1
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DasGupta S, Zhang S, Szostak JW. Molecular Crowding Facilitates Ribozyme-Catalyzed RNA Assembly. ACS CENTRAL SCIENCE 2023; 9:1670-1678. [PMID: 37637737 PMCID: PMC10451029 DOI: 10.1021/acscentsci.3c00547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Indexed: 08/29/2023]
Abstract
Catalytic RNAs or ribozymes are considered to be central to primordial biology. Most ribozymes require moderate to high concentrations of divalent cations such as Mg2+ to fold into their catalytically competent structures and perform catalysis. However, undesirable effects of Mg2+ such as hydrolysis of reactive RNA building blocks and degradation of RNA structures are likely to undermine its beneficial roles in ribozyme catalysis. Further, prebiotic cell-like compartments bounded by fatty acid membranes are destabilized in the presence of Mg2+, making ribozyme function inside prebiotically relevant protocells a significant challenge. Therefore, we sought to identify conditions that would enable ribozymes to retain activity at low concentrations of Mg2+. Inspired by the ability of ribozymes to function inside crowded cellular environments with <1 mM free Mg2+, we tested molecular crowding as a potential mechanism to lower the Mg2+ concentration required for ribozyme-catalyzed RNA assembly. Here, we show that the ribozyme-catalyzed ligation of phosphorimidazolide RNA substrates is significantly enhanced in the presence of the artificial crowding agent polyethylene glycol. We also found that molecular crowding preserves ligase activity under denaturing conditions such as alkaline pH and the presence of urea. Additionally, we show that crowding-induced stimulation of RNA-catalyzed RNA assembly is not limited to phosphorimidazolide ligation but extends to the RNA-catalyzed polymerization of nucleoside triphosphates. RNA-catalyzed RNA ligation is also stimulated by the presence of prebiotically relevant small molecules such as ethylene glycol, ribose, and amino acids, consistent with a role for molecular crowding in primordial ribozyme function and more generally in the emergence of RNA-based cellular life.
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Affiliation(s)
- Saurja DasGupta
- Department
of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Howard
Hughes Medical Institute, Massachusetts General
Hospital, Boston, Massachusetts 02114, United States
- Department
of Genetics, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Stephanie Zhang
- Department
of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Department
of Chemistry and Chemical Biology, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - Jack W. Szostak
- Department
of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, United States
- Howard
Hughes Medical Institute, Massachusetts General
Hospital, Boston, Massachusetts 02114, United States
- Department
of Genetics, Harvard Medical School, Boston, Massachusetts 02115, United States
- Department
of Chemistry and Chemical Biology, Harvard
University, Cambridge, Massachusetts 02138, United States
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2
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Holler S, Bartlett S, Löffler RJG, Casiraghi F, Diaz CIS, Cartwright JHE, Hanczyc MM. Hybrid organic-inorganic structures trigger the formation of primitive cell-like compartments. Proc Natl Acad Sci U S A 2023; 120:e2300491120. [PMID: 37561785 PMCID: PMC10438843 DOI: 10.1073/pnas.2300491120] [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: 01/19/2023] [Accepted: 07/07/2023] [Indexed: 08/12/2023] Open
Abstract
Alkaline hydrothermal vents have become a candidate setting for the origins of life on Earth and beyond. This is due to several key features including the presence of gradients of temperature, redox potential, pH, the availability of inorganic minerals, and the existence of a network of inorganic pore spaces that could have served as primitive compartments. Chemical gardens have long been used as experimental proxies for hydrothermal vents. This paper investigates-10pc]Please note that the spelling of the following author name in the manuscript differs from the spelling provided in the article metadata: Richard J. G. Löffler. The spelling provided in the manuscript has been retained; please confirm. a set of prebiotic interactions between such inorganic structures and fatty alcohols. The integration of a medium-chain fatty alcohol, decanol, within these inorganic minerals, produced a range of emergent 3 dimensions structures at both macroscopic and microscopic scales. Fatty alcohols can be considered plausible prebiotic amphiphiles that might have assisted the formation of protocellular structures such as vesicles. The experiments presented herein show that neither chemical gardens nor decanol alone promote vesicle formation, but chemical gardens grown in the presence of decanol, which is then integrated into inorganic mineral structures, support vesicle formation. These observations suggest that the interaction of fatty alcohols and inorganic mineral structures could have played an important role in the emergence of protocells, yielding support for the evolution of living cells.
