aarhus University, Aarhus, Denmark
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3
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Zuzic L, Marzinek JK, Anand GS, Warwicker J, Bond PJ. A pH-dependent cluster of charges in a conserved cryptic pocket on flaviviral envelopes. eLife 2023; 12:82447. [PMID: 37144875 PMCID: PMC10162804 DOI: 10.7554/elife.82447] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 04/18/2023] [Indexed: 05/06/2023] Open
Abstract
Flaviviruses are enveloped viruses which include human pathogens that are predominantly transmitted by mosquitoes and ticks. Some, such as dengue virus, exhibit the phenomenon of antibody-dependent enhancement (ADE) of disease, making vaccine-based routes of fighting infections problematic. The pH-dependent conformational change of the envelope (E) protein required for fusion between the viral and endosomal membranes is an attractive point of inhibition by antivirals as it has the potential to diminish the effects of ADE. We examined six flaviviruses by employing large-scale molecular dynamics (MD) simulations of raft systems that represent a substantial portion of the flaviviral envelope. We utilised a benzene-mapping approach that led to a discovery of shared hotspots and conserved cryptic sites. A cryptic pocket previously shown to bind a detergent molecule exhibited strain-specific characteristics. An alternative conserved cryptic site at the E protein domain interfaces showed a consistent dynamic behaviour across flaviviruses and contained a conserved cluster of ionisable residues. Constant-pH simulations revealed cluster and domain-interface disruption under low pH conditions. Based on this, we propose a cluster-dependent mechanism that addresses inconsistencies in the histidine-switch hypothesis and highlights the role of cluster protonation in orchestrating the domain dissociation pivotal for the formation of the fusogenic trimer.
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Affiliation(s)
- Lorena Zuzic
- Bioinformatics Institute (A*STAR), Singapore, Singapore
- Department of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
| | | | - Ganesh S Anand
- Department of Biological Sciences, 16 Science Drive 4, National University of Singapore, Singapore, Singapore
- Department of Chemistry, The Pennsylvania State University, University Park, United States
| | - Jim Warwicker
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
| | - Peter J Bond
- Bioinformatics Institute (A*STAR), Singapore, Singapore
- Department of Biological Sciences, 16 Science Drive 4, National University of Singapore, Singapore, Singapore
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4
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Zuzic L, Stange AD, Bavnhøj L, Driller JH, Schiøtt B, Pedersen BP. Sweet and sour transport: Simulation insights into H +/sugar symport in plants. Biophys J 2023; 122:197a. [PMID: 36782947 DOI: 10.1016/j.bpj.2022.11.1201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- Lorena Zuzic
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | | | - Laust Bavnhøj
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jan H Driller
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Birgit Schiøtt
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | - Bjørn P Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
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5
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Zuzic L, Samsudin F, Shivgan AT, Raghuvamsi PV, Marzinek JK, Boags A, Pedebos C, Tulsian NK, Warwicker J, MacAry P, Crispin M, Khalid S, Anand GS, Bond PJ. Uncovering cryptic pockets in the SARS-CoV-2 spike glycoprotein. Structure 2022; 30:1062-1074.e4. [PMID: 35660160 PMCID: PMC9164293 DOI: 10.1016/j.str.2022.05.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 04/19/2022] [Accepted: 05/10/2022] [Indexed: 11/30/2022]
Abstract
The COVID-19 pandemic has prompted a rapid response in vaccine and drug development. Herein, we modeled a complete membrane-embedded SARS-CoV-2 spike glycoprotein and used molecular dynamics simulations with benzene probes designed to enhance discovery of cryptic pockets. This approach recapitulated lipid and host metabolite binding sites previously characterized by cryo-electron microscopy, revealing likely ligand entry routes, and uncovered a novel cryptic pocket with promising druggable properties located underneath the 617-628 loop. A full representation of glycan moieties was essential to accurately describe pocket dynamics. A multi-conformational behavior of the 617-628 loop in simulations was validated using hydrogen-deuterium exchange mass spectrometry experiments, supportive of opening and closing dynamics. The pocket is the site of multiple mutations associated with increased transmissibility found in SARS-CoV-2 variants of concern including Omicron. Collectively, this work highlights the utility of the benzene mapping approach in uncovering potential druggable sites on the surface of SARS-CoV-2 targets.
