1
|
Monck C, Elani Y, Ceroni F. Genetically programmed synthetic cells for thermo-responsive protein synthesis and cargo release. Nat Chem Biol 2024:10.1038/s41589-024-01673-7. [PMID: 38969863 DOI: 10.1038/s41589-024-01673-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 06/06/2024] [Indexed: 07/07/2024]
Abstract
Synthetic cells containing genetic programs and protein expression machinery are increasingly recognized as powerful counterparts to engineered living cells in the context of biotechnology, therapeutics and cellular modelling. So far, genetic regulation of synthetic cell activity has been largely confined to chemical stimuli; to unlock their potential in applied settings, engineering stimuli-responsive synthetic cells under genetic regulation is imperative. Here we report the development of temperature-sensitive synthetic cells that control protein production by exploiting heat-responsive mRNA elements. This is achieved by combining RNA thermometer technology, cell-free protein expression and vesicle-based synthetic cell design to create cell-sized capsules able to initiate synthesis of both soluble proteins and membrane proteins at defined temperatures. We show that the latter allows for temperature-controlled cargo release phenomena with potential implications for biomedicine. Platforms like the one presented here can pave the way for customizable, genetically programmed synthetic cells under thermal control to be used in biotechnology.
Collapse
Affiliation(s)
- Carolina Monck
- Department of Chemical Engineering, Imperial College London, London, UK
- Imperial College Centre for Synthetic Biology, London, UK
- fabriCELL, Imperial College London, London, UK
| | - Yuval Elani
- Department of Chemical Engineering, Imperial College London, London, UK.
- Imperial College Centre for Synthetic Biology, London, UK.
- fabriCELL, Imperial College London, London, UK.
| | - Francesca Ceroni
- Department of Chemical Engineering, Imperial College London, London, UK.
- Imperial College Centre for Synthetic Biology, London, UK.
| |
Collapse
|
2
|
Joshi SHN, Jenkins C, Ulaeto D, Gorochowski TE. Accelerating Genetic Sensor Development, Scale-up, and Deployment Using Synthetic Biology. BIODESIGN RESEARCH 2024; 6:0037. [PMID: 38919711 PMCID: PMC11197468 DOI: 10.34133/bdr.0037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 04/23/2024] [Indexed: 06/27/2024] Open
Abstract
Living cells are exquisitely tuned to sense and respond to changes in their environment. Repurposing these systems to create engineered biosensors has seen growing interest in the field of synthetic biology and provides a foundation for many innovative applications spanning environmental monitoring to improved biobased production. In this review, we present a detailed overview of currently available biosensors and the methods that have supported their development, scale-up, and deployment. We focus on genetic sensors in living cells whose outputs affect gene expression. We find that emerging high-throughput experimental assays and evolutionary approaches combined with advanced bioinformatics and machine learning are establishing pipelines to produce genetic sensors for virtually any small molecule, protein, or nucleic acid. However, more complex sensing tasks based on classifying compositions of many stimuli and the reliable deployment of these systems into real-world settings remain challenges. We suggest that recent advances in our ability to precisely modify nonmodel organisms and the integration of proven control engineering principles (e.g., feedback) into the broader design of genetic sensing systems will be necessary to overcome these hurdles and realize the immense potential of the field.
Collapse
Affiliation(s)
| | - Christopher Jenkins
- CBR Division, Defence Science and Technology Laboratory, Porton Down, Wiltshire SP4 0JQ, UK
| | - David Ulaeto
- CBR Division, Defence Science and Technology Laboratory, Porton Down, Wiltshire SP4 0JQ, UK
| | - Thomas E. Gorochowski
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK
- BrisEngBio,
School of Chemistry, University of Bristol, Bristol BS8 1TS, UK
| |
Collapse
|
3
|
Ribeiro ALJL, Pérez-Arnaiz P, Sánchez-Costa M, Pérez L, Almendros M, van Vliet L, Gielen F, Lim J, Charnock S, Hollfelder F, González-Pastor JE, Berenguer J, Hidalgo A. Thermostable in vitro transcription-translation compatible with microfluidic droplets. Microb Cell Fact 2024; 23:169. [PMID: 38858677 PMCID: PMC11165818 DOI: 10.1186/s12934-024-02440-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 05/25/2024] [Indexed: 06/12/2024] Open
Abstract
BACKGROUND In vitro expression involves the utilization of the cellular transcription and translation machinery in an acellular context to produce one or more proteins of interest and has found widespread application in synthetic biology and in pharmaceutical biomanufacturing. Most in vitro expression systems available are active at moderate temperatures, but to screen large libraries of natural or artificial genetic diversity for highly thermostable enzymes or enzyme variants, it is instrumental to enable protein synthesis at high temperatures. OBJECTIVES Develop an in vitro expression system operating at high temperatures compatible with enzymatic assays and with technologies that enable ultrahigh-throughput protein expression in reduced volumes, such as microfluidic water-in-oil (w/o) droplets. RESULTS We produced cell-free extracts from Thermus thermophilus for in vitro translation including thermostable enzymatic cascades for energy regeneration and a moderately thermostable RNA polymerase for transcription, which ultimately limited the temperature of protein synthesis. The yield was comparable or superior to other thermostable in vitro expression systems, while the preparation procedure is much simpler and can be suited to different Thermus thermophilus strains. Furthermore, these extracts have enabled in vitro expression in microfluidic droplets at high temperatures for the first time. CONCLUSIONS Cell-free extracts from Thermus thermophilus represent a simpler alternative to heavily optimized or pure component thermostable in vitro expression systems. Moreover, due to their compatibility with droplet microfluidics and enzyme assays at high temperatures, the reported system represents a convenient gateway for enzyme screening at higher temperatures with ultrahigh-throughput.
Collapse
Grants
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- 324439, 635595, 685474, 695669 and 10100560 European Commission
- BIO-2013-44963-R, RED2022-134755-T, CEX2021-001154-S Ministerio de Ciencia e Innovación
- BIO-2013-44963-R, RED2022-134755-T, CEX2021-001154-S Ministerio de Ciencia e Innovación
Collapse
Affiliation(s)
- Ana L J L Ribeiro
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Patricia Pérez-Arnaiz
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Mercedes Sánchez-Costa
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Lara Pérez
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Marcos Almendros
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Liisa van Vliet
- Departament of Biochemistry, Cambridge University, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
- DropTech Ltd, 91 Canterbury Court, Cambridge, CB4 3QU, UK
| | - Fabrice Gielen
- DropTech Ltd, 91 Canterbury Court, Cambridge, CB4 3QU, UK
- Living Systems Institute, Faculty of Health and Life Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
- Department of Physics and Astronomy, Faculty of Environment, Science and Economy, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
| | - Jesmine Lim
- Prozomix Ltd, Building 4, West End Ind. Estate, Haltwhistle, Northumberland, NE49 9HA, UK
| | - Simon Charnock
- Prozomix Ltd, Building 4, West End Ind. Estate, Haltwhistle, Northumberland, NE49 9HA, UK
| | - Florian Hollfelder
- Departament of Biochemistry, Cambridge University, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - J Eduardo González-Pastor
- Centro de Astrobiología (CAB), CSIC-INTA, Ctra de Torrejón a Ajalvir, Km 4, 28850, Torrejón de Ardoz, Spain
| | - José Berenguer
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain
- Instituto de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049, Madrid, Spain
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Aurelio Hidalgo
- Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Nicolás Cabrera 1, 28049, Madrid, Spain.
- Instituto de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049, Madrid, Spain.
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049, Madrid, Spain.
| |
Collapse
|
4
|
Lee SJ, Kim DM. Cell-Free Synthesis: Expediting Biomanufacturing of Chemical and Biological Molecules. Molecules 2024; 29:1878. [PMID: 38675698 PMCID: PMC11054211 DOI: 10.3390/molecules29081878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 04/14/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
The increasing demand for sustainable alternatives underscores the critical need for a shift away from traditional hydrocarbon-dependent processes. In this landscape, biomanufacturing emerges as a compelling solution, offering a pathway to produce essential chemical materials with significantly reduced environmental impacts. By utilizing engineered microorganisms and biomass as raw materials, biomanufacturing seeks to achieve a carbon-neutral footprint, effectively counteracting the carbon dioxide emissions associated with fossil fuel use. The efficiency and specificity of biocatalysts further contribute to lowering energy consumption and enhancing the sustainability of the production process. Within this context, cell-free synthesis emerges as a promising approach to accelerate the shift towards biomanufacturing. Operating with cellular machinery in a controlled environment, cell-free synthesis offers multiple advantages: it enables the rapid evaluation of biosynthetic pathways and optimization of the conditions for the synthesis of specific chemicals. It also holds potential as an on-demand platform for the production of personalized and specialized products. This review explores recent progress in cell-free synthesis, highlighting its potential to expedite the transformation of chemical processes into more sustainable biomanufacturing practices. We discuss how cell-free techniques not only accelerate the development of new bioproducts but also broaden the horizons for sustainable chemical production. Additionally, we address the challenges of scaling these technologies for commercial use and ensuring their affordability, which are critical for cell-free systems to meet the future demands of industries and fully realize their potential.
Collapse
Affiliation(s)
| | - Dong-Myung Kim
- Department of Chemical Engineering and Applied Chemistry, Chungnam National University, 99 Daehak-Ro, Daejeon 34134, Republic of Korea;
| |
Collapse
|
5
|
Levrier A, Karpathakis I, Nash B, Bowden SD, Lindner AB, Noireaux V. PHEIGES: all-cell-free phage synthesis and selection from engineered genomes. Nat Commun 2024; 15:2223. [PMID: 38472230 PMCID: PMC10933291 DOI: 10.1038/s41467-024-46585-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
Bacteriophages constitute an invaluable biological reservoir for biotechnology and medicine. The ability to exploit such vast resources is hampered by the lack of methods to rapidly engineer, assemble, package genomes, and select phages. Cell-free transcription-translation (TXTL) offers experimental settings to address such a limitation. Here, we describe PHage Engineering by In vitro Gene Expression and Selection (PHEIGES) using T7 phage genome and Escherichia coli TXTL. Phage genomes are assembled in vitro from PCR-amplified fragments and directly expressed in batch TXTL reactions to produce up to 1011 PFU/ml engineered phages within one day. We further demonstrate a significant genotype-phenotype linkage of phage assembly in bulk TXTL. This enables rapid selection of phages with altered rough lipopolysaccharides specificity from phage genomes incorporating tail fiber mutant libraries. We establish the scalability of PHEIGES by one pot assembly of such mutants with fluorescent gene integration and 10% length-reduced genome.
Collapse
Affiliation(s)
- Antoine Levrier
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
- Université Paris Cité, INSERM U1284, Center for Research and Interdisciplinarity, F-75006, Paris, France
| | - Ioannis Karpathakis
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
- Facultatea de Biotehnologii, USAMV Bucuresti, Sector 1, Cod 011464, Bucureşti, Romania
| | - Bruce Nash
- DNA Learning Center, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | - Steven D Bowden
- Department of Food Science and Nutrition, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Ariel B Lindner
- Université Paris Cité, INSERM U1284, Center for Research and Interdisciplinarity, F-75006, Paris, France.
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA.
| |
Collapse
|
6
|
Meyerowitz JT, Larsson EM, Murray RM. Development of Cell-Free Transcription-Translation Systems in Three Soil Pseudomonads. ACS Synth Biol 2024; 13:530-537. [PMID: 38319019 DOI: 10.1021/acssynbio.3c00468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
In vitro transcription-translation (TX-TL) can enable faster engineering of biological systems. This speed-up can be significant, especially in difficult-to-transform chassis. This work shows the successful development of TX-TL systems using three soil-derived wild-type Pseudomonads known to promote plant growth: Pseudomonas synxantha, Pseudomonas chlororaphis, and Pseudomonas aureofaciens. All three species demonstrated multiple sonication, runoff, and salt conditions producing detectable protein synthesis. One of these new TX-TL systems, P. synxantha, demonstrated a maximum protein yield of 2.5 μM at 125 proteins per DNA template, a maximum protein synthesis rate of 20 nM/min, and a range of DNA concentrations with a linear correspondence with the resulting protein synthesis. A set of different constitutive promoters driving mNeonGreen expression were tested in TX-TL and integrated into the genome, showing similar normalized strengths for in vivo and in vitro fluorescence. This correspondence between the TX-TL-derived promoter strength and the in vivo promoter strength indicates that these lysate-based cell-free systems can be used to characterize and engineer biological parts without genomic integration, enabling a faster design-build-test cycle.