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Affiliation(s)
- Silvia Holler
- Cellular, Computational and Integrative Biology Department, Laboratory for Artificial Biology, University of Trento, Povo38123, Italy
| | - Stuart Bartlett
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
| | - Richard J. G. Löffler
- Cellular, Computational and Integrative Biology Department, Laboratory for Artificial Biology, University of Trento, Povo38123, Italy
| | - Federica Casiraghi
- Cellular, Computational and Integrative Biology Department, Laboratory for Artificial Biology, University of Trento, Povo38123, Italy
| | - Claro Ignacio Sainz Diaz
- Instituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Cientificas–Universidad de Granada, Armilla, Granada18100, Spain
| | - Julyan H. E. Cartwright
- Instituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Cientificas–Universidad de Granada, Armilla, Granada18100, Spain
- Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, Granada18071, Spain
| | - Martin M. Hanczyc
- Cellular, Computational and Integrative Biology Department, Laboratory for Artificial Biology, University of Trento, Povo38123, Italy
- Chemical and Biological Engineering, University of New Mexico, Albuquerque, NM87106
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3
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Li L, Fang Y, Xia Y, Bo C, Fan Y. Monosaccharides driving the formation of conjugated linoleic acid vesicles in near-neutral solutions via weak noncovalent bonding interactions. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118656] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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4
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Ranjan S, Kufner CL, Lozano GG, Todd ZR, Haseki A, Sasselov DD. UV Transmission in Natural Waters on Prebiotic Earth. ASTROBIOLOGY 2022; 22:242-262. [PMID: 34939825 PMCID: PMC8968845 DOI: 10.1089/ast.2020.2422] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Ultraviolet (UV) light plays a key role in surficial theories of the origin of life, and numerous studies have focused on constraining the atmospheric transmission of UV radiation on early Earth. However, the UV transmission of the natural waters in which origins-of-life chemistry (prebiotic chemistry) is postulated to have occurred is poorly constrained. In this work, we combine laboratory and literature-derived absorption spectra of potential aqueous-phase prebiotic UV absorbers with literature estimates of their concentrations on early Earth to constrain the prebiotic UV environment in marine and terrestrial natural waters, and we consider the implications for prebiotic chemistry. We find that prebiotic freshwaters were largely transparent in the UV, contrary to assumptions in some models of prebiotic chemistry. Some waters, such as high-salinity waters like carbonate lakes, may be deficient in shortwave (≤220 nm) UV flux. More dramatically, ferrous waters can be strongly UV-shielded, particularly if the Fe2+ forms highly UV-absorbent species such as FeCN64-. Such waters may be compelling venues for UV-averse origin-of-life scenarios but are unfavorable for some UV-dependent prebiotic chemistries. UV light can trigger photochemistry even if attenuated through photochemical transformations of the absorber (e.g., eaq- production from halide irradiation), which may have both constructive and destructive effects for prebiotic syntheses. Prebiotic chemistries that invoke waters that contain such absorbers must self-consistently account for the chemical effects of these transformations. The speciation and abundance of Fe2+ in natural waters on early Earth is a major uncertainty and should be prioritized for further investigation, as it played a major role in UV transmission in prebiotic natural waters.