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Affiliation(s)
- Lorena Zuzic
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), Singapore 138671, Singapore; Department of Chemistry, Faculty of Science and Engineering, Manchester Institute of Biotechnology, The University of Manchester, Manchester M1 7DN, UK
| | - Firdaus Samsudin
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), Singapore 138671, Singapore
| | - Aishwary T Shivgan
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), Singapore 138671, Singapore
| | - Palur V Raghuvamsi
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Jan K Marzinek
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), Singapore 138671, Singapore
| | - Alister Boags
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), Singapore 138671, Singapore; School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK
| | - Conrado Pedebos
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK; Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Nikhil K Tulsian
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore; Department of Biochemistry, National University of Singapore, Singapore 117546, Singapore
| | - Jim Warwicker
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Institute of Biotechnology, The University of Manchester, Manchester M1 7DN, UK
| | - Paul MacAry
- Life Sciences Institute, Centre for Life Sciences, National University of Singapore, Singapore 117546, Singapore
| | - Max Crispin
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Syma Khalid
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK; Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
| | - Ganesh S Anand
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore; Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA.
| | - Peter J Bond
- Bioinformatics Institute, Agency for Science, Technology and Research (A∗STAR), Singapore 138671, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
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6
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Tupiņa D, Krah A, Marzinek JK, Zuzic L, Moverley AA, Constantinidou C, Bond PJ. Bridging the N-terminal and middle domains in FliG of the flagellar rotor. Curr Res Struct Biol 2022; 4:59-67. [PMID: 35345452 PMCID: PMC8956890 DOI: 10.1016/j.crstbi.2022.02.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 01/28/2022] [Accepted: 02/28/2022] [Indexed: 11/27/2022] Open
Abstract
Flagella are necessary for bacterial movement and contribute to various aspects of virulence. They are complex cylindrical structures built of multiple molecular rings with self-assembly properties. The flagellar rotor is composed of the MS-ring and the C-ring. The FliG protein of the C-ring is central to flagellar assembly and function due to its roles in linking the C-ring with the MS-ring and in torque transmission from stator to rotor. No high-resolution structure of an assembled C-ring has been resolved to date, and the conformation adopted by FliG within the ring is unclear due to variations in available crystallographic data. Here, we use molecular dynamics (MD) simulations to study the conformation and dynamics of FliG in different states of assembly, including both in physiologically relevant and crystallographic lattice environments. We conclude that the linker between the FliG N-terminal and middle domain likely adopts an extended helical conformation in vivo, in contrast with the contracted conformation observed in some previous X-ray studies. We further support our findings with integrative model building of full-length FliG and a FliG ring model that is compatible with cryo-electron tomography (cryo-ET) and electron microscopy (EM) densities of the C-ring. Collectively, our study contributes to a better mechanistic understanding of the flagellar rotor assembly and its function.
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Allen JD, Chawla H, Samsudin F, Zuzic L, Shivgan AT, Watanabe Y, He WT, Callaghan S, Song G, Yong P, Brouwer PJM, Song Y, Cai Y, Duyvesteyn HME, Malinauskas T, Kint J, Pino P, Wurm MJ, Frank M, Chen B, Stuart DI, Sanders RW, Andrabi R, Burton DR, Li S, Bond PJ, Crispin M. Site-Specific Steric Control of SARS-CoV-2 Spike Glycosylation. Biochemistry 2021; 60:2153-2169. [PMID: 34213308 PMCID: PMC8262170 DOI: 10.1021/acs.biochem.1c00279] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/18/2021] [Indexed: 02/08/2023]
Abstract
A central tenet in the design of vaccines is the display of native-like antigens in the elicitation of protective immunity. The abundance of N-linked glycans across the SARS-CoV-2 spike protein is a potential source of heterogeneity among the many different vaccine candidates under investigation. Here, we investigate the glycosylation of recombinant SARS-CoV-2 spike proteins from five different laboratories and compare them against S protein from infectious virus, cultured in Vero cells. We find patterns that are conserved across all samples, and this can be associated with site-specific stalling of glycan maturation that acts as a highly sensitive reporter of protein structure. Molecular dynamics simulations of a fully glycosylated spike support a model of steric restrictions that shape enzymatic processing of the glycans. These results suggest that recombinant spike-based SARS-CoV-2 immunogen glycosylation reproducibly recapitulates signatures of viral glycosylation.
