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Rodríguez-Espinosa MJ, Rodríguez JM, Castón JR, de Pablo PJ. Mechanical disassembly of human picobirnavirus like particles indicates that cargo retention is tuned by the RNA-coat protein interaction. NANOSCALE HORIZONS 2023; 8:1665-1676. [PMID: 37842804 DOI: 10.1039/d3nh00195d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Here we investigate the cargo retention of individual human picobirnavirus (hPBV) virus-like particles (VLPs) which differ in the N-terminal of their capsid protein (CP): (i) hPBV CP contains the full-length CP sequence; (ii) hPBV Δ45-CP lacks the first 45 N-terminal residues; and (iii) hPBV Ht-CP is the full-length CP with a N-terminal 36-residue tag that includes a 6-His segment. Consequently, each VLP variant holds a different interaction with the ssRNA cargo. We used atomic force microscopy (AFM) to induce and monitor the mechanical disassembly of individual hPBV particles. First, while Δ45-CP particles that lack ssRNA allowed a fast tip indentation after breakage, CP and Ht-CP particles that pack heterologous ssRNA showed a slower tip penetration after being fractured. Second, mechanical fatigue experiments revealed that the increased length in 8% of the N-terminal (Ht-CP) makes the virus particles to crumble ∼10 times slower than the wild type N-terminal CP, indicating enhanced RNA cargo retention. Our results show that the three differentiated N-terminal topologies of the capsid result in distinct cargo release dynamics during mechanical disassembly experiments because of the different interaction with RNA.
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Affiliation(s)
- María J Rodríguez-Espinosa
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain.
| | - Javier M Rodríguez
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain.
| | - José R Castón
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain.
- Nanobiotechnology Associated Unit CNB-CSIC-IMDEA, Campus Cantoblanco, 28049 Madrid, Spain
| | - Pedro J de Pablo
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
- Instituto de Física de la Materia Condensada (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
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2
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Clark AB, Safdari M, Zoorob S, Zandi R, van der Schoot P. Relaxational dynamics of the T-number conversion of virus capsids. J Chem Phys 2023; 159:084904. [PMID: 37610017 DOI: 10.1063/5.0160822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 08/07/2023] [Indexed: 08/24/2023] Open
Abstract
We extend a recently proposed kinetic theory of virus capsid assembly based on Model A kinetics and study the dynamics of the interconversion of virus capsids of different sizes triggered by a quench, that is, by sudden changes in the solution conditions. The work is inspired by in vitro experiments on functionalized coat proteins of the plant virus cowpea chlorotic mottle virus, which undergo a reversible transition between two different shell sizes (T = 1 and T = 3) upon changing the acidity and salinity of the solution. We find that the relaxation dynamics are governed by two time scales that, in almost all cases, can be identified as two distinct processes. Initially, the monomers and one of the two types of capsids respond to the quench. Subsequently, the monomer concentration remains essentially constant, and the conversion between the two capsid species completes. In the intermediate stages, a long-lived metastable steady state may present itself, where the thermodynamically less stable species predominate. We conclude that a Model A based relaxational model can reasonably describe the early and intermediate stages of the conversion experiments. However, it fails to provide a good representation of the time evolution of the state of assembly of the coat proteins in the very late stages of equilibration when one of the two species disappears from the solution. It appears that explicitly incorporating the nucleation barriers to assembly and disassembly is crucial for an accurate description of the experimental findings, at least under conditions where these barriers are sufficiently large.
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Affiliation(s)
- Alexander Bryan Clark
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Mohammadamin Safdari
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Selim Zoorob
- Biophysics Graduate Program, University of California, Riverside, California 92521, USA
| | - Roya Zandi
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
- Biophysics Graduate Program, University of California, Riverside, California 92521, USA
| | - Paul van der Schoot
- Department of Applied Physics and Science Education, Eindhoven University of Technology, Postbus 513, 5600 MB Eindhoven, The Netherlands
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3
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Muhren HJ, van der Schoot P. Electrostatic Theory of the Acidity of the Solution in the Lumina of Viruses and Virus-Like Particles. J Phys Chem B 2023; 127:2160-2168. [PMID: 36881522 PMCID: PMC10026070 DOI: 10.1021/acs.jpcb.2c08604] [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: 03/08/2023]
Abstract
Recently, Maassen et al. measured an appreciable pH difference between the bulk solution and the solution in the lumen of virus-like particles, self-assembled in an aqueous buffer solution containing the coat proteins of a simple plant virus and polyanions (Maassen, S. J.; et al. Small 2018, 14, 1802081). They attribute this to the Donnan effect, caused by an imbalance between the number of negative charges on the encapsulated polyelectrolyte molecules and the number of positive charges on the RNA binding domains of the coat proteins that make up the virus shell or capsid. By applying Poisson-Boltzmann theory, we confirm this conclusion and show that simple Donnan theory is accurate even for the smallest of viruses and virus-like particles. This, in part, is due to the additional screening caused by the presence of a large number of immobile charges in the cavity of the shell. The presence of a net charge on the outer surface of the capsid we find in practice to not have a large effect on the pH shift. Hence, Donnan theory can indeed be applied to connect the local pH and the amount of encapsulated material. The large shifts up to a full pH unit that we predict must have consequences for applications of virus capsids as nanocontainers in bionanotechnology and artificial cell organelles.
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Affiliation(s)
- H J Muhren
- Soft Matter and Biological Physics, Department of Applied Physics and Science Education, Eindhoven University of Technology, Postbus 513, 5600 MB Eindhoven, The Netherlands
| | - Paul van der Schoot
- Soft Matter and Biological Physics, Department of Applied Physics and Science Education, Eindhoven University of Technology, Postbus 513, 5600 MB Eindhoven, The Netherlands
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4
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Mizrahi I, Bruinsma R, Rudnick J. Spanning tree model and the assembly kinetics of RNA viruses. Phys Rev E 2022; 106:044405. [PMID: 36397584 DOI: 10.1103/physreve.106.044405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 05/17/2022] [Indexed: 06/16/2023]
Abstract
Single-stranded RNA (ssRNA) viruses self-assemble spontaneously in solutions that contain the viral RNA genome molecules and viral capsid proteins. The self-assembly of empty capsids can be understood on the basis of free energy minimization. However, during the self-assembly of complete viral particles in the cytoplasm of an infected cell, the viral genome molecules must be selected from a large pool of very similar host messenger RNA molecules and it is not known whether this also can be understood by free energy minimization. We address this question using a simple mathematical model, the spanning tree model, that was recently proposed for the assembly of small ssRNA viruses. We present a statistical physics analysis of the properties of this model. RNA selection takes place via a kinetic mechanism that operates during the formation of the nucleation complex and that is related to Hopfield kinetic proofreading.
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Affiliation(s)
- Inbal Mizrahi
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Robijn Bruinsma
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA
| | - Joseph Rudnick
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
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5
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Single-particle studies of the effects of RNA-protein interactions on the self-assembly of RNA virus particles. Proc Natl Acad Sci U S A 2022; 119:e2206292119. [PMID: 36122222 PMCID: PMC9522328 DOI: 10.1073/pnas.2206292119] [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] [Indexed: 11/25/2022] Open
Abstract
Understanding the pathways by which simple RNA viruses self-assemble from their coat proteins and RNA is of practical and fundamental interest. Although RNA-protein interactions are thought to play a critical role in the assembly, our understanding of their effects is limited because the assembly process is difficult to observe directly. We address this problem by using interferometric scattering microscopy, a sensitive optical technique with high dynamic range, to follow the in vitro assembly kinetics of more than 500 individual particles of brome mosaic virus (BMV)-for which RNA-protein interactions can be controlled by varying the ionic strength of the buffer. We find that when RNA-protein interactions are weak, BMV assembles by a nucleation-and-growth pathway in which a small cluster of RNA-bound proteins must exceed a critical size before additional proteins can bind. As the strength of RNA-protein interactions increases, the nucleation time becomes shorter and more narrowly distributed, but the time to grow a capsid after nucleation is largely unaffected. These results suggest that the nucleation rate is controlled by RNA-protein interactions, while the growth process is driven less by RNA-protein interactions and more by protein-protein interactions and intraprotein forces. The nucleated pathway observed with the plant virus BMV is strikingly similar to that previously observed with bacteriophage MS2, a phylogenetically distinct virus with a different host kingdom. These results raise the possibility that nucleated assembly pathways might be common to other RNA viruses.
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6
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Shrestha N, Duvall MR, Bujarski JJ. Variability among the Isolates of Broad Bean Mottle Virus and Encapsidation of Host RNAs. Pathogens 2022; 11:pathogens11070817. [PMID: 35890061 PMCID: PMC9321246 DOI: 10.3390/pathogens11070817] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/03/2022] [Accepted: 07/18/2022] [Indexed: 02/05/2023] Open
Abstract
Broad bean mottle bromovirus infects legume plants and is transmissible by insects. Several broad bean mottle virus (BBMV) isolates have been identified, including one in England (isolate Ba) and five in the Mediterranean countries: Libya (LyV), Morocco (MV), Syria (SV), Sudan (TU) and Tunisia (TV). Previously, we analyzed the nucleotide sequence of the Ba RNA and here we report on and compare it with another five Mediterranean variants. The RNA segments in the latter ones were extensively homologous, with some SNPs, single nucleotide deletions and insertions, while the number of mutations was higher in isolate Ba. Both the 5′ and 3′ untranslated terminal regions (UTRs) among the corresponding RNAs are highly conserved, reflecting their functionality in virus replication. The AUG initiation codons are within suboptimal contexts, possibly to adjust/regulate translation. The proteins 1a, 2a, 3a and coat protein (CP) are almost identical among the five isolates, but in Ba they have more amino acid (aa) substitutions. Phylogenetic analysis revealed the isolates from Morocco and Syria clustering with the isolate from England, while the variants from Libya, Tunisia and Sudan created a different clade. The BBMV isolates encapsidate a high content of host (ribosomal and messenger) RNAs. Our studies present BBMV as a useful model for bromoviruses infecting legumes.