Collapse
Affiliation(s)
- Joseph T Meyerowitz
- Division of Biology and Biological Engineering, California Institute of Technology 1200 E. California Blvd, MC 138-78, Pasadena, California 91125, United States
| | - Elin M Larsson
- Division of Biology and Biological Engineering, California Institute of Technology 1200 E. California Blvd, MC 138-78, Pasadena, California 91125, United States
| | - Richard M Murray
- Division of Biology and Biological Engineering, California Institute of Technology 1200 E. California Blvd, MC 138-78, Pasadena, California 91125, United States
| |
Collapse
|
7
|
Effendi SSW, Ng IS. Challenges and opportunities for engineered Escherichia coli as a pivotal chassis toward versatile tyrosine-derived chemicals production. Biotechnol Adv 2023; 69:108270. [PMID: 37852421 DOI: 10.1016/j.biotechadv.2023.108270] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 08/30/2023] [Accepted: 10/11/2023] [Indexed: 10/20/2023]
Abstract
Growing concerns over limited fossil resources and associated environmental problems are motivating the development of sustainable processes for the production of high-volume fuels and high-value-added compounds. The shikimate pathway, an imperative pathway in most microorganisms, is branched with tyrosine as the rate-limiting step precursor of valuable aromatic substances. Such occurrence suggests the shikimate pathway as a promising route in developing microbial cell factories with multiple applications in the nutraceutical, pharmaceutical, and chemical industries. Therefore, an increasing number of studies have focused on this pathway to enable the biotechnological manufacture of pivotal and versatile aromatic products. With advances in genome databases and synthetic biology tools, genetically programmed Escherichia coli strains are gaining immense interest in the sustainable synthesis of chemicals. Engineered E. coli is expected to be the next bio-successor of fossil fuels and plants in commercial aromatics synthesis. This review summarizes successful and applicable genetic and metabolic engineering strategies to generate new chassis and engineer the iterative pathway of the tyrosine route in E. coli, thus addressing the opportunities and current challenges toward the realization of sustainable tyrosine-derived aromatics.
Collapse
Affiliation(s)
| | - I-Son Ng
- Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan.
| |
Collapse
|
8
|
Bartelds MW, García-Blay Ó, Verhagen PGA, Wubbolts EJ, van Sluijs B, Heus HA, de Greef TFA, Huck WTS, Hansen MMK. Noise Minimization in Cell-Free Gene Expression. ACS Synth Biol 2023; 12:2217-2225. [PMID: 37478000 PMCID: PMC10443034 DOI: 10.1021/acssynbio.3c00174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Indexed: 07/23/2023]
Abstract
Biochemical reactions that involve small numbers of molecules are accompanied by a degree of inherent randomness that results in noisy reaction outcomes. In synthetic biology, the ability to minimize noise particularly during the reconstitution of future synthetic protocells is an outstanding challenge to secure robust and reproducible behavior. Here we show that by encapsulation of a bacterial cell-free gene expression system in water-in-oil droplets, in vitro-synthesized MazF reduces cell-free gene expression noise >2-fold. With stochastic simulations we identify that this noise minimization acts through both increased degradation and the autoregulatory feedback of MazF. Specifically, we find that the expression of MazF enhances the degradation rate of mRNA up to 18-fold in a sequence-dependent manner. This sequence specificity of MazF would allow targeted noise control, making it ideal to integrate into synthetic gene networks. Therefore, including MazF production in synthetic biology can significantly minimize gene expression noise, impacting future design principles of more complex cell-free gene circuits.
Collapse
Affiliation(s)
- Mart W. Bartelds
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Óscar García-Blay
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Pieter G. A. Verhagen
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Elise J. Wubbolts
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Bob van Sluijs
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Hans A. Heus
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Tom F. A. de Greef
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Laboratory
of Chemical Biology, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Computational
Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology,
P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Center
for Living Technologies, Eindhoven-Wageningen-Utrecht
Alliance, 5600 MB Eindhoven, The Netherlands
| | - Wilhelm T. S. Huck
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Maike M. K. Hansen
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| |
Collapse
|
9
|
Nam H, Kim T, Moon S, Ji Y, Lee JB. Self-assembly of a multimeric genomic hydrogel via multi-primed chain reaction of dual single-stranded circular plasmids for cell-free protein production. iScience 2023; 26:107089. [PMID: 37416467 PMCID: PMC10319821 DOI: 10.1016/j.isci.2023.107089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 04/20/2023] [Accepted: 06/07/2023] [Indexed: 07/08/2023] Open
Abstract
Recent technical advances in cell-free protein synthesis (CFPS) offer several advantages over cell-based expression systems, including the application of cellular machinery, such as transcription and translation, in the test tube. Inspired by the advantages of CFPS, we have fabricated a multimeric genomic DNA hydrogel (mGD-gel) via rolling circle chain amplification (RCCA) using dual single-stranded circular plasmids with multiple primers. The mGD-gel exhibited significantly enhanced protein yield. In addition, mGD-gel can be reused at least five times, and the shape of the mGD-gel can be easily manipulated without losing the feasibility of protein expression. The mGD-gel platform based on the self-assembly of multimeric genomic DNA strands (mGD strands) has the potential to be used in CFPS systems for a variety of biotechnological applications.
Collapse
Affiliation(s)
- Hyangsu Nam
- Department of Chemical Engineering, University of Seoul, 163 Seoulsiripdaero, Dongdaemun-gu, Seoul 02504, Republic of Korea
| | - Taehyeon Kim
- Department of Chemical Engineering, University of Seoul, 163 Seoulsiripdaero, Dongdaemun-gu, Seoul 02504, Republic of Korea
| | - Sunghyun Moon
- Department of Chemical Engineering, University of Seoul, 163 Seoulsiripdaero, Dongdaemun-gu, Seoul 02504, Republic of Korea
| | - Yoonbin Ji
- Department of Chemical Engineering, University of Seoul, 163 Seoulsiripdaero, Dongdaemun-gu, Seoul 02504, Republic of Korea
| | - Jong Bum Lee
- Department of Chemical Engineering, University of Seoul, 163 Seoulsiripdaero, Dongdaemun-gu, Seoul 02504, Republic of Korea
| |
Collapse
|
10
|
Hunt AC, Vögeli B, Hassan AO, Guerrero L, Kightlinger W, Yoesep DJ, Krüger A, DeWinter M, Diamond MS, Karim AS, Jewett MC. A rapid cell-free expression and screening platform for antibody discovery. Nat Commun 2023; 14:3897. [PMID: 37400446 DOI: 10.1038/s41467-023-38965-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 05/23/2023] [Indexed: 07/05/2023] Open
Abstract
Antibody discovery is bottlenecked by the individual expression and evaluation of antigen-specific hits. Here, we address this bottleneck by developing a workflow combining cell-free DNA template generation, cell-free protein synthesis, and binding measurements of antibody fragments in a process that takes hours rather than weeks. We apply this workflow to evaluate 135 previously published antibodies targeting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including all 8 antibodies previously granted emergency use authorization for coronavirus disease 2019 (COVID-19), and demonstrate identification of the most potent antibodies. We also evaluate 119 anti-SARS-CoV-2 antibodies from a mouse immunized with the SARS-CoV-2 spike protein and identify neutralizing antibody candidates, including the antibody SC2-3, which binds the SARS-CoV-2 spike protein of all tested variants of concern. We expect that our cell-free workflow will accelerate the discovery and characterization of antibodies for future pandemics and for research, diagnostic, and therapeutic applications more broadly.
Collapse
Affiliation(s)
- Andrew C Hunt
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Bastian Vögeli
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Ahmed O Hassan
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Laura Guerrero
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Weston Kightlinger
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Danielle J Yoesep
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Antje Krüger
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Madison DeWinter
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
- Medical Scientist Training Program, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Michael S Diamond
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Ashty S Karim
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA.
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA.
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, 60208, USA.
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, 60611, USA.
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA.
| |
Collapse
|
11
|
Seki K, Galindo JL, Karim AS, Jewett MC. A Cell-Free Gene Expression Platform for Discovering and Characterizing Stop Codon Suppressing tRNAs. ACS Chem Biol 2023; 18:1324-1334. [PMID: 37257197 DOI: 10.1021/acschembio.3c00051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Non-canonical amino acids (ncAAs) can be incorporated into peptides and proteins to create new properties and functions. Site-specific ncAA incorporation is typically enabled by orthogonal translation systems comprising a stop codon suppressing tRNA (typically UAG), an aminoacyl-tRNA synthetase, and an ncAA of interest. Unfortunately, methods to discover and characterize suppressor tRNAs are limited because of laborious and time-consuming workflows in living cells. In this work, we develop anEscherichia coli crude extract-based cell-free gene expression system to rapidly express and characterize functional suppressor tRNAs. Our approach co-expresses orthogonal tRNAs using endogenous machinery alongside a stop-codon containing superfolder green fluorescent protein (sfGFP) reporter, which can be used as a simple read-out for suppression. As a model, we evaluate the UAG and UAA suppressing activity of several orthogonal tRNAs. Then, we demonstrate that co-transcription of two mutually orthogonal tRNAs can direct the incorporation of two unique ncAAs within a single modified sfGFP. Finally, we show that the cell-free workflow can be used to discover putative UAG-suppressor tRNAs found in metagenomic data, which are nonspecifically recognized by endogenous aminoacyl-tRNA synthetases. We anticipate that our cell-free system will accelerate the development of orthogonal translation systems for synthetic biology.
Collapse
Affiliation(s)
- Kosuke Seki
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
| | - Joey L Galindo
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
| | - Ashty S Karim
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
- Robert H. Lurie Comprehensive Cancer Center and Simpson Querrey Institute, Northwestern University, Chicago, Illinois 60611, United States
| |
Collapse
|
12
|
Li J, Li P, Liu Q, Li J, Qi H. Translation initiation consistency between in vivo and in vitro bacterial protein expression systems. Front Bioeng Biotechnol 2023; 11:1201580. [PMID: 37304134 PMCID: PMC10248181 DOI: 10.3389/fbioe.2023.1201580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 05/17/2023] [Indexed: 06/13/2023] Open
Abstract
Strict on-demand control of protein synthesis is a crucial aspect of synthetic biology. The 5'-terminal untranslated region (5'-UTR) is an essential bacterial genetic element that can be designed for the regulation of translation initiation. However, there is insufficient systematical data on the consistency of 5'-UTR function among various bacterial cells and in vitro protein synthesis systems, which is crucial for the standardization and modularization of genetic elements in synthetic biology. Here, more than 400 expression cassettes comprising the GFP gene under the regulation of various 5'-UTRs were systematically characterized to evaluate the protein translation consistency in the two popular Escherichia coli strains of JM109 and BL21, as well as an in vitro protein expression system based on cell lysate. In contrast to the very strong correlation between the two cellular systems, the consistency between in vivo and in vitro protein translation was lost, whereby both in vivo and in vitro translation evidently deviated from the estimation of the standard statistical thermodynamic model. Finally, we found that the absence of nucleotide C and complex secondary structure in the 5'-UTR significantly improve the efficiency of protein translation, both in vitro and in vivo.