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Affiliation(s)
- Joel D. Allen
- School
of Biological Sciences, University of Southampton, Southampton SO17 1BJ, U.K.
| | - Himanshi Chawla
- School
of Biological Sciences, University of Southampton, Southampton SO17 1BJ, U.K.
| | - Firdaus Samsudin
- Bioinformatics
Institute, Agency for Science, Technology
and Research (A*STAR), Singapore 138671
| | - Lorena Zuzic
- Bioinformatics
Institute, Agency for Science, Technology
and Research (A*STAR), Singapore 138671
- Department
of Chemistry, Faculty of Science and Engineering, Manchester Institute
of Biotechnology, The University of Manchester, Manchester M1 7DN, U.K.
| | - Aishwary Tukaram Shivgan
- Bioinformatics
Institute, Agency for Science, Technology
and Research (A*STAR), Singapore 138671
- Department
of Biological Sciences, National University
of Singapore, Singapore 117543
| | - Yasunori Watanabe
- School
of Biological Sciences, University of Southampton, Southampton SO17 1BJ, U.K.
| | - Wan-ting He
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
- IAVI
Neutralizing Antibody Center, The Scripps
Research Institute, La Jolla, California 92037, United States
- Consortium
for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California 92037, United States
| | - Sean Callaghan
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
- IAVI
Neutralizing Antibody Center, The Scripps
Research Institute, La Jolla, California 92037, United States
- Consortium
for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California 92037, United States
| | - Ge Song
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
- IAVI
Neutralizing Antibody Center, The Scripps
Research Institute, La Jolla, California 92037, United States
- Consortium
for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California 92037, United States
| | - Peter Yong
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
- IAVI
Neutralizing Antibody Center, The Scripps
Research Institute, La Jolla, California 92037, United States
- Consortium
for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California 92037, United States
| | - Philip J. M. Brouwer
- Department
of Medical Microbiology, Amsterdam UMC,
University of Amsterdam, Amsterdam Infection & Immunity Institute, 1007 MB Amsterdam, The Netherlands
| | - Yutong Song
- Tsinghua-Peking
Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Beijing
Advanced Innovation Center for Structural Biology and Frontier Research
Center for Biological Structure, Beijing 100084, China
| | - Yongfei Cai
- Division
of Molecular Medicine, Boston Children’s
Hospital, 3 Blackfan
Street, Boston, Massachusetts 02115, United States
| | - Helen M. E. Duyvesteyn
- Division
of Structural Biology, University of Oxford,
The Wellcome Centre for Human Genetics, Headington, Oxford OX3 7BN, U.K.
| | - Tomas Malinauskas
- Division
of Structural Biology, University of Oxford,
The Wellcome Centre for Human Genetics, Headington, Oxford OX3 7BN, U.K.
| | - Joeri Kint
- ExcellGene SA, CH1870 Monthey, Switzerland
| | - Paco Pino
- ExcellGene SA, CH1870 Monthey, Switzerland
| | | | - Martin Frank
- Biognos AB, Generatorsgatan
1, 41705 Göteborg, Sweden
| | - Bing Chen
- Division
of Molecular Medicine, Boston Children’s
Hospital, 3 Blackfan
Street, Boston, Massachusetts 02115, United States
- Department
of Pediatrics, Harvard Medical School, 3 Blackfan Street, Boston, Massachusetts 02115, United States
| | - David I. Stuart
- Division
of Structural Biology, University of Oxford,
The Wellcome Centre for Human Genetics, Headington, Oxford OX3 7BN, U.K.
- Diamond Light Source Ltd., Harwell Science
& Innovation Campus, Didcot OX11 0DE, U.K.
| | - Rogier W. Sanders
- Department
of Medical Microbiology, Amsterdam UMC,
University of Amsterdam, Amsterdam Infection & Immunity Institute, 1007 MB Amsterdam, The Netherlands
- Department
of Microbiology and Immunology, Weill Medical
College of Cornell University, New York, New York 10065, United States
| | - Raiees Andrabi
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
- IAVI
Neutralizing Antibody Center, The Scripps
Research Institute, La Jolla, California 92037, United States
- Consortium
for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California 92037, United States
| | - Dennis R. Burton
- Department
of Immunology and Microbiology, The Scripps
Research Institute, La Jolla, California 92037, United States
- IAVI
Neutralizing Antibody Center, The Scripps
Research Institute, La Jolla, California 92037, United States
- Consortium
for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California 92037, United States
- Ragon Institute of Massachusetts General
Hospital, Massachusetts
Institute of Technology, and Harvard University, Cambridge, Massachusetts 02139, United States
| | - Sai Li
- Tsinghua-Peking
Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Beijing
Advanced Innovation Center for Structural Biology and Frontier Research
Center for Biological Structure, Beijing 100084, China
| | - Peter J. Bond
- Bioinformatics
Institute, Agency for Science, Technology
and Research (A*STAR), Singapore 138671
- Department
of Biological Sciences, National University
of Singapore, Singapore 117543
| | - Max Crispin
- School
of Biological Sciences, University of Southampton, Southampton SO17 1BJ, U.K.