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Affiliation(s)
- Nipin Shrestha
- Correspondence: (N.S.); (J.J.B.); Tel.: +1-305-684-2589 (N.S.); +1-815-753-0601 (J.J.B.); Fax: +1-815-753-7855 (J.J.B.)
| | | | - Jozef J. Bujarski
- Correspondence: (N.S.); (J.J.B.); Tel.: +1-305-684-2589 (N.S.); +1-815-753-0601 (J.J.B.); Fax: +1-815-753-7855 (J.J.B.)
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7
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Abstract
Charge detection mass spectrometry (CDMS) is a single-particle technique where the masses of individual ions are determined from simultaneous measurement of their mass-to-charge ratio (m/z) and charge. Masses are determined for thousands of individual ions, and then the results are binned to give a mass spectrum. Using this approach, accurate mass distributions can be measured for heterogeneous and high-molecular-weight samples that are usually not amenable to analysis by conventional mass spectrometry. Recent applications include heavily glycosylated proteins, protein complexes, protein aggregates such as amyloid fibers, infectious viruses, gene therapies, vaccines, and vesicles such as exosomes.
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Affiliation(s)
- Martin F Jarrold
- Chemistry Department, Indiana University, 800 E. Kirkwood Avenue, Bloomington, Indiana 47404, United States
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8
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Edwardson TGW, Levasseur MD, Tetter S, Steinauer A, Hori M, Hilvert D. Protein Cages: From Fundamentals to Advanced Applications. Chem Rev 2022; 122:9145-9197. [PMID: 35394752 DOI: 10.1021/acs.chemrev.1c00877] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Proteins that self-assemble into polyhedral shell-like structures are useful molecular containers both in nature and in the laboratory. Here we review efforts to repurpose diverse protein cages, including viral capsids, ferritins, bacterial microcompartments, and designed capsules, as vaccines, drug delivery vehicles, targeted imaging agents, nanoreactors, templates for controlled materials synthesis, building blocks for higher-order architectures, and more. A deep understanding of the principles underlying the construction, function, and evolution of natural systems has been key to tailoring selective cargo encapsulation and interactions with both biological systems and synthetic materials through protein engineering and directed evolution. The ability to adapt and design increasingly sophisticated capsid structures and functions stands to benefit the fields of catalysis, materials science, and medicine.
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Affiliation(s)
| | | | - Stephan Tetter
- Laboratory of Organic Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Angela Steinauer
- Laboratory of Organic Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Mao Hori
- Laboratory of Organic Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Donald Hilvert
- Laboratory of Organic Chemistry, ETH Zurich, 8093 Zurich, Switzerland
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9
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Mizrahi I, Bruinsma R, Rudnick J. Packaging contests between viral RNA molecules and kinetic selectivity. PLoS Comput Biol 2022; 18:e1009913. [PMID: 35363785 PMCID: PMC9022832 DOI: 10.1371/journal.pcbi.1009913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 04/21/2022] [Accepted: 02/09/2022] [Indexed: 11/18/2022] Open
Abstract
The paper presents a statistical-mechanics model for the kinetic selection of viral RNA molecules by packaging signals during the nucleation stage of the assembly of small RNA viruses. The effects of the RNA secondary structure and folding geometry of the packaging signals on the assembly activation energy barrier are encoded by a pair of characteristics: the wrapping number and the maximum ladder distance. Kinetic selection is found to be optimal when assembly takes place under conditions of supersaturation and also when the concentration ratio of capsid protein and viral RNA concentrations equals the stoichiometric ratio of assembled viral particles. As a function of the height of the activation energy barrier, there is a form of order-disorder transition such that for sufficiently low activation energy barriers, kinetic selectivity is erased by entropic effects associated with the number of assembly pathways.
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Affiliation(s)
- Inbal Mizrahi
- Department of Physics and Astronomy, University of California, Los Angeles, California, United States of America
| | - Robijn Bruinsma
- Department of Physics and Astronomy, University of California, Los Angeles, California, United States of America
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California, United States of America
- * E-mail:
| | - Joseph Rudnick
- Department of Physics and Astronomy, University of California, Los Angeles, California, United States of America
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10
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Bond K, Tsvetkova IB, Wang JCY, Jarrold MF, Dragnea B. Virus Assembly Pathways: Straying Away but Not Too Far. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2004475. [PMID: 33241653 DOI: 10.1002/smll.202004475] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/21/2020] [Indexed: 06/11/2023]
Abstract
Non-enveloped RNA viruses pervade all domains of life. In a cell, they co-assemble from viral RNA and capsid proteins. Virus-like particles can form in vitro where virtually any non-cognate polyanionic cargo can be packaged. How only viral RNA gets selected for packaging in vivo, in presence of myriad other polyanionic species, has been a puzzle. Through a combination of charge detection mass spectrometry and cryo-electron microscopy, it is determined that co-assembling brome mosaic virus (BMV) coat proteins and nucleic acid oligomers results in capsid structures and stoichiometries that differ from the icosahedral virion. These previously unknown shell structures are strained and less stable than the native one. However, they contain large native structure fragments that can be recycled to form BMV virions, should a viral genome become available. The existence of such structures suggest the possibility of a previously unknown regulatory pathway for the packaging process inside cells.
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Affiliation(s)
- Kevin Bond
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
| | - Irina B Tsvetkova
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
| | | | - Martin F Jarrold
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
| | - Bogdan Dragnea
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
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11
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Dong Y, Li S, Zandi R. Effect of the charge distribution of virus coat proteins on the length of packaged RNAs. Phys Rev E 2020; 102:062423. [PMID: 33466113 DOI: 10.1103/physreve.102.062423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/17/2020] [Indexed: 01/20/2023]
Abstract
Single-stranded RNA viruses efficiently encapsulate their genome into a protein shell called the capsid. Electrostatic interactions between the positive charges in the capsid protein's N-terminal tail and the negatively charged genome have been postulated as the main driving force for virus assembly. Recent experimental results indicate that the N-terminal tail with the same number of charges and same lengths packages different amounts of RNA, which reveals that electrostatics alone cannot explain all the observed outcomes of the RNA self-assembly experiments. Using a mean-field theory, we show that the combined effect of genome configurational entropy and electrostatics can explain to some extent the amount of packaged RNA with mutant proteins where the location and number of charges on the tails are altered. Understanding the factors contributing to the virus assembly could promote the attempt to block viral infections or to build capsids for gene therapy applications.
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Affiliation(s)
- Yinan Dong
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Siyu Li
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Roya Zandi
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
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12
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Theoretical Modeling of Chemical Equilibrium in Weak Polyelectrolyte Layers on Curved Nanosystems. Polymers (Basel) 2020; 12:polym12102282. [PMID: 33027995 PMCID: PMC7601300 DOI: 10.3390/polym12102282] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/24/2020] [Accepted: 09/24/2020] [Indexed: 12/19/2022] Open
Abstract
Surface functionalization with end-tethered weak polyelectrolytes (PE) is a versatile way to modify and control surface properties, given their ability to alter their degree of charge depending on external cues like pH and salt concentration. Weak PEs find usage in a wide range of applications, from colloidal stabilization, lubrication, adhesion, wetting to biomedical applications such as drug delivery and theranostics applications. They are also ubiquitous in many biological systems. Here, we present an overview of some of the main theoretical methods that we consider key in the field of weak PE at interfaces. Several applications involving engineered nanoparticles, synthetic and biological nanopores, as well as biological macromolecules are discussed to illustrate the salient features of systems involving weak PE near an interface or under (nano)confinement. The key feature is that by confining weak PEs near an interface the degree of charge is different from what would be expected in solution. This is the result of the strong coupling between structural organization of weak PE and its chemical state. The responsiveness of engineered and biological nanomaterials comprising weak PE combined with an adequate level of modeling can provide the keys to a rational design of smart nanosystems.
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13
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Beren C, Cui Y, Chakravarty A, Yang X, Rao ALN, Knobler CM, Zhou ZH, Gelbart WM. Genome organization and interaction with capsid protein in a multipartite RNA virus. Proc Natl Acad Sci U S A 2020; 117:10673-10680. [PMID: 32358197 PMCID: PMC7245085 DOI: 10.1073/pnas.1915078117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We report the asymmetric reconstruction of the single-stranded RNA (ssRNA) content in one of the three otherwise identical virions of a multipartite RNA virus, brome mosaic virus (BMV). We exploit a sample consisting exclusively of particles with the same RNA content-specifically, RNAs 3 and 4-assembled in planta by agrobacterium-mediated transient expression. We find that the interior of the particle is nearly empty, with most of the RNA genome situated at the capsid shell. However, this density is disordered in the sense that the RNA is not associated with any particular structure but rather, with an ensemble of secondary/tertiary structures that interact with the capsid protein. Our results illustrate a fundamental difference between the ssRNA organization in the multipartite BMV viral capsid and the monopartite bacteriophages MS2 and Qβ for which a dominant RNA conformation is found inside the assembled viral capsids, with RNA density conserved even at the center of the particle. This can be understood in the context of the differing demands on their respective lifecycles: BMV must package separately each of several different RNA molecules and has been shown to replicate and package them in isolated, membrane-bound, cytoplasmic complexes, whereas the bacteriophages exploit sequence-specific "packaging signals" throughout the viral RNA to package their monopartite genomes.
