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Read CM, Plante K, Rafael G, Rossi SL, Braun W, Weaver SC, Schein CH. Designing multivalent immunogens for alphavirus vaccine optimization. Virology 2021; 561:117-124. [PMID: 33823988 DOI: 10.1016/j.virol.2020.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/15/2020] [Accepted: 11/22/2020] [Indexed: 11/16/2022]
Abstract
There is a pressing need for vaccines against mosquito-borne alphaviruses such as Venezualen and eastern equine encephalitis viruses (VEEV, EEEV). We demonstrate an approach to vaccine development based on physicochemical properties (PCP) of amino acids to design a PCP-consensus sequence of the epitope-rich B domain of the VEEV major antigenic E2 protein. The consensus "spike" domain was incorporated into a live-attenuated VEEV vaccine candidate (ZPC/IRESv1). Mice inoculated with either ZPC/IRESv1 or the same virus containing the consensus E2 protein fragment (VEEVconE2) were protected against lethal challenge with VEEV strains ZPC-738 and 3908, and Mucambo virus (MUCV, related to VEEV), and had comparable neutralizing antibody titers against each virus. Both vaccines induced partial protection against Madariaga virus (MADV), a close relative of EEEV, lowering mortality from 60% to 20%. Thus PCP-consensus sequences can be integrated into a replicating virus that could, with further optimization, provide a broad-spectrum vaccine against encephalitic alphaviruses.
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Affiliation(s)
- C M Read
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA
| | - Kenneth Plante
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA; Institute for Human Infections and Immunity (IHII), University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA; World Reference Center for Emerging Viruses and Arboviruses, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA
| | - Grace Rafael
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA
| | - Shannan L Rossi
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA; Department of Pathology, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA; Institute for Human Infections and Immunity (IHII), University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA
| | - Werner Braun
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA
| | - Scott C Weaver
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA; Institute for Human Infections and Immunity (IHII), University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA; World Reference Center for Emerging Viruses and Arboviruses, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA
| | - Catherine H Schein
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA; Institute for Human Infections and Immunity (IHII), University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX, 77555, USA.
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Functional classification of protein toxins as a basis for bioinformatic screening. Sci Rep 2017; 7:13940. [PMID: 29066768 PMCID: PMC5655178 DOI: 10.1038/s41598-017-13957-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/02/2017] [Indexed: 01/05/2023] Open
Abstract
Proteins are fundamental to life and exhibit a wide diversity of activities, some of which are toxic. Therefore, assessing whether a specific protein is safe for consumption in foods and feeds is critical. Simple BLAST searches may reveal homology to a known toxin, when in fact the protein may pose no real danger. Another challenge to answer this question is the lack of curated databases with a representative set of experimentally validated toxins. Here we have systematically analyzed over 10,000 manually curated toxin sequences using sequence clustering, network analysis, and protein domain classification. We also developed a functional sequence signature method to distinguish toxic from non-toxic proteins. The current database, combined with motif analysis, can be used by researchers and regulators in a hazard screening capacity to assess the potential of a protein to be toxic at early stages of development. Identifying key signatures of toxicity can also aid in redesigning proteins, so as to maintain their desirable functions while reducing the risk of potential health hazards.
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Nash MA, Smith SP, Fontes CM, Bayer EA. Single versus dual-binding conformations in cellulosomal cohesin-dockerin complexes. Curr Opin Struct Biol 2016; 40:89-96. [PMID: 27579515 DOI: 10.1016/j.sbi.2016.08.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 07/22/2016] [Accepted: 08/02/2016] [Indexed: 12/24/2022]
Abstract
Cohesins and dockerins are complementary interacting protein modules that form stable and highly specific receptor-ligand complexes. They play a crucial role in the assembly of cellulose-degrading multi-enzyme complexes called cellulosomes and have potential applicability in several technology areas, including biomass conversion processes. Here, we describe several exceptional properties of cohesin-dockerin complexes, including their tenacious biochemical affinity, remarkably high mechanostability and a dual-binding mode of recognition that is contrary to the conventional lock-and-key model of receptor-ligand interactions. We focus on structural aspects of the dual mode of cohesin-dockerin binding, highlighting recent single-molecule analysis techniques for its explicit characterization.