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8
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Allen JD, Chawla H, Samsudin F, Zuzic L, Shivgan AT, Watanabe Y, He WT, Callaghan S, Song G, Yong P, Brouwer PJM, Song Y, Cai Y, Duyvesteyn HME, Malinauskas T, Kint J, Pino P, Wurm MJ, Frank M, Chen B, Stuart DI, Sanders RW, Andrabi R, Burton DR, Li S, Bond PJ, Crispin M. Site-specific steric control of SARS-CoV-2 spike glycosylation. bioRxiv 2021:2021.03.08.433764. [PMID: 33758835 PMCID: PMC7986994 DOI: 10.1101/2021.03.08.433764] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
A central tenet in the design of vaccines is the display of native-like antigens in the elicitation of protective immunity. The abundance of N-linked glycans across the SARS-CoV-2 spike protein is a potential source of heterogeneity between the many different vaccine candidates under investigation. Here, we investigate the glycosylation of recombinant SARS-CoV-2 spike proteins from five different laboratories and compare them against infectious virus S protein. We find patterns which are conserved across all samples and this can be associated with site-specific stalling of glycan maturation which act as a highly sensitive reporter of protein structure. Molecular dynamics (MD) simulations of a fully glycosylated spike support s a model of steric restrictions that shape enzymatic processing of the glycans. These results suggest that recombinant spike-based SARS-CoV-2 immunogen glycosylation reproducibly recapitulates signatures of viral glycosylation.
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9
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Zuzic L, Marzinek JK, Warwicker J, Bond PJ. A Benzene-Mapping Approach for Uncovering Cryptic Pockets in Membrane-Bound Proteins. J Chem Theory Comput 2020; 16:5948-5959. [PMID: 32786908 DOI: 10.1021/acs.jctc.0c00370] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular dynamics (MD) simulations in combination with small organic probes present in the solvent have previously been used as a method to reveal cryptic pockets that may not have been identified in experimental structures. We report such a method implemented within the CHARMM force field using the GROMACS simulation package to effectively explore cryptic pockets on the surfaces of membrane-embedded proteins using benzene as a probe molecule. This method, for which we have made implementation files freely available, relies on modified nonbonded parameters in addition to repulsive potentials between membrane lipids and benzene molecules. The method was tested on part of the outer shell of the dengue virus (DENV), for which research into a safe and effective neutralizing antibody or drug molecule is still ongoing. In particular, the envelope (E) protein, associated with the membrane (M) protein, is a lipid membrane-embedded complex which forms a dimer in the mature viral envelope. Solvent mapping was performed for the full, membrane-embedded EM protein complex and compared with similar calculations performed for the isolated, soluble E protein ectodomain dimer in the solvent. Ectodomain-only simulations with benzene exhibited unfolding effects not observed in the more physiologically relevant membrane-associated systems. A cryptic pocket which has been experimentally shown to bind n-octyl-β-d-glucoside detergent was consistently revealed in all benzene-containing simulations. The addition of benzene also enhanced the flexibility and hydrophobic exposure of cryptic pockets at a key, functional interface in the E protein and revealed a novel, potentially druggable pocket that may be targeted to prevent conformational changes associated with viral entry into the cell.
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Affiliation(s)
- Lorena Zuzic
- Bioinformatics Institute (A*STAR), 30 Biopolis Street, 07-01 Matrix, Singapore 138671, Singapore.,Department of Chemistry, Faculty of Science and Engineering, Manchester Institute of Biotechnology, The University of Manchester, Manchester M1 7DN, United Kingdom
| | - Jan K Marzinek
- Bioinformatics Institute (A*STAR), 30 Biopolis Street, 07-01 Matrix, Singapore 138671, Singapore
| | - Jim Warwicker
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Institute of Biotechnology, The University of Manchester, Manchester M1 7DN, United Kingdom
| | - Peter J Bond
- Bioinformatics Institute (A*STAR), 30 Biopolis Street, 07-01 Matrix, Singapore 138671, Singapore.,Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore 117558, Singapore
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