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Mrnjavac N, Wimmer JLE, Brabender M, Schwander L, Martin WF. The Moon-Forming Impact and the Autotrophic Origin of Life. Chempluschem 2023; 88:e202300270. [PMID: 37812146 PMCID: PMC7615287 DOI: 10.1002/cplu.202300270] [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: 06/05/2023] [Revised: 09/29/2023] [Accepted: 10/03/2023] [Indexed: 10/10/2023]
Abstract
The Moon-forming impact vaporized part of Earth's mantle, and turned the rest into a magma ocean, from which carbon dioxide degassed into the atmosphere, where it stayed until water rained out to form the oceans. The rain dissolved CO2 and made it available to react with transition metal catalysts in the Earth's crust so as to ultimately generate the organic compounds that form the backbone of microbial metabolism. The Moon-forming impact was key in building a planet with the capacity to generate life in that it converted carbon on Earth into a homogeneous and accessible substrate for organic synthesis. Today all ecosystems, without exception, depend upon primary producers, organisms that fix CO2 . According to theories of autotrophic origin, it has always been that way, because autotrophic theories posit that the first forms of life generated all the molecules needed to build a cell from CO2 , forging a direct line of continuity between Earth's initial CO2 -rich atmosphere and the first microorganisms. By modern accounts these were chemolithoautotrophic archaea and bacteria that initially colonized the crust and still inhabit that environment today.
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Affiliation(s)
- Natalia Mrnjavac
- Department of Biology Institute for Molecular Evolution Heinrich Heine University Duesseldorf Universitaetsstr. 1, 40225 Düsseldorf (Germany)
| | - Jessica L. E. Wimmer
- Department of Biology Institute for Molecular Evolution Heinrich Heine University Duesseldorf Universitaetsstr. 1, 40225 Düsseldorf (Germany)
| | - Max Brabender
- Department of Biology Institute for Molecular Evolution Heinrich Heine University Duesseldorf Universitaetsstr. 1, 40225 Düsseldorf (Germany)
| | - Loraine Schwander
- Department of Biology Institute for Molecular Evolution Heinrich Heine University Duesseldorf Universitaetsstr. 1, 40225 Düsseldorf (Germany)
| | - William F. Martin
- Department of Biology Institute for Molecular Evolution Heinrich Heine University Duesseldorf Universitaetsstr. 1, 40225 Düsseldorf (Germany)
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2
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Harrison SA, Webb WL, Rammu H, Lane N. Prebiotic Synthesis of Aspartate Using Life's Metabolism as a Guide. Life (Basel) 2023; 13:life13051177. [PMID: 37240822 DOI: 10.3390/life13051177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 04/29/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
A protometabolic approach to the origins of life assumes that the conserved biochemistry of metabolism has direct continuity with prebiotic chemistry. One of the most important amino acids in modern biology is aspartic acid, serving as a nodal metabolite for the synthesis of many other essential biomolecules. Aspartate's prebiotic synthesis is complicated by the instability of its precursor, oxaloacetate. In this paper, we show that the use of the biologically relevant cofactor pyridoxamine, supported by metal ion catalysis, is sufficiently fast to offset oxaloacetate's degradation. Cu2+-catalysed transamination of oxaloacetate by pyridoxamine achieves around a 5% yield within 1 h, and can operate across a broad range of pH, temperature, and pressure. In addition, the synthesis of the downstream product β-alanine may also take place in the same reaction system at very low yields, directly mimicking an archaeal synthesis route. Amino group transfer supported by pyridoxal is shown to take place from aspartate to alanine, but the reverse reaction (alanine to aspartate) shows a poor yield. Overall, our results show that the nodal metabolite aspartate and related amino acids can indeed be synthesised via protometabolic pathways that foreshadow modern metabolism in the presence of the simple cofactor pyridoxamine and metal ions.
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Affiliation(s)
- Stuart A Harrison
- Centre for Life's Origins and Evolution (CLOE), Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | - William L Webb
- Centre for Life's Origins and Evolution (CLOE), Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | - Hanadi Rammu
- Centre for Life's Origins and Evolution (CLOE), Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | - Nick Lane
- Centre for Life's Origins and Evolution (CLOE), Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
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3
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Feng J, Guo X, Cai F, Fu H, Wang J. Model-based driving mechanism analysis for butyric acid production in Clostridium tyrobutyricum. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:71. [PMID: 35752796 PMCID: PMC9233315 DOI: 10.1186/s13068-022-02169-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 06/13/2022] [Indexed: 11/10/2022]
Abstract
Abstract
Background
Butyric acid, an essential C4 platform chemical, is widely used in food, pharmaceutical, and animal feed industries. Clostridium tyrobutyricum is the most promising microorganism for industrial bio-butyrate production. However, the metabolic driving mechanism for butyrate synthesis was still not profoundly studied.
