1
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Controlled metabolic cascades for protein synthesis in an artificial cell. Biochem Soc Trans 2021; 49:2143-2151. [PMID: 34623386 DOI: 10.1042/bst20210175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 09/04/2021] [Accepted: 09/07/2021] [Indexed: 11/17/2022]
Abstract
In recent years, researchers have been pursuing a method to design and to construct life forms from scratch - in other words, to create artificial cells. In many studies, artificial cellular membranes have been successfully fabricated, allowing the research field to grow by leaps and bounds. Moreover, in addition to lipid bilayer membranes, proteins are essential factors required to construct any cellular metabolic reaction; for that reason, different cell-free expression systems under various conditions to achieve the goal of controlling the synthetic cascades of proteins in a confined area have been reported. Thus, in this review, we will discuss recent issues and strategies, enabling to control protein synthesis cascades that are being used, particularly in research on artificial cells.
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2
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Laohakunakorn N, Grasemann L, Lavickova B, Michielin G, Shahein A, Swank Z, Maerkl SJ. Bottom-Up Construction of Complex Biomolecular Systems With Cell-Free Synthetic Biology. Front Bioeng Biotechnol 2020; 8:213. [PMID: 32266240 PMCID: PMC7105575 DOI: 10.3389/fbioe.2020.00213] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 03/03/2020] [Indexed: 12/16/2022] Open
Abstract
Cell-free systems offer a promising approach to engineer biology since their open nature allows for well-controlled and characterized reaction conditions. In this review, we discuss the history and recent developments in engineering recombinant and crude extract systems, as well as breakthroughs in enabling technologies, that have facilitated increased throughput, compartmentalization, and spatial control of cell-free protein synthesis reactions. Combined with a deeper understanding of the cell-free systems themselves, these advances improve our ability to address a range of scientific questions. By mastering control of the cell-free platform, we will be in a position to construct increasingly complex biomolecular systems, and approach natural biological complexity in a bottom-up manner.
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Affiliation(s)
- Nadanai Laohakunakorn
- School of Biological Sciences, Institute of Quantitative Biology, Biochemistry, and Biotechnology, University of Edinburgh, Edinburgh, United Kingdom
| | - Laura Grasemann
- School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Barbora Lavickova
- School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Grégoire Michielin
- School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Amir Shahein
- School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Zoe Swank
- School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Sebastian J. Maerkl
- School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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3
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Pols T, Sikkema HR, Gaastra BF, Frallicciardi J, Śmigiel WM, Singh S, Poolman B. A synthetic metabolic network for physicochemical homeostasis. Nat Commun 2019; 10:4239. [PMID: 31534136 PMCID: PMC6751199 DOI: 10.1038/s41467-019-12287-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 09/02/2019] [Indexed: 12/21/2022] Open
Abstract
One of the grand challenges in chemistry is the construction of functional out-of-equilibrium networks, which are typical of living cells. Building such a system from molecular components requires control over the formation and degradation of the interacting chemicals and homeostasis of the internal physical-chemical conditions. The provision and consumption of ATP lies at the heart of this challenge. Here we report the in vitro construction of a pathway in vesicles for sustained ATP production that is maintained away from equilibrium by control of energy dissipation. We maintain a constant level of ATP with varying load on the system. The pathway enables us to control the transmembrane fluxes of osmolytes and to demonstrate basic physicochemical homeostasis. Our work demonstrates metabolic energy conservation and cell volume regulatory mechanisms in a cell-like system at a level of complexity minimally needed for life.
