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Su Y, Liu B, Huang Z, Teng Z, Yang L, Zhu J, Huo S, Liu A. Virus-like particles nanoreactors: from catalysis towards bio-applications. J Mater Chem B 2023; 11:9084-9098. [PMID: 37697810 DOI: 10.1039/d3tb01112g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/13/2023]
Abstract
Virus-like particles (VLPs) are self-assembled supramolecular structures found in nature, often used for compartmentalization. Exploiting their inherent properties, including precise nanoscale structures, monodispersity, and high stability, these architectures have been widely used as nanocarriers to protect or enrich catalysts, facilitating catalytic reactions and avoiding interference from the bulk solutions. In this review, we summarize the current progress of virus-like particles (VLPs)-based nanoreactors. First, we briefly introduce the physicochemical properties of the most commonly used virus particles to understand their roles in catalytic reactions beyond the confined space. Next, we summarize the self-assembly of nanoreactors forming higher-order hierarchical structures, highlighting the emerging field of nanoreactors as artificial organelles and their potential biomedical applications. Finally, we discuss the current findings and future perspectives of VLPs-based nanoreactors.
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Affiliation(s)
- Yuqing Su
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen 361102, China.
| | - Beibei Liu
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen 361102, China.
| | - Zhenkun Huang
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen 361102, China.
| | - Zihao Teng
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen 361102, China.
| | - Liulin Yang
- State Key Laboratory of Physical Chemistry of Solid Surface, Key Laboratory of Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
| | - Jie Zhu
- National-Local Joint Engineering Research and High-Quality Utilization, Changzhou University, Changzhou 213164, China
| | - Shuaidong Huo
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen 361102, China.
| | - Aijie Liu
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University, Xiamen 361102, China.
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2
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Harder OF, Barrass SV, Drabbels M, Lorenz UJ. Fast viral dynamics revealed by microsecond time-resolved cryo-EM. Nat Commun 2023; 14:5649. [PMID: 37704664 PMCID: PMC10499870 DOI: 10.1038/s41467-023-41444-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 09/01/2023] [Indexed: 09/15/2023] Open
Abstract
Observing proteins as they perform their tasks has largely remained elusive, which has left our understanding of protein function fundamentally incomplete. To enable such observations, we have recently proposed a technique that improves the time resolution of cryo-electron microscopy (cryo-EM) to microseconds. Here, we demonstrate that microsecond time-resolved cryo-EM enables observations of fast protein dynamics. We use our approach to elucidate the mechanics of the capsid of cowpea chlorotic mottle virus (CCMV), whose large-amplitude motions play a crucial role in the viral life cycle. We observe that a pH jump causes the extended configuration of the capsid to contract on the microsecond timescale. While this is a concerted process, the motions of the capsid proteins involve different timescales, leading to a curved reaction path. It is difficult to conceive how such a detailed picture of the dynamics could have been obtained with any other method, which highlights the potential of our technique. Crucially, our experiments pave the way for microsecond time-resolved cryo-EM to be applied to a broad range of protein dynamics that previously could not have been observed. This promises to fundamentally advance our understanding of protein function.
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Affiliation(s)
- Oliver F Harder
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Molecular Nanodynamics, CH-1015, Lausanne, Switzerland
| | - Sarah V Barrass
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Molecular Nanodynamics, CH-1015, Lausanne, Switzerland
| | - Marcel Drabbels
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Molecular Nanodynamics, CH-1015, Lausanne, Switzerland
| | - Ulrich J Lorenz
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Molecular Nanodynamics, CH-1015, Lausanne, Switzerland.