Collapse
Affiliation(s)
- Jiaojiao Li
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Frontier Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, China
| | - Peixian Li
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Frontier Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, China
| | - Qian Liu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Frontier Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, China
| | - Jinjin Li
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Frontier Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, China
| | - Hao Qi
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Frontier Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, China
- Zhejiang Shaoxing Research Institute of Tianjin University, Shaoxing, China
| |
Collapse
|
13
|
Yuan Q, Wu M, Liao Y, Liang S, Lu Y, Lin Y. Rapid prototyping enzyme homologs to improve titer of nicotinamide mononucleotide using a strategy combining cell-free protein synthesis with split GFP. Biotechnol Bioeng 2023; 120:1133-1146. [PMID: 36585353 DOI: 10.1002/bit.28326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/18/2022] [Accepted: 12/29/2022] [Indexed: 01/01/2023]
Abstract
Engineering biological systems to test new pathway variants containing different enzyme homologs is laborious and time-consuming. To tackle this challenge, a strategy was developed for rapidly prototyping enzyme homologs by combining cell-free protein synthesis (CFPS) with split green fluorescent protein (GFP). This strategy featured two main advantages: (1) dozens of enzyme homologs were parallelly produced by CFPS within hours, and (2) the expression level and activity of each homolog was determined simultaneously by using the split GFP assay. As a model, this strategy was applied to optimize a 3-step pathway for nicotinamide mononucleotide (NMN) synthesis. Ten enzyme homologs from different organisms were selected for each step. Here, the most productive homolog of each step was identified within 24 h rather than weeks or months. Finally, the titer of NMN was increased to 1213 mg/L by improving physiochemical conditions, tuning enzyme ratios and cofactor concentrations, and decreasing the feedback inhibition, which was a more than 12-fold improvement over the initial setup. This strategy would provide a promising way to accelerate design-build-test cycles for metabolic engineering to improve the production of desired products.
Collapse
Affiliation(s)
- Qingyan Yuan
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Minhui Wu
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Yibo Liao
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Shuli Liang
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Yuan Lu
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Ying Lin
- Guangdong Key Laboratory of Fermentation and Enzyme Engineering, Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| |
Collapse
|
14
|
Fochtman TJ, Oza JP. Established and Emerging Methods for Protecting Linear DNA in Cell-Free Expression Systems. Methods Protoc 2023; 6:mps6020036. [PMID: 37104018 PMCID: PMC10146267 DOI: 10.3390/mps6020036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/17/2023] [Accepted: 03/21/2023] [Indexed: 04/03/2023] Open
Abstract
Cell-free protein synthesis (CFPS) is a method utilized for producing proteins without the limits of cell viability. The plug-and-play utility of CFPS is a key advantage over traditional plasmid-based expression systems and is foundational to the potential of this biotechnology. A key limitation of CFPS is the varying stability of DNA types, limiting the effectiveness of cell-free protein synthesis reactions. Researchers generally rely on plasmid DNA for its ability to support robust protein expression in vitro. However, the overhead required to clone, propagate, and purify plasmids reduces the potential of CFPS for rapid prototyping. While linear templates overcome the limits of plasmid DNA preparation, linear expression templates (LETs) were under-utilized due to their rapid degradation in extract based CFPS systems, limiting protein synthesis. To reach the potential of CFPS using LETs, researchers have made notable progress toward protection and stabilization of linear templates throughout the reaction. The current advancements range from modular solutions, such as supplementing nuclease inhibitors and genome engineering to produce strains lacking nuclease activity. Effective application of LET protection techniques improves expression yields of target proteins to match that of plasmid-based expression. The outcome of LET utilization in CFPS is rapid design–build–test–learn cycles to support synthetic biology applications. This review describes the various protection mechanisms for linear expression templates, methodological insights for implementation, and proposals for continued efforts that may further advance the field.
Collapse
|
15
|
Rasor BJ, Karim AS, Alper HS, Jewett MC. Cell Extracts from Bacteria and Yeast Retain Metabolic Activity after Extended Storage and Repeated Thawing. ACS Synth Biol 2023; 12:904-908. [PMID: 36848582 DOI: 10.1021/acssynbio.2c00685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Cell-free synthetic biology enables rapid prototyping of biological parts and synthesis of proteins or metabolites in the absence of cell growth constraints. Cell-free systems are frequently made from crude cell extracts, where composition and activity can vary significantly based on source strain, preparation and processing, reagents, and other considerations. This variability can cause extracts to be treated as black boxes for which empirical observations guide practical laboratory practices, including a hesitance to use dated or previously thawed extracts. To better understand the robustness of cell extracts over time, we assessed the activity of cell-free metabolism during storage. As a model, we studied conversion of glucose to 2,3-butanediol. We found that cell extracts from Escherichia coli and Saccharomyces cerevisiae subjected to an 18-month storage period and repeated freeze-thaw cycles retain consistent metabolic activity. This work gives users of cell-free systems a better understanding of the impacts of storage on extract behavior.
Collapse
|
16
|
Rasor BJ, Chirania P, Rybnicky GA, Giannone RJ, Engle NL, Tschaplinski TJ, Karim AS, Hettich RL, Jewett MC. Mechanistic Insights into Cell-Free Gene Expression through an Integrated -Omics Analysis of Extract Processing Methods. ACS Synth Biol 2023; 12:405-418. [PMID: 36700560 DOI: 10.1021/acssynbio.2c00339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cell-free systems derived from crude cell extracts have developed into tools for gene expression, with applications in prototyping, biosensing, and protein production. Key to the development of these systems is optimization of cell extract preparation methods. However, the applied nature of these optimizations often limits investigation into the complex nature of the extracts themselves, which contain thousands of proteins and reaction networks with hundreds of metabolites. Here, we sought to uncover the black box of proteins and metabolites in Escherichia coli cell-free reactions based on different extract preparation methods. We assess changes in transcription and translation activity from σ70 promoters in extracts prepared with acetate or glutamate buffer and the common post-lysis processing steps of a runoff incubation and dialysis. We then utilize proteomic and metabolomic analyses to uncover potential mechanisms behind these changes in gene expression, highlighting the impact of cold shock-like proteins and the role of buffer composition.
Collapse
Affiliation(s)
- Blake J Rasor
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States.,Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States.,Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
| | - Payal Chirania
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.,Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Grant A Rybnicky
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States.,Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States.,Interdisciplinary Biological Sciences Graduate Program, Northwestern University, Evanston, Illinois 60208, United States
| | - Richard J Giannone
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Nancy L Engle
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Timothy J Tschaplinski
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Ashty S Karim
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States.,Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States.,Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
| | - Robert L Hettich
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States.,Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States.,Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States.,Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois 60611, United States.,Simpson Querrey Institute, Northwestern University, Chicago, Illinois 60611, United States
| |
Collapse
|
17
|
Using CIVT-SELEX to Select Aptamers as Genetic Parts to Regulate Gene Circuits in a Cell-Free System. Int J Mol Sci 2023; 24:ijms24032833. [PMID: 36769156 PMCID: PMC9917220 DOI: 10.3390/ijms24032833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/13/2023] [Accepted: 01/24/2023] [Indexed: 02/05/2023] Open
Abstract
The complexity of genetic circuits has not seen a significant increase over the last decades, even with the rapid development of synthetic biology tools. One of the bottlenecks is the limited number of orthogonal transcription factor-operator pairs. Researchers have tried to use aptamer-ligand pairs as genetic parts to regulate transcription. However, most aptamers selected using traditional methods cannot be directly applied in gene circuits for transcriptional regulation. To that end, we report a new method called CIVT-SELEX to select DNA aptamers that can not only bind to macromolecule ligands but also undergo significant conformational changes, thus affecting transcription. The single-stranded DNA library with affinity to our example ligand human thrombin protein is first selected and enriched. Then, these ssDNAs are inserted into a genetic circuit and tested in the in vitro transcription screening to obtain the ones with significant inhibitory effects on downstream gene transcription when thrombins are present. These aptamer-thrombin pairs can inhibit the transcription of downstream genes, demonstrating the feasibility and robustness of their use as genetic parts in both linear DNAs and plasmids. We believe that this method can be applied to select aptamers of any target ligands and vastly expand the genetic part library for transcriptional regulation.
Collapse
|
18
|
Deich C, Cash B, Sato W, Sharon J, Aufdembrink L, Gaut NJ, Heili J, Stokes K, Engelhart AE, Adamala KP. T7Max transcription system. J Biol Eng 2023; 17:4. [PMID: 36691081 PMCID: PMC9872363 DOI: 10.1186/s13036-023-00323-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 01/04/2023] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Efficient cell-free protein expression from linear DNA templates has remained a challenge primarily due to template degradation. In addition, the yields of transcription in cell-free systems lag behind transcriptional efficiency of live cells. Most commonly used in vitro translation systems utilize T7 RNA polymerase, which is also the enzyme included in many commercial kits. RESULTS Here we present characterization of a variant of T7 RNA polymerase promoter that acts to significantly increase the yields of gene expression within in vitro systems. We have demonstrated that T7Max increases the yield of translation in many types of commonly used in vitro protein expression systems. We also demonstrated increased protein expression yields from linear templates, allowing the use of T7Max driven expression from linear templates. CONCLUSIONS The modified promoter, termed T7Max, recruits standard T7 RNA polymerase, so no protein engineering is needed to take advantage of this method. This technique could be used with any T7 RNA polymerase- based in vitro protein expression system.
Collapse
Affiliation(s)
- Christopher Deich
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Brock Cash
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Wakana Sato
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Judee Sharon
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Lauren Aufdembrink
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Nathaniel J Gaut
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Joseph Heili
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Kaitlin Stokes
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Aaron E Engelhart
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA.
| | - Katarzyna P Adamala
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA.
| |
Collapse
|
19
|
Yue K, Li Y, Cao M, Shen L, Gu J, Kai L. Bottom-Up Synthetic Biology Using Cell-Free Protein Synthesis. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2023; 185:1-20. [PMID: 37526707 DOI: 10.1007/10_2023_232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Technical advances in biotechnology have greatly accelerated the development of bottom-up synthetic biology. Unlike top-down approaches, bottom-up synthetic biology focuses on the construction of a minimal cell from scratch and the application of these principles to solve challenges. Cell-free protein synthesis (CFPS) systems provide minimal machinery for transcription and translation, from either a fractionated cell lysate or individual purified protein elements, thus speeding up the development of synthetic cell projects. In this review, we trace the history of the cell-free technique back to the first in vitro fermentation experiment using yeast cell lysate. Furthermore, we summarized progresses of individual cell mimicry modules, such as compartmentalization, gene expression regulation, energy regeneration and metabolism, growth and division, communication, and motility. Finally, current challenges and future perspectives on the field are outlined.
Collapse
Affiliation(s)
- Ke Yue
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Yingqiu Li
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Mengjiao Cao
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Lulu Shen
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Jingsheng Gu
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Lei Kai
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China.
| |
Collapse
|
20
|
Choi YN, Cho N, Lee K, Gwon DA, Lee JW, Lee J. Programmable Synthesis of Biobased Materials Using Cell-Free Systems. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2203433. [PMID: 36108274 DOI: 10.1002/adma.202203433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 08/26/2022] [Indexed: 06/15/2023]
Abstract
Motivated by the intricate mechanisms underlying biomolecule syntheses in cells that chemistry is currently unable to mimic, researchers have harnessed biological systems for manufacturing novel materials. Cell-free systems (CFSs) utilizing the bioactivity of transcriptional and translational machineries in vitro are excellent tools that allow supplementation of exogenous materials for production of innovative materials beyond the capability of natural biological systems. Herein, recent studies that have advanced the ability to expand the scope of biobased materials using CFS are summarized and approaches enabling the production of high-value materials, prototyping of genetic parts and modules, and biofunctionalization are discussed. By extending the reach of chemical and enzymatic reactions complementary to cellular materials, CFSs provide new opportunities at the interface of materials science and synthetic biology.
