1
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Sword TT, Dinglasan JLN, Abbas GSK, Barker JW, Spradley ME, Greene ER, Gooden DS, Emrich SJ, Gilchrist MA, Doktycz MJ, Bailey CB. Profiling expression strategies for a type III polyketide synthase in a lysate-based, cell-free system. Sci Rep 2024; 14:12983. [PMID: 38839808 PMCID: PMC11153635 DOI: 10.1038/s41598-024-61376-w] [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: 12/16/2023] [Accepted: 05/06/2024] [Indexed: 06/07/2024] Open
Abstract
Some of the most metabolically diverse species of bacteria (e.g., Actinobacteria) have higher GC content in their DNA, differ substantially in codon usage, and have distinct protein folding environments compared to tractable expression hosts like Escherichia coli. Consequentially, expressing biosynthetic gene clusters (BGCs) from these bacteria in E. coli often results in a myriad of unpredictable issues with regard to protein expression and folding, delaying the biochemical characterization of new natural products. Current strategies to achieve soluble, active expression of these enzymes in tractable hosts can be a lengthy trial-and-error process. Cell-free expression (CFE) has emerged as a valuable expression platform as a testbed for rapid prototyping expression parameters. Here, we use a type III polyketide synthase from Streptomyces griseus, RppA, which catalyzes the formation of the red pigment flaviolin, as a reporter to investigate BGC refactoring techniques. We applied a library of constructs with different combinations of promoters and rppA coding sequences to investigate the synergies between promoter and codon usage. Subsequently, we assess the utility of cell-free systems for prototyping these refactoring tactics prior to their implementation in cells. Overall, codon harmonization improves natural product synthesis more than traditional codon optimization across cell-free and cellular environments. More importantly, the choice of coding sequences and promoters impact protein expression synergistically, which should be considered for future efforts to use CFE for high-yield protein expression. The promoter strategy when applied to RppA was not completely correlated with that observed with GFP, indicating that different promoter strategies should be applied for different proteins. In vivo experiments suggest that there is correlation, but not complete alignment between expressing in cell free and in vivo. Refactoring promoters and/or coding sequences via CFE can be a valuable strategy to rapidly screen for catalytically functional production of enzymes from BCGs, which advances CFE as a tool for natural product research.
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Affiliation(s)
- Tien T Sword
- Department of Chemistry, University of Tennessee-Knoxville, Knoxville, TN, USA
| | - Jaime Lorenzo N Dinglasan
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- Graduate School of Genome Science and Technology, University of Tennessee-Knoxville, Knoxville, TN, USA
| | - Ghaeath S K Abbas
- Department of Chemistry, University of Tennessee-Knoxville, Knoxville, TN, USA
- School of Chemistry, University of Sydney, Sydney, NSW, Australia
| | - J William Barker
- Department of Chemistry, University of Tennessee-Knoxville, Knoxville, TN, USA
| | - Madeline E Spradley
- Department of Biochemistry, Cellular, and Molecular Biology, University of Tennessee-Knoxville, Knoxville, TN, USA
| | - Elijah R Greene
- Department of Chemistry, University of Tennessee-Knoxville, Knoxville, TN, USA
| | - Damian S Gooden
- Department of Chemistry, University of Tennessee-Knoxville, Knoxville, TN, USA
| | - Scott J Emrich
- Graduate School of Genome Science and Technology, University of Tennessee-Knoxville, Knoxville, TN, USA
- Department of Electrical Engineering and Computer Science, University of Tennessee-Knoxville, Knoxville, TN, USA
- Department of Ecology and Evolutionary Biology, University of Tennessee-Knoxville, Knoxville, TN, USA
| | - Michael A Gilchrist
- Graduate School of Genome Science and Technology, University of Tennessee-Knoxville, Knoxville, TN, USA
- Department of Ecology and Evolutionary Biology, University of Tennessee-Knoxville, Knoxville, TN, USA
| | - Mitchel J Doktycz
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
- Graduate School of Genome Science and Technology, University of Tennessee-Knoxville, Knoxville, TN, USA.
| | - Constance B Bailey
- Department of Chemistry, University of Tennessee-Knoxville, Knoxville, TN, USA.
- Graduate School of Genome Science and Technology, University of Tennessee-Knoxville, Knoxville, TN, USA.
- School of Chemistry, University of Sydney, Sydney, NSW, Australia.