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3
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Castells-Graells R, Ribeiro JRS, Domitrovic T, Hesketh EL, Scarff CA, Johnson JE, Ranson NA, Lawson DM, Lomonossoff GP. Plant-expressed virus-like particles reveal the intricate maturation process of a eukaryotic virus. Commun Biol 2021; 4:619. [PMID: 34031522 PMCID: PMC8144610 DOI: 10.1038/s42003-021-02134-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 04/20/2021] [Indexed: 11/25/2022] Open
Abstract
Many virus capsids undergo exquisitely choreographed maturation processes in their host cells to produce infectious virions, and these remain poorly understood. As a tool for studying virus maturation, we transiently expressed the capsid protein of the insect virus Nudaurelia capensis omega virus (NωV) in Nicotiana benthamiana and were able to purify both immature procapsids and mature capsids from infiltrated leaves by varying the expression time. Cryo-EM analysis of the plant-produced procapsids and mature capsids to 6.6 Å and 2.7 Å resolution, respectively, reveals that in addition to large scale rigid body motions, internal regions of the subunits are extensively remodelled during maturation, creating the active site required for autocatalytic cleavage and infectivity. The mature particles are biologically active in terms of their ability to lyse membranes and have a structure that is essentially identical to authentic virus. The ability to faithfully recapitulate and visualize a complex maturation process in plants, including the autocatalytic cleavage of the capsid protein, has revealed a ~30 Å translation-rotation of the subunits during maturation as well as conformational rearrangements in the N and C-terminal helical regions of each subunit.
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Affiliation(s)
- Roger Castells-Graells
- Department of Biological Chemistry, John Innes Centre, Colney, UK
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Jonas R S Ribeiro
- Virology Department, Instituto de Microbiologia Paulo de Goes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Tatiana Domitrovic
- Virology Department, Instituto de Microbiologia Paulo de Goes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Emma L Hesketh
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Charlotte A Scarff
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - John E Johnson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Neil A Ranson
- Astbury Centre for Structural Molecular Biology, School of Molecular & Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - David M Lawson
- Department of Biological Chemistry, John Innes Centre, Colney, UK
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4
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Johnson JE, Domitrovic T, Matsui T, Castells-Graells R, Lomonossoff G. Dynamics and stability in the maturation of a eukaryotic virus: a paradigm for chemically programmed large-scale macromolecular reorganization. Arch Virol 2021; 166:1547-1563. [PMID: 33683475 DOI: 10.1007/s00705-021-05007-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 01/02/2021] [Indexed: 12/16/2022]
Abstract
Virus maturation is found in all animal viruses and dsDNA bacteriophages that have been studied. It is a programmed process, cued by cellular environmental factors, that transitions a noninfectious, initial assembly product (provirus) to an infectious particle (virion). Nudaurelia capensis omega virus (NωV) is an ssRNA insect virus with T=4 quasi-symmetry. Over the last 20 years, NωV virus-like particles (VLPs) have been an attractive model for the detailed study of maturation. The novel feature of the system is the progressive transition from procapsid to capsid controlled by pH. Homogeneous populations of maturation intermediates can be readily produced at arbitrary intervals by adjusting the pH between 7.6 and 5.0. These intermediates were investigated using biochemical and biophysical methods to create a stop-frame transition series of this complex process. The studies reviewed here characterized the large-scale subunit reorganization during maturation (the particle changes size from 48 nm to 41 nm) as well as the mechanism of a maturation cleavage, a time-resolved study of cleavage site formation, and specific roles of quasi-equivalent subunits in the release of membrane lytic peptides required for cellular entry.
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Affiliation(s)
- John E Johnson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA, 92037, USA.
| | - Tatiana Domitrovic
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Rio de Janeiro, 21941-902, Brazil
| | - Tsutomu Matsui
- Stanford Synchrotron Radiation Lightsource (SSRL), 2575 Sand Hill Rd, MS69, Menlo Park, CA, 94025, USA
| | - Roger Castells-Graells
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 611 Charles Young Dr. East, Los Angeles, CA, 90095-1569, USA
| | - George Lomonossoff
- John Innes Centre, The John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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5
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Berardi A, Castells-Graells R, Lomonossoff GP. High stability of plant-expressed virus-like particles of an insect virus in artificial gastric and intestinal fluids. Eur J Pharm Biopharm 2020; 155:103-111. [PMID: 32805362 DOI: 10.1016/j.ejpb.2020.08.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 08/04/2020] [Accepted: 08/10/2020] [Indexed: 01/15/2023]
Abstract
The harsh conditions of the gastro-intestinal (GI) milieu pose a major barrier to the oral delivery of protein nanocages. Here we studied the stability of Nudaurelia capensis omega virus (NωV) virus-like particles (VLPs) in simulated GI fluids. NωV VLPs capsids and procapsids were transiently expressed in plants, the VLPs were incubated in various simulated GI fluids and their stability was determined by gel electrophoresis, density gradient ultracentrifugation and transmission electron microscopy (TEM). The results showed that the capsids were highly resistant to simulated gastric fluids at pH ≥ 3. Even under the harshest conditions, which consisted of a pepsin solution at pH 1.2, NωV capsids remained assembled as VLPs, though some digestion of the coat protein occurred. Moreover, 80.8% (±10.2%) stability was measured for NωV capsids upon 4 h incubation in simulated intestinal fluids. The high resistance of this protein cage to digestion and denaturation can be attributed to its distinctively compact structure. The more porous form of the VLPs, the procapsid, was less stable under all conditions. Our results suggest that NωV VLPs capsids are likely to endure transit through the GI tract, designating them as promising candidate protein nanocages for oral drug delivery.