Collapse
Affiliation(s)
- Yun-Nam Choi
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Namjin Cho
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Kanghun Lee
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Da-Ae Gwon
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Jeong Wook Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Joongoo Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| |
Collapse
|
21
|
Mathur D, Thakur M, Díaz SA, Susumu K, Stewart MH, Oh E, Walper SA, Medintz IL. Hybrid Nucleic Acid-Quantum Dot Assemblies as Multiplexed Reporter Platforms for Cell-Free Transcription Translation-Based Biosensors. ACS Synth Biol 2022; 11:4089-4102. [PMID: 36441919 PMCID: PMC9829448 DOI: 10.1021/acssynbio.2c00394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cell-free synthetic biology has emerged as a valuable tool for the development of rapid, portable biosensors that can be readily transported in the freeze-dried form to the point of need eliminating cold chain requirements. One of the challenges associated with cell-free sensors is the ability to simultaneously detect multiple analytes within a single reaction due to the availability of a limited set of fluorescent and colorimetric reporters. To potentially provide multiplexing capabilities to cell-free biosensors, we designed a modular semiconductor quantum dot (QD)-based reporter platform that is plugged in downstream of the transcription-translation functionality in the cell-free reaction and which converts enzymatic activity in the reaction into distinct optical signals. We demonstrate proof of concept by converting restriction enzyme activity, utilized as our prototypical sensing output, into optical changes across several distinct spectral output channels that all use a common excitation wavelength. These hybrid Förster resonance energy transfer (FRET)-based QD peptide PNA-DNA-Dye reporters (QD-PDDs) are completely self-assembled and consist of differentially emissive QD donors paired to a dye-acceptor displayed on a unique DNA encoding a given enzyme's cleavage site. Three QD-based PDDs, independently activated by the enzymes BamHI, EcoRI, and NcoI, were prototyped in mixed enzyme assays where all three demonstrated the ability to convert enzymatic activity into fluorescent output. Simultaneous monitoring of each of the three paired QD-donor dye-acceptor spectral channels in cell-free biosensing reactions supplemented with added linear genes encoding each enzyme confirmed robust multiplexing capabilities for at least two enzymes when co-expressed. The modular QD-PDDs are easily adapted to respond to other restriction enzymes or even proteases if desired.
Collapse
Affiliation(s)
| | | | - Sebastián A. Díaz
- Center for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington 20375, United States
| | - Kimihiro Susumu
- Jacobs Corporation, Hanover, Maryland 21076, United States; Optical Sciences Division Code 5600, U.S. Naval Research Laboratory, Washington 20375, United States
| | - Michael H. Stewart
- Optical Sciences Division Code 5600, U.S. Naval Research Laboratory, Washington 20375, United States
| | - Eunkeu Oh
- Optical Sciences Division Code 5600, U.S. Naval Research Laboratory, Washington 20375, United States
| | - Scott A. Walper
- Center for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington 20375, United States
| | - Igor L. Medintz
- Center for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington 20375, United States
| |
Collapse
|
22
|
Liyanagedera SBW, Williams J, Wheatley JP, Biketova AY, Hasan M, Sagona AP, Purdy KJ, Puxty RJ, Feher T, Kulkarni V. SpyPhage: A Cell-Free TXTL Platform for Rapid Engineering of Targeted Phage Therapies. ACS Synth Biol 2022; 11:3330-3342. [PMID: 36194543 DOI: 10.1021/acssynbio.2c00244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The past decade has seen the emergence of multidrug resistant pathogens as a leading cause of death worldwide, reigniting interest in the field of phage therapy. Modern advances in the genetic engineering of bacteriophages have enabled several useful results including host range alterations, constitutive lytic growth, and control over phage replication. However, the slow licensing process of genetically modified organisms clearly inhibits the rapid therapeutic application of novel engineered variants necessary to fight mutant pathogens that emerge throughout the course of a pandemic. As a solution to this problem, we propose the SpyPhage system where a "scaffold" bacteriophage is engineered to incorporate a SpyTag moiety on its capsid head to enable rapid postsynthetic modification of their surfaces with SpyCatcher-fused therapeutic proteins. As a proof of concept, through CRISPR/Cas-facilitated phage engineering and whole genome assembly, we targeted a SpyTag capsid fusion to K1F, a phage targeting the pathogenic strain Escherichia coli K1. We demonstrate for the first time the cell-free assembly and decoration of the phage surface with two alternative fusion proteins, SpyCatcher-mCherry-EGF and SpyCatcher-mCherry-Rck, both of which facilitate the endocytotic uptake of the phages by a urinary bladder epithelial cell line. Overall, our work presents a cell-free phage production pipeline for the generation of multiple phenotypically distinct phages with a single underlying "scaffold" genotype. These phages could become the basis of next-generation phage therapies where the knowledge-based engineering of numerous phage variants would be quickly achievable without the use of live bacteria or the need to repeatedly license novel genetic alterations.
Collapse
Affiliation(s)
| | - Joshua Williams
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Joseph P Wheatley
- School of Engineering, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Alona Yu Biketova
- Institute of Biochemistry, Eötvös Lóránd Research Network, Szeged Biological Research Centre, Szeged 6726, Hungary.,Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond TW9 3AE, United Kingdom
| | - Muhammad Hasan
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Antonia P Sagona
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Kevin J Purdy
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Richard J Puxty
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Tamas Feher
- Institute of Biochemistry, Eötvös Lóránd Research Network, Szeged Biological Research Centre, Szeged 6726, Hungary
| | | |
Collapse
|
23
|
Nagappa LK, Sato W, Alam F, Chengan K, Smales CM, Von Der Haar T, Polizzi KM, Adamala KP, Moore SJ. A ubiquitous amino acid source for prokaryotic and eukaryotic cell-free transcription-translation systems. Front Bioeng Biotechnol 2022; 10:992708. [PMID: 36185432 PMCID: PMC9524191 DOI: 10.3389/fbioe.2022.992708] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 08/30/2022] [Indexed: 11/28/2022] Open
Abstract
Cell-free gene expression (CFE) systems are an attractive tool for engineering within synthetic biology and for industrial production of high-value recombinant proteins. CFE reactions require a cell extract, energy system, amino acids, and DNA, to catalyse mRNA transcription and protein synthesis. To provide an amino acid source, CFE systems typically use a commercial standard, which is often proprietary. Herein we show that a range of common microbiology rich media (i.e., tryptone, peptone, yeast extract and casamino acids) unexpectedly provide an effective and low-cost amino acid source. We show that this approach is generalisable, by comparing batch variability and protein production in the following range of CFE systems: Escherichia coli (Rosetta™ 2 (DE3), BL21(DE3)), Streptomyces venezuelae and Pichia pastoris. In all CFE systems, we show equivalent or increased protein synthesis capacity upon replacement of the commercial amino acid source. In conclusion, we suggest rich microbiology media provides a new amino acid source for CFE systems with potential broad use in synthetic biology and industrial biotechnology applications.
Collapse
Affiliation(s)
| | - Wakana Sato
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, United States
| | - Farzana Alam
- Centre for Synthetic Biology, Imperial College London, London, United Kingdom
| | | | | | | | - Karen M Polizzi
- Centre for Synthetic Biology, Imperial College London, London, United Kingdom
- Department of Chemical Engineering, Imperial College London, London, United Kingdom
| | - Katarzyna P Adamala
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, United States
| | - Simon J Moore
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| |
Collapse
|
24
|
Ranji Charna A, Des Soye BJ, Ntai I, Kelleher NL, Jewett MC. An efficient cell-free protein synthesis platform for producing proteins with pyrrolysine-based noncanonical amino acids. Biotechnol J 2022; 17:e2200096. [PMID: 35569121 PMCID: PMC9452482 DOI: 10.1002/biot.202200096] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/04/2022] [Accepted: 05/09/2022] [Indexed: 11/08/2022]
Abstract
Incorporation of noncanonical amino acids (ncAAs) into proteins opens new opportunities in biotechnology and synthetic biology. Pyrrolysine (Pyl)-based ncAAs are some of the most predominantly used, but expression systems suffer from low yields. Here, we report a highly efficient cell-free protein synthesis (CFPS) platform for site-specific incorporation of Pyl-based ncAAs into proteins using amber suppression. This platform is based on cellular extracts derived from genomically recoded Escherichia coli lacking release factor 1 and enhanced through deletion of endonuclease A. To enable ncAA incorporation, orthogonal translation system (OTS) components (i.e., the orthogonal transfer RNA [tRNA] and orthogonal aminoacyl tRNA synthetase) were coexpressed in the source strain prior to lysis and the orthogonal tRNACUA Pyl that decodes the amber codon was further enriched in the CFPS reaction via co-synthesis with the product. Using this platform, we demonstrate production of up to 442 ± 23 µg/mL modified superfolder green fluorescent protein (sfGFP) containing a single Pyl-based ncAA at high (>95%) suppression efficiency, as well as sfGFP variants harboring multiple, identical ncAAs. Our CFPS platform can be used for the synthesis of modified proteins containing multiple precisely positioned, genetically encoded Pyl-based ncAAs. We anticipate that it will facilitate more general use of CFPS in synthetic biology.
Collapse
Affiliation(s)
- Arnaz Ranji Charna
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Benjamin J Des Soye
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Ioanni Ntai
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Neil L Kelleher
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
- Department of Chemistry, Northwestern University, Evanston, Illinois, USA
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois, USA
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois, USA
- Member, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Northwestern University, Chicago, Illinois, USA
| |
Collapse
|
25
|
Evaluating and mitigating clinical samples matrix effects on TX-TL cell-free performance. Sci Rep 2022; 12:13785. [PMID: 35962056 PMCID: PMC9374283 DOI: 10.1038/s41598-022-17583-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/27/2022] [Indexed: 12/03/2022] Open
Abstract
Cell-free biosensors are promising tools for medical diagnostics, yet their performance can be affected by matrix effects arising from the sample itself or from external components. Here we systematically evaluate the performance and robustness of cell-free systems in serum, plasma, urine, and saliva using two reporter systems, sfGFP and luciferase. In all cases, clinical samples have a strong inhibitory effect. Of the different inhibitors, only RNase inhibitor mitigated matrix effects. However, we found that the recovery potential of RNase inhibitor was partially muted by interference from glycerol contained in the commercial buffer. We solved this issue by designing a strain producing an RNase inhibitor protein requiring no additional step in extract preparation. Furthermore, our new extract yielded higher reporter levels than previous conditions and tempered interpatient variability associated with matrix effects. This systematic evaluation and improvements of cell-free system robustness unified across many types of clinical samples is a significant step towards developing cell-free diagnostics for a wide range of conditions.
Collapse
|
26
|
Rhea KA, McDonald ND, Cole SD, Noireaux V, Lux MW, Buckley PE. Variability in cell-free expression reactions can impact qualitative genetic circuit characterization. Synth Biol (Oxf) 2022; 7:ysac011. [PMID: 35966404 PMCID: PMC9365049 DOI: 10.1093/synbio/ysac011] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/24/2022] [Accepted: 08/01/2022] [Indexed: 09/21/2023] Open
Abstract
Cell-free expression systems provide a suite of tools that are used in applications from sensing to biomanufacturing. One of these applications is genetic circuit prototyping, where the lack of cloning is required and a high degree of control over reaction components and conditions enables rapid testing of design candidates. Many studies have shown utility in the approach for characterizing genetic regulation elements, simple genetic circuit motifs, protein variants or metabolic pathways. However, variability in cell-free expression systems is a known challenge, whether between individuals, laboratories, instruments, or batches of materials. While the issue of variability has begun to be quantified and explored, little effort has been put into understanding the implications of this variability. For genetic circuit prototyping, it is unclear when and how significantly variability in reaction activity will impact qualitative assessments of genetic components, e.g. relative activity between promoters. Here, we explore this question by assessing DNA titrations of seven genetic circuits of increasing complexity using reaction conditions that ostensibly follow the same protocol but vary by person, instrument and material batch. Although the raw activities vary widely between the conditions, by normalizing within each circuit across conditions, reasonably consistent qualitative performance emerges for the simpler circuits. For the most complex case involving expression of three proteins, we observe a departure from this qualitative consistency, offering a provisional cautionary line where normal variability may disrupt reliable reuse of prototyping results. Our results also suggest that a previously described closed loop controller circuit may help to mitigate such variability, encouraging further work to design systems that are robust to variability. Graphical Abstract.