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2
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Liu WQ, Ji X, Ba F, Zhang Y, Xu H, Huang S, Zheng X, Liu Y, Ling S, Jewett MC, Li J. Cell-free biosynthesis and engineering of ribosomally synthesized lanthipeptides. Nat Commun 2024; 15:4336. [PMID: 38773100 PMCID: PMC11109155 DOI: 10.1038/s41467-024-48726-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: 02/05/2024] [Accepted: 05/13/2024] [Indexed: 05/23/2024] Open
Abstract
Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a major class of natural products with diverse chemical structures and potent biological activities. A vast majority of RiPP gene clusters remain unexplored in microbial genomes, which is partially due to the lack of rapid and efficient heterologous expression systems for RiPP characterization and biosynthesis. Here, we report a unified biocatalysis (UniBioCat) system based on cell-free gene expression for rapid biosynthesis and engineering of RiPPs. We demonstrate UniBioCat by reconstituting a full biosynthetic pathway for de novo biosynthesis of salivaricin B, a lanthipeptide RiPP. Next, we delete several protease/peptidase genes from the source strain to enhance the performance of UniBioCat, which then can synthesize and screen salivaricin B variants with enhanced antimicrobial activity. Finally, we show that UniBioCat is generalizable by synthesizing and evaluating the bioactivity of ten uncharacterized lanthipeptides. We expect UniBioCat to accelerate the discovery, characterization, and synthesis of RiPPs.
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Affiliation(s)
- Wan-Qiu Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Xiangyang Ji
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Fang Ba
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Yufei Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Huiling Xu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Shuhui Huang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Xiao Zheng
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Yifan Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China.
- State Key Laboratory of Advanced Medical Materials and Devices, ShanghaiTech University, Shanghai, China.
- Shanghai Clinical Research and Trial Center, Shanghai, China.
| | - Shengjie Ling
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China.
- State Key Laboratory of Advanced Medical Materials and Devices, ShanghaiTech University, Shanghai, China.
- Shanghai Clinical Research and Trial Center, Shanghai, China.
| | - Michael C Jewett
- Department of Bioengineering, Stanford University, Stanford, CA, US.
| | - Jian Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China.
- State Key Laboratory of Advanced Medical Materials and Devices, ShanghaiTech University, Shanghai, China.
- Shanghai Clinical Research and Trial Center, Shanghai, China.
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3
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Levitskaya Z, Ser Z, Koh H, Mei WS, Chee S, Sobota RM, Ghadessy JF. Engineering cell-free systems by chemoproteomic-assisted phenotypic screening. RSC Chem Biol 2024; 5:372-385. [PMID: 38576719 PMCID: PMC10989505 DOI: 10.1039/d4cb00004h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 02/16/2024] [Indexed: 04/06/2024] Open
Abstract
Phenotypic screening is a valuable tool to both understand and engineer complex biological systems. We demonstrate the functionality of this approach in the development of cell-free protein synthesis (CFPS) technology. Phenotypic screening identified numerous compounds that enhanced protein production in yeast lysate CFPS reactions. Notably, many of these were competitive ATP kinase inhibitors, with the exploitation of their inherent substrate promiscuity redirecting ATP flux towards heterologous protein expression. Chemoproteomic-guided strain engineering partially phenocopied drug effects, with a 30% increase in protein yield observed upon deletion of the ATP-consuming SSA1 component of the HSP70 chaperone. Moreover, drug-mediated metabolic rewiring coupled with template optimization generated the highest protein yields in yeast CFPS to date using a hitherto less efficient, but more cost-effective glucose energy regeneration system. Our approach highlights the utility of target-agnostic phenotypic screening and target identification to deconvolute cell-lysate complexity, adding to the expanding repertoire of strategies for improving CFPS.