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Affiliation(s)
- Tjeerd Pols
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Hendrik R Sikkema
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Bauke F Gaastra
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Jacopo Frallicciardi
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Wojciech M Śmigiel
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Shubham Singh
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Bert Poolman
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
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4
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Chan MA, Hinman NW, Potter-McIntyre SL, Schubert KE, Gillams RJ, Awramik SM, Boston PJ, Bower DM, Des Marais DJ, Farmer JD, Jia TZ, King PL, Hazen RM, Léveillé RJ, Papineau D, Rempfert KR, Sánchez-Román M, Spear JR, Southam G, Stern JC, Cleaves HJ. Deciphering Biosignatures in Planetary Contexts. ASTROBIOLOGY 2019; 19:1075-1102. [PMID: 31335163 PMCID: PMC6708275 DOI: 10.1089/ast.2018.1903] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 03/10/2019] [Indexed: 05/05/2023]
Abstract
Microbial life permeates Earth's critical zone and has likely inhabited nearly all our planet's surface and near subsurface since before the beginning of the sedimentary rock record. Given the vast time that Earth has been teeming with life, do astrobiologists truly understand what geological features untouched by biological processes would look like? In the search for extraterrestrial life in the Universe, it is critical to determine what constitutes a biosignature across multiple scales, and how this compares with "abiosignatures" formed by nonliving processes. Developing standards for abiotic and biotic characteristics would provide quantitative metrics for comparison across different data types and observational time frames. The evidence for life detection falls into three categories of biosignatures: (1) substances, such as elemental abundances, isotopes, molecules, allotropes, enantiomers, minerals, and their associated properties; (2) objects that are physical features such as mats, fossils including trace-fossils and microbialites (stromatolites), and concretions; and (3) patterns, such as physical three-dimensional or conceptual n-dimensional relationships of physical or chemical phenomena, including patterns of intermolecular abundances of organic homologues, and patterns of stable isotopic abundances between and within compounds. Five key challenges that warrant future exploration by the astrobiology community include the following: (1) examining phenomena at the "right" spatial scales because biosignatures may elude us if not examined with the appropriate instrumentation or modeling approach at that specific scale; (2) identifying the precise context across multiple spatial and temporal scales to understand how tangible biosignatures may or may not be preserved; (3) increasing capability to mine big data sets to reveal relationships, for example, how Earth's mineral diversity may have evolved in conjunction with life; (4) leveraging cyberinfrastructure for data management of biosignature types, characteristics, and classifications; and (5) using three-dimensional to n-D representations of biotic and abiotic models overlain on multiple overlapping spatial and temporal relationships to provide new insights.
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Affiliation(s)
- Marjorie A. Chan
- Department of Geology & Geophysics, University of Utah, Salt Lake City, Utah
| | - Nancy W. Hinman
- Department of Geosciences, University of Montana, Missoula, Montana
| | | | - Keith E. Schubert
- Department of Electrical and Computer Engineering, Baylor University, Waco, Texas
| | - Richard J. Gillams
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- Electronics and Computer Science, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Stanley M. Awramik
- Department of Earth Science, University of California, Santa Barbara, Santa Barbara, California
| | - Penelope J. Boston
- NASA Astrobiology Institute, NASA Ames Research Center, Moffett Field, California
| | - Dina M. Bower
- Department of Astronomy, University of Maryland College Park (CRESST), College Park, Maryland
- NASA Goddard Space Flight Center, Greenbelt, Maryland
| | | | - Jack D. Farmer
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona
| | - Tony Z. Jia
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
| | - Penelope L. King
- Research School of Earth Sciences, The Australian National University, Canberra, Australia
| | - Robert M. Hazen
- Geophysical Laboratory, Carnegie Institution for Science, Washington, District of Columbia
| | - Richard J. Léveillé
- Department of Earth and Planetary Sciences, McGill University, Montreal, Canada
- Geosciences Department, John Abbott College, Sainte-Anne-de-Bellevue, Canada
| | - Dominic Papineau
- London Centre for Nanotechnology, University College London, London, United Kingdom
- Department of Earth Sciences, University College London, London, United Kingdom
- Centre for Planetary Sciences, University College London, London, United Kingdom
- BioGeology and Environmental Geology State Key Laboratory, School of Earth Sciences, China University of Geosciences, Wuhan, China
| | - Kaitlin R. Rempfert
- Department of Geological Sciences, University of Colorado Boulder, Boulder, Colorado
| | - Mónica Sánchez-Román
- Earth Sciences Department, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - John R. Spear
- Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado
| | - Gordon Southam
- School of Earth and Environmental Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | | | - Henderson James Cleaves
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
- Program in Interdisciplinary Studies, Institute for Advanced Study, Princeton, New Jersey
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5
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Sikkema HR, Gaastra BF, Pols T, Poolman B. Cell Fuelling and Metabolic Energy Conservation in Synthetic Cells. Chembiochem 2019; 20:2581-2592. [PMID: 31381223 DOI: 10.1002/cbic.201900398] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Indexed: 12/14/2022]
Abstract
We are aiming for a blue print for synthesizing (moderately complex) subcellular systems from molecular components and ultimately for constructing life. However, without comprehensive instructions and design principles, we rely on simple reaction routes to operate the essential functions of life. The first forms of synthetic life will not make every building block for polymers de novo according to complex pathways, rather they will be fed with amino acids, fatty acids and nucleotides. Controlled energy supply is crucial for any synthetic cell, no matter how complex. Herein, we describe the simplest pathways for the efficient generation of ATP and electrochemical ion gradients. We have estimated the demand for ATP by polymer synthesis and maintenance processes in small cell-like systems, and we describe circuits to control the need for ATP. We also present fluorescence-based sensors for pH, ionic strength, excluded volume, ATP/ADP, and viscosity, which allow the major physicochemical conditions inside cells to be monitored and tuned.