Collapse
Affiliation(s)
- Katherine A Rhea
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| | - Nathan D McDonald
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| | - Stephanie D Cole
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Matthew W Lux
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| | - Patricia E Buckley
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| |
Collapse
|
27
|
Copeland CE, Kim J, Copeland PL, Heitmeier CJ, Kwon YC. Characterizing a New Fluorescent Protein for a Low Limit of Detection Sensing in the Cell-Free System. ACS Synth Biol 2022; 11:2800-2810. [PMID: 35850511 PMCID: PMC9396652 DOI: 10.1021/acssynbio.2c00180] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cell-free protein synthesis-based biosensors have been developed as highly accurate, low-cost biosensors. However, since most biomarkers exist at low concentrations in various types of biopsies, the biosensor's dynamic range must be increased in the system to achieve low limits of detection necessary while deciphering from higher background signals. Many attempts to increase the dynamic range have relied on amplifying the input signal from the analyte, which can lead to complications of false positives. In this study, we aimed to increase the protein synthesis capability of the cell-free protein synthesis system and the output signal of the reporter protein to achieve a lower limit of detection. We utilized a new fluorescent protein, mNeonGreen, which produces a higher output than those commonly used in cell-free biosensors. Optimizations of DNA sequence and the subsequent cell-free protein synthesis reaction conditions allowed characterizing protein expression variability by given DNA template types, reaction environment, and storage additives that cause the greatest time constraint on designing the cell-free biosensor. Finally, we characterized the fluorescence kinetics of mNeonGreen compared to the commonly used reporter protein, superfolder green fluorescent protein. We expect that this finely tuned cell-free protein synthesis platform with the new reporter protein can be used with sophisticated synthetic gene circuitry networks to increase the dynamic range of a cell-free biosensor to reach lower detection limits and reduce the false-positive proportion.
Collapse
Affiliation(s)
- Caroline E Copeland
- Department of Biological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Jeehye Kim
- Department of Biological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Pearce L Copeland
- Department of Biological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Chloe J Heitmeier
- Department of Biological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Yong-Chan Kwon
- Department of Biological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States.,Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803, United States
| |
Collapse
|
28
|
Harbaugh SV, Silverman AD, Chushak YG, Zimlich K, Wolfe M, Thavarajah W, Jewett MC, Lucks JB, Chávez JL. Engineering a Synthetic Dopamine-Responsive Riboswitch for In Vitro Biosensing. ACS Synth Biol 2022; 11:2275-2283. [PMID: 35775197 DOI: 10.1021/acssynbio.1c00560] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The detection of chemicals using natural allosteric transcription factors is a powerful strategy for point-of-use molecular sensing, particularly using fieldable cell-free gene expression (CFE) systems. However, the reliance of detection schemes on characterized protein-based sensors limits the number of measurable analytes. One alternative solution to this issue is to develop new sensors by generating RNA aptamers against the target analyte and then incorporating them directly into a riboswitch scaffold for ligand-inducible genetic control of a reporter protein. However, this strategy has not generated more than a handful of successful portable cell-free molecular sensors. To address this gap, here we convert dopamine-binding aptamers into functional dopamine-sensing riboswitches that regulate gene expression in a freeze-dried CFE reaction. We then develop an assay for direct detection and semi-quantification of dopamine in human urine. We anticipate that this work will be broadly applicable for converting many in vitro-generated RNA aptamers into fieldable molecular diagnostics.
Collapse
Affiliation(s)
- Svetlana V Harbaugh
- 711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, United States
| | - Adam D Silverman
- Sherlock Biosciences, Boston, Massachusetts 02135, United States
| | - Yaroslav G Chushak
- 711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, United States.,Henry M. Jackson Foundation, Dayton, Ohio 45433, United States
| | - Kathryn Zimlich
- 711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, United States.,Henry M. Jackson Foundation, Dayton, Ohio 45433, United States
| | - Monica Wolfe
- 711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, United States.,UES, Inc., Dayton, Ohio 45432, United States
| | - Walter Thavarajah
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States.,Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States.,Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States.,Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois 60208, United States.,International Institute of Nanotechnology, Northwestern University, Evanston, Illinois 60208, United States
| | - Julius B Lucks
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States.,Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States.,Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois 60208, United States.,International Institute of Nanotechnology, Northwestern University, Evanston, Illinois 60208, United States
| | - Jorge L Chávez
- 711th Human Performance Wing, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, United States
| |
Collapse
|
29
|
A microfluidic optimal experimental design platform for forward design of cell-free genetic networks. Nat Commun 2022; 13:3626. [PMID: 35750678 PMCID: PMC9232554 DOI: 10.1038/s41467-022-31306-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 06/14/2022] [Indexed: 12/20/2022] Open
Abstract
Cell-free protein synthesis has been widely used as a “breadboard” for design of synthetic genetic networks. However, due to a severe lack of modularity, forward engineering of genetic networks remains challenging. Here, we demonstrate how a combination of optimal experimental design and microfluidics allows us to devise dynamic cell-free gene expression experiments providing maximum information content for subsequent non-linear model identification. Importantly, we reveal that applying this methodology to a library of genetic circuits, that share common elements, further increases the information content of the data resulting in higher accuracy of model parameters. To show modularity of model parameters, we design a pulse decoder and bistable switch, and predict their behaviour both qualitatively and quantitatively. Finally, we update the parameter database and indicate that network topology affects parameter estimation accuracy. Utilizing our methodology provides us with more accurate model parameters, a necessity for forward engineering of complex genetic networks. Characterization of cell-free genetic networks is inherently difficult. Here the authors use optimal experimental design and microfluidics to improve characterization, demonstrating modularity and predictability of parts in applied test cases.
Collapse
|
30
|
Hunt AC, Case JB, Park YJ, Cao L, Wu K, Walls AC, Liu Z, Bowen JE, Yeh HW, Saini S, Helms L, Zhao YT, Hsiang TY, Starr TN, Goreshnik I, Kozodoy L, Carter L, Ravichandran R, Green LB, Matochko WL, Thomson CA, Vögeli B, Krüger A, VanBlargan LA, Chen RE, Ying B, Bailey AL, Kafai NM, Boyken SE, Ljubetič A, Edman N, Ueda G, Chow CM, Johnson M, Addetia A, Navarro MJ, Panpradist N, Gale M, Freedman BS, Bloom JD, Ruohola-Baker H, Whelan SPJ, Stewart L, Diamond MS, Veesler D, Jewett MC, Baker D. Multivalent designed proteins neutralize SARS-CoV-2 variants of concern and confer protection against infection in mice. Sci Transl Med 2022; 14:eabn1252. [PMID: 35412328 PMCID: PMC9258422 DOI: 10.1126/scitranslmed.abn1252] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
New variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to arise and prolong the coronavirus disease 2019 (COVID-19) pandemic. Here, we used a cell-free expression workflow to rapidly screen and optimize constructs containing multiple computationally designed miniprotein inhibitors of SARS-CoV-2. We found the broadest efficacy was achieved with a homotrimeric version of the 75-residue angiotensin-converting enzyme 2 (ACE2) mimic AHB2 (TRI2-2) designed to geometrically match the trimeric spike architecture. Consistent with the design model, in the cryo-electron microscopy structure TRI2-2 forms a tripod at the apex of the spike protein that engaged all three receptor binding domains simultaneously. TRI2-2 neutralized Omicron (B.1.1.529), Delta (B.1.617.2), and all other variants tested with greater potency than the monoclonal antibodies used clinically for the treatment of COVID-19. TRI2-2 also conferred prophylactic and therapeutic protection against SARS-CoV-2 challenge when administered intranasally in mice. Designed miniprotein receptor mimics geometrically arrayed to match pathogen receptor binding sites could be a widely applicable antiviral therapeutic strategy with advantages over antibodies in greater resistance to viral escape and antigenic drift, and advantages over native receptor traps in lower chances of autoimmune responses.
Collapse
Affiliation(s)
- Andrew C. Hunt
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - James Brett Case
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Young-Jun Park
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Longxing Cao
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Kejia Wu
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Alexandra C. Walls
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| | - Zhuoming Liu
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - John E. Bowen
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Hsien-Wei Yeh
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Shally Saini
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine, Seattle, WA, 98109, USA
| | - Louisa Helms
- Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine, Seattle, WA, 98109, USA
- Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, 98109, USA
- Kidney Research Institute, University of Washington School of Medicine, Seattle, WA, 98109, USA
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, 98109, USA
| | - Yan Ting Zhao
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine, Seattle, WA, 98109, USA
- Oral Health Sciences, School of Dentistry, University of Washington, Seattle, WA, 98195, USA
| | - Tien-Ying Hsiang
- Department of Immunology, Center for Innate Immunity and Immune Disease, University of Washington, Seattle, WA, 98195, USA
| | - Tyler N. Starr
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA
| | - Inna Goreshnik
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Lisa Kozodoy
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Lauren Carter
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Rashmi Ravichandran
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Lydia B. Green
- Amgen Research, Biologic Discovery, Burnaby, V5A 1V7, BC, Canada
| | | | | | - Bastian Vögeli
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
- Invizyne Technologies Inc., Monrovia, CA, 91016, USA
| | - Antje Krüger
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Laura A. VanBlargan
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Rita E. Chen
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Baoling Ying
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Adam L. Bailey
- Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Pathology & Laboratory Medicine, University of Wisconsin – Madison, Madison, WI, 53705, USA
| | - Natasha M. Kafai
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Scott E. Boyken
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Ajasja Ljubetič
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
- Department for Synthetic Biology and Immunology, National Institute of Chemistry, Ljubljana, SI-1000, Slovenia
| | - Natasha Edman
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA, 98195, USA
- USA Medical Scientist Training Program, University of Washington, Seattle, WA, 98195, USA
| | - George Ueda
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Cameron M. Chow
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
- Neolukin Therapeutics Inc., Seattle, WA, 98102, USA
| | - Max Johnson
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Amin Addetia
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- The Molecular and Cellular Biology Program, University of Washington, Seattle, WA, 98195, USA
| | - Mary Jane Navarro
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Nuttada Panpradist
- Department of Bioengineering, University of Washington, Seattle, WA, 98195, USA
| | - Michael Gale
- Department of Immunology, Center for Innate Immunity and Immune Disease, University of Washington, Seattle, WA, 98195, USA
| | - Benjamin S. Freedman
- Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine, Seattle, WA, 98109, USA
- Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, 98109, USA
- Kidney Research Institute, University of Washington School of Medicine, Seattle, WA, 98109, USA
- Department of Bioengineering, University of Washington, Seattle, WA, 98195, USA
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, 98109, USA
| | - Jesse D. Bloom
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA
- Department of Genome Sciences, University of Washington, Seattle, WA, 98195, USA
| | - Hannele Ruohola-Baker
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine, Seattle, WA, 98109, USA
- Oral Health Sciences, School of Dentistry, University of Washington, Seattle, WA, 98195, USA
- Department of Bioengineering, University of Washington, Seattle, WA, 98195, USA
| | - Sean P. J. Whelan
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Lance Stewart
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
| | - Michael S. Diamond
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - David Veesler
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| | - Michael C. Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, 60208, USA
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, 60611, USA
| | - David Baker
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, 98195, USA
| |
Collapse
|
31
|
Aufinger L, Brenner J, Simmel FC. Complex dynamics in a synchronized cell-free genetic clock. Nat Commun 2022; 13:2852. [PMID: 35606356 PMCID: PMC9126873 DOI: 10.1038/s41467-022-30478-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 05/04/2022] [Indexed: 11/10/2022] Open
Abstract
Complex dynamics such as period doubling and chaos occur in a wide variety of non-linear dynamical systems. In the context of biological circadian clocks, such phenomena have been previously found in computational models, but their experimental study in biological systems has been challenging. Here, we present experimental evidence of period doubling in a forced cell-free genetic oscillator operated in a microfluidic reactor, where the system is periodically perturbed by modulating the concentration of one of the oscillator components. When the external driving matches the intrinsic period, we experimentally find period doubling and quadrupling in the oscillator dynamics. Our results closely match the predictions of a theoretical model, which also suggests conditions under which our system would display chaotic dynamics. We show that detuning of the external and intrinsic period leads to more stable entrainment, suggesting a simple design principle for synchronized synthetic and natural genetic clocks. In theory, driven biological oscillators can display complex dynamic behaviors, but these are experimentally difficult to observe. Here the authors, using microfluidics, show that a synthetic cell-free gene oscillator displays period doubling and even quadrupling.