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Affiliation(s)
- Christian Beren
- Department of Chemistry & Biochemistry, University of California, Los Angeles, CA 90095
| | - Yanxiang Cui
- California NanoSystems Institute, University of California, Los Angeles, CA 90095
| | - Antara Chakravarty
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521
| | - Xue Yang
- California NanoSystems Institute, University of California, Los Angeles, CA 90095
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, CA 90095
| | - A L N Rao
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521;
| | - Charles M Knobler
- Department of Chemistry & Biochemistry, University of California, Los Angeles, CA 90095
| | - Z Hong Zhou
- California NanoSystems Institute, University of California, Los Angeles, CA 90095;
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, CA 90095
| | - William M Gelbart
- Department of Chemistry & Biochemistry, University of California, Los Angeles, CA 90095;
- California NanoSystems Institute, University of California, Los Angeles, CA 90095
- Molecular Biology Institute, University of California, Los Angeles, CA 90095
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14
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Viruses with different genome types adopt a similar strategy to pack nucleic acids based on positively charged protein domains. Sci Rep 2020; 10:5470. [PMID: 32214181 PMCID: PMC7096446 DOI: 10.1038/s41598-020-62328-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 03/02/2020] [Indexed: 11/17/2022] Open
Abstract
Capsid proteins often present a positively charged arginine-rich sequence at their terminal regions, which has a fundamental role in genome packaging and particle stability for some icosahedral viruses. These sequences show little to no conservation and are structurally dynamic such that they cannot be easily detected by common sequence or structure comparisons. As a result, the occurrence and distribution of positively charged domains across the viral universe are unknown. Based on the net charge calculation of discrete protein segments, we identified proteins containing amino acid stretches with a notably high net charge (Q > + 17), which are enriched in icosahedral viruses with a distinctive bias towards arginine over lysine. We used viral particle structural data to calculate the total electrostatic charge derived from the most positively charged protein segment of capsid proteins and correlated these values with genome charges arising from the phosphates of each nucleotide. We obtained a positive correlation (r = 0.91, p-value <0001) for a group of 17 viral families, corresponding to 40% of all families with icosahedral structures described to date. These data indicated that unrelated viruses with diverse genome types adopt a common underlying mechanism for capsid assembly based on R-arms.
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15
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Bond KM, Lyktey NA, Tsvetkova IB, Dragnea B, Jarrold MF. Disassembly Intermediates of the Brome Mosaic Virus Identified by Charge Detection Mass Spectrometry. J Phys Chem B 2020; 124:2124-2131. [PMID: 32141748 DOI: 10.1021/acs.jpcb.0c00008] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Capsid disassembly and genome release are critical steps in the lifecycle of a virus. However, their mechanisms are poorly understood, both in vivo and in vitro. Here, we have identified two in vitro disassembly pathways of the brome mosaic virus (BMV) by charge detection mass spectrometry and transmission electron microscopy. When subjected to a pH jump to a basic environment at low ionic strength, protein-RNA interactions are disrupted. Under these conditions, BMV appears to disassemble mainly through a global cleavage event into two main fragments: a near complete capsid that has released the RNA and the released RNA complexed to a small number of the capsid proteins. Upon slow buffer exchange to remove divalent cations at neutral pH, capsid protein interactions are disrupted. The BMV virions swell but there is no measurable loss of the RNA. Some of the virions break into small fragments, leading to an increase in the abundance of species with masses less than 1 MDa. The peak attributed to the BMV virion shifts to a higher mass with time. The mass increase is attributed to additional capsid proteins associating with the disrupted capsid protein-RNA complex, where the RNA is presumably partially exposed. It is likely that this pathway is more closely related to how the capsid disassembles in vivo, as it offers the advantage of protecting the RNA with the capsid protein until translation begins.
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Affiliation(s)
- Kevin M Bond
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Nicholas A Lyktey
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Irina B Tsvetkova
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Bogdan Dragnea
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Martin F Jarrold
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
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16
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Buzón P, Maity S, Roos WH. Physical virology: From virus self-assembly to particle mechanics. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2020; 12:e1613. [PMID: 31960585 PMCID: PMC7317356 DOI: 10.1002/wnan.1613] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 10/01/2019] [Accepted: 12/11/2019] [Indexed: 12/19/2022]
Abstract
Viruses are highly ordered supramolecular complexes that have evolved to propagate by hijacking the host cell's machinery. Although viruses are very diverse, spreading through cells of all kingdoms of life, they share common functions and properties. Next to the general interest in virology, fundamental viral mechanisms are of growing importance in other disciplines such as biomedicine and (bio)nanotechnology. However, in order to optimally make use of viruses and virus-like particles, for instance as vehicle for targeted drug delivery or as building blocks in electronics, it is essential to understand their basic chemical and physical properties and characteristics. In this context, the number of studies addressing the mechanisms governing viral properties and processes has recently grown drastically. This review summarizes a specific part of these scientific achievements, particularly addressing physical virology approaches aimed to understand the self-assembly of viruses and the mechanical properties of viral particles. Using a physicochemical perspective, we have focused on fundamental studies providing an overview of the molecular basis governing these key aspects of viral systems. This article is categorized under: Biology-Inspired Nanomaterials > Protein and Virus-Based Structures Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.
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Affiliation(s)
- Pedro Buzón
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, The Netherlands
| | - Sourav Maity
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, The Netherlands
| | - Wouter H Roos
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, The Netherlands
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Garmann RF, Knobler CM, Gelbart WM. Protocol for Efficient Cell-Free Synthesis of Cowpea Chlorotic Mottle Virus-Like Particles Containing Heterologous RNAs. Methods Mol Biol 2019; 1776:249-265. [PMID: 29869247 DOI: 10.1007/978-1-4939-7808-3_17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report a protocol for efficient cell-free synthesis of cowpea chlorotic mottle virus (CCMV)-like particles containing a broad range of lengths and sequences of RNA. Our protocol starts with a purified stock of wild-type CCMV (protocols for harvesting and purifying the virus are detailed elsewhere) and features three basic steps: disassembly of the CCMV and purification of the capsid protein (CP) from the viral RNA; coassembly of the purified CP and an RNA of choice; and characterization of the assembly products. We highlight several key factors that increase the yield of the assembly reaction: the CP should be uncleaved and sufficiently free of viral RNA; the length of the RNA should be between about 100 and 4000 nucleotides; and the stoichiometry of CP and RNA should be 6-1 by mass. Additionally, we point out that separating the assembly reaction into multiple steps-by successively lowering the ionic strength and then the pH of the assembly buffers-results in the highest yields of well-formed, nuclease-resistant, CCMV-like particles. Finally, we describe methods for characterizing the assembly products using native agarose gel electrophoresis and negative-stain transmission electron microscopy.
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Affiliation(s)
- Rees F Garmann
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA.
| | - Charles M Knobler
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, USA
| | - William M Gelbart
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, USA.,California NanoSystems Institute, UCLA, Los Angeles, CA, USA.,Molecular Biology Institute, UCLA, Los Angeles, CA, USA
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18
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Lošdorfer Božič A, Šiber A. Electrostatics-Driven Inflation of Elastic Icosahedral Shells as a Model for Swelling of Viruses. Biophys J 2018; 115:822-829. [PMID: 30139522 DOI: 10.1016/j.bpj.2018.07.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 07/20/2018] [Accepted: 07/30/2018] [Indexed: 01/13/2023] Open
Abstract
We develop a clear theoretical description of radial swelling in virus-like particles that delineates the importance of electrostatic contributions to swelling in the absence of any conformational changes. The model couples the elastic parameters of the capsid-represented as a continuous elastic shell-to the electrostatic pressure acting on it. We show that different modifications of the electrostatic interactions brought about by, for instance, changes in pH or solution ionic strength are often sufficient to achieve the experimentally observed swelling (∼10% of the capsid radius). Additionally, we derive analytical expressions for the electrostatics-driven radial swelling of virus-like particles that enable one to quickly estimate the magnitudes of physical quantities involved.
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19
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Shrestha N, Weber PH, Burke SV, Wysocki WP, Duvall MR, Bujarski JJ. Next generation sequencing reveals packaging of host RNAs by brome mosaic virus. Virus Res 2018; 252:82-90. [PMID: 29753892 DOI: 10.1016/j.virusres.2018.05.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/05/2018] [Accepted: 05/09/2018] [Indexed: 12/28/2022]
Abstract
Although RNA viruses evolved the mechanisms of specific encapsidation, miss-packaging of cellular RNAs has been reported in such RNA virus systems as flock house virus or cucumber necrosis virus. To find out if brome mosaic virus (BMV), a tripartite RNA virus, can package cellular RNAs, BMV was propagated in barley and in Nicotiana benthamiana hosts, purified by cesium chloride (CsCl) gradient ultracentrifugation followed by nuclease treatment to remove any contaminating cellular (host) RNAs. The extracted virion RNA was then sequenced by using next-generation sequencing (NGS RNA-Seq) with the Illumina protocol. Bioinformatic analysis revealed the content of host RNAs ranging from 0.07% for BMV extracted from barley to 0.10% for the virus extracted from N. benthamiana. The viruses from two sources appeared to co-encapsidate different patterns of host-RNAs, including ribosomal RNAs (rRNAs), messenger RNAs (mRNAs) but also mitochondrial and plastid RNAs and, interestingly, transposable elements, both transposons and retrotransposons. Our data reveal that BMV virions can carry host RNAs, having a potential to mediate horizontal gene transfer (HGT) in plants.