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Affiliation(s)
- Michael A Nash
- Lehrstuhl für Angewandte Physik and Center for Nanoscience, Ludwig-Maximilians-Universität, 80799 Munich, Germany; Department of Chemistry, University of Basel, 4056 Basel, Switzerland; Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule (ETH-Zürich), 4058 Basel, Switzerland.
| | - Steven P Smith
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Carlos Mga Fontes
- CIISA-Faculdade de Medicina Veterinária, ULisboa, Pólo Universitário do Alto da Ajuda, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Edward A Bayer
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
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Tych KM, Batchelor M, Hoffmann T, Wilson MC, Paci E, Brockwell DJ, Dougan L. Tuning protein mechanics through an ionic cluster graft from an extremophilic protein. SOFT MATTER 2016; 12:2688-2699. [PMID: 26809452 DOI: 10.1039/c5sm02938d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Proteins from extremophilic organisms provide excellent model systems to determine the role of non-covalent interactions in defining protein stability and dynamics as well as being attractive targets for the development of robust biomaterials. Hyperthermophilic proteins have a prevalence of salt bridges, relative to their mesophilic homologues, which are thought to be important for enhanced thermal stability. However, the impact of salt bridges on the mechanical properties of proteins is far from understood. Here, a combination of protein engineering, biophysical characterisation, single molecule force spectroscopy (SMFS) and molecular dynamics (MD) simulations directly investigates the role of salt bridges in the mechanical stability of two cold shock proteins; BsCSP from the mesophilic organism Bacillus subtilis and TmCSP from the hyperthermophilic organism Thermotoga maritima. Single molecule force spectroscopy shows that at ambient temperatures TmCSP is mechanically stronger yet, counter-intuitively, its native state can withstand greater deformation before unfolding (i.e. it is mechanically soft) compared with BsCSP. MD simulations were used to identify the location and quantify the population of salt bridges, and reveal that TmCSP contains a larger number of highly occupied salt bridges than BsCSP. To test the hypothesis that salt-bridges endow these mechanical properties on the hyperthermophilic CSP, a charged triple mutant (CTM) variant of BsCSP was generated by grafting an ionic cluster from TmCSP into the BsCSP scaffold. As expected CTM is thermodynamically more stable and mechanically softer than BsCSP. We show that a grafted ionic cluster can increase the mechanical softness of a protein and speculate that it could provide a mechanical recovery mechanism and that it may be a design feature applicable to other proteins.
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Affiliation(s)
- Katarzyna M Tych
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK.
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Hoffmann T, Tych KM, Brockwell DJ, Dougan L. Single-molecule force spectroscopy identifies a small cold shock protein as being mechanically robust. J Phys Chem B 2013; 117:1819-26. [PMID: 23293964 DOI: 10.1021/jp310442s] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Single-molecule force spectroscopy has emerged as a powerful approach to examine the stability and dynamics of single proteins. We have completed force extension experiments on the small cold shock protein B from Thermotoga maritima, using a specially constructed chimeric polyprotein. The protein's simple topology, which is distinct from the mechanically well-characterized β-grasp and immunoglobulin (Ig)-like folds, in addition to the wide range of structural homologues resulting from its ancient origin, provides an attractive model protein for single-molecule force spectroscopy studies. We have determined that the protein has mechanical stability, unfolding at greater than 70 pN at a pulling velocity of 100 nm s(-1). We reveal features of the unfolding energy landscape by measuring the dependence of the mechanical stability on pulling velocity, in combination with Monte Carlo simulations. We show that the cold shock protein has mechanically robust, yet malleable, features that may be important in providing the protein with stability and flexibility to function over a range of environmental conditions. These results provide insights into the relationship between the secondary structure and topology of a protein and its mechanical strength. This lays the foundation for the investigation of the effects of changes in environmental conditions on the mechanical and dynamic properties of cold shock proteins.
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Affiliation(s)
- Toni Hoffmann
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom
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