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Affiliation(s)
- Hendrik R Sikkema
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Bauke F Gaastra
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Tjeerd Pols
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Bert Poolman
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
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6
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Beppu K, Izri Z, Maeda YT, Sakamoto R. Geometric Effect for Biological Reactors and Biological Fluids. Bioengineering (Basel) 2018; 5:E110. [PMID: 30551608 PMCID: PMC6316181 DOI: 10.3390/bioengineering5040110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 12/07/2018] [Accepted: 12/10/2018] [Indexed: 01/21/2023] Open
Abstract
As expressed "God made the bulk; the surface was invented by the devil" by W. Pauli, the surface has remarkable properties because broken symmetry in surface alters the material properties. In biological systems, the smallest functional and structural unit, which has a functional bulk space enclosed by a thin interface, is a cell. Cells contain inner cytosolic soup in which genetic information stored in DNA can be expressed through transcription (TX) and translation (TL). The exploration of cell-sized confinement has been recently investigated by using micron-scale droplets and microfluidic devices. In the first part of this review article, we describe recent developments of cell-free bioreactors where bacterial TX-TL machinery and DNA are encapsulated in these cell-sized compartments. Since synthetic biology and microfluidics meet toward the bottom-up assembly of cell-free bioreactors, the interplay between cellular geometry and TX-TL advances better control of biological structure and dynamics in vitro system. Furthermore, biological systems that show self-organization in confined space are not limited to a single cell, but are also involved in the collective behavior of motile cells, named active matter. In the second part, we describe recent studies where collectively ordered patterns of active matter, from bacterial suspensions to active cytoskeleton, are self-organized. Since geometry and topology are vital concepts to understand the ordered phase of active matter, a microfluidic device with designed compartments allows one to explore geometric principles behind self-organization across the molecular scale to cellular scale. Finally, we discuss the future perspectives of a microfluidic approach to explore the further understanding of biological systems from geometric and topological aspects.
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Affiliation(s)
- Kazusa Beppu
- Department of Physics, Kyushu University, Fukuoka 819-0395, Japan.
| | - Ziane Izri
- Department of Physics, Kyushu University, Fukuoka 819-0395, Japan.
| | - Yusuke T Maeda
- Department of Physics, Kyushu University, Fukuoka 819-0395, Japan.
| | - Ryota Sakamoto
- Department of Physics, Kyushu University, Fukuoka 819-0395, Japan.
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7
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Hybrid cell reactor system from Escherichia coli protoplast cells and arrayed lipid bilayer chamber device. Sci Rep 2018; 8:11757. [PMID: 30082826 PMCID: PMC6078950 DOI: 10.1038/s41598-018-30231-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/25/2018] [Indexed: 11/09/2022] Open
Abstract
We developed a novel hybrid cell reactor system via functional fusion of single Escherichia coli protoplast cells, that are deficient in cell wall and expose plasma membrane, with arrayed lipid bilayer chambers on a device in order to incorporate the full set of cytosolic and membrane constituents into the artificial chambers. We investigated gene expression activity to represent the viability of the hybrid cell reactors: over 20% of hybrid cells showed gene expression activity from plasmid or mRNA. This suggests that the hybrid cell reactors retained fundamental activity of genetic information transduction. To expand the applicability of the hybrid cell reactors, we also developed the E. coli-in-E. coli cytoplasm system as an artificial parasitism system. Over 30% of encapsulated E. coli cells exhibited normal cell division, showing that hybrid cells can accommodate and cultivate living cells. This novel artificial cell reactor technology would enable unique approaches for synthetic cell researches such as reconstruction of living cell, artificial parasitism/symbiosis system, or physical simulation to test functionality of synthetic genome.