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Affiliation(s)
- Sukrit Ranjan
- Department of Earth, Atmospheric & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Physics and Astronomy, Center for Interdisciplinary Exploration and Research in Astrophysics, Northwestern University, Evanston, Illinois, USA
- Blue Marble Space Institute of Science, Seattle, Washington, USA
- Address correspondence to: Sukrit Ranjan, Department of Physics and Astronomy, Center for Interdisciplinary Exploration and Research in Astrophysics, Northwestern University, 1800 Sherman Avenue, 6th Floor, Evanston, IL 60601, USA
| | - Corinna L. Kufner
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA
| | | | - Zoe R. Todd
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA
- Department of Earth and Space Sciences, University of Washington, Seattle, Washington, USA
| | - Azra Haseki
- Department of Earth, Atmospheric & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Harvard College, Cambridge, Massachusetts, USA
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5
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Joshi MP, Steller L, Van Kranendonk MJ, Rajamani S. Influence of Metal Ions on Model Protoamphiphilic Vesicular Systems: Insights from Laboratory and Analogue Studies. Life (Basel) 2021; 11:life11121413. [PMID: 34947944 PMCID: PMC8708898 DOI: 10.3390/life11121413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 02/03/2023] Open
Abstract
Metal ions strongly affect the self-assembly and stability of membranes composed of prebiotically relevant amphiphiles (protoamphiphiles). Therefore, evaluating the behavior of such amphiphiles in the presence of ions is a crucial step towards assessing their potential as model protocell compartments. We have recently reported vesicle formation by N-acyl amino acids (NAAs), an interesting class of protoamphiphiles containing an amino acid linked to a fatty acid via an amide linkage. Herein, we explore the effect of ions on the self-assembly and stability of model N-oleoyl glycine (NOG)-based membranes. Microscopic analysis showed that the blended membranes of NOG and Glycerol 1-monooleate (GMO) were more stable than pure NOG vesicles, both in the presence of monovalent and divalent cations, with the overall vesicle stability being 100-fold higher in the presence of a monovalent cation. Furthermore, both pure NOG and NOG + GMO mixed systems were able to self-assemble into vesicles in natural water samples containing multiple ions that were collected from active hot spring sites. Our study reveals that several aspects of the metal ion stability of NAA-based membranes are comparable to those of fatty acid-based systems, while also confirming the robustness of compositionally heterogeneous membranes towards high metal ion concentrations. Pertinently, the vesicle formation by NAA-based systems in terrestrial hot spring samples indicates the conduciveness of these low ionic strength freshwater systems for facilitating prebiotic membrane-assembly processes. This further highlights their potential to serve as a plausible niche for the emergence of cellular life on the early Earth.
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Affiliation(s)
- Manesh Prakash Joshi
- Department of Biology, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India
- Correspondence: (M.P.J.); (S.R.); Tel.: +91-20-2590-8061 (S.R.)
| | - Luke Steller
- Australian Centre for Astrobiology, and School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, NSW 2052, Australia; (L.S.); (M.J.V.K.)
| | - Martin J. Van Kranendonk
- Australian Centre for Astrobiology, and School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, NSW 2052, Australia; (L.S.); (M.J.V.K.)
| | - Sudha Rajamani
- Department of Biology, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India
- Correspondence: (M.P.J.); (S.R.); Tel.: +91-20-2590-8061 (S.R.)
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6
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Vincent L, Colón-Santos S, Cleaves HJ, Baum DA, Maurer SE. The Prebiotic Kitchen: A Guide to Composing Prebiotic Soup Recipes to Test Origins of Life Hypotheses. Life (Basel) 2021; 11:life11111221. [PMID: 34833097 PMCID: PMC8618940 DOI: 10.3390/life11111221] [Citation(s) in RCA: 1] [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: 08/20/2021] [Revised: 10/14/2021] [Accepted: 10/30/2021] [Indexed: 01/20/2023] Open
Abstract
“Prebiotic soup” often features in discussions of origins of life research, both as a theoretical concept when discussing abiological pathways to modern biochemical building blocks and, more recently, as a feedstock in prebiotic chemistry experiments focused on discovering emergent, systems-level processes such as polymerization, encapsulation, and evolution. However, until now, little systematic analysis has gone into the design of well-justified prebiotic mixtures, which are needed to facilitate experimental replicability and comparison among researchers. This paper explores principles that should be considered in choosing chemical mixtures for prebiotic chemistry experiments by reviewing the natural environmental conditions that might have created such mixtures and then suggests reasonable guidelines for designing recipes. We discuss both “assembled” mixtures, which are made by mixing reagent grade chemicals, and “synthesized” mixtures, which are generated directly from diversity-generating primary prebiotic syntheses. We discuss different practical concerns including how to navigate the tremendous uncertainty in the chemistry of the early Earth and how to balance the desire for using prebiotically realistic mixtures with experimental tractability and replicability. Examples of two assembled mixtures, one based on materials likely delivered by carbonaceous meteorites and one based on spark discharge synthesis, are presented to illustrate these challenges. We explore alternative procedures for making synthesized mixtures using recursive chemical reaction systems whose outputs attempt to mimic atmospheric and geochemical synthesis. Other experimental conditions such as pH and ionic strength are also considered. We argue that developing a handful of standardized prebiotic recipes may facilitate coordination among researchers and enable the identification of the most promising mechanisms by which complex prebiotic mixtures were “tamed” during the origin of life to give rise to key living processes such as self-propagation, information processing, and adaptive evolution. We end by advocating for the development of a public prebiotic chemistry database containing experimental methods (including soup recipes), results, and analytical pipelines for analyzing complex prebiotic mixtures.