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Affiliation(s)
- Zarina Levitskaya
- Protein and Peptide Engineering and Research Laboratory, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR) 8A Biomedical Grove Singapore 138648
| | - Zheng Ser
- Function Proteomics Laboratory, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR) 8A Biomedical Grove Singapore 138648
| | - Hiromi Koh
- Function Proteomics Laboratory, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR) 8A Biomedical Grove Singapore 138648
| | - Wang Shi Mei
- Function Proteomics Laboratory, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR) 8A Biomedical Grove Singapore 138648
| | - Sharon Chee
- Protein and Peptide Engineering and Research Laboratory, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR) 8A Biomedical Grove Singapore 138648
| | - Radoslaw Mikolaj Sobota
- Function Proteomics Laboratory, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR) 8A Biomedical Grove Singapore 138648
| | - John F Ghadessy
- Protein and Peptide Engineering and Research Laboratory, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR) 8A Biomedical Grove Singapore 138648
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4
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Brookwell AW, Gonzalez JL, Martinez AW, Oza JP. Development of Solid-State Storage for Cell-Free Expression Systems. ACS Synth Biol 2023; 12:2561-2577. [PMID: 37490644 DOI: 10.1021/acssynbio.3c00111] [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: 07/27/2023]
Abstract
The fragility of biological systems during storage, transport, and utilization necessitates reliable cold-chain infrastructure and limits the potential of biotechnological applications. In order to unlock the broad applications of existing and emerging biological technologies, we report the development of a novel solid-state storage platform for complex biologics. The resulting solid-state biologics (SSB) platform meets four key requirements: facile rehydration of solid materials, activation of biochemical activity, ability to support complex downstream applications and functionalities, and compatibility for deployment in a variety of reaction formats and environments. As a model system of biochemical complexity, we utilized crudeEscherichia colicell extracts that retain active cellular metabolism and support robust levels of in vitro transcription and translation. We demonstrate broad versatility and utility of SSB through proof-of-concepts for on-demand in vitro biomanufacturing of proteins at a milliliter scale, the activation of downstream CRISPR activity, as well as deployment on paper-based devices. SSBs unlock a breadth of applications in biomanufacturing, discovery, diagnostics, and education in resource-limited environments on Earth and in space.
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Affiliation(s)
- August W Brookwell
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California 93407, United States
- Center for Applications in Biotechnology, California Polytechnic State University, San Luis Obispo, California 93407, United States
| | - Jorge L Gonzalez
- Chemistry & Biochemistry Department, California Polytechnic State University, San Luis Obispo, California 93407, United States
| | - Andres W Martinez
- Chemistry & Biochemistry Department, California Polytechnic State University, San Luis Obispo, California 93407, United States
| | - Javin P Oza
- Chemistry & Biochemistry Department, California Polytechnic State University, San Luis Obispo, California 93407, United States
- Center for Applications in Biotechnology, California Polytechnic State University, San Luis Obispo, California 93407, United States
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5
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Liu J, Hu Y, Gu W, Lan H, Zhang Z, Jiang L, Xu X. Research progress on the application of cell-free synthesis systems for enzymatic processes. Crit Rev Biotechnol 2023; 43:938-955. [PMID: 35994247 DOI: 10.1080/07388551.2022.2090314] [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: 10/13/2021] [Revised: 02/24/2022] [Accepted: 04/09/2022] [Indexed: 11/03/2022]
Abstract
Cell-free synthesis systems can complete the transcription and translation process in vitro to produce complex proteins that are difficult to be expressed in traditional cell-based systems. Such systems also can be used for the assembly of efficient localized multienzyme cascades to synthesize products that are toxic to cells. Cell-free synthesis systems provide a simpler and faster engineering solution than living cells, allowing unprecedented design freedom. This paper reviews the latest progress on the application of cell-free synthesis systems in the field of enzymatic catalysis, including cell-free protein synthesis and cell-free metabolic engineering. In cell-free protein synthesis: complex proteins, toxic proteins, membrane proteins, and artificial proteins containing non-natural amino acids can be easily synthesized by directly controlling the reaction conditions in the cell-free system. In cell-free metabolic engineering, the synthesis of desired products can be made more specific and efficient by designing metabolic pathways and screening biocatalysts based on purified enzymes or crude extracts. Through the combination of cell-free synthesis systems and emerging technologies, such as: synthetic biology, microfluidic control, cofactor regeneration, and artificial scaffolds, we will be able to build increasingly complex biomolecule systems. In the next few years, these technologies are expected to mature and reach industrialization, providing innovative platforms for a wide range of biotechnological applications.
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Affiliation(s)
- Jie Liu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Yongqi Hu
- School of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Wanyi Gu
- School of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Haiquan Lan
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
| | - Zhidong Zhang
- Institute of Microbiology, Xinjiang Academy of Agricultural Sciences, Urumqi, China
| | - Ling Jiang
- College of Food Science and Light Industry, Nanjing Tech University, Nanjing, China
| | - Xian Xu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China
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6
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Manzer ZA, Selivanovitch E, Ostwalt AR, Daniel S. Membrane protein synthesis: no cells required. Trends Biochem Sci 2023; 48:642-654. [PMID: 37087310 DOI: 10.1016/j.tibs.2023.03.006] [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: 11/07/2022] [Revised: 02/20/2023] [Accepted: 03/22/2023] [Indexed: 04/24/2023]
Abstract
Despite advances in membrane protein (MP) structural biology and a growing interest in their applications, these proteins remain challenging to study. Progress has been hindered by the complex nature of MPs and innovative methods will be required to circumvent technical hurdles. Cell-free protein synthesis (CFPS) is a burgeoning technique for synthesizing MPs directly into a membrane environment using reconstituted components of the cellular transcription and translation machinery in vitro. We provide an overview of CFPS and how this technique can be applied to the synthesis and study of MPs. We highlight numerous strategies including synthesis methods and folding environments, each with advantages and limitations, to provide a survey of how CFPS techniques can advance the study of MPs.