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8
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Sunami T, Ichihashi N, Nishikawa T, Kazuta Y, Yomo T. Effect of Liposome Size on Internal RNA Replication Coupled with Replicase Translation. Chembiochem 2016; 17:1282-9. [DOI: 10.1002/cbic.201500662] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Takeshi Sunami
- Institute for Academic Initiatives; Osaka University; 1-5 Yamadaoka Suita Osaka 565-0871 Japan
- Exploratory Research for Advanced Technology (ERATO); Japan Science and Technology Agency (JST); 1-5 Yamadaoka Suita Osaka 565-0871 Japan
| | - Norikazu Ichihashi
- Exploratory Research for Advanced Technology (ERATO); Japan Science and Technology Agency (JST); 1-5 Yamadaoka Suita Osaka 565-0871 Japan
- Department of Bioinformatics Engineering; Graduate School of Information Science and Technology; Osaka University; 1-5 Yamadaoka Suita Osaka 565-0871 Japan
| | - Takehiro Nishikawa
- Exploratory Research for Advanced Technology (ERATO); Japan Science and Technology Agency (JST); 1-5 Yamadaoka Suita Osaka 565-0871 Japan
| | - Yasuaki Kazuta
- Exploratory Research for Advanced Technology (ERATO); Japan Science and Technology Agency (JST); 1-5 Yamadaoka Suita Osaka 565-0871 Japan
| | - Tetsuya Yomo
- Exploratory Research for Advanced Technology (ERATO); Japan Science and Technology Agency (JST); 1-5 Yamadaoka Suita Osaka 565-0871 Japan
- Department of Bioinformatics Engineering; Graduate School of Information Science and Technology; Osaka University; 1-5 Yamadaoka Suita Osaka 565-0871 Japan
- Graduate School of Frontier Biosciences; Osaka University; 1-5 Yamadaoka Suita Osaka 565-0871 Japan
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9
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Kapsner K, Simmel FC. Partitioning Variability of a Compartmentalized In Vitro Transcriptional Thresholding Circuit. ACS Synth Biol 2015; 4:1136-43. [PMID: 25974035 DOI: 10.1021/acssynbio.5b00051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Encapsulation of in vitro biochemical reaction circuits into small, cell-sized compartments can result in considerable variations in the dynamical properties of the circuits. As a model system, we here investigate a simple in vitro transcriptional reaction circuit, which generates an ultrasensitive fluorescence response when the concentration of an RNA transcript reaches a preset threshold. The reaction circuit is compartmentalized into spherical water-in-oil microemulsion droplets, and the reaction progress is monitored by fluorescence microscopy. A quantitative statistical analysis of thousands of individual droplets ranging in size from a few up to 20 μm reveals a strong variability in effective RNA production rates, which by computational modeling is traced back to a larger-than-Poisson variability in RNAP activities in the droplets. The noise level in terms of the noise strength (the Fano factor) is strongly dependent on the ratio between transcription templates and polymerases, and increases for higher template concentrations.