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Affiliation(s)
- Alberto Berardi
- Department of Pharmaceutical Sciences and Pharmaceutics, Faculty of Pharmacy, Applied Science Private University, Amman 11931, Jordan; Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
| | - Roger Castells-Graells
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - George P Lomonossoff
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
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6
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Asor R, Khaykelson D, Ben-Nun-Shaul O, Levi-Kalisman Y, Oppenheim A, Raviv U. pH stability and disassembly mechanism of wild-type simian virus 40. SOFT MATTER 2020; 16:2803-2814. [PMID: 32104873 PMCID: PMC7189960 DOI: 10.1039/c9sm02436k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Viruses are remarkable self-assembled nanobiomaterial-based machines, exposed to a wide range of pH values. Extreme pH values can induce dramatic structural changes, critical for the function of the virus nanoparticles, including assembly and genome uncoating. Tuning cargo-capsid interactions is essential for designing virus-based delivery systems. Here we show how pH controls the structure and activity of wild-type simian virus 40 (wtSV40) and the interplay between its cargo and capsid. Using cryo-TEM and solution X-ray scattering, we found that wtSV40 was stable between pH 5.5 and 9, and only slightly swelled with increasing pH. At pH 3, the particles aggregated, while capsid protein pentamers continued to coat the virus cargo but lost their positional correlations. Infectivity was only partly lost after the particles were returned to pH 7. At pH 10 or higher, the particles were unstable, lost their infectivity, and disassembled. Using time-resolved experiments we discovered that disassembly began by swelling of the particles, poking a hole in the capsid through which the genetic cargo escaped, followed by a slight shrinking of the capsids and complete disassembly. These findings provide insight into the fundamental intermolecular forces, essential for SV40 function, and for designing virus-based nanobiomaterials, including delivery systems and antiviral drugs.
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Affiliation(s)
- Roi Asor
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel.
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7
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Khaykelson D, Raviv U. Studying viruses using solution X-ray scattering. Biophys Rev 2020; 12:41-48. [PMID: 32062837 PMCID: PMC7040123 DOI: 10.1007/s12551-020-00617-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 01/07/2020] [Indexed: 12/23/2022] Open
Abstract
Viruses have been of interest to mankind since their discovery as small infectious agents in the nineteenth century. Because many viruses cause diseases to humans and agriculture, they were rigorously studied for biological and medical purposes. Viruses have remarkable properties such as the symmetry and self-assembly of their protein envelope, maturation into infectious virions, structural stability, and disassembly. Solution X-ray scattering can probe structures and reactions in solutions, down to subnanometer spatial resolution and millisecond temporal resolution. It probes the bulk solution and reveals the average shape and average mass of particles in solution and can be used to study kinetics and thermodynamics of viruses at different stages of their life cycle. Here we review recent work that demonstrates the capabilities of solution X-ray scattering to study in vitro the viral life cycle.
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Affiliation(s)
- Daniel Khaykelson
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 9190401, Israel.
| | - Uri Raviv
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 9190401, Israel.
- Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 9190401, Israel.