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Affiliation(s)
- N Shrestha
- Department of Biological Sciences and Plant Molecular and Bioinformatics Center, Northern Illinois University, DeKalb, IL 60115, USA
| | - P H Weber
- Department of Biological Sciences and Plant Molecular and Bioinformatics Center, Northern Illinois University, DeKalb, IL 60115, USA.
| | - S V Burke
- Department of Biological Sciences and Plant Molecular and Bioinformatics Center, Northern Illinois University, DeKalb, IL 60115, USA
| | - W P Wysocki
- Department of Biological Sciences and Plant Molecular and Bioinformatics Center, Northern Illinois University, DeKalb, IL 60115, USA.
| | - M R Duvall
- Department of Biological Sciences and Plant Molecular and Bioinformatics Center, Northern Illinois University, DeKalb, IL 60115, USA
| | - J J Bujarski
- Department of Biological Sciences and Plant Molecular and Bioinformatics Center, Northern Illinois University, DeKalb, IL 60115, USA; Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
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20
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Systematic analysis of biological roles of charged amino acid residues located throughout the structured inner wall of a virus capsid. Sci Rep 2018; 8:9543. [PMID: 29934575 PMCID: PMC6015035 DOI: 10.1038/s41598-018-27749-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 06/01/2018] [Indexed: 12/31/2022] Open
Abstract
Structure-based mutational analysis of viruses is providing many insights into the relationship between structure and biological function of macromolecular complexes. We have systematically investigated the individual biological roles of charged residues located throughout the structured capsid inner wall (outside disordered peptide segments) of a model spherical virus, the minute virus of mice (MVM). The functional effects of point mutations that altered the electrical charge at 16 different positions at the capsid inner wall were analyzed. The results revealed that MVM capsid self-assembly is rather tolerant to point mutations that alter the number and distribution of charged residues at the capsid inner wall. However, mutations that either increased or decreased the number of positive charges around capsid-bound DNA segments reduced the thermal resistance of the virion. Moreover, mutations that either removed or changed the positions of negatively charged carboxylates in rings of acidic residues around capsid pores were deleterious by precluding a capsid conformational transition associated to through-pore translocation events. The results suggest that number, distribution and specific position of electrically charged residues across the inner wall of a spherical virus may have been selected through evolution as a compromise between several different biological requirements.
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21
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Li S, Orland H, Zandi R. Self consistent field theory of virus assembly. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:144002. [PMID: 29460850 PMCID: PMC7104907 DOI: 10.1088/1361-648x/aab0c6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 02/12/2018] [Accepted: 02/20/2018] [Indexed: 05/04/2023]
Abstract
The ground state dominance approximation (GSDA) has been extensively used to study the assembly of viral shells. In this work we employ the self-consistent field theory (SCFT) to investigate the adsorption of RNA onto positively charged spherical viral shells and examine the conditions when GSDA does not apply and SCFT has to be used to obtain a reliable solution. We find that there are two regimes in which GSDA does work. First, when the genomic RNA length is long enough compared to the capsid radius, and second, when the interaction between the genome and capsid is so strong that the genome is basically localized next to the wall. We find that for the case in which RNA is more or less distributed uniformly in the shell, regardless of the length of RNA, GSDA is not a good approximation. We observe that as the polymer-shell interaction becomes stronger, the energy gap between the ground state and first excited state increases and thus GSDA becomes a better approximation. We also present our results corresponding to the genome persistence length obtained through the tangent-tangent correlation length and show that it is zero in case of GSDA but is equal to the inverse of the energy gap when using SCFT.
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Affiliation(s)
- Siyu Li
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, United States of America
- Institut de Physique Théorique, CEA-Saclay, CEA, F-91191 Gif-sur-Yvette, France
- Beijing Computational Science Research Center, No.10 East Xibeiwang Road, Haidan District, Beijing 100193, People’s Republic of China
| | - Henri Orland
- Institut de Physique Théorique, CEA-Saclay, CEA, F-91191 Gif-sur-Yvette, France
- Beijing Computational Science Research Center, No.10 East Xibeiwang Road, Haidan District, Beijing 100193, People’s Republic of China
| | - Roya Zandi
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, United States of America
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Intrinsically-disordered N-termini in human parechovirus 1 capsid proteins bind encapsidated RNA. Sci Rep 2018; 8:5820. [PMID: 29643409 PMCID: PMC5895611 DOI: 10.1038/s41598-018-23552-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 03/15/2018] [Indexed: 12/22/2022] Open
Abstract
Human parechoviruses (HPeV) are picornaviruses with a highly-ordered RNA genome contained within icosahedrally-symmetric capsids. Ordered RNA structures have recently been shown to interact with capsid proteins VP1 and VP3 and facilitate virus assembly in HPeV1. Using an assay that combines reversible cross-linking, RNA affinity purification and peptide mass fingerprinting (RCAP), we mapped the RNA-interacting regions of the capsid proteins from the whole HPeV1 virion in solution. The intrinsically-disordered N-termini of capsid proteins VP1 and VP3, and unexpectedly, VP0, were identified to interact with RNA. Comparing these results to those obtained using recombinantly-expressed VP0 and VP1 confirmed the virion binding regions, and revealed unique RNA binding regions in the isolated VP0 not previously observed in the crystal structure of HPeV1. We used RNA fluorescence anisotropy to confirm the RNA-binding competency of each of the capsid proteins’ N-termini. These findings suggests that dynamic interactions between the viral RNA and the capsid proteins modulate virus assembly, and suggest a novel role for VP0.
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23
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van der Holst B, Kegel WK, Zandi R, van der Schoot P. The different faces of mass action in virus assembly. J Biol Phys 2018; 44:163-179. [PMID: 29616429 PMCID: PMC5928020 DOI: 10.1007/s10867-018-9487-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 03/16/2018] [Indexed: 02/06/2023] Open
Abstract
The spontaneous encapsulation of genomic and non-genomic polyanions by coat proteins of simple icosahedral viruses is driven, in the first instance, by electrostatic interactions with polycationic RNA binding domains on these proteins. The efficiency with which the polyanions can be encapsulated in vitro, and presumably also in vivo, must in addition be governed by the loss of translational and mixing entropy associated with co-assembly, at least if this co-assembly constitutes a reversible process. These forms of entropy counteract the impact of attractive interactions between the constituents and hence they counteract complexation. By invoking mass action-type arguments and a simple model describing electrostatic interactions, we show how these forms of entropy might settle the competition between negatively charged polymers of different molecular weights for co-assembly with the coat proteins. In direct competition, mass action turns out to strongly work against the encapsulation of RNAs that are significantly shorter, which is typically the case for non-viral (host) RNAs. We also find that coat proteins favor forming virus particles over nonspecific binding to other proteins in the cytosol even if these are present in vast excess. Our results rationalize a number of recent in vitro co-assembly experiments showing that short polyanions are less effective at attracting virus coat proteins to form virus-like particles than long ones do, even if both are present at equal weight concentrations in the assembly mixture.
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Affiliation(s)
- Bart van der Holst
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Willem K Kegel
- Department of Chemistry, Utrecht University, Utrecht, The Netherlands
| | - Roya Zandi
- Department of Physics and Astronomy, University of California Riverside, Riverside, USA
| | - Paul van der Schoot
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands. .,Institute for Theoretical Physics, Utrecht University, Utrecht, The Netherlands.
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24
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Lošdorfer Božič A, Micheletti C, Podgornik R, Tubiana L. Compactness of viral genomes: effect of disperse and localized random mutations. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:084006. [PMID: 29334364 PMCID: PMC7104904 DOI: 10.1088/1361-648x/aaa7b0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/29/2017] [Accepted: 01/15/2018] [Indexed: 06/07/2023]
Abstract
Genomes of single-stranded RNA viruses have evolved to optimize several concurrent properties. One of them is the architecture of their genomic folds, which must not only feature precise structural elements at specific positions, but also allow for overall spatial compactness. The latter was shown to be disrupted by random synonymous mutations, a disruption which can consequently negatively affect genome encapsidation. In this study, we use three mutation schemes with different degrees of locality to mutate the genomes of phage MS2 and Brome Mosaic virus in order to understand the observed sensitivity of the global compactness of their folds. We find that mutating local stretches of their genomes' sequence or structure is less disruptive to their compactness compared to inducing randomly-distributed mutations. Our findings are indicative of a mechanism for the conservation of compactness acting on a global scale of the genomes, and have several implications for understanding the interplay between local and global architecture of viral RNA genomes.
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Affiliation(s)
- Anže Lošdorfer Božič
- Department of Theoretical Physics, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | | | - Rudolf Podgornik
- Department of Theoretical Physics, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
- Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Luca Tubiana
- Faculty of Physics, University of Vienna, A-1090 Vienna, Austria
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25
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Lošdorfer BoŽič A. From discrete to continuous description of spherical surface charge distributions. SOFT MATTER 2018; 14:1149-1161. [PMID: 29345714 DOI: 10.1039/c7sm02207g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The importance of electrostatic interactions in soft matter and biological systems can often be traced to non-uniform charge effects, which are commonly described using a multipole expansion of the corresponding charge distribution. The standard approach when extracting the charge distribution of a given system is to treat the constituent charges as points. This can, however, lead to an overestimation of multipole moments of high order, such as dipole, quadrupole, and higher moments. Focusing on distributions of charges located on a spherical surface - characteristic of numerous biological macromolecules, such as globular proteins and viral capsids, as well as of inverse patchy colloids - we develop a novel way of representing spherical surface charge distributions based on the von Mises-Fisher distribution. This approach takes into account the finite spatial extension of individual charges, and leads to a simple yet powerful way of describing surface charge distributions and their multipole expansions. In this manner, we analyze charge distributions and the derived multipole moments of a number of different spherical configurations of identical charges with various degrees of symmetry. We show how the number of charges, their size, and the geometry of their configuration influence the behavior and relative importance of multipole magnitudes of different order. Importantly, we clearly demonstrate how neglecting the effect of charge size leads to an overestimation of high-order multipoles. The results of our work can be applied to construct analytical models of electrostatic interactions and multipole expansion of charged particles in diverse soft matter and biological systems.
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26
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Li S, Erdemci-Tandogan G, van der Schoot P, Zandi R. The effect of RNA stiffness on the self-assembly of virus particles. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:044002. [PMID: 29235442 PMCID: PMC7104906 DOI: 10.1088/1361-648x/aaa159] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/06/2017] [Accepted: 12/13/2017] [Indexed: 05/21/2023]
Abstract
Under many in vitro conditions, some small viruses spontaneously encapsidate a single stranded (ss) RNA into a protein shell called the capsid. While viral RNAs are found to be compact and highly branched because of long distance base-pairing between nucleotides, recent experiments reveal that in a head-to-head competition between an ssRNA with no secondary or higher order structure and a viral RNA, the capsid proteins preferentially encapsulate the linear polymer! In this paper, we study the impact of genome stiffness on the encapsidation free energy of the complex of RNA and capsid proteins. We show that an increase in effective chain stiffness because of base-pairing could be the reason why under certain conditions linear chains have an advantage over branched chains when it comes to encapsidation efficiency. While branching makes the genome more compact, RNA base-pairing increases the effective Kuhn length of the RNA molecule, which could result in an increase of the free energy of RNA confinement, that is, the work required to encapsidate RNA, and thus less efficient packaging.