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Affiliation(s)
| | - Friedrich C. Simmel
- Physics
Department, TU München, 85748 Garching, Germany
- Nanosystems Initiative Munich, Schellingstrasse
4, 80539 München, Germany
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10
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Grochmal A, Prout L, Makin-Taylor R, Prohens R, Tomas S. Modulation of reactivity in the cavity of liposomes promotes the formation of peptide bonds. J Am Chem Soc 2015; 137:12269-75. [PMID: 26356087 DOI: 10.1021/jacs.5b06207] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In living cells, reactions take place in membrane-bound compartments, often in response to changes in the environment. Learning how the reactions are influenced by this compartmentalization will help us gain an optimal understanding of living organisms at the molecular level and, at the same time, will offer vital clues on the behavior of simple compartmentalized systems, such as prebiotic precursors of cells and cell-inspired artificial systems. In this work we show that a reactive building block (an activated amino acid derivative) trapped in the cavity of a liposome is protected against hydrolysis and reacts nearly quantitatively with another building block, which is membrane-permeable and free in solution, to form the dipeptide. By contrast, when the activated amino acid is found outside the liposome, hydrolysis is the prevalent reaction, showing that the cavity of the liposomes promotes the formation of peptide bonds. We attribute this result to the large lipid concentration in small compartments from the point of view of a membrane-impermeable molecule. Based on this result, we show how the outcome of the reaction can be predicted as a function of the size of the compartment. The implications of these results on the behavior of biomolecules in cell compartments, abiogenesis, and the design of artificial cell-inspired systems are considered.
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Affiliation(s)
- Anna Grochmal
- Institute of Structural and Molecular Biology and Department of Biological Sciences, School of Science, Birkbeck University of London , Malet Street, London WC1E 7HX, U.K
| | - Luba Prout
- Institute of Structural and Molecular Biology and Department of Biological Sciences, School of Science, Birkbeck University of London , Malet Street, London WC1E 7HX, U.K
| | - Robert Makin-Taylor
- Institute of Structural and Molecular Biology and Department of Biological Sciences, School of Science, Birkbeck University of London , Malet Street, London WC1E 7HX, U.K
| | - Rafel Prohens
- CIRCE Crystal Engineering , 07121 Palma de Mallorca, Spain.,Unitat de Polimorfisme i Calorimetria, CCiT, Universitat de Barcelona , 08028 Barcelona, Spain
| | - Salvador Tomas
- Institute of Structural and Molecular Biology and Department of Biological Sciences, School of Science, Birkbeck University of London , Malet Street, London WC1E 7HX, U.K
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11
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Mavelli F, Marangoni R, Stano P. A Simple Protein Synthesis Model for the PURE System Operation. Bull Math Biol 2015; 77:1185-212. [PMID: 25911591 DOI: 10.1007/s11538-015-0082-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 04/07/2015] [Indexed: 11/24/2022]
Abstract
The encapsulation of transcription-translation (TX-TL) cell-free machinery inside lipid vesicles (liposomes) is a key element in synthetic cell technology. The PURE system is a TX-TL kit composed of well-characterized parts, whose concentrations are fine tunable, which works according to a modular architecture. For these reasons, the PURE system perfectly fulfils the requirements of synthetic biology and is widely used for constructing synthetic cells. In this work, we present a simplified mathematical model to simulate the PURE system operations. Based on Michaelis-Menten kinetics and differential equations, the model describes protein synthesis dynamics by using 9 chemical species, 6 reactions and 16 kinetic parameters. The model correctly predicts the time course for messenger RNA and protein production and allows quantitative predictions. By means of this model, it is possible to foresee how the PURE system species affect the mechanism of proteins synthesis and therefore help in understanding scenarios where the concentration of the PURE system components has been modified purposely or as a result of stochastic fluctuations (for example after random encapsulation inside vesicles). The model also makes the determination of response coefficients for all species involved in the TX-TL mechanism possible and allows for scrutiny on how chemical energy is consumed by the three PURE system modules (transcription, translation and aminoacylation).
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Affiliation(s)
- Fabio Mavelli
- Chemistry Department, University of Bari, Via Orabona 4, Bari, Italy,
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12
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Lewis DD, Villarreal FD, Wu F, Tan C. Synthetic biology outside the cell: linking computational tools to cell-free systems. Front Bioeng Biotechnol 2014; 2:66. [PMID: 25538941 PMCID: PMC4260521 DOI: 10.3389/fbioe.2014.00066] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 11/23/2014] [Indexed: 12/22/2022] Open
Abstract
As mathematical models become more commonly integrated into the study of biology, a common language for describing biological processes is manifesting. Many tools have emerged for the simulation of in vivo synthetic biological systems, with only a few examples of prominent work done on predicting the dynamics of cell-free synthetic systems. At the same time, experimental biologists have begun to study dynamics of in vitro systems encapsulated by amphiphilic molecules, opening the door for the development of a new generation of biomimetic systems. In this review, we explore both in vivo and in vitro models of biochemical networks with a special focus on tools that could be applied to the construction of cell-free expression systems. We believe that quantitative studies of complex cellular mechanisms and pathways in synthetic systems can yield important insights into what makes cells different from conventional chemical systems.