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8
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Konarev PV, Svergun DI. Direct shape determination of intermediates in evolving macromolecular solutions from small-angle scattering data. IUCRJ 2018; 5:402-409. [PMID: 30002841 PMCID: PMC6038953 DOI: 10.1107/s2052252518005900] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 04/16/2018] [Indexed: 06/08/2023]
Abstract
Many important biological processes like amyloid formation, viral assembly etc. can be monitored in vitro. Small-angle X-ray scattering (SAXS) is one of the most effective techniques to structurally characterize these processes in solution. For monodisperse systems and some oligomeric mixtures, low-resolution shapes can be determined ab initio from the SAXS data, but for evolving systems, such analysis is hampered by the presence of multiple species and no direct reconstruction procedures are available. The authors consider a frequently occurring case where the scattering from the initial and final states of the process are known but there exists a major (unknown) intermediate component. A method is presented to directly reconstruct the low-resolution shape of this transient component together with its volume fractions from multiple scattering patterns recorded from an evolving system. The method is implemented in the computer program DAMMIX freely available to academic users and its effectiveness is illustrated in several synthetic and experimental examples.
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Affiliation(s)
- Petr V. Konarev
- Laboratory of Reflectometry and Small-angle Scattering, A. V. Shubnikov Institute of Crystallography of Federal Scientific Research Centre ‘Crystallography and Photonics’ of Russian Academy of Sciences, Leninsky pr. 59, Moscow 119333, Russian Federation
- National Research Centre ‘Kurchatov Institute’, Akademika Kurchatova pl. 1, Moscow 123182, Russian Federation
| | - Dmitri I. Svergun
- Hamburg Outstation, European Molecular Biology Laboratory, Notkestrasse 85, Hamburg 22607, Germany
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9
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Thomas M, Schwartz R. A method for efficient Bayesian optimization of self-assembly systems from scattering data. BMC SYSTEMS BIOLOGY 2018; 12:65. [PMID: 29884203 PMCID: PMC5994016 DOI: 10.1186/s12918-018-0592-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/24/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND The ability of collections of molecules to spontaneously assemble into large functional complexes is central to all cellular processes. Using the viral capsid as a model system for complicated macro-molecular assembly, we develop methods for probing fine details of the process by learning kinetic rate parameters consistent with experimental measures of assembly. We have previously shown that local rule based stochastic simulation methods in conjunction with bulk indirect experimental data can meaningfully constrain the space of possible assembly trajectories and allow inference of experimentally unobservable features of the real system. RESULTS In the present work, we introduce a new Bayesian optimization framework using multi-Gaussian process model regression. We also extend our prior work to encompass small-angle X-ray/neutron scattering (SAXS/SANS) as a possibly richer experimental data source than the previously used static light scattering (SLS). Method validation is based on synthetic experiments generated using protein data bank (PDB) structures of cowpea chlorotic mottle virus. We also apply the same approach to computationally cheaper differential equation based simulation models. CONCLUSIONS We present a flexible approach for the global optimization of computationally costly objective functions associated with dynamic, multidimensional models. When applied to the stochastic viral capsid system, our method outperforms a current state of the art black box solver tailored for use with noisy objectives. Our approach also has wide applicability to general stochastic optimization problems.
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Affiliation(s)
- Marcus Thomas
- Computational Biology Department, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, USA
| | - Russell Schwartz
- Computational Biology Department, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, USA. .,Department of Biological Sciences, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, USA.
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10
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Safi M, Domitrovic T, Kapur A, Zhan N, Aldeek F, Johnson JE, Mattoussi H. Intracellular Delivery of Luminescent Quantum Dots Mediated by a Virus-Derived Lytic Peptide. Bioconjug Chem 2016; 28:64-74. [DOI: 10.1021/acs.bioconjchem.6b00609] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Malak Safi
- Florida State University, Department of Chemistry
and Biochemistry, 95 Chieftan
Way, Tallahassee, Florida 32306, United States
| | - Tatiana Domitrovic
- The Scripps Research Institute, Department of
Integrative Structural and Computational Biology, MB31, La Jolla, California 92037, United States
| | | | - Naiqian Zhan
- Florida State University, Department of Chemistry
and Biochemistry, 95 Chieftan
Way, Tallahassee, Florida 32306, United States
| | - Fadi Aldeek
- Florida State University, Department of Chemistry
and Biochemistry, 95 Chieftan
Way, Tallahassee, Florida 32306, United States