Collapse
|
32
|
van der Linden AJ, Pieters PA, Bartelds MW, Nathalia BL, Yin P, Huck WTS, Kim J, de Greef TFA. DNA Input Classification by a Riboregulator-Based Cell-Free Perceptron. ACS Synth Biol 2022; 11:1510-1520. [PMID: 35381174 PMCID: PMC9016768 DOI: 10.1021/acssynbio.1c00596] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The ability to recognize molecular patterns is essential for the continued survival of biological organisms, allowing them to sense and respond to their immediate environment. The design of synthetic gene-based classifiers has been explored previously; however, prior strategies have focused primarily on DNA strand-displacement reactions. Here, we present a synthetic in vitro transcription and translation (TXTL)-based perceptron consisting of a weighted sum operation (WSO) coupled to a downstream thresholding function. We demonstrate the application of toehold switch riboregulators to construct a TXTL-based WSO circuit that converts DNA inputs into a GFP output, the concentration of which correlates to the input pattern and the corresponding weights. We exploit the modular nature of the WSO circuit by changing the output protein to the Escherichia coli σ28-factor, facilitating the coupling of the WSO output to a downstream reporter network. The subsequent introduction of a σ28 inhibitor enabled thresholding of the WSO output such that the expression of the downstream reporter protein occurs only when the produced σ28 exceeds this threshold. In this manner, we demonstrate a genetically implemented perceptron capable of binary classification, i.e., the expression of a single output protein only when the desired minimum number of inputs is exceeded.
Collapse
Affiliation(s)
- Ardjan J. van der Linden
- Laboratory of Chemical Biology and Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Computational Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Pascal A. Pieters
- Laboratory of Chemical Biology and Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Computational Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Mart W. Bartelds
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands
| | - Bryan L. Nathalia
- Computational Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Peng Yin
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Wilhelm T. S. Huck
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands
| | - Jongmin Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Tom F. A. de Greef
- Laboratory of Chemical Biology and Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Computational Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands
- Center for Living Technologies, Eindhoven-Wageningen-Utrecht Alliance, 3584 CB Utrecht, The Netherlands
| |
Collapse
|
33
|
Guzman-Chavez F, Arce A, Adhikari A, Vadhin S, Pedroza-Garcia JA, Gandini C, Ajioka JW, Molloy J, Sanchez-Nieto S, Varner JD, Federici F, Haseloff J. Constructing Cell-Free Expression Systems for Low-Cost Access. ACS Synth Biol 2022; 11:1114-1128. [PMID: 35259873 PMCID: PMC9098194 DOI: 10.1021/acssynbio.1c00342] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Indexed: 11/29/2022]
Abstract
Cell-free systems for gene expression have gained attention as platforms for the facile study of genetic circuits and as highly effective tools for teaching. Despite recent progress, the technology remains inaccessible for many in low- and middle-income countries due to the expensive reagents required for its manufacturing, as well as specialized equipment required for distribution and storage. To address these challenges, we deconstructed processes required for cell-free mixture preparation and developed a set of alternative low-cost strategies for easy production and sharing of extracts. First, we explored the stability of cell-free reactions dried through a low-cost device based on silica beads, as an alternative to commercial automated freeze dryers. Second, we report the positive effect of lactose as an additive for increasing protein synthesis in maltodextrin-based cell-free reactions using either circular or linear DNA templates. The modifications were used to produce active amounts of two high-value reagents: the isothermal polymerase Bst and the restriction enzyme BsaI. Third, we demonstrated the endogenous regeneration of nucleoside triphosphates and synthesis of pyruvate in cell-free systems (CFSs) based on phosphoenol pyruvate (PEP) and maltodextrin (MDX). We exploited this novel finding to demonstrate the use of a cell-free mixture completely free of any exogenous nucleotide triphosphates (NTPs) to generate high yields of sfGFP expression. Together, these modifications can produce desiccated extracts that are 203-424-fold cheaper than commercial versions. These improvements will facilitate wider use of CFS for research and education purposes.
Collapse
Affiliation(s)
| | - Anibal Arce
- ANID
− Millennium Institute for Integrative Biology (iBio), FONDAP
Center for Genome Regulation, Institute for Biological and Medical
Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8330005, Chile
| | - Abhinav Adhikari
- Robert
Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Sandra Vadhin
- Robert
Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Jose Antonio Pedroza-Garcia
- Department
of Biochemistry, Faculty of Chemistry, National
Autonomous University of Mexico (UNAM), 04510 Mexico City, Mexico
| | - Chiara Gandini
- Department
of Chemical Engineering and Biotechnology, University of Cambridge, CB3 0FD Cambridge, U.K.
| | - Jim W. Ajioka
- Department
of Pathology, University of Cambridge, Tennis Court Road, CB2 1QP Cambridge, U.K.
| | - Jenny Molloy
- Department
of Chemical Engineering and Biotechnology, University of Cambridge, CB3 0FD Cambridge, U.K.
| | - Sobeida Sanchez-Nieto
- Department
of Biochemistry, Faculty of Chemistry, National
Autonomous University of Mexico (UNAM), 04510 Mexico City, Mexico
| | - Jeffrey D. Varner
- Robert
Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Fernan Federici
- ANID
− Millennium Institute for Integrative Biology (iBio), FONDAP
Center for Genome Regulation, Institute for Biological and Medical
Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago 8330005, Chile
| | - Jim Haseloff
- Department
of Plant Sciences, University of Cambridge, CB2 3EA Cambridge, U.K.
| |
Collapse
|
34
|
Tabuchi T, Yokobayashi Y. High-throughput screening of cell-free riboswitches by fluorescence-activated droplet sorting. Nucleic Acids Res 2022; 50:3535-3550. [PMID: 35253887 PMCID: PMC8989549 DOI: 10.1093/nar/gkac152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/15/2022] [Accepted: 02/20/2022] [Indexed: 11/14/2022] Open
Abstract
Cell-free systems that display complex functions without using living cells are emerging as new platforms to test our understanding of biological systems as well as for practical applications such as biosensors and biomanufacturing. Those that use cell-free protein synthesis (CFPS) systems to enable genetically programmed protein synthesis have relied on genetic regulatory components found or engineered in living cells. However, biological constraints such as cell permeability, metabolic stability, and toxicity of signaling molecules prevent development of cell-free devices using living cells even if cell-free systems are not subject to such constraints. Efforts to engineer regulatory components directly in CFPS systems thus far have been based on low-throughput experimental approaches, limiting the availability of basic components to build cell-free systems with diverse functions. Here, we report a high-throughput screening method to engineer cell-free riboswitches that respond to small molecules. Droplet-sorting of riboswitch variants in a CFPS system rapidly identified cell-free riboswitches that respond to compounds that are not amenable to bacterial screening methods. Finally, we used a histamine riboswitch to demonstrate chemical communication between cell-sized droplets.
Collapse
Affiliation(s)
- Takeshi Tabuchi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| |
Collapse
|
35
|
Rasor BJ, Vögeli B, Jewett MC, Karim AS. Cell-Free Protein Synthesis for High-Throughput Biosynthetic Pathway Prototyping. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2433:199-215. [PMID: 34985746 DOI: 10.1007/978-1-0716-1998-8_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Biological systems provide a sustainable and complimentary approach to synthesizing useful chemical products. Metabolic engineers seeking to establish economically viable biosynthesis platforms strive to increase product titers, rates, and yields. Despite continued advances in genetic tools and metabolic engineering techniques, cellular workflows remain limited in throughput. It may take months to test dozens of unique pathway designs even in a robust model organism, such as Escherichia coli. In contrast, cell-free protein synthesis enables the rapid generation of enzyme libraries that can be combined to reconstitute metabolic pathways in vitro for biochemical synthesis in days rather than weeks. Cell-free reactions thereby enable comparison of hundreds to thousands of unique combinations of enzyme homologs and concentrations, which can quickly identify the most productive pathway variants to test in vivo or further characterize in vitro. This cell-free pathway prototyping strategy provides a complementary approach to accelerate cellular metabolic engineering efforts toward highly productive strains for metabolite production.
Collapse
Affiliation(s)
- Blake J Rasor
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA.,Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA.,Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
| | - Bastian Vögeli
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA.,Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA.,Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Chemistry of Life Processes Institute, Center for Synthetic Biology, Robert H. Lurie Comprehensive Cancer Center, and Simpson Querrey Institute, Northwestern University, Evanston, IL, USA.
| | - Ashty S Karim
- Department of Chemical and Biological Engineering, Chemistry of Life Processes Institute, and Center for Synthetic Biology, Northwestern University, Evanston, IL, USA.
| |
Collapse
|
36
|
Gaut NJ, Gomez-Garcia J, Heili JM, Cash B, Han Q, Engelhart AE, Adamala KP. Programmable Fusion and Differentiation of Synthetic Minimal Cells. ACS Synth Biol 2022; 11:855-866. [PMID: 35089706 DOI: 10.1021/acssynbio.1c00519] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Synthetic cells can mimic the intricate complexities of live cells, while mitigating the level of noise that is present natural systems; however, many crucial processes still need to be demonstrated in synthetic cells to use them to comprehensively study and engineer biology. Here we demonstrate key functionalities of synthetic cells previously available only to natural life: differentiation and mating. This work presents a toolset for engineering combinatorial genetic circuits in synthetic cells. We demonstrate how progenitor populations can differentiate into new lineages in response to small molecule stimuli or as a result of fusion, and we provide practical demonstration of utility for metabolic engineering. This work provides a tool for bioengineering and for natural pathway studies, as well as paving the way toward the construction of live artificial cells.
Collapse
Affiliation(s)
- Nathaniel J. Gaut
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55407 United States
| | - Jose Gomez-Garcia
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55407 United States
| | - Joseph M. Heili
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55407 United States
| | - Brock Cash
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55407 United States
| | - Qiyuan Han
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55407 United States
| | - Aaron E. Engelhart
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55407 United States
| | - Katarzyna P. Adamala
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55407 United States
| |
Collapse
|
37
|
Batista AC, Levrier A, Soudier P, Voyvodic PL, Achmedov T, Reif-Trauttmansdorff T, DeVisch A, Cohen-Gonsaud M, Faulon JL, Beisel CL, Bonnet J, Kushwaha M. Differentially Optimized Cell-Free Buffer Enables Robust Expression from Unprotected Linear DNA in Exonuclease-Deficient Extracts. ACS Synth Biol 2022; 11:732-746. [PMID: 35034449 DOI: 10.1021/acssynbio.1c00448] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The use of linear DNA templates in cell-free systems promises to accelerate the prototyping and engineering of synthetic gene circuits. A key challenge is that linear templates are rapidly degraded by exonucleases present in cell extracts. Current approaches tackle the problem by adding exonuclease inhibitors and DNA-binding proteins to protect the linear DNA, requiring additional time- and resource-intensive steps. Here, we delete the recBCD exonuclease gene cluster from the Escherichia coli BL21 genome. We show that the resulting cell-free systems, with buffers optimized specifically for linear DNA, enable near-plasmid levels of expression from σ70 promoters in linear DNA templates without employing additional protection strategies. When using linear or plasmid DNA templates at the buffer calibration step, the optimal potassium glutamate concentrations obtained when using linear DNA were consistently lower than those obtained when using plasmid DNA for the same extract. We demonstrate the robustness of the exonuclease deficient extracts across seven different batches and a wide range of experimental conditions across two different laboratories. Finally, we illustrate the use of the ΔrecBCD extracts for two applications: toehold switch characterization and enzyme screening. Our work provides a simple, efficient, and cost-effective solution for using linear DNA templates in cell-free systems and highlights the importance of specifically tailoring buffer composition for the final experimental setup. Our data also suggest that similar exonuclease deletion strategies can be applied to other species suitable for cell-free synthetic biology.