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Affiliation(s)
- Daniel D. Lewis
- Integrative Genetics and Genomics, University of California Davis, Davis, CA, USA
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
| | | | - Fan Wu
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
| | - Cheemeng Tan
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
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13
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Ichihashi N, Yomo T. Positive roles of compartmentalization in internal reactions. Curr Opin Chem Biol 2014; 22:12-7. [PMID: 25032508 DOI: 10.1016/j.cbpa.2014.06.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 06/09/2014] [Accepted: 06/14/2014] [Indexed: 12/23/2022]
Abstract
Recently, many researchers have attempted to construct artificial cell models using a bottom-up approach in which various biochemical reactions that involve a defined set of molecules are reconstructed in cell-like compartments, such as liposomes and water-in-oil droplets. In many of these studies, the cell-like compartments have acted only as containers for the encapsulated biochemical reactions, whereas other studies have indicated that compartmentalization improves the rates and yields of these reactions. Here, we introduce two ways in which compartmentalization can improve internal reactions: the isolation effect and the condensation effect. These positive effects of compartmentalization might have played an important role in the genesis of the first primitive cell on early Earth.
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Affiliation(s)
- Norikazu Ichihashi
- Department of Bioinformatics Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan; Exploratory Research for Advanced Technology, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tetsuya Yomo
- Department of Bioinformatics Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan; Exploratory Research for Advanced Technology, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan; Graduate School of Frontier Biosciences, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan.
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14
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Soga H, Fujii S, Yomo T, Kato Y, Watanabe H, Matsuura T. In vitro membrane protein synthesis inside cell-sized vesicles reveals the dependence of membrane protein integration on vesicle volume. ACS Synth Biol 2014; 3:372-9. [PMID: 24328098 DOI: 10.1021/sb400094c] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Giant unilamellar vesicles (GUVs) are vesicles>1 μm in diameter that provide an environment in which the effect of a confined reaction volume on intravesicular reactions can be investigated. By synthesizing EmrE, a multidrug transporter from Escherichia coli, as a model membrane protein using a reconstituted in vitro transcription-translation system inside GUVs, we investigated the effect of a confined volume on the synthesis and membrane integration of EmrE. Flow cytometry was used to analyze multiple properties of the vesicles and to quantify EmrE synthesis inside GUVs composed of only 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine. We found that EmrE was synthesized and integrated into the GUV membrane in its active form. We also found that the ratio of membrane-integrated EmrE to total synthesized EmrE increased with decreasing vesicle volume; this finding is explained by the effect of an increased surface-area-to-volume ratio in smaller vesicles. In vitro membrane synthesis inside GUVs is a useful approach to study quantitatively the properties of membrane proteins and their interaction with the membrane under cell-mimicking environments.
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Affiliation(s)
- Haruka Soga
- Department
of Biotechnology, Graduate School of Engineering, Osaka University, 2-1
Yamadaoka, Suita, Osaka, Japan
| | - Satoshi Fujii
- Exploratory
Research for Advanced Technology, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka, Japan
| | - Tetsuya Yomo
- Exploratory
Research for Advanced Technology, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka, Japan
- Department
of Bioinformatic Engineering, Graduate School of Information Science
and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, Japan
| | - Yasuhiko Kato
- Department
of Biotechnology, Graduate School of Engineering, Osaka University, 2-1
Yamadaoka, Suita, Osaka, Japan
| | - Hajime Watanabe
- Department
of Biotechnology, Graduate School of Engineering, Osaka University, 2-1
Yamadaoka, Suita, Osaka, Japan
| | - Tomoaki Matsuura
- Department
of Biotechnology, Graduate School of Engineering, Osaka University, 2-1
Yamadaoka, Suita, Osaka, Japan
- Exploratory
Research for Advanced Technology, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka, Japan
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15
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Okano T, Matsuura T, Suzuki H, Yomo T. Cell-free protein synthesis in a microchamber revealed the presence of an optimum compartment volume for high-order reactions. ACS Synth Biol 2014; 3:347-52. [PMID: 23991849 DOI: 10.1021/sb400087e] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The application of microelectromechanical systems (MEMS) to chemistry and biochemistry allows various reactions to be performed in microscale compartments. Here, we aimed to use the glass microchamber to study the compartment size dependency of the protein synthesis, one of the most important reactions in the cell. By encapsulating the cell-free protein synthesis system with different reaction orders in femtoliter microchambers, chamber size dependency of the reaction initiated with a constant copy number of DNA was investigated. We were able to observe the properties specific to the high order reactions in microcompartments with high precision and found the presence of an optimum compartment volume for a high-order reaction using real biological molecules.