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Affiliation(s)
- Zachary A Manzer
- R.F. School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Ekaterina Selivanovitch
- R.F. School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Alexis R Ostwalt
- R.F. School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Susan Daniel
- R.F. School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA.
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7
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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.
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8
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Cell-free protein synthesis system for bioanalysis: Advances in methods and applications. Trends Analyt Chem 2023. [DOI: 10.1016/j.trac.2023.117015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
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9
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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.
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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
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10
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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.
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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
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11
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Jew K, Smith PEJ, So B, Kasman J, Oza JP, Black MW. Characterizing and Improving pET Vectors for Cell-free Expression. Front Bioeng Biotechnol 2022; 10:895069. [PMID: 35814024 PMCID: PMC9259831 DOI: 10.3389/fbioe.2022.895069] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 05/26/2022] [Indexed: 11/15/2022] Open
Abstract
Cell-free protein synthesis (CFPS) is an in vitro process that enables diverse applications in research, biomanufacturing, point-of-care diagnostics, therapeutics, and education using minimal laboratory equipment and reagents. One of the major limitations of CFPS implementation is its sensitivity to plasmid type. Specifically, plasmid templates based on commonly used vector backbones such as the pET series of bacterial expression vectors result in the inferior production of proteins. To overcome this limitation, we have evaluated the effect of expression cassette elements present in the pET30 vector on protein production across three different CFPS systems: NEBExpress, PURExpress, and CFAI-based E. coli extracts. Through the systematic elimination of genetic elements within the pET30 vector, we have identified elements that are responsible for the poor performance of pET30 vectors in the various CFPS systems. As a result, we demonstrate that through the removal of the lac operator (lacO) and N-terminal tags included in the vector backbone sequence, a pET vector can support high titers of protein expression when using extract-based CFPS systems. This work provides two key advances for the research community: 1) identification of vector sequence elements that affect robust production of proteins; 2) evaluation of expression across three unique CFPS systems including CFAI extracts, NEBexpress, and PURExpress. We anticipate that this work will improve access to CFPS by enabling researchers to choose the correct expression backbone within the context of their preferred expression system.
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Affiliation(s)
- Kara Jew
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA, United States
| | - Philip E. J. Smith
- Chemistry & Biochemistry Department, California Polytechnic State University, San Luis Obispo, CA, United States
| | - Byungcheol So
- Chemistry & Biochemistry Department, California Polytechnic State University, San Luis Obispo, CA, United States
| | - Jillian Kasman
- Chemistry & Biochemistry Department, California Polytechnic State University, San Luis Obispo, CA, United States
| | - Javin P. Oza
- Chemistry & Biochemistry Department, California Polytechnic State University, San Luis Obispo, CA, United States
- *Correspondence: Javin P. Oza, ; Michael W. Black,
| | - Michael W. Black
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA, United States
- *Correspondence: Javin P. Oza, ; Michael W. Black,
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12
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Danchin A. In vivo, in vitro and in silico: an open space for the development of microbe-based applications of synthetic biology. Microb Biotechnol 2022; 15:42-64. [PMID: 34570957 PMCID: PMC8719824 DOI: 10.1111/1751-7915.13937] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 09/14/2021] [Indexed: 12/24/2022] Open
Abstract
Living systems are studied using three complementary approaches: living cells, cell-free systems and computer-mediated modelling. Progresses in understanding, allowing researchers to create novel chassis and industrial processes rest on a cycle that combines in vivo, in vitro and in silico studies. This design-build-test-learn iteration loop cycle between experiments and analyses combines together physiology, genetics, biochemistry and bioinformatics in a way that keeps going forward. Because computer-aided approaches are not directly constrained by the material nature of the entities of interest, we illustrate here how this virtuous cycle allows researchers to explore chemistry which is foreign to that present in extant life, from whole chassis to novel metabolic cycles. Particular emphasis is placed on the importance of evolution.
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Affiliation(s)
- Antoine Danchin
- Kodikos LabsInstitut Cochin24 rue du Faubourg Saint‐JacquesParis75014France
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