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Affiliation(s)
- Lena Vincent
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA; (L.V.); (S.C.-S.)
| | - Stephanie Colón-Santos
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA; (L.V.); (S.C.-S.)
| | - H. James Cleaves
- Earth and Planets Laboratory, The Carnegie Institution for Science, Washington, DC 20015, USA;
- Earth-Life Science Institute, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
- Blue Marble Space Institute for Science, Seattle, WA 97154, USA
| | - David A. Baum
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA; (L.V.); (S.C.-S.)
- Department of Botany, University of Wisconsin-Madison, Madison, WI 53705, USA
- Correspondence: (D.A.B.); (S.E.M.)
| | - Sarah E. Maurer
- Department of Chemistry and Biochemistry, Central Connecticut State University, New Britain, CT 06050, USA
- Correspondence: (D.A.B.); (S.E.M.)
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7
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Matreux T, Le Vay K, Schmid A, Aikkila P, Belohlavek L, Çalışkanoğlu AZ, Salibi E, Kühnlein A, Springsklee C, Scheu B, Dingwell DB, Braun D, Mutschler H, Mast CB. Heat flows in rock cracks naturally optimize salt compositions for ribozymes. Nat Chem 2021; 13:1038-1045. [PMID: 34446924 DOI: 10.1038/s41557-021-00772-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 07/13/2021] [Indexed: 11/09/2022]
Abstract
Catalytic nucleic acids, such as ribozymes, are central to a variety of origin-of-life scenarios. Typically, they require elevated magnesium concentrations for folding and activity, but their function can be inhibited by high concentrations of monovalent salts. Here we show that geologically plausible high-sodium, low-magnesium solutions derived from leaching basalt (rock and remelted glass) inhibit ribozyme catalysis, but that this activity can be rescued by selective magnesium up-concentration by heat flow across rock fissures. In contrast to up-concentration by dehydration or freezing, this system is so far from equilibrium that it can actively alter the Mg:Na salt ratio to an extent that enables key ribozyme activities, such as self-replication and RNA extension, in otherwise challenging solution conditions. The principle demonstrated here is applicable to a broad range of salt concentrations and compositions, and, as such, highly relevant to various origin-of-life scenarios.
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Affiliation(s)
- T Matreux
- Systems Biophysics, Ludwig Maximilians University Munich, Munich, Germany
| | - K Le Vay
- MPI für Biochemie, Biomimetische Systeme, Martinsried, Germany
| | - A Schmid
- Systems Biophysics, Ludwig Maximilians University Munich, Munich, Germany
| | - P Aikkila
- Systems Biophysics, Ludwig Maximilians University Munich, Munich, Germany
| | - L Belohlavek
- Earth and Environmental Sciences, Ludwig Maximilians University Munich, Munich, Germany
| | - A Z Çalışkanoğlu
- Earth and Environmental Sciences, Ludwig Maximilians University Munich, Munich, Germany
| | - E Salibi
- MPI für Biochemie, Biomimetische Systeme, Martinsried, Germany
| | - A Kühnlein
- Systems Biophysics, Ludwig Maximilians University Munich, Munich, Germany
| | - C Springsklee
- Earth and Environmental Sciences, Ludwig Maximilians University Munich, Munich, Germany
| | - B Scheu
- Earth and Environmental Sciences, Ludwig Maximilians University Munich, Munich, Germany
| | - D B Dingwell
- Earth and Environmental Sciences, Ludwig Maximilians University Munich, Munich, Germany
| | - D Braun
- Systems Biophysics, Ludwig Maximilians University Munich, Munich, Germany
| | | | - C B Mast
- Systems Biophysics, Ludwig Maximilians University Munich, Munich, Germany.