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Affiliation(s)
- Siyu Li
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, United States of America
| | - Gonca Erdemci-Tandogan
- Department of Physics, Syracuse University, Syracuse, NY 13244, United States of America
| | - Paul van der Schoot
- Group Theory of Polymers and Soft Matter, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, Netherlands
- Institute for Theoretical Physics, Utrecht University, Princetonplein 5, 3584 CC Utrecht, Netherlands
| | - Roya Zandi
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, United States of America
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27
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Lošdorfer Božič A, Podgornik R. Varieties of charge distributions in coat proteins of ssRNA+ viruses. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:024001. [PMID: 29182522 PMCID: PMC7104810 DOI: 10.1088/1361-648x/aa9ded] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 11/21/2017] [Accepted: 11/28/2017] [Indexed: 06/07/2023]
Abstract
A major part of the interactions involved in the assembly and stability of icosahedral, positive-sense single-stranded RNA (ssRNA+) viruses is electrostatic in nature, as can be inferred from the strong pH- and salt-dependence of their assembly phase diagrams. Electrostatic interactions do not act only between the capsid coat proteins (CPs), but just as often provide a significant contribution to the interactions of the CPs with the genomic RNA, mediated to a large extent by positively charged, flexible N-terminal tails of the CPs. In this work, we provide two clear and complementary definitions of an N-terminal tail of a protein, and use them to extract the tail sequences of a large number of CPs of ssRNA+ viruses. We examine the pH-dependent interplay of charge on both tails and CPs alike, and show that-in contrast to the charge on the CPs-the net positive charge on the N-tails persists even to very basic pH values. In addition, we note a limit to the length of the wild-type genomes of those viruses which utilize positively charged tails, when compared to viruses without charged tails and similar capsid size. At the same time, we observe no clear connection between the charge on the N-tails and the genome lengths of the viruses included in our study.
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Affiliation(s)
- Anže Lošdorfer Božič
- Department of Theoretical Physics, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - Rudolf Podgornik
- Department of Theoretical Physics, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
- Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, SI-1000 Ljubljana, Slovenia
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28
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Jacobs A, Hoover H, Smith E, Clemmer DE, Kim CH, Kao CC. The intrinsically disordered N-terminal arm of the brome mosaic virus coat protein specifically recognizes the RNA motif that directs the initiation of viral RNA replication. Nucleic Acids Res 2018; 46:324-335. [PMID: 29140480 PMCID: PMC5758871 DOI: 10.1093/nar/gkx1087] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 09/28/2017] [Accepted: 10/20/2017] [Indexed: 12/18/2022] Open
Abstract
In the brome mosaic virus (BMV) virion, the coat protein (CP) selectively contacts the RNA motifs that regulate translation and RNA replication (Hoover et al., 2016. J. Virol. 90, 7748). We hypothesize that the unstructured N-terminal arm (NTA) of the BMV CP can specifically recognize RNA motifs. Using ion mobility spectrometry-mass spectrometry, we demonstrate that peptides containing the NTA of the CP were found to preferentially bind to an RNA hairpin motif that directs the initiation of BMV RNA synthesis. RNA binding causes the peptide to change from heterogeneous structures to a single family of structures. Fluorescence anisotropy, fluorescence quenching and size exclusion chromatography experiments all confirm that the NTA can specific recognize the RNA motif. The peptide introduced into plants along with BMV virion increased accumulation of the BMV CP and accelerated the rate of minus-strand RNA synthesis. The intrinsically disordered BMV NTA could thus specifically recognize BMV RNAs to affect viral infection.
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Affiliation(s)
- Alexander Jacobs
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Haley Hoover
- Department of Molecular & Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Edward Smith
- Department of Chemistry and Biochemistry, California State University East Bay, Hayward, CA 94542, USA
| | - David E Clemmer
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Chul-Hyun Kim
- Department of Chemistry and Biochemistry, California State University East Bay, Hayward, CA 94542, USA
| | - C Cheng Kao
- Department of Molecular & Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
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29
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Hernandez-Garcia A, Cohen Stuart MA, de Vries R. Templated co-assembly into nanorods of polyanions and artificial virus capsid proteins. SOFT MATTER 2017; 14:132-139. [PMID: 29218341 DOI: 10.1039/c7sm02012k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Recombinant triblock polypeptides C-Sn-B, where C is a 400 amino acid long hydrophilic random coil block, Sn is a multimer of the silk-like octapeptide S = (GAGAGAGQ), and B = K12 is an oligolysine, have previously been shown to encapsulate double stranded DNA into rod-shaped, virus-like particles. In order to gain insight of the co-assembly process, and in order to be able to use these proteins for templating other types of nanorods, we here explore their co-assembly with a range of polyanionic templates: poly(acrylic acids) (PAA) of a wide range of lengths, poly(styrene sulphonate) (PSS) and the stiff anionic polysaccharide xanthan. The formation of the complexes was characterized using Dynamic Light Scattering (DLS), cryogenic Transmission Electronic Microscopy (Cryo-TEM) and Atomic Force Microscopy (AFM). Except at very high molar masses, we find that flexible anionic PAA and PSS lead to co-assembly of proteins with single polyanion chains into nanorods, with a packing factor as expected on the basis of charge stochiometry. Only for very long PAA templates (8 × 105 Da) we find evidence for heterogeneous complexes with thin and thick sections. For the very stiff xanthan chains, we find that its stiffness precludes co-assembly with the artificial viral capsid proteins into condensed and regular nanorods. Given the simple and robust formation of rod-like structures with a range of polyanionic templates, we anticipate that the artificial virus proteins will be useful for preparing high-aspect ratio nanoparticles and scaffolds of precise size and find applications in nanotechnology and materials science for which currently natural rod-like viruses are being explored.
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Affiliation(s)
- A Hernandez-Garcia
- Laboratory of Physical Chemistry and Soft Matter, Wageningen University and Research Centre, Wageningen, The Netherlands
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30
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Angelescu DG. Role of polyion length in the co-assembly of stoichiometric viral-like nanoparticles. JOURNAL OF POLYMER RESEARCH 2017. [DOI: 10.1007/s10965-017-1416-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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31
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Rayaprolu V, Moore A, Wang JCY, Goh BC, Perilla JR, Zlotnick A, Mukhopadhyay S. Length of encapsidated cargo impacts stability and structure of in vitro assembled alphavirus core-like particles. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:484003. [PMID: 28975896 PMCID: PMC7103146 DOI: 10.1088/1361-648x/aa90d0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/28/2017] [Accepted: 10/04/2017] [Indexed: 05/21/2023]
Abstract
In vitro assembly of alphavirus nucleocapsid cores, called core-like particles (CLPs), requires a polyanionic cargo. There are no sequence or structure requirements to encapsidate single-stranded nucleic acid cargo. In this work, we wanted to determine how the length of the cargo impacts the stability and structure of the assembled CLPs. We hypothesized that cargo neutralizes the basic region of the alphavirus capsid protein and if the cargo is long enough, it will also act to scaffold the CP monomers together. Experimentally we found that CLPs encapsidating short 27mer oligonucleotides were less stable than CLPs encapsidating 48mer or 90mer oligonucleotides under different chemical and thermal conditions. Furthermore, cryo-EM studies showed there were structural differences between CLPs assembled with 27mer and 48mer cargo. To mimic the role of the cargo in CLP assembly we made a mutant (4D) where we substituted a cluster of four Lys residues in the CP with four Asp residues. We found that these few amino acid substitutions were enough to initiate CLP assembly in the absence of cargo. The cargo-free 4D CLPs show higher resistance to ionic strength and increased temperature compared to wild-type cargo containing CLPs suggesting their CLP assembly mechanism might also be different.
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Affiliation(s)
- Vamseedhar Rayaprolu
- Departments of Biology, Indiana University, Bloomington, IN, United States of America
| | - Alan Moore
- Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, United States of America
| | - Joseph Che-Yen Wang
- Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, United States of America
| | - Boon Chong Goh
- Physics and Beckman Institute, University of Illinois Urbana-Champaign, Champaign, IL, United States of America
| | - Juan R Perilla
- Physics and Beckman Institute, University of Illinois Urbana-Champaign, Champaign, IL, United States of America
- Center of Physics for Living Cells, University of Illinois Urbana-Champaign, Champaign, IL, United States of America
| | - Adam Zlotnick
- Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, United States of America
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32
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Alam SB, Reade R, Theilmann J, Rochon D. Evidence for the role of basic amino acids in the coat protein arm region of Cucumber necrosis virus in particle assembly and selective encapsidation of viral RNA. Virology 2017; 512:83-94. [PMID: 28946005 DOI: 10.1016/j.virol.2017.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 08/31/2017] [Accepted: 09/02/2017] [Indexed: 01/21/2023]
Abstract
Cucumber necrosis virus (CNV) is a T = 3 icosahedral virus with a (+)ssRNA genome. The N-terminal CNV coat protein arm contains a conserved, highly basic sequence ("KGRKPR"), which we postulate is involved in RNA encapsidation during virion assembly. Seven mutants were constructed by altering the CNV "KGRKPR" sequence; the four basic residues were mutated to alanine individually, in pairs, or in total. Virion accumulation and vRNA encapsidation were significantly reduced in mutants containing two or four substitutions and virion morphology was also affected, where both T = 1 and intermediate-sized particles were produced. Mutants with two or four substitutions encapsidated significantly greater levels of truncated RNA than that of WT, suggesting that basic residues in the "KGRKPR" sequence are important for encapsidation of full-length CNV RNA. Interestingly, "KGRKPR" mutants also encapsidated relatively higher levels of host RNA, suggesting that the "KGRKPR" sequence also contributes to selective encapsidation of CNV RNA.