Collapse
Affiliation(s)
- Angelo Cardoso Batista
- Université Paris-Saclay, INRAe, AgroParisTech, Micalis Institute, 78352 Jouy-en-Josas, France
| | - Antoine Levrier
- Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, University of Montpellier, 34090 Montpellier, France
| | - Paul Soudier
- Université Paris-Saclay, INRAe, AgroParisTech, Micalis Institute, 78352 Jouy-en-Josas, France
- Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, University of Montpellier, 34090 Montpellier, France
| | - Peter L. Voyvodic
- Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, University of Montpellier, 34090 Montpellier, France
| | - Tatjana Achmedov
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | | | - Angelique DeVisch
- Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, University of Montpellier, 34090 Montpellier, France
| | - Martin Cohen-Gonsaud
- Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, University of Montpellier, 34090 Montpellier, France
| | - Jean-Loup Faulon
- Université Paris-Saclay, INRAe, AgroParisTech, Micalis Institute, 78352 Jouy-en-Josas, France
| | - Chase L. Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
- Medical Faculty, University of Würzburg, 97080 Würzburg, Germany
| | - Jerome Bonnet
- Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, University of Montpellier, 34090 Montpellier, France
| | - Manish Kushwaha
- Université Paris-Saclay, INRAe, AgroParisTech, Micalis Institute, 78352 Jouy-en-Josas, France
| |
Collapse
|
38
|
Romantseva EF, Tack DS, Alperovich N, Ross D, Strychalski EA. Best Practices for DNA Template Preparation Toward Improved Reproducibility in Cell-Free Protein Production. Methods Mol Biol 2022; 2433:3-50. [PMID: 34985735 DOI: 10.1007/978-1-0716-1998-8_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Performance variability is a common challenge in cell-free protein production and hinders a wider adoption of these systems for both research and biomanufacturing. While the inherent stochasticity and complexity of biology likely contributes to variability, other systematic factors may also play a role, including the source and preparation of the cell extract, the composition of the supplemental reaction buffer, the facility at which experiments are conducted, and the human operator (Cole et al. ACS Synth Biol 8:2080-2091, 2019). Variability in protein production could also arise from differences in the DNA template-specifically the amount of functional DNA added to a cell-free reaction and the quality of the DNA preparation in terms of contaminants and strand breakage. Here, we present protocols and suggest best practices optimized for DNA template preparation and quantitation for cell-free systems toward reducing variability in cell-free protein production.
Collapse
Affiliation(s)
| | - Drew S Tack
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Nina Alperovich
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - David Ross
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | | |
Collapse
|
39
|
Guo S, Wang M, Xu W, Zou F, Lin J, Peng Q, Xu W, Xu S, Shi X. Rapid screening of glycosyltransferases in plants using a linear DNA expression template based cell-free transcription-translation system. PHYTOCHEMISTRY 2022; 193:113007. [PMID: 34768185 DOI: 10.1016/j.phytochem.2021.113007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/02/2021] [Accepted: 11/04/2021] [Indexed: 06/13/2023]
Abstract
Plants have an extensively large number of enzymes including glycosyltransferases that are important in the biosynthesis of natural products. However, it is time-consuming and challenging to study these enzymes and only a small percentage of them have been well-characterized. Here, we report a rapid method to screen plant glycosyltransferases using a linear DNA expression template (LET) based cell-free transcription-translation system (TX-TL). As a proof of concept, we amplified and tested glycosyltransferases from Arabidopsis thaliana and showed that the catalytic activity results of these glycosyltransferases from LET-based-TX-TL were consistent with previous studies. We then chose a local medicinal plant Anoectochilus roxburghii, acquired its transcriptome sequences, and applied this method to study its glycosyltransferases. We rapidly expressed all the putative UDP-glucose glycosyltransferases using LET-based-TX-TL and discovered 6 unreported active glycosyltransferases which can catalyze the glycosylation of quercetin into isoquercitrin. Thus, LET-based-TX-TL was shown to be a powerful tool for researchers to rapidly screen plant glycosyltransferases for the first time.
Collapse
Affiliation(s)
- Shaobin Guo
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China.
| | - Mingdi Wang
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Wen Xu
- School of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, 350122, China
| | - Fuxian Zou
- School of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, 350122, China
| | - Jingjing Lin
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Qin Peng
- School of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, 350122, China
| | - Wei Xu
- School of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, 350122, China
| | - Shaohua Xu
- School of Pharmacy, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, 350122, China
| | - Xianai Shi
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China; Fujian Key Laboratory of Medical Instrument and Pharmaceutical Technology, Fuzhou University, Fuzhou, Fujian, 350108, China
| |
Collapse
|
40
|
Soudier P, Faure L, Kushwaha M, Faulon JL. Cell-Free Biosensors and AI Integration. Methods Mol Biol 2022; 2433:303-323. [PMID: 34985753 DOI: 10.1007/978-1-0716-1998-8_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Cell-free biosensors hold a great potential as alternatives for traditional analytical chemistry methods providing low-cost low-resource measurement of specific chemicals. However, their large-scale use is limited by the complexity of their development.In this chapter, we present a standard methodology based on computer-aided design (CAD ) tools that enables fast development of new cell-free biosensors based on target molecule information transduction and reporting through metabolic and genetic layers, respectively. Such systems can then be repurposed to represent complex computational problems, allowing defined multiplex sensing of various inputs and integration of artificial intelligence in synthetic biological systems.
Collapse
Affiliation(s)
- Paul Soudier
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Léon Faure
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Manish Kushwaha
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Jean-Loup Faulon
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France. .,Université Paris-Saclay, Systems & Synthetic Biology Lab (iSSB), UMR, Evry, France. .,Manchester Institute of Biotechnology, SYNBIOCHEM Center, School of Chemistry, The University of Manchester, Manchester, UK.
| |
Collapse
|
41
|
Meyer C, Zhou C, Fang Z, Longo ML, Pan T, Tan C. High-Throughput Experimentation Using Cell-Free Protein Synthesis Systems. Methods Mol Biol 2022; 2433:121-134. [PMID: 34985741 DOI: 10.1007/978-1-0716-1998-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Cell-free protein synthesis can enable the combinatorial screening of many different components and concentrations. However, manual pipetting methods are unfit to handle many cell-free reactions. Here, we describe a microfluidic method that can generate hundreds of unique submicroliter scale reactions. The method is coupled with a high yield cell-free system that can be applied for broad protein screening assays.
Collapse
Affiliation(s)
- Conary Meyer
- Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Chuqing Zhou
- Department of Biomedical Engineering, University of California, Davis, CA, USA
| | - Zecong Fang
- Department of Biomedical Engineering, University of California, Davis, CA, USA
- Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Shenzhen Engineering Laboratory of Single-Molecule Detection and Instrument Development, Shenzhen, China
| | - Marjorie L Longo
- Department of Chemical Engineering, University of California, Davis, CA, USA
| | - Tingrui Pan
- Department of Biomedical Engineering, University of California, Davis, CA, USA
- Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Shenzhen Engineering Laboratory of Single-Molecule Detection and Instrument Development, Shenzhen, China
- Suzhou Institute for Advanced Research, University of Science and Technology of China, Suzhou, China
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, China
| | - Cheemeng Tan
- Department of Biomedical Engineering, University of California, Davis, CA, USA.
| |
Collapse
|
42
|
Brookwell A, Oza JP, Caschera F. Biotechnology Applications of Cell-Free Expression Systems. Life (Basel) 2021; 11:life11121367. [PMID: 34947898 PMCID: PMC8705439 DOI: 10.3390/life11121367] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 12/13/2022] Open
Abstract
Cell-free systems are a rapidly expanding platform technology with an important role in the engineering of biological systems. The key advantages that drive their broad adoption are increased efficiency, versatility, and low cost compared to in vivo systems. Traditionally, in vivo platforms have been used to synthesize novel and industrially relevant proteins and serve as a testbed for prototyping numerous biotechnologies such as genetic circuits and biosensors. Although in vivo platforms currently have many applications within biotechnology, they are hindered by time-constraining growth cycles, homeostatic considerations, and limited adaptability in production. Conversely, cell-free platforms are not hindered by constraints for supporting life and are therefore highly adaptable to a broad range of production and testing schemes. The advantages of cell-free platforms are being leveraged more commonly by the biotechnology community, and cell-free applications are expected to grow exponentially in the next decade. In this study, new and emerging applications of cell-free platforms, with a specific focus on cell-free protein synthesis (CFPS), will be examined. The current and near-future role of CFPS within metabolic engineering, prototyping, and biomanufacturing will be investigated as well as how the integration of machine learning is beneficial to these applications.
Collapse
Affiliation(s)
- August Brookwell
- Department of Chemistry & Biochemistry, College of Science & Mathematics, California Polytechnic State University, San Luis Obispo, CA 93407, USA;
| | - Javin P. Oza
- Department of Chemistry & Biochemistry, College of Science & Mathematics, California Polytechnic State University, San Luis Obispo, CA 93407, USA;
- Correspondence: (J.P.O.); (F.C.)
| | - Filippo Caschera
- Nuclera Nucleics Ltd., Cambridge CB4 0GD, UK
- Correspondence: (J.P.O.); (F.C.)
| |
Collapse
|
43
|
Beabout K, Bernhards CB, Thakur M, Turner KB, Cole SD, Walper SA, Chávez JL, Lux MW. Optimization of Heavy Metal Sensors Based on Transcription Factors and Cell-Free Expression Systems. ACS Synth Biol 2021; 10:3040-3054. [PMID: 34723503 DOI: 10.1021/acssynbio.1c00331] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Many bacterial mechanisms for highly specific and sensitive detection of heavy metals and other hazards have been reengineered to serve as sensors. In some cases, these sensors have been implemented in cell-free expression systems, enabling easier design optimization and deployment in low-resource settings through lyophilization. Here, we apply the advantages of cell-free expression systems to optimize sensors based on three separate bacterial response mechanisms for arsenic, cadmium, and mercury. We achieved detection limits below the World Health Organization-recommended levels for arsenic and mercury and below the short-term US Military Exposure Guideline levels for all three. The optimization of each sensor was approached differently, leading to observations useful for the development of future sensors: (1) there can be a strong dependence of specificity on the particular cell-free expression system used, (2) tuning of relative concentrations of the sensing and reporter elements improves sensitivity, and (3) sensor performance can vary significantly with linear vs plasmid DNA. In addition, we show that simply combining DNA for the three sensors into a single reaction enables detection of each target heavy metal without any further optimization. This combined approach could lead to sensors that detect a range of hazards at once, such as a panel of water contaminants or all known variants of a target virus. For low-resource settings, such "all-hazard" sensors in a cheap, easy-to-use format could have high utility.
Collapse
Affiliation(s)
- Kathryn Beabout
- UES, Inc., Dayton, Ohio 45432, United States
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Casey B. Bernhards
- Excet, Inc., 6225 Brandon Avenue #360, Springfield, Virginia 22150, United States
- U.S. Army Combat Capabilities Development Command Chemical Biological Center, 8198 Blackhawk Road, Aberdeen Proving Ground, Maryland 21010, United States
| | - Meghna Thakur
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, United States
- College of Science, George Mason University, Fairfax, Virginia 22030, United States
| | - Kendrick B. Turner
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, United States
| | - Stephanie D. Cole
- U.S. Army Combat Capabilities Development Command Chemical Biological Center, 8198 Blackhawk Road, Aberdeen Proving Ground, Maryland 21010, United States
| | - Scott A. Walper
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, United States
| | - Jorge L. Chávez
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Matthew W. Lux
- U.S. Army Combat Capabilities Development Command Chemical Biological Center, 8198 Blackhawk Road, Aberdeen Proving Ground, Maryland 21010, United States
| |
Collapse
|
44
|
|
45
|
Arce A, Guzman Chavez F, Gandini C, Puig J, Matute T, Haseloff J, Dalchau N, Molloy J, Pardee K, Federici F. Decentralizing Cell-Free RNA Sensing With the Use of Low-Cost Cell Extracts. Front Bioeng Biotechnol 2021; 9:727584. [PMID: 34497801 PMCID: PMC8419261 DOI: 10.3389/fbioe.2021.727584] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 08/06/2021] [Indexed: 11/13/2022] Open
Abstract
Cell-free gene expression systems have emerged as a promising platform for field-deployed biosensing and diagnostics. When combined with programmable toehold switch-based RNA sensors, these systems can be used to detect arbitrary RNAs and freeze-dried for room temperature transport to the point-of-need. These sensors, however, have been mainly implemented using reconstituted PURE cell-free protein expression systems that are difficult to source in the Global South due to their high commercial cost and cold-chain shipping requirements. Based on preliminary demonstrations of toehold sensors working on lysates, we describe the fast prototyping of RNA toehold switch-based sensors that can be produced locally and reduce the cost of sensors by two orders of magnitude. We demonstrate that these in-house cell lysates provide sensor performance comparable to commercial PURE cell-free systems. We further optimize these lysates with a CRISPRi strategy to enhance the stability of linear DNAs by knocking-down genes responsible for linear DNA degradation. This enables the direct use of PCR products for fast screening of new designs. As a proof-of-concept, we develop novel toehold sensors for the plant pathogen Potato Virus Y (PVY), which dramatically reduces the yield of this important staple crop. The local implementation of low-cost cell-free toehold sensors could enable biosensing capacity at the regional level and lead to more decentralized models for global surveillance of infectious disease.