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8
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Abstract
A major goal of synthetic biology is to understand the transition between non-living matter and life. The bottom-up development of an artificial cell would provide a minimal system with which to study the border between chemistry and biology. So far, a fully synthetic cell has remained elusive, but chemists are progressing towards this goal by reconstructing cellular subsystems. Cell boundaries, likely in the form of lipid membranes, were necessary for the emergence of life. In addition to providing a protective barrier between cellular cargo and the external environment, lipid compartments maintain homeostasis with other subsystems to regulate cellular processes. In this Review, we examine different chemical approaches to making cell-mimetic compartments. Synthetic strategies to drive membrane formation and function, including bioorthogonal ligations, dissipative self-assembly and reconstitution of biochemical pathways, are discussed. Chemical strategies aim to recreate the interactions between lipid membranes, the external environment and internal biomolecules, and will clarify our understanding of life at the interface of chemistry and biology.
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9
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Vasiliadou R, Dimov N, Szita N, Jordan SF, Lane N. Possible mechanisms of CO 2 reduction by H 2 via prebiotic vectorial electrochemistry. Interface Focus 2019; 9:20190073. [PMID: 31641439 PMCID: PMC6802132 DOI: 10.1098/rsfs.2019.0073] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2019] [Indexed: 02/07/2023] Open
Abstract
Methanogens are putatively ancestral autotrophs that reduce CO2 with H2 to form biomass using a membrane-bound, proton-motive Fe(Ni)S protein called the energy-converting hydrogenase (Ech). At the origin of life, geologically sustained H+ gradients across inorganic barriers containing Fe(Ni)S minerals could theoretically have driven CO2 reduction by H2 through vectorial chemistry in a similar way to Ech. pH modulation of the redox potentials of H2, CO2 and Fe(Ni)S minerals could in principle enable an otherwise endergonic reaction. Here, we analyse whether vectorial electrochemistry can facilitate the reduction of CO2 by H2 under alkaline hydrothermal conditions using a microfluidic reactor. We present pilot data showing that steep pH gradients of approximately 5 pH units can be sustained over greater than 5 h across Fe(Ni)S barriers, with H+-flux across the barrier about two million-fold faster than OH--flux. This high flux produces a calculated 3-pH unit-gradient (equating to 180 mV) across single approximately 25-nm Fe(Ni)S nanocrystals, which is close to that required to reduce CO2. However, the poor solubility of H2 at atmospheric pressure limits CO2 reduction by H2, explaining why organic synthesis has so far proved elusive in our reactor. Higher H2 concentration will be needed in future to facilitate CO2 reduction through prebiotic vectorial electrochemistry.
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Affiliation(s)
- Rafaela Vasiliadou
- Centre for Life's Origin and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Nikolay Dimov
- School of Engineering and Computer Science, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK
| | - Nicolas Szita
- Department of Biochemical Engineering, University College London, Bernard Katz Building, Gower Street, London WC1E 6BT, UK
| | - Sean F. Jordan
- Centre for Life's Origin and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Nick Lane
- Centre for Life's Origin and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
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10
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Promotion of protocell self-assembly from mixed amphiphiles at the origin of life. Nat Ecol Evol 2019; 3:1705-1714. [PMID: 31686020 DOI: 10.1038/s41559-019-1015-y] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 09/25/2019] [Indexed: 01/01/2023]
Abstract
Vesicles formed from single-chain amphiphiles (SCAs) such as fatty acids probably played an important role in the origin of life. A major criticism of the hypothesis that life arose in an early ocean hydrothermal environment is that hot temperatures, large pH gradients, high salinity and abundant divalent cations should preclude vesicle formation. However, these arguments are based on model vesicles using 1-3 SCAs, even though Fischer-Tropsch-type synthesis under hydrothermal conditions produces a wide array of fatty acids and 1-alkanols, including abundant C10-C15 compounds. Here, we show that mixtures of these C10-C15 SCAs form vesicles in aqueous solutions between pH ~6.5 and >12 at modern seawater concentrations of NaCl, Mg2+ and Ca2+. Adding C10 isoprenoids improves vesicle stability even further. Vesicles form most readily at temperatures of ~70 °C and require salinity and strongly alkaline conditions to self-assemble. Thus, alkaline hydrothermal conditions not only permit protocell formation at the origin of life but actively favour it.