| | - John E. Johnson
- The Scripps Research Institute, Department of
Integrative Structural and Computational Biology, MB31, La Jolla, California 92037, United States
| | - Hedi Mattoussi
- Florida State University, Department of Chemistry
and Biochemistry, 95 Chieftan
Way, Tallahassee, Florida 32306, United States
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11
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Doerschuk PC, Gong Y, Xu N, Domitrovic T, Johnson JE. Virus particle dynamics derived from CryoEM studies. Curr Opin Virol 2016; 18:57-63. [DOI: 10.1016/j.coviro.2016.02.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 02/29/2016] [Indexed: 12/13/2022]
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12
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Chaudhuri BN. Emerging applications of small angle solution scattering in structural biology. Protein Sci 2015; 24:267-76. [PMID: 25516491 PMCID: PMC4353354 DOI: 10.1002/pro.2624] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 12/05/2014] [Indexed: 12/12/2022]
Abstract
Small angle solution X-ray and neutron scattering recently resurfaced as powerful tools to address an array of biological problems including folding, intrinsic disorder, conformational transitions, macromolecular crowding, and self or hetero-assembling of biomacromolecules. In addition, small angle solution scattering complements crystallography, nuclear magnetic resonance spectroscopy, and other structural methods to aid in the structure determinations of multidomain or multicomponent proteins or nucleoprotein assemblies. Neutron scattering with hydrogen/deuterium contrast variation, or X-ray scattering with sucrose contrast variation to a certain extent, is a convenient tool for characterizing the organizations of two-component systems such as a nucleoprotein or a lipid-protein assembly. Time-resolved small and wide-angle solution scattering to study biological processes in real time, and the use of localized heavy-atom labeling and anomalous solution scattering for applications as FRET-like molecular rulers, are amongst promising newer developments. Despite the challenges in data analysis and interpretation, these X-ray/neutron solution scattering based approaches hold great promise for understanding a wide variety of complex processes prevalent in the biological milieu.
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Affiliation(s)
- Barnali N Chaudhuri
- Faculty of Life Sciences and Biotechnology, South Asian UniversityAkbar Bhawan, Chanakyapuri, New Delhi, India
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13
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Berman HM, Gabanyi MJ, Groom CR, Johnson JE, Murshudov GN, Nicholls RA, Reddy V, Schwede T, Zimmerman MD, Westbrook J, Minor W. Data to knowledge: how to get meaning from your result. IUCRJ 2015; 2:45-58. [PMID: 25610627 PMCID: PMC4285880 DOI: 10.1107/s2052252514023306] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 10/22/2014] [Indexed: 05/19/2023]
Abstract
Structural and functional studies require the development of sophisticated 'Big Data' technologies and software to increase the knowledge derived and ensure reproducibility of the data. This paper presents summaries of the Structural Biology Knowledge Base, the VIPERdb Virus Structure Database, evaluation of homology modeling by the Protein Model Portal, the ProSMART tool for conformation-independent structure comparison, the LabDB 'super' laboratory information management system and the Cambridge Structural Database. These techniques and technologies represent important tools for the transformation of crystallographic data into knowledge and information, in an effort to address the problem of non-reproducibility of experimental results.
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Affiliation(s)
- Helen M. Berman
- Center for Integrative Proteomics Research, Department of Chemistry and Chemical Biology, Rutgers, State University of New Jersey, Piscataway, NJ 08854, USA
| | - Margaret J. Gabanyi
- Center for Integrative Proteomics Research, Department of Chemistry and Chemical Biology, Rutgers, State University of New Jersey, Piscataway, NJ 08854, USA
| | - Colin R. Groom
- Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, England
| | - John E. Johnson
- Department of Integrative Structural and Computational Biology, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Garib N. Murshudov
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, England
| | - Robert A. Nicholls
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, England
| | - Vijay Reddy
- Department of Integrative Structural and Computational Biology, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Torsten Schwede
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, 4056 Basel, Switzerland
- SIB-Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Matthew D. Zimmerman
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA
| | - John Westbrook
- Center for Integrative Proteomics Research, Department of Chemistry and Chemical Biology, Rutgers, State University of New Jersey, Piscataway, NJ 08854, USA
| | - Wladek Minor
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA
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14
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Abstract