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Affiliation(s)
- Taiji Okano
- Exploratory Research
for Advanced Technology, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tomoaki Matsuura
- Exploratory Research
for Advanced Technology, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
- Department
of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita,
Osaka 565-0871, Japan
| | - Hiroaki Suzuki
- Exploratory Research
for Advanced Technology, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
- Department
of Precision Mechanics, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Tetsuya Yomo
- Exploratory Research
for Advanced Technology, Japan Science and Technology Agency, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
- Department
of Bioinformatic Engineering, Graduate School of Information
Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
- Graduate School
of Frontier Biosciences, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
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16
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Smith MT, Wilding KM, Hunt JM, Bennett AM, Bundy BC. The emerging age of cell-free synthetic biology. FEBS Lett 2014; 588:2755-61. [PMID: 24931378 DOI: 10.1016/j.febslet.2014.05.062] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 05/29/2014] [Accepted: 05/30/2014] [Indexed: 01/16/2023]
Abstract
The engineering of and mastery over biological parts has catalyzed the emergence of synthetic biology. This field has grown exponentially in the past decade. As increasingly more applications of synthetic biology are pursued, more challenges are encountered, such as delivering genetic material into cells and optimizing genetic circuits in vivo. An in vitro or cell-free approach to synthetic biology simplifies and avoids many of the pitfalls of in vivo synthetic biology. In this review, we describe some of the innate features that make cell-free systems compelling platforms for synthetic biology and discuss emerging improvements of cell-free technologies. We also select and highlight recent and emerging applications of cell-free synthetic biology.
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Affiliation(s)
- Mark Thomas Smith
- Department of Chemical Engineering, Brigham Young University, Provo, UT, USA
| | - Kristen M Wilding
- Department of Chemical Engineering, Brigham Young University, Provo, UT, USA
| | - Jeremy M Hunt
- Department of Chemical Engineering, Brigham Young University, Provo, UT, USA
| | - Anthony M Bennett
- Department of Chemical Engineering, Brigham Young University, Provo, UT, USA
| | - Bradley C Bundy
- Department of Chemical Engineering, Brigham Young University, Provo, UT, USA.
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17
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Wu F, Tan C. The engineering of artificial cellular nanosystems using synthetic biology approaches. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2014; 6:369-83. [PMID: 24668724 DOI: 10.1002/wnan.1265] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 02/05/2014] [Accepted: 02/08/2014] [Indexed: 12/26/2022]
Abstract
Artificial cellular systems are minimal systems that mimic certain properties of natural cells, including signaling pathways, membranes, and metabolic pathways. These artificial cells (or protocells) can be constructed following a synthetic biology approach by assembling biomembranes, synthetic gene circuits, and cell-free expression systems. As artificial cells are built from bottom-up using minimal and a defined number of components, they are more amenable to predictive mathematical modeling and engineered controls when compared with natural cells. Indeed, artificial cells have been implemented as drug delivery machineries and in situ protein expression systems. Furthermore, artificial cells have been used as biomimetic systems to unveil new insights into functions of natural cells, which are otherwise difficult to investigate owing to their inherent complexity. It is our vision that the development of artificial cells would bring forth parallel advancements in synthetic biology, cell-free systems, and in vitro systems biology. For further resources related to this article, please visit the WIREs website. Conflict of interests: The authors declare that they have no competing financial interests.