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Affiliation(s)
- Syed Benazir Alam
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, B.C., Canada
| | - Ron Reade
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, B.C., Canada
| | - Jane Theilmann
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, B.C., Canada
| | - D'Ann Rochon
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, B.C., Canada; Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, B.C., Canada.
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33
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Dutta R, Pyne A, Kundu S, Banerjee P, Sarkar N. Concentration-Driven Fascinating Vesicle-Fibril Transition Employing Merocyanine 540 and 1-Octyl-3-methylimidazolium Chloride. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:9811-9821. [PMID: 28849933 DOI: 10.1021/acs.langmuir.7b02136] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this article, anionic lipophilic dye merocyanine 540(MC540) and cationic surface-active ionic liquid (SAIL) 1-octyl-3-methylimidazolium chloride (C8mimCl) are employed to construct highly ordered fibrillar and vesicular aggregates exploiting an ionic self-assembly (ISA) strategy. It is noteworthy that the concentration of the counterions has exquisite control over the morphology, in which lowering the concentration of both the building blocks in a stoichiometric ratio of 1:1 provides a vesicle to fibril transition. Here, we have reported the concentration-controlled fibril-vesicle transition utilizing the emerging fluorescence lifetime imaging microscopy (FLIM) technique. Furthermore, we have detected this morphological transformation by means of other microscopic techniques such as field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and cryogenic-transmission electron microscopy (cryo-TEM) to gain additional support. Besides, multiwavelength FLIM (MW-FLIM) and atomic force microscopy (AFM) techniques assist us in knowing the microheterogeneity and the height profile of the vesicles, respectively. We have replaced the SAIL, C8mimCl, by an analogous traditional surfactant, n-octyltrimethylammonium bromide (OTAB), and it provides a discernible change in morphology similar to that of C8mimCl, whereas 1-octanol is unable to exhibit any structural aggregation and thus reveals the importance of electrostatic interaction in supramolecular aggregate formation. However, the SAILs having the same imidazolium headgroup with different chain lengths other than C8mimCl are unable to display any structural transition and determine the importance of the correct chain length for efficient packing of the counterions to form a specific self-assembly. Therefore, this study reveals the synergistic interplay of electrostatic, hydrophobic, and π-π stacking interactions to construct the self-assembly and their concentration-dependent morphological transition.
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Affiliation(s)
- Rupam Dutta
- Department of Chemistry, Indian Institute of Technology , Kharagpur 721302, WB India
| | - Arghajit Pyne
- Department of Chemistry, Indian Institute of Technology , Kharagpur 721302, WB India
| | - Sangita Kundu
- Department of Chemistry, Indian Institute of Technology , Kharagpur 721302, WB India
| | - Pavel Banerjee
- Department of Chemistry, Indian Institute of Technology , Kharagpur 721302, WB India
| | - Nilmoni Sarkar
- Department of Chemistry, Indian Institute of Technology , Kharagpur 721302, WB India
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34
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In Situ Atomic Force Microscopy Studies on Nucleation and Self-Assembly of Biogenic and Bio-Inspired Materials. MINERALS 2017. [DOI: 10.3390/min7090158] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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35
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Li S, Erdemci-Tandogan G, Wagner J, van der Schoot P, Zandi R. Impact of a nonuniform charge distribution on virus assembly. Phys Rev E 2017; 96:022401. [PMID: 28950450 DOI: 10.1103/physreve.96.022401] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Indexed: 01/04/2023]
Abstract
Many spherical viruses encapsulate their genomes in protein shells with icosahedral symmetry. This process is spontaneous and driven by electrostatic interactions between positive domains on the virus coat proteins and the negative genomes. We model the effect of the nonuniform icosahedral charge distribution from the protein shell instead using a mean-field theory. We find that this nonuniform charge distribution strongly affects the optimal genome length and that it can explain the experimentally observed phenomenon of overcharging of virus and viruslike particles.
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Affiliation(s)
- Siyu Li
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Gonca Erdemci-Tandogan
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Jef Wagner
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Paul van der Schoot
- Group Theory of Polymers and Soft Matter, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.,Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands
| | - Roya Zandi
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
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36
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Zeng C, Hernando-Pérez M, Dragnea B, Ma X, van der Schoot P, Zandi R. Contact Mechanics of a Small Icosahedral Virus. PHYSICAL REVIEW LETTERS 2017; 119:038102. [PMID: 28777631 DOI: 10.1103/physrevlett.119.038102] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Indexed: 06/07/2023]
Abstract
A virus binding to a surface causes stress of the virus cage near the contact area. Here, we investigate the potential role of substrate-induced structural perturbation in the mechanical response of virus particles to adsorption. This is particularly relevant to the broad category of viruses stabilized by weak noncovalent interactions. We utilize atomic force microscopy to measure height distributions of the brome mosaic virus upon adsorption from solution on atomically flat substrates and present a continuum model that captures our observations and provides estimates of elastic properties and of the interfacial energy of the virus, without recourse to indentation.
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Affiliation(s)
- Cheng Zeng
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | | | - Bogdan Dragnea
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Xiang Ma
- Department of Chemistry, Idaho State University, Pocatello, Idaho 83209, USA
| | - Paul van der Schoot
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
| | - Roya Zandi
- Department of Physics and Astronomy, University of California at Riverside, 900 University Avenue, Riverside, California 92521, USA
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37
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Beren C, Dreesens LL, Liu KN, Knobler CM, Gelbart WM. The Effect of RNA Secondary Structure on the Self-Assembly of Viral Capsids. Biophys J 2017; 113:339-347. [PMID: 28711172 DOI: 10.1016/j.bpj.2017.06.038] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 05/31/2017] [Accepted: 06/20/2017] [Indexed: 12/31/2022] Open
Abstract
Previous work has shown that purified capsid protein (CP) of cowpea chlorotic mottle virus (CCMV) is capable of packaging both purified single-stranded RNA molecules of normal composition (comparable numbers of A, U, G, and C nucleobases) and of varying length and sequence, and anionic synthetic polymers such as polystyrene sulfonate. We find that CCMV CP is also capable of packaging polyU RNAs, which-unlike normal-composition RNAs-do not form secondary structures and which act as essentially structureless linear polymers. Following our canonical two-step assembly protocol, polyU RNAs ranging in length from 1000 to 9000 nucleotides (nt) are completely packaged. Surprisingly, negative-stain electron microscopy shows that all lengths of polyU are packaged into 22-nm-diameter particles despite the fact that CCMV CP prefers to form 28-nm-diameter (T = 3) particles when packaging normal-composition RNAs. PolyU RNAs >5000 nt in length are packaged into multiplet capsids, in which a single RNA molecule is shared between two or more 22-nm-diameter capsids, in analogy with the multiplets of 28-nm-diameter particles formed with normal-composition RNAs >5000 nt long. Experiments in which viral RNA competes for viral CP with polyUs of equal length show that polyU, despite its lack of secondary structure, is packaged more efficiently than viral RNA. These findings illustrate that the secondary structure of the RNA molecule-and its absence-plays an essential role in determining capsid structure during the self-assembly of CCMV-like particles.
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Affiliation(s)
- Christian Beren
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California
| | - Lisa L Dreesens
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California
| | - Katherine N Liu
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California
| | - Charles M Knobler
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California.
| | - William M Gelbart
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California
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38
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Poudel L, Twarock R, Steinmetz NF, Podgornik R, Ching WY. Impact of Hydrogen Bonding in the Binding Site between Capsid Protein and MS2 Bacteriophage ssRNA. J Phys Chem B 2017; 121:6321-6330. [PMID: 28581757 DOI: 10.1021/acs.jpcb.7b02569] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
MS2 presents a well-studied example of a single-stranded RNA virus for which the genomic RNA plays a pivotal role in the virus assembly process based on the packaging signal-mediated mechanism. Packaging signals (PSs) are multiple dispersed RNA sequence/structure motifs varying around a central recognition motif that interact in a specific way with the capsid protein in the assembly process. Although the discovery and identification of these PSs was based on bioinformatics and geometric approaches, in tandem with sophisticated experimental protocols, we approach this problem using large-scale ab initio computation centered on critical aspects of the consensus protein-RNA interactions recognition motif. DFT calculations are carried out on two nucleoprotein complexes: wild-type and mutated (PDB IDs: 1ZDH and 5MSF ). The calculated partial charge distribution of residues and the strength of hydrogen bonding (HB) between them enabled us to locate the exact binding sites with the strongest HBs, identified to be LYS43-A-4, ARG49-C-13, TYR85-C-5, and LYS61-C-5, due to the change in the sequence of the mutated RNA.
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Affiliation(s)
- Lokendra Poudel
- Department of Physics and Astronomy, University of Missouri-Kansas City , Kansas City, Missouri 64110, United States
| | - Reidun Twarock
- Department of Mathematics and Biology and York Centre for Complex Systems Analysis, University of York , York YO10 5DD, United Kingdom
| | | | - Rudolf Podgornik
- Department of Theoretical Physics, J. Stefan Institute , SI-1000 Ljubljana, Slovenia.,Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana , SI-1000 Ljubljana, Slovenia
| | - Wai-Yim Ching
- Department of Physics and Astronomy, University of Missouri-Kansas City , Kansas City, Missouri 64110, United States
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39
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Li C, Kneller AR, Jacobson SC, Zlotnick A. Single Particle Observation of SV40 VP1 Polyanion-Induced Assembly Shows That Substrate Size and Structure Modulate Capsid Geometry. ACS Chem Biol 2017; 12:1327-1334. [PMID: 28323402 DOI: 10.1021/acschembio.6b01066] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Simian virus 40 capsid protein (VP1) is a unique system for studying substrate-dependent assembly of a nanoparticle. Here, we investigate a simplest case of this system where 12 VP1 pentamers and a single polyanion, e.g., RNA, form a T = 1 particle. To test the roles of polyanion substrate length and structure during assembly, we characterized the assembly products with size exclusion chromatography, transmission electron microscopy, and single-particle resistive-pulse sensing. We found that 500 and 600 nt RNAs had the optimal length and structure for assembly of uniform T = 1 particles. Longer 800 nt RNA, shorter 300 nt RNA, and a linear 600 unit poly(styrene sulfonate) (PSS) polyelectrolyte produced heterogeneous populations of products. This result was surprising as the 600mer PSS and 500-600 nt RNA have similar mass and charge. Like ssRNA, PSS also has a short 4 nm persistence length, but unlike RNA, PSS lacks a compact tertiary structure. These data indicate that even for flexible substrates, shape as well as size affect assembly and are consistent with the hypothesis that work, derived from protein-protein and protein-substrate interactions, is used to compact the substrate.