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11
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12
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Cornell CE, Black RA, Xue M, Litz HE, Ramsay A, Gordon M, Mileant A, Cohen ZR, Williams JA, Lee KK, Drobny GP, Keller SL. Prebiotic amino acids bind to and stabilize prebiotic fatty acid membranes. Proc Natl Acad Sci U S A 2019; 116:17239-17244. [PMID: 31405964 PMCID: PMC6717294 DOI: 10.1073/pnas.1900275116] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The membranes of the first protocells on the early Earth were likely self-assembled from fatty acids. A major challenge in understanding how protocells could have arisen and withstood changes in their environment is that fatty acid membranes are unstable in solutions containing high concentrations of salt (such as would have been prevalent in early oceans) or divalent cations (which would have been required for RNA catalysis). To test whether the inclusion of amino acids addresses this problem, we coupled direct techniques of cryoelectron microscopy and fluorescence microscopy with techniques of NMR spectroscopy, centrifuge filtration assays, and turbidity measurements. We find that a set of unmodified, prebiotic amino acids binds to prebiotic fatty acid membranes and that a subset stabilizes membranes in the presence of salt and Mg2+ Furthermore, we find that final concentrations of the amino acids need not be high to cause these effects; membrane stabilization persists after dilution as would have occurred during the rehydration of dried or partially dried pools. In addition to providing a means to stabilize protocell membranes, our results address the challenge of explaining how proteins could have become colocalized with membranes. Amino acids are the building blocks of proteins, and our results are consistent with a positive feedback loop in which amino acids bound to self-assembled fatty acid membranes, resulting in membrane stabilization and leading to more binding in turn. High local concentrations of molecular building blocks at the surface of fatty acid membranes may have aided the eventual formation of proteins.
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Affiliation(s)
- Caitlin E Cornell
- Department of Chemistry, University of Washington, Seattle, WA 98195
| | - Roy A Black
- Department of Chemistry, University of Washington, Seattle, WA 98195;
- Department of Bioengineering, University of Washington, Seattle, WA 98195
| | - Mengjun Xue
- Department of Chemistry, University of Washington, Seattle, WA 98195
| | - Helen E Litz
- Department of Chemistry, University of Washington, Seattle, WA 98195
| | - Andrew Ramsay
- Department of Chemistry, University of Washington, Seattle, WA 98195
| | - Moshe Gordon
- Department of Chemistry, University of Washington, Seattle, WA 98195
| | - Alexander Mileant
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195
- Biological Structure, Physics, and Design Graduate Program, University of Washington, Seattle, WA 98195
| | - Zachary R Cohen
- Department of Chemistry, University of Washington, Seattle, WA 98195
| | - James A Williams
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195
| | - Kelly K Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195
| | - Gary P Drobny
- Department of Chemistry, University of Washington, Seattle, WA 98195
| | - Sarah L Keller
- Department of Chemistry, University of Washington, Seattle, WA 98195;
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13
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Shah A, Kuddushi M, Rajput S, El Seoud OA, Malek NI. Ionic Liquid-Based Catanionic Coacervates: Novel Microreactors for Membrane-Free Sequestration of Dyes and Curcumin. ACS OMEGA 2018; 3:17751-17761. [PMID: 31458372 PMCID: PMC6643423 DOI: 10.1021/acsomega.8b02455] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 12/04/2018] [Indexed: 05/08/2023]
Abstract
Surfactant-mediated coacervates are termed as the new age microreactors for their ability to spontaneously sequester the molecules with varied polarities and functionalities. Efforts to emulate this applicability of coacervates through synthetic control of surfactant structures are finding success; however, there is little understanding of how to translate these changes into tailor-made properties. Herein, we designed 3-methyl-1-(octyloxycarbonylmethyl)imidazolium bromide (C8EMeImBr), an ester-functionalized ionic liquid-based surfactant, which shows better surface active properties than the nonfunctionalized and conventional cationic surfactant and forms complex coacervates over the broad range of concentration with sodium salicylate (NaSal). Mono- and divalent cations as well as ionic strength, viscosity, and time-dependent stability of the coacervates had also been addressed in order to study whether these coacervates could work as microreactors to encapsulate various molecules. The anionic charged complex coacervates with sponge morphology and honey comb-like interior show good efficiency to sequester cationic dyes from water because of electrostatic and hydrophobic interactions and good encapsulation efficiency for curcumin owing to their high surface area. Results suggest that ionic liquid-based coacervates studied here could be exploited as a novel low-cost, effective, and environmentally benign alternative to sequester dyes from the contaminated water and their recovery.