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Affiliation(s)
- Fan Wu
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
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18
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Diversity in the dynamical behaviour of a compartmentalized programmable biochemical oscillator. Nat Chem 2014; 6:295-302. [PMID: 24651195 DOI: 10.1038/nchem.1869] [Citation(s) in RCA: 162] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 01/13/2014] [Indexed: 12/12/2022]
Abstract
In vitro compartmentalization of biochemical reaction networks is a crucial step towards engineering artificial cell-scale devices and systems. At this scale the dynamics of molecular systems becomes stochastic, which introduces several engineering challenges and opportunities. Here we study a programmable transcriptional oscillator system that is compartmentalized into microemulsion droplets with volumes between 33 fl and 16 pl. Simultaneous measurement of large populations of droplets reveals major variations in the amplitude, frequency and damping of the oscillations. Variability increases for smaller droplets and depends on the operating point of the oscillator. Rather than reflecting the stochastic kinetics of the chemical reaction network itself, the variability can be attributed to the statistical variation of reactant concentrations created during their partitioning into droplets. We anticipate that robustness to partitioning variability will be a critical challenge for engineering cell-scale systems, and that highly parallel time-series acquisition from microemulsion droplets will become a key tool for characterization of stochastic circuit function.
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19
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Ichii T, Tanahashi G, Suzuki H, Yomo T. Modification of an amplification reaction in recursively dynamic compartments driven by stirring. Anal Chem 2013; 85:12002-10. [PMID: 24219119 DOI: 10.1021/ac402958b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In living systems, biochemical reactions are confined to cellular or subcellular compartments, such as the plasma membrane and the organelles within a cell. These biological compartments are usually subjected to recursive changes, such as combinations of growth, fusion, and division, to constitute repeating cell cycles. In such recursively dynamic compartments, the encapsulated biochemical reaction may exhibit dynamics that differ from those of the static compartment (i.e., test tubes) used in conventional biochemistry experiments. To test this hypothesis in a simplified model, we mechanically stirred femtoliter-sized water-in-oil emulsion droplets so that individual droplets were subjected to repeated coalescence and breakage. We show that recursive dynamics appeared in the emulsion, which were measured by the exponential propagation of a water-soluble dye. The rate of the propagation, μ, was controlled by modulating the pulse-width of stirring in an electromagnetic stirrer. Within this system, we studied the dynamics of an RNA-amplification reaction in recursively increasing reaction compartments at various values of μ. We showed that there was an optimal value of μ that maximized RNA amplification. This effect was explained by the balance between the opposing effects of supply of substrate and the dilution of amplified RNA both resulting from coalescence. Moreover, when we mixed two RNA species with different kinetic properties, we found a preferential amplification for one of the species only in the recursively dynamic emulsion. This effect was partly explained by a separation effect which preferentially amplifies the number of compartments for the molecular specie that can better follow the breakage dynamics of the compartments. The present work demonstrated how the recursive dynamics of compartments modifies the internal biochemical reaction.
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Affiliation(s)
- Tetsuo Ichii
- ERATO, Japan Science and Technology Agency , 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
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20
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Directed Evolution of Proteins through In Vitro Protein Synthesis in Liposomes. J Nucleic Acids 2012; 2012:923214. [PMID: 22957209 PMCID: PMC3431101 DOI: 10.1155/2012/923214] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 07/10/2012] [Indexed: 11/17/2022] Open
Abstract
Directed evolution of proteins is a technique used to modify protein functions through "Darwinian selection." In vitro compartmentalization (IVC) is an in vitro gene screening system for directed evolution of proteins. IVC establishes the link between genetic information (genotype) and the protein translated from the information (phenotype), which is essential for all directed evolution methods, by encapsulating both in a nonliving microcompartment. Herein, we introduce a new liposome-based IVC system consisting of a liposome, the protein synthesis using recombinant elements (PURE) system and a fluorescence-activated cell sorter (FACS) used as a microcompartment, in vitro protein synthesis system, and high-throughput screen, respectively. Liposome-based IVC is characterized by in vitro protein synthesis from a single copy of a gene in a cell-sized unilamellar liposome and quantitative functional evaluation of the synthesized proteins. Examples of liposome-based IVC for screening proteins such as GFP and β-glucuronidase are described. We discuss the future directions for this method and its applications.
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