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Affiliation(s)
- Chenglei Li
- Department
of Molecular and Cellular Biochemistry and ‡Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Andrew R. Kneller
- Department
of Molecular and Cellular Biochemistry and ‡Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Stephen C. Jacobson
- Department
of Molecular and Cellular Biochemistry and ‡Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Adam Zlotnick
- Department
of Molecular and Cellular Biochemistry and ‡Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
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40
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Zeng C, Moller-Tank S, Asokan A, Dragnea B. Probing the Link among Genomic Cargo, Contact Mechanics, and Nanoindentation in Recombinant Adeno-Associated Virus 2. J Phys Chem B 2017; 121:1843-1853. [PMID: 28142241 DOI: 10.1021/acs.jpcb.6b10131] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recombinant adeno-associated virus (AAV) is a promising gene therapy vector. To make progress in this direction, the relationship between the characteristics of the genomic cargo and the capsid stability must be understood in detail. The goal of this study is to determine the role of the packaged vector genome in the response of AAV particles to mechanical compression and adhesion to a substrate. Specifically, we used atomic force microscopy to compare the mechanical properties of empty AAV serotype 2 (AAV2) capsids and AAV2 vectors packaging single-stranded DNA or self-complementary DNA. We found that all species underwent partial deformation upon adsorption from buffer on an atomically flat graphite surface. Upon adsorption, a preferred orientation toward the twofold symmetry axis on the capsid, relative to the substrate, was observed. The magnitude of the bias depended on the cargo type, indicating that the interfacial properties may be influenced by cargo. All particles showed a significant relative strain before rupture. Different from interfacial interactions, which were clearly cargo-dependent, the elastic response to directional stress was largely dominated by the capsid properties. Nevertheless, small differences between particles laden with different cargo were measurable; scAAV vectors were the most resilient to external compression. We also show how elastic constant and rupture force data sets can be analyzed according a multivariate conditional probability approach to determine the genome content on the basis of a database of mechanical properties acquired from nanoindentation assays. Implications for understanding how recombinant AAV capsid-genome interactions can affect vector stability and effectiveness of gene therapy applications are discussed.
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Affiliation(s)
- Cheng Zeng
- Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States
| | | | | | - Bogdan Dragnea
- Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States
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41
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HBV maintains electrostatic homeostasis by modulating negative charges from phosphoserine and encapsidated nucleic acids. Sci Rep 2016; 6:38959. [PMID: 27958343 PMCID: PMC5154190 DOI: 10.1038/srep38959] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 11/14/2016] [Indexed: 12/22/2022] Open
Abstract
Capsid assembly and stability of hepatitis B virus (HBV) core protein (HBc) particles depend on balanced electrostatic interactions between encapsidated nucleic acids and an arginine-rich domain (ARD) of HBc in the capsid interior. Arginine-deficient ARD mutants preferentially encapsidated spliced viral RNA and shorter DNA, which can be fully or partially rescued by reducing the negative charges from acidic residues or serine phosphorylation of HBc, dose-dependently. Similarly, empty capsids without RNA encapsidation can be generated by ARD hyper-phosphorylation in insect, bacteria, and human hepatocytes. De-phosphorylation of empty capsids by phosphatase induced capsid disassembly. Empty capsids can convert into RNA-containing capsids by increasing HBc serine de-phosphorylation. In an HBV replicon system, we observed a reciprocal relationship between viral and non-viral RNA encapsidation, suggesting both non-viral RNA and serine-phosphorylation could serve as a charge balance buffer in maintaining electrostatic homeostasis. In addition, by comparing the biochemistry assay results between a replicon and a non-replicon system, we observed a correlation between HBc de-phosphorylation and viral replication. Balanced electrostatic interactions may be important to other icosahedral particles in nature.
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42
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Li J, Li X, Xu J, Wang Y, Wu L, Wang Y, Wang L, Lee M, Li W. Engineering the Ionic Self-Assembly of Polyoxometalates and Facial-Like Peptides. Chemistry 2016; 22:15751-15759. [DOI: 10.1002/chem.201602449] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Indexed: 12/31/2022]
Affiliation(s)
- Jingfang Li
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry; Jilin University; Qianjin Avenue 2699 Changchun 130012 P.R. China
| | - Xiaodong Li
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry; Jilin University; Qianjin Avenue 2699 Changchun 130012 P.R. China
| | - Jing Xu
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry; Jilin University; Qianjin Avenue 2699 Changchun 130012 P.R. China
| | - Yang Wang
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry; Jilin University; Qianjin Avenue 2699 Changchun 130012 P.R. China
| | - Lixin Wu
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry; Jilin University; Qianjin Avenue 2699 Changchun 130012 P.R. China
| | - Yanqiu Wang
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry; Jilin University; Qianjin Avenue 2699 Changchun 130012 P.R. China
| | - Liyan Wang
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry; Jilin University; Qianjin Avenue 2699 Changchun 130012 P.R. China
| | - Myongsoo Lee
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry; Jilin University; Qianjin Avenue 2699 Changchun 130012 P.R. China
| | - Wen Li
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry; Jilin University; Qianjin Avenue 2699 Changchun 130012 P.R. China
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43
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Phosphorylation of the Brome Mosaic Virus Capsid Regulates the Timing of Viral Infection. J Virol 2016; 90:7748-60. [PMID: 27334588 DOI: 10.1128/jvi.00833-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 06/10/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The four brome mosaic virus (BMV) RNAs (RNA1 to RNA4) are encapsidated in three distinct virions that have different disassembly rates in infection. The mechanism for the differential release of BMV RNAs from virions is unknown, since 180 copies of the same coat protein (CP) encapsidate each of the BMV genomic RNAs. Using mass spectrometry, we found that the BMV CP contains a complex pattern of posttranslational modifications. Treatment with phosphatase was found to not significantly affect the stability of the virions containing RNA1 but significantly impacted the stability of the virions that encapsidated BMV RNA2 and RNA3/4. Cryo-electron microscopy reconstruction revealed dramatic structural changes in the capsid and the encapsidated RNA. A phosphomimetic mutation in the flexible N-terminal arm of the CP increased BMV RNA replication and virion production. The degree of phosphorylation modulated the interaction of CP with the encapsidated RNA and the release of three of the BMV RNAs. UV cross-linking and immunoprecipitation methods coupled to high-throughput sequencing experiments showed that phosphorylation of the BMV CP can impact binding to RNAs in the virions, including sequences that contain regulatory motifs for BMV RNA gene expression and replication. Phosphatase-treated virions affected the timing of CP expression and viral RNA replication in plants. The degree of phosphorylation decreased when the plant hosts were grown at an elevated temperature. These results show that phosphorylation of the capsid modulates BMV infection. IMPORTANCE How icosahedral viruses regulate the release of viral RNA into the host is not well understood. The selective release of viral RNA can regulate the timing of replication and gene expression. Brome mosaic virus (BMV) is an RNA virus, and its three genomic RNAs are encapsidated in separate virions. Through proteomic, structural, and biochemical analyses, this work shows that posttranslational modifications, specifically, phosphorylation, on the capsid protein regulate the capsid-RNA interaction and the stability of the virions and affect viral gene expression. Mutational analysis confirmed that changes in modification affected virion stability and the timing of viral infection. The mechanism for modification of the virion has striking parallels to the mechanism of regulation of chromatin packaging by nucleosomes.
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44
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Erdemci-Tandogan G, Wagner J, van der Schoot P, Podgornik R, Zandi R. Effects of RNA branching on the electrostatic stabilization of viruses. Phys Rev E 2016; 94:022408. [PMID: 27627336 DOI: 10.1103/physreve.94.022408] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Indexed: 11/07/2022]
Abstract
Many single-stranded (ss) ribonucleic acid (RNA) viruses self-assemble from capsid protein subunits and the nucleic acid to form an infectious virion. It is believed that the electrostatic interactions between the negatively charged RNA and the positively charged viral capsid proteins drive the encapsidation, although there is growing evidence that the sequence of the viral RNA also plays a role in packaging. In particular, the sequence will determine the possible secondary structures that the ssRNA will take in solution. In this work, we use a mean-field theory to investigate how the secondary structure of the RNA combined with electrostatic interactions affects the efficiency of assembly and stability of the assembled virions. We show that the secondary structure of RNA may result in negative osmotic pressures while a linear polymer causes positive osmotic pressures for the same conditions. This may suggest that the branched structure makes the RNA more effectively packaged and the virion more stable.