As they mature, many capsids undergo massive conformational changes that transform their stability, reactivity, and capacity for DNA. In some cases, maturation proceeds via one or more intermediate states. These structures represent local minima in a rich energy landscape that combines contributions from subunit folding, association of subunits into capsomers, and intercapsomer interactions. We have used scanning calorimetry and cryo-electron microscopy to explore the range of capsid conformations accessible to bacteriophage HK97. To separate conformational effects from those associated with covalent cross-linking (a stabilization mechanism of HK97), a cross-link-incompetent mutant was used. The mature capsid Head I undergoes an endothermic phase transition at 60°C in which it shrinks by 7%, primarily through changes in its hexamer conformation. The transition is reversible, with a half-life of ~3 min; however, >50% of reverted capsids are severely distorted or ruptured. This observation implies that such damage is a potential hazard of large-scale structural changes such as those involved in maturation. Assuming that the risk is lower for smaller changes, this suggests a rationalization for the existence of metastable intermediates: that they serve as stepping stones that preserve capsid integrity as it switches between the radically different conformations of its precursor and mature states. Large-scale conformational changes are widespread in virus maturation and infection processes. These changes are accompanied by the release of conformational free energy as the virion (or fusogenic glycoprotein) switches from a precursor state to its mature state. Each state corresponds to a local minimum in an energy landscape. The conformational changes in capsid maturation are so radical that the question arises of how maturing capsids avoid being torn apart. Offering proof of principle, severe damage is inflicted when a bacteriophage HK97 capsid reverts from the (nonphysiological) state that it enters when heated past 60°C. We suggest that capsid proteins have been selected in part by the criterion of being able to avoid sustaining collateral damage as they mature. One way of achieving this—as with the HK97 capsid—involves breaking the overall transition down into several smaller steps in which the risk of damage is reduced.
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15
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Assembly and maturation of a T = 4 quasi-equivalent virus is guided by electrostatic and mechanical forces. Viruses 2014; 6:3348-62. [PMID: 25153346 PMCID: PMC4147699 DOI: 10.3390/v6083348] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 08/15/2014] [Accepted: 08/18/2014] [Indexed: 11/17/2022] Open
Abstract
Nudaurelia capensis w virus (NωV) is a eukaryotic RNA virus that is well suited for the study of virus maturation. The virus initially assembles at pH 7.6 into a marginally stable 480-Å procapsid formed by 240 copies of a single type of protein subunit. During maturation, which occurs during apoptosis at pH 5.0, electrostatic forces guide subunit trajectories into a robust 410-Å virion that is buttressed by subunit associated molecular switches. We discuss the competing factors in the virus capsid of requiring near-reversible interactions during initial assembly to avoid kinetic traps, while requiring robust stability to survive in the extra-cellular environment. In addition, viruses have a variety of mechanisms to deliver the genome, which must remain off while still inside the infected cell, yet turn on under the proper conditions of infection. We conclude that maturation is the process that provides a solution to these conflicting requirements through a program that is encoded in the procapsid and that leads to stability and infectivity.
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Domitrovic T, Movahed N, Bothner B, Matsui T, Wang Q, Doerschuk PC, Johnson JE. Virus assembly and maturation: auto-regulation through allosteric molecular switches. J Mol Biol 2013; 425:1488-96. [PMID: 23485419 PMCID: PMC3664304 DOI: 10.1016/j.jmb.2013.02.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 02/15/2013] [Accepted: 02/16/2013] [Indexed: 11/24/2022]
Abstract
We generalize the concept of allostery from the traditional non-active-site control of enzymes to virus maturation. Virtually, all animal viruses transition from a procapsid noninfectious state to a mature infectious state. The procapsid contains an encoded chemical program that is executed following an environmental cue. We developed an exceptionally accessible virus system for the study of the activators of maturation and the downstream consequences that result in particle stability and infectivity. Nudaurelia capensis omega virus (NωV) is a T=4 icosahedral virus that undergoes a dramatic maturation in which the 490-Å spherical procapsid condenses to a 400-Å icosahedral-shaped capsid with associated specific auto-proteolysis and stabilization. Employing X-ray crystallography, time-resolved electron cryo-microscopy and hydrogen/deuterium exchange as well as biochemistry, it was possible to define the mechanisms of allosteric communication among the four quasi-equivalent subunits in the icosahedral asymmetric unit. These gene products undergo proteolysis at different rates, dependent on quaternary structure environment, while particle stability is conferred globally following only a few local subunit transitions. We show that there is a close similarity between the concepts of tensegrity (associated with geodesic domes and mechanical engineering) and allostery (associated with biochemical control mechanisms).