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Affiliation(s)
- Ankit Shah
- Applied
Chemistry Department, S.V. National Institute
of Technology, Surat 395007, Gujarat, India
| | - Muzammil Kuddushi
- Applied
Chemistry Department, S.V. National Institute
of Technology, Surat 395007, Gujarat, India
| | - Sargam Rajput
- Applied
Chemistry Department, S.V. National Institute
of Technology, Surat 395007, Gujarat, India
| | - Omar A. El Seoud
- Institute
of Chemistry, The University of Sao Paulo, 748 Prof. Lineu Prestes Av., Sao Paulo SP 05508-000, Brazil
| | - Naved I. Malek
- Applied
Chemistry Department, S.V. National Institute
of Technology, Surat 395007, Gujarat, India
- E-mail: , (N.I.M.)
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Milshteyn D, Damer B, Havig J, Deamer D. Amphiphilic Compounds Assemble into Membranous Vesicles in Hydrothermal Hot Spring Water but Not in Seawater. Life (Basel) 2018; 8:life8020011. [PMID: 29748464 PMCID: PMC6027054 DOI: 10.3390/life8020011] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/28/2018] [Accepted: 05/02/2018] [Indexed: 12/28/2022] Open
Abstract
There is a general assumption that amphiphilic compounds, such as fatty acids, readily form membranous vesicles when dispersed in aqueous phases. However, from earlier studies, it is known that vesicle stability depends strongly on pH, temperature, chain length, ionic concentration and the presence or absence of divalent cations. To test how robust simple amphiphilic compounds are in terms of their ability to assemble into stable vesicles, we chose to study 10- and 12-carbon monocarboxylic acids and a mixture of the latter with its monoglyceride. These were dispersed in hydrothermal water samples drawn directly from hot springs in Yellowstone National Park at two pH ranges, and the results were compared with sea water under the same conditions. We found that the pure acids could form membranous vesicles in hydrothermal pool water, but that a mixture of dodecanoic acid and glycerol monododecanoate was less temperature-sensitive and assembled into relatively stable membranes at both acidic and alkaline pH ranges. Furthermore, the vesicles were able to encapsulate nucleic acids and pyranine, a fluorescent anionic dye. None of the amphiphiles that were tested formed stable vesicles in sea water because the high ionic concentrations disrupted membrane stability.
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Affiliation(s)
- Daniel Milshteyn
- Department of Biomolecular Engineering, University of California Santa, Cruz, CA 95064, USA.
| | - Bruce Damer
- Department of Biomolecular Engineering, University of California Santa, Cruz, CA 95064, USA.
| | - Jeff Havig
- Department of Earth Sciences, University of Minnesota Minneapolis, Minneapolis, MN 55455, USA.
| | - David Deamer
- Department of Biomolecular Engineering, University of California Santa, Cruz, CA 95064, USA.
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Fiore M. The synthesis of mono-alkyl phosphates and their derivatives: an overview of their nature, preparation and use, including synthesis under plausible prebiotic conditions. Org Biomol Chem 2018; 16:3068-3086. [DOI: 10.1039/c8ob00469b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Nucleic acids, phospholipids and other organic phosphates play central roles in biological pathways.
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Affiliation(s)
- Michele Fiore
- Institut de Chimie et Biochimie Moléculaires et Supramoléculaires
- Université de Lyon
- F-69622 Villeurbanne Cedex
- France
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