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Affiliation(s)
- Gonca Erdemci-Tandogan
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Jef Wagner
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Paul van der Schoot
- Group Theory of Polymers and Soft Matter, Eindhoven University of Technology, P. O. Box 513, 5600 MB Eindhoven, The Netherlands.,Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, The Netherlands
| | - Rudolf Podgornik
- Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, USA.,Department of Theoretical Physics, J. Stefan Institute, SI-1000 Ljubljana, Slovenia.,Department of Physics, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Roya Zandi
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
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45
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Kim J, Wu J. A Thermodynamic Model for Genome Packaging in Hepatitis B Virus. Biophys J 2016; 109:1689-97. [PMID: 26488660 DOI: 10.1016/j.bpj.2015.08.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 08/02/2015] [Accepted: 08/10/2015] [Indexed: 12/12/2022] Open
Abstract
Understanding the fundamentals of genome packaging in viral capsids is important for finding effective antiviral strategies and for utilizing benign viral particles for gene therapy. While the structure of encapsidated genomic materials has been routinely characterized with experimental techniques such as cryo-electron microscopy and x-ray diffraction, much less is known about the molecular driving forces underlying genome assembly in an intracellular environment and its in vivo interactions with the capsid proteins. Here we study the thermodynamic basis of the pregenomic RNA encapsidation in human Hepatitis B virus in vivo using a coarse-grained molecular model that captures the essential components of nonspecific intermolecular interactions. The thermodynamic model is used to examine how the electrostatic interaction between the packaged RNA and the highly charged C-terminal domains (CTD) of capsid proteins regulate the nucleocapsid formation. The theoretical model predicts optimal RNA content in Hepatitis B virus nucleocapsids with different CTD lengths in good agreement with mutagenesis measurements, confirming the predominant role of electrostatic interactions and molecular excluded-volume effects in genome packaging. We find that the amount of encapsidated RNA is not linearly correlated with the net charge of CTD tails as suggested by earlier theoretical studies. Our thermodynamic analysis of the nucleocapsid structure and stability indicates that ∼10% of the CTD residues are free from complexation with RNA, resulting in partially exposed CTD tails. The thermodynamic model also predicts the free energy of complex formation between macromolecules, which corroborates experimental results for the impact of CTD truncation on the nucleocapsid stability.
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Affiliation(s)
- Jehoon Kim
- Department of Chemical and Environmental Engineering, University of California at Riverside, Riverside, California
| | - Jianzhong Wu
- Department of Chemical and Environmental Engineering, University of California at Riverside, Riverside, California.
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Reddy T, Sansom MSP. Computational virology: From the inside out. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1858:1610-8. [PMID: 26874202 PMCID: PMC4884666 DOI: 10.1016/j.bbamem.2016.02.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/05/2016] [Accepted: 02/08/2016] [Indexed: 12/23/2022]
Abstract
Viruses typically pack their genetic material within a protein capsid. Enveloped viruses also have an outer membrane made up of a lipid bilayer and membrane-spanning glycoproteins. X-ray diffraction and cryoelectron microscopy provide high resolution static views of viral structure. Molecular dynamics (MD) simulations may be used to provide dynamic insights into the structures of viruses and their components. There have been a number of simulations of viral capsids and (in some cases) of the inner core of RNA or DNA packaged within them. These simulations have generally focussed on the structural integrity and stability of the capsid and/or on the influence of the nucleic acid core on capsid stability. More recently there have been a number of simulation studies of enveloped viruses, including HIV-1, influenza A, and dengue virus. These have addressed the dynamic behaviour of the capsid, the matrix, and/or of the outer envelope. Analysis of the dynamics of the lipid bilayer components of the envelopes of influenza A and of dengue virus reveals a degree of biophysical robustness, which may contribute to the stability of virus particles in different environments. Significant computational challenges need to be addressed to aid simulation of complex viruses and their membranes, including the need to integrate structural data from a range of sources to enable us to move towards simulations of intact virions. This article is part of a Special Issue entitled: Membrane Proteins edited by J.C. Gumbart and Sergei Noskov.
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Affiliation(s)
- Tyler Reddy
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
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47
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Wagner J, Zandi R. The Robust Assembly of Small Symmetric Nanoshells. Biophys J 2016; 109:956-65. [PMID: 26331253 DOI: 10.1016/j.bpj.2015.07.041] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 06/18/2015] [Accepted: 07/28/2015] [Indexed: 12/20/2022] Open
Abstract
Highly symmetric nanoshells are found in many biological systems, such as clathrin cages and viral shells. Many studies have shown that symmetric shells appear in nature as a result of the free-energy minimization of a generic interaction between their constituent subunits. We examine the physical basis for the formation of symmetric shells, and by using a minimal model, demonstrate that these structures can readily grow from the irreversible addition of identical subunits. Our model of nanoshell assembly shows that the spontaneous curvature regulates the size of the shell while the mechanical properties of the subunit determine the symmetry of the assembled structure. Understanding the minimum requirements for the formation of closed nanoshells is a necessary step toward engineering of nanocontainers, which will have far-reaching impact in both material science and medicine.
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Affiliation(s)
- Jef Wagner
- Department of Physics and Astronomy, University of California at Riverside, Riverside, California.
| | - Roya Zandi
- Department of Physics and Astronomy, University of California at Riverside, Riverside, California
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48
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van de Waterbeemd M, Snijder J, Tsvetkova IB, Dragnea BG, Cornelissen JJ, Heck AJR. Examining the Heterogeneous Genome Content of Multipartite Viruses BMV and CCMV by Native Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:1000-9. [PMID: 26926442 PMCID: PMC4869746 DOI: 10.1007/s13361-016-1348-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 01/19/2016] [Accepted: 01/20/2016] [Indexed: 05/09/2023]
Abstract
Since the concept was first introduced by Brian Chait and co-workers in 1991, mass spectrometry of proteins and protein complexes under non-denaturing conditions (native MS) has strongly developed, through parallel advances in instrumentation, sample preparation, and data analysis tools. However, the success rate of native MS analysis, particularly in heterogeneous mega-Dalton (MDa) protein complexes, still strongly depends on careful instrument modification. Here, we further explore these boundaries in native mass spectrometry, analyzing two related endogenous multipartite viruses: the Brome Mosaic Virus (BMV) and the Cowpea Chlorotic Mottle Virus (CCMV). Both CCMV and BMV are approximately 4.6 megadalton (MDa) in mass, of which approximately 1 MDA originates from the genomic content of the virion. Both viruses are produced as mixtures of three particles carrying different segments of the genome, varying by approximately 0.1 MDA in mass (~2%). This mixture of particles poses a challenging analytical problem for high-resolution native MS analysis, given the large mass scales involved. We attempt to unravel the particle heterogeneity using both Q-TOF and Orbitrap mass spectrometers extensively modified for analysis of very large assemblies. We show that manipulation of the charging behavior can provide assistance in assigning the correct charge states. Despite their challenging size and heterogeneity, we obtained native mass spectra with resolved series of charge states for both BMV and CCMV, demonstrating that native MS of endogenous multipartite virions is feasible. Graphical Abstract ᅟ.
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Affiliation(s)
- Michiel van de Waterbeemd
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH, Utrecht, The Netherlands
- Netherlands Proteomics Center, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Joost Snijder
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH, Utrecht, The Netherlands
- Netherlands Proteomics Center, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Irina B Tsvetkova
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
| | - Bogdan G Dragnea
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
| | - Jeroen J Cornelissen
- Laboratory for Biomolecular Nanotechnology, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH, Utrecht, The Netherlands.
- Netherlands Proteomics Center, Padualaan 8, Utrecht, 3584 CH, The Netherlands.
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49
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Sivanandam V, Mathews D, Garmann R, Erdemci-Tandogan G, Zandi R, Rao ALN. Functional analysis of the N-terminal basic motif of a eukaryotic satellite RNA virus capsid protein in replication and packaging. Sci Rep 2016; 6:26328. [PMID: 27193742 PMCID: PMC4872054 DOI: 10.1038/srep26328] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 04/29/2016] [Indexed: 02/06/2023] Open
Abstract
Efficient replication and assembly of virus particles are integral to the establishment of infection. In addition to the primary role of the capsid protein (CP) in encapsidating the RNA progeny, experimental evidence on positive sense single-stranded RNA viruses suggests that the CP also regulates RNA synthesis. Here, we demonstrate that replication of Satellite tobacco mosaic virus (STMV) is controlled by the cooperative interaction between STMV CP and the helper virus (HV) Tobacco mosaic virus (TMV) replicase. We identified that the STMV CP-HV replicase interaction requires a positively charged residue at the third position (3R) in the N-terminal 13 amino acid (aa) motif. Far-Northwestern blotting showed that STMV CP promotes binding between HV-replicase and STMV RNA. An STMV CP variant having an arginine to alanine substitution at position 3 in the N-terminal 13aa motif abolished replicase-CP binding. The N-terminal 13aa motif of the CP bearing alanine substitutions for positively charged residues located at positions 5, 7, 10 and 11 are defective in packaging full-length STMV, but can package a truncated STMV RNA lacking the 3' terminal 150 nt region. These findings provide insights into the mechanism underlying the regulation of STMV replication and packaging.
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Affiliation(s)
- Venkatesh Sivanandam
- Department of Plant Pathology & Microbiology, University of California, Riverside, CA 92521, USA
| | - Deborah Mathews
- Department of Plant Pathology & Microbiology, University of California, Riverside, CA 92521, USA
| | - Rees Garmann
- Department of Chemistry & Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | | | - Roya Zandi
- Department of Physics & Astronomy, University of California, Riverside, CA 92521, USA
| | - A. L. N. Rao
- Department of Plant Pathology & Microbiology, University of California, Riverside, CA 92521, USA
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50
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Shojaei HR, Božič AL, Muthukumar M, Podgornik R. Effects of long-range interactions on curvature energies of viral shells. Phys Rev E 2016; 93:052415. [PMID: 27300932 DOI: 10.1103/physreve.93.052415] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Indexed: 06/06/2023]
Abstract
We formulate a theory of the effects of long-range interactions on the surface tension and spontaneous curvature of proteinaceous shells based on the general Deryaguin-Landau-Verwey-Overbeek mesoscale approach to colloid stability. We derive the full renormalization formulas for the elastic properties of the shell and consider in detail the renormalization of the spontaneous curvature as a function of the corresponding Hamaker coefficient, inner and outer capsid charges, and bathing solution properties. The renormalized spontaneous curvature is found to be a nonmonotonic function of several parameters describing the system.
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Affiliation(s)
- Hamid R Shojaei
- Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, USA
| | | | - Murugappan Muthukumar
- Department of Polymer Science and Engineering, Materials Research Science and Engineering Center, University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - Rudolf Podgornik
- Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, USA
- Department of Theoretical Physics, J. Stefan Institute, Ljubljana, Slovenia
- Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenia
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