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Affiliation(s)
- Tatiana Domitrovic
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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17
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Abstract
This is a personal history of my structural studies of icosahedral viruses that evolved from crystallographic studies, to hybrid methods with electron cryo-microscopy and image reconstruction (cryoEM) and then developed further by incorporating a variety of physical methods to augment the high resolution crystallographic studies. It is not meant to be comprehensive, even for my own work, but hopefully provides some perspective on the growth of our understanding of these remarkable biologic assemblies. The goal is to provide a historical perspective for those new to the field and to emphasize the limitations of any one method, even those that provide atomic resolution information about viruses.
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Affiliation(s)
- John E Johnson
- Department of Molecular Biology, MB31, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA.
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Domitrovic T, Matsui T, Johnson JE. Dissecting quasi-equivalence in nonenveloped viruses: membrane disruption is promoted by lytic peptides released from subunit pentamers, not hexamers. J Virol 2012; 86:9976-82. [PMID: 22761380 PMCID: PMC3446560 DOI: 10.1128/jvi.01089-12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 06/28/2012] [Indexed: 11/20/2022] Open
Abstract
Nonenveloped viruses often invade membranes by exposing hydrophobic or amphipathic peptides generated by a proteolytic maturation step that leaves a lytic peptide noncovalently associated with the viral capsid. Since multiple copies of the same protein form many nonenveloped virus capsids, it is unclear if lytic peptides derived from subunits occupying different positions in a quasi-equivalent icosahedral capsid play different roles in host infection. We addressed this question with Nudaurelia capensis omega virus (NωV), an insect RNA virus with an icosahedral capsid formed by protein α, which undergoes autocleavage during maturation, producing the lytic γ peptide. NωV is a unique model because autocatalysis can be precisely initiated in vitro and is sufficiently slow to correlate lytic activity with γ peptide production. Using liposome-based assays, we observed that autocatalysis is essential for the potent membrane disruption caused by NωV. We observed that lytic activity is acquired rapidly during the maturation program, reaching 100% activity with less than 50% of the subunits cleaved. Previous time-resolved structural studies of partially mature NωV particles showed that, during this time frame, γ peptides derived from the pentamer subunits are produced and are organized in a vertical helical bundle that is projected toward the particle surface, while identical polypeptides in quasi-equivalent subunits are produced later or are in positions inappropriate for release. Our functional data provide experimental support for the hypothesis that pentamers containing a central helical bundle, observed in different nonenveloped virus families, are a specialized lytic motif.
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Affiliation(s)
- Tatiana Domitrovic
- Department of Molecular Biology, The Scripps Research Institute, La Jolla California, USA
| | - Tsutomu Matsui
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California, USA
| | - John E. Johnson
- Department of Molecular Biology, The Scripps Research Institute, La Jolla California, USA
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Lander GC, Saibil HR, Nogales E. Go hybrid: EM, crystallography, and beyond. Curr Opin Struct Biol 2012; 22:627-35. [PMID: 22835744 DOI: 10.1016/j.sbi.2012.07.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 06/21/2012] [Accepted: 07/09/2012] [Indexed: 01/30/2023]
Abstract
A mechanistic understanding of the molecular transactions that govern cellular function requires knowledge of the dynamic organization of the macromolecular machines involved in these processes. Structural biologists employ a variety of biophysical methods to study large macromolecular complexes, but no single technique is likely to provide a complete description of the structure-function relationship of all the constituent components. Since structural studies generally only provide snapshots of these dynamic machines as they accomplish their molecular functions, combining data from many methodologies is crucial to our understanding of molecular function.
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Affiliation(s)
- Gabriel C Lander
- Life Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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Schneidman-Duhovny D, Kim SJ, Sali A. Integrative structural modeling with small angle X-ray scattering profiles. BMC STRUCTURAL BIOLOGY 2012; 12:17. [PMID: 22800408 PMCID: PMC3427135 DOI: 10.1186/1472-6807-12-17] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 07/16/2012] [Indexed: 01/24/2023]
Abstract
Recent technological advances enabled high-throughput collection of Small Angle X-ray Scattering (SAXS) profiles of biological macromolecules. Thus, computational methods for integrating SAXS profiles into structural modeling are needed more than ever. Here, we review specifically the use of SAXS profiles for the structural modeling of proteins, nucleic acids, and their complexes. First, the approaches for computing theoretical SAXS profiles from structures are presented. Second, computational methods for predicting protein structures, dynamics of proteins in solution, and assembly structures are covered. Third, we discuss the use of SAXS profiles in integrative structure modeling approaches that depend simultaneously on several data types.