Collapse
Affiliation(s)
- Anibal Arce
- ANID – Millennium Science Initiative Program – Millennium Institute for Integrative Biology (iBio), Santiago, Chile
- Schools of Engineering, Institute for Biological and Medical Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Chiara Gandini
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | - Juan Puig
- ANID – Millennium Science Initiative Program – Millennium Institute for Integrative Biology (iBio), Santiago, Chile
- Schools of Engineering, Institute for Biological and Medical Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Tamara Matute
- ANID – Millennium Science Initiative Program – Millennium Institute for Integrative Biology (iBio), Santiago, Chile
- Schools of Engineering, Institute for Biological and Medical Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jim Haseloff
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | | | - Jenny Molloy
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | - Keith Pardee
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada
| | - Fernán Federici
- ANID – Millennium Science Initiative Program – Millennium Institute for Integrative Biology (iBio), Santiago, Chile
- Schools of Engineering, Institute for Biological and Medical Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago, Chile
- FONDAP Center for Genome Regulation, Santiago, Chile
| |
Collapse
|
46
|
Chen X, Liu Y, Hou J, Lu Y. A linear DNA template-based framework for site-specific unnatural amino acid incorporation. Synth Syst Biotechnol 2021; 6:192-199. [PMID: 34401545 PMCID: PMC8347695 DOI: 10.1016/j.synbio.2021.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/16/2021] [Accepted: 07/27/2021] [Indexed: 11/28/2022] Open
Abstract
Site-specific incorporation of unnatural amino acids (UNAAs) into proteins using an orthogonal translation system (OTS) has expanded the scope of protein-coding chemistry. The key factor affecting UNAA embedding efficiency is the orthogonality of the OTS. Compared to traditional cell systems, cell-free systems are more convenient to control the reaction process and improve the utilization rate of UNAA. In this study, a linear DNA template-based cell-free unnatural protein synthesis system for rapid high-throughput screening and evolution was proposed. A total of 14 cell extracts were selected for screening out cell extract with high expression level. The result showed that EcAR7 ΔA ΔSer cell extract was optimal for the cell-free system. In addition, the screening results of four UNAAs, p-propargyloxy-l-phenylalanine (pPaF), p-azyl-phenylalanine (pAzF), p-acetyl-l-phenylalanine (pAcF), and p-benzoyl-l-phenylalanine (pBpF), showed that o-aaRS and o-tRNA of pPaF had good orthogonality. A new pair of corresponding o-aaRS and o-tRNA for pBpF was screened out. These results proved that this method could speed up the screening of optimal OTS components for UNAAs with versatile functions.
Collapse
Affiliation(s)
- Xinjie Chen
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Yingying Liu
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Jiaqi Hou
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| | - Yuan Lu
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, 100084, China
| |
Collapse
|
47
|
Garenne D, Thompson S, Brisson A, Khakimzhan A, Noireaux V. The all-E. coliTXTL toolbox 3.0: new capabilities of a cell-free synthetic biology platform. Synth Biol (Oxf) 2021; 6:ysab017. [PMID: 34712841 PMCID: PMC8546610 DOI: 10.1093/synbio/ysab017] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/19/2021] [Accepted: 07/12/2021] [Indexed: 12/12/2022] Open
Abstract
The new generation of cell-free gene expression systems enables the prototyping and engineering of biological systems in vitro over a remarkable scope of applications and physical scales. As the utilization of DNA-directed in vitro protein synthesis expands in scope, developing more powerful cell-free transcription-translation (TXTL) platforms remains a major goal to either execute larger DNA programs or improve cell-free biomanufacturing capabilities. In this work, we report the capabilities of the all-E. coli TXTL toolbox 3.0, a multipurpose cell-free expression system specifically developed for synthetic biology. In non-fed batch-mode reactions, the synthesis of the fluorescent reporter protein eGFP (enhanced green fluorescent protein) reaches 4 mg/ml. In synthetic cells, consisting of liposomes loaded with a TXTL reaction, eGFP is produced at concentrations of >8 mg/ml when the chemical building blocks feeding the reaction diffuse through membrane channels to facilitate exchanges with the outer solution. The bacteriophage T7, encoded by a genome of 40 kb and ∼60 genes, is produced at a concentration of 1013 PFU/ml (plaque forming unit/ml). This TXTL system extends the current cell-free expression capabilities by offering unique strength and properties, for testing regulatory elements and circuits, biomanufacturing biologics or building synthetic cells.
Collapse
Affiliation(s)
- David Garenne
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Seth Thompson
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Amaury Brisson
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Aset Khakimzhan
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
48
|
McSweeney MA, Styczynski MP. Effective Use of Linear DNA in Cell-Free Expression Systems. Front Bioeng Biotechnol 2021; 9:715328. [PMID: 34354989 PMCID: PMC8329657 DOI: 10.3389/fbioe.2021.715328] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/06/2021] [Indexed: 12/27/2022] Open
Abstract
Cell-free expression systems (CFEs) are cutting-edge research tools used in the investigation of biological phenomena and the engineering of novel biotechnologies. While CFEs have many benefits over in vivo protein synthesis, one particularly significant advantage is that CFEs allow for gene expression from both plasmid DNA and linear expression templates (LETs). This is an important and impactful advantage because functional LETs can be efficiently synthesized in vitro in a few hours without transformation and cloning, thus expediting genetic circuit prototyping and allowing expression of toxic genes that would be difficult to clone through standard approaches. However, native nucleases present in the crude bacterial lysate (the basis for the most affordable form of CFEs) quickly degrade LETs and limit expression yield. Motivated by the significant benefits of using LETs in lieu of plasmid templates, numerous methods to enhance their stability in lysate-based CFEs have been developed. This review describes approaches to LET stabilization used in CFEs, summarizes the advancements that have come from using LETs with these methods, and identifies future applications and development goals that are likely to be impactful to the field. Collectively, continued improvement of LET-based expression and other linear DNA tools in CFEs will help drive scientific discovery and enable a wide range of applications, from diagnostics to synthetic biology research tools.
Collapse
Affiliation(s)
- Megan A McSweeney
- Georgia Institute of Technology, School of Chemical & Biomolecular Engineering, Atlanta, GA, United States
| | - Mark P Styczynski
- Georgia Institute of Technology, School of Chemical & Biomolecular Engineering, Atlanta, GA, United States
| |
Collapse
|
49
|
Norouzi M, Panfilov S, Pardee K. High-Efficiency Protection of Linear DNA in Cell-Free Extracts from Escherichia coli and Vibrio natriegens. ACS Synth Biol 2021; 10:1615-1624. [PMID: 34161082 DOI: 10.1021/acssynbio.1c00110] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The field of cell-free synthetic biology is an emerging branch of engineered biology that allows for rapid prototyping of biological designs and, in its own right, is becoming a venue for the in vitro operation of gene circuit-based sensors and biomanufacturing. To date, the related DNA encoded tools that operate in cell-free reactions have primarily relied on plasmid DNA inputs, as linear templates are highly susceptible to degradation by exonucleases present in cell-free extracts. This incompatibility has precluded significant throughput, time and cost benefits that could be gained with the use of linear DNA in the cell-free expression workflow. Here to tackle this limitation, we report that terminal incorporation of Ter binding sites for the DNA-binding protein Tus enables highly efficient protection of linear expression templates encoding mCherry and deGFP. In Escherichia coli extracts, our method compares favorably with the previously reported GamS-mediated protection scheme. Importantly, we extend the Tus-Ter system to Vibrio natriegens extracts, and demonstrate that this simple and easily implemented method can enable an unprecedented plasmid-level expression from linear templates in this emerging chassis organism.
Collapse
Affiliation(s)
- Masoud Norouzi
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Sabina Panfilov
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Keith Pardee
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
| |
Collapse
|
50
|
Orlov MA, Sorokin AA. DNA sequence, physics, and promoter function: Analysis of high-throughput data On T7 promoter variants activity. J Bioinform Comput Biol 2021; 18:2040001. [PMID: 32404013 DOI: 10.1142/s0219720020400016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
RNA polymerase/promoter recognition represents a basic problem of molecular biology. Decades-long efforts were made in the area, and yet certain challenges persist. The usage of certain most suitable model subjects is pivotal for the research. System of T7 bacteriophage RNA-polymerase/T7 native promoter represents an exceptional example for the purpose. Moreover, it has been studied the most and successfully applied to aims of biotechnology and bioengineering. Both structural simplicity and high specificity of this molecular duo are the reason for this. Despite highly similar sequences of distinct T7 native promoters, the T7 RNA-polymerase enzyme is capable of binding respective promoter in a highly specific and adjustable manner. One explanation here is that the process relies primarily on DNA physical properties rather than nucleotide sequence. Here, we address the issue by analyzing massive data recently published by Komura and colleagues. This initial study employed Next Generation Sequencing (NGS) in order to quantify activity of promoter variants including ones with multiple substitutions. As a result of our work substantial bias in simultaneous occurrence of single-nucleotide sequence alterations was found: the highest rate of co-occurrence was evidenced within specificity loop of binding region while the lowest - in initiation region of promoter. If both location and a kind of nucleotides involved in replacement (both initial and resulting) are taken into consideration, one can easily note that N to A substitutions are most preferred ones across the whole 19 b.p.-long sequence. At the same time, N to C are tolerated only at crucial position in recognition loop of binding region, and N to G are uniformly least tolerable. Later in this work the complete set of variants was split into groups with mutations (1) exclusively in binding region; (2) exclusively in melting region; (3) in both regions. Among these three groups second comprises extremely few variants (at triple-digit rate lesser than in two other groups, 46 versus over one and six thousand). Yet these are all promoter with substantial to high activity. This group two appeared heterogenous by primary sequence; indeed, upon further subdivision into above versus below average activity subgroups first one was found to comprise promoters with negligible conservation at -2 position of melting region; the second was hardly conserved in this region at all. This draws our attention to perfect consensus sequence of class III T7 promoter with -2 nucleotide randomized (all four are present by one to several copies in the previously published source dataset), the picture becomes even more pronounced. We therefore suggest that mutations at the position therefore do not cause significant changes in terms of promoter activity. At the same time, such modifications dramatically change DNA physical properties which were calculated in our study (namely electrostatic potential and propensity to bend). One possible suggestion here is that -2 nucleotide might function as a generic switch; if so, substitution -2A to -2T has important regulatory consequences. The fact that that -2 b.p. is the most evidently different nucleotide between class II versus class III promoters of T7 genome and that it also distinguishes the class III promoter in T7 genome versus promoters of its relative but reproductively isolated bacteriophage T3. In other words, it appears feasible that mutation at -2 nucleotide does not impede promoter activity yet alter its physical properties thus affecting differential RNA polymerase/promoter interaction.
Collapse
Affiliation(s)
- Mikhail A Orlov
- Institute of Cell Biophysics of RAS, 3 Institutskaya str., Poushchino, 142290, Russia
| | - Anatoly A Sorokin
- Institute of Cell Biophysics of RAS, 3 Institutskaya str., Poushchino, 142290, Russia
| |
Collapse
|