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Affiliation(s)
- Dina Schneidman-Duhovny
- Department of Bioengineering and Therapeutic Sciences, University of California at San Francisco, San Francisco, USA.
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21
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ElSawy KM, Twarock R, Verma CS, Caves LSD. Peptide inhibitors of viral assembly: a novel route to broad-spectrum antivirals. J Chem Inf Model 2012; 52:770-6. [PMID: 22390317 DOI: 10.1021/ci200467s] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated the potential of small peptide segments to function as broad-spectrum antiviral drug leads. We extracted the α-helical peptide segments that share common secondary-structure environments in the capsid protein-protein interfaces of three unrelated virus classes (PRD1-like, HK97-like, and BTV-like) that encompass different levels of pathogenicity to humans, animals, and plants. The potential for the binding of these peptides to the individual capsid proteins was then investigated using blind docking simulations. Most of the extracted α-helical peptides were found to interact favorably with one or more of the protein-protein interfaces within the capsid in all three classes of virus. Moreover, binding of these peptides to the interface regions was found to block one or more of the putative "hot spot" regions on the protein interface, thereby providing the potential to disrupt virus capsid assembly via competitive interaction with other capsid proteins. In particular, binding of the GDFNALSN peptide was found to block interface "hot spot" regions in most of the viruses, providing a potential lead for broad-spectrum antiviral drug therapy.
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Affiliation(s)
- Karim M ElSawy
- York Centre for Complex Systems Analysis (YCCSA), University of York, York YO10 5YW, UK
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Abstract
We examine virus maturation of selected nonenveloped and enveloped single-stranded RNA viruses, retroviruses, bacteriophages, and herpesviruses. Processes associated with maturation in the RNA viruses range from subtle (nodaviruses and picornaviruses) to dramatic (tetraviruses and togaviruses). The elaborate assembly and maturation pathway of HIV is discussed in contrast to the less sophisticated but highly efficient processes associated with togaviruses. Bacteriophage assembly and maturation are discussed in general terms, with specific examples chosen for emphasis. Finally the herpesviruses are compared with bacteriophages. The data support divergent evolution of nodaviruses, picornaviruses, and tetraviruses from a common ancestor and divergent evolution of alphaviruses and flaviviruses from a common ancestor. Likewise, bacteriophages and herpesviruses almost certainly share a common ancestor in their evolution. Comparing all the viruses, we conclude that maturation is a convergent process that is required to solve conflicting requirements in biological dynamics and function.
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Affiliation(s)
- David Veesler
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
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Subunits fold at position-dependent rates during maturation of a eukaryotic RNA virus. Proc Natl Acad Sci U S A 2010; 107:14111-5. [PMID: 20660783 DOI: 10.1073/pnas.1004221107] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Effective antiviral agents are difficult to develop because of the close relationship between the cell biology of the virus and host. However, viral capsid maturation, the in vivo process where the particle transitions from a noninfectious provirion to an infectious virion, is an ideal process to interrupt because the provirion is usually fragile and the conversion to the virion often involves large conformational changes and autocatalytic chemistry that can be hampered by small molecules. The Nudaurelia capensis omega virus (N omegaV) is one of the few eukaryotic viruses where this process can be investigated in vitro with a variety of biophysical methods, allowing fundamental chemical and structural principles of the maturation to be established. It has a T = 4 quasi-equivalent capsid with a dramatic maturation pathway that includes a particle size reduction of 100 A and an autocatalytic cleavage. Here we use cryo-EM and difference maps, computed at three time points following maturation initiation, to show that regions of N omegaV subunit folding are maturation dependent and occur at rates determined by their quasi-equivalent position in the capsid, explaining the unusual kinetics of the maturation cleavage. This study shows that folding is rapid and peptide chain self-cleavage occurs early for subunits adjacent to 3-fold and 5-fold icosahedral symmetry elements and that folding is slower in regions where molecular switches are required for the formation of the proper interfacial contacts. The results connect viral maturation to the well-studied assembly-dependent folding that occurs in the formation of cellular complexes.
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