Results
This study reports a first-generation genome-scale model (GEM) for C. tyrobutyricum, which provides a comprehensive and systematic analysis for the butyrate synthesis driving mechanisms. Based on the analysis in silico, an energy conversion system, which couples the proton efflux with butyryl-CoA transformation by two redox loops of ferredoxin, could be the main driving force for butyrate synthesis. For verifying the driving mechanism, a hydrogenase (HydA) expression was perturbed by inducible regulation and knockout. The results showed that HydA deficiency significantly improved the intracellular NADH/NAD+ rate, decreased acetate accumulation (63.6% in serum bottle and 58.1% in bioreactor), and improved the yield of butyrate (26.3% in serum bottle and 34.5% in bioreactor). It was in line with the expectation based on the energy conversion coupling driving mechanism.
Conclusions
This work show that the first-generation GEM and coupling metabolic analysis effectively promoted in-depth understanding of the metabolic driving mechanism in C. tyrobutyricum and provided a new insight for tuning metabolic flux direction in Clostridium chassis cells.
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4
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Cyanide as a primordial reductant enables a protometabolic reductive glyoxylate pathway. Nat Chem 2022; 14:170-178. [PMID: 35115655 DOI: 10.1038/s41557-021-00878-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 12/14/2021] [Indexed: 11/08/2022]
Abstract
Investigation of prebiotic metabolic pathways is predominantly based on abiotically replicating the reductive citric acid cycle. While attractive from a parsimony point of view, attempts using metal/mineral-mediated reductions have produced complex mixtures with inefficient and uncontrolled reactions. Here we show that cyanide acts as a mild and efficient reducing agent mediating abiotic transformations of tricarboxylic acid intermediates and derivatives. The hydrolysis of the cyanide adducts followed by their decarboxylation enables the reduction of oxaloacetate to malate and of fumarate to succinate, whereas pyruvate and α-ketoglutarate themselves are not reduced. In the presence of glyoxylate, malonate and malononitrile, alternative pathways emerge that bypass the challenging reductive carboxylation steps to produce metabolic intermediates and compounds found in meteorites. These results suggest a simpler prebiotic forerunner of today's metabolism, involving a reductive glyoxylate pathway without oxaloacetate and α-ketoglutarate-implying that the extant metabolic reductive carboxylation chemistries are an evolutionary invention mediated by complex metalloproteins.
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5
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Wimmer JLE, Kleinermanns K, Martin WF. Pyrophosphate and Irreversibility in Evolution, or why PP i Is Not an Energy Currency and why Nature Chose Triphosphates. Front Microbiol 2021; 12:759359. [PMID: 34759911 PMCID: PMC8575175 DOI: 10.3389/fmicb.2021.759359] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 09/15/2021] [Indexed: 11/13/2022] Open
Abstract
The possible evolutionary significance of pyrophosphate (PPi) has been discussed since the early 1960s. Lipmann suggested that PPi could have been an ancient currency or a possible environmental source of metabolic energy at origins, while Kornberg proposed that PPi vectorializes metabolism because ubiquitous pyrophosphatases render PPi forming reactions kinetically irreversible. To test those ideas, we investigated the reactions that consume phosphoanhydride bonds among the 402 reactions of the universal biosynthetic core that generates amino acids, nucleotides, and cofactors from H2, CO2, and NH3. We find that 36% of the core's phosphoanhydride hydrolyzing reactions generate PPi, while no reactions use PPi as an energy currency. The polymerization reactions that generate ~80% of cell mass - protein, RNA, and DNA synthesis - all generate PPi, while none use PPi as an energy source. In typical prokaryotic cells, aminoacyl tRNA synthetases (AARS) underlie ~80% of PPi production. We show that the irreversibility of the AARS reaction is a kinetic, not a thermodynamic effect. The data indicate that PPi is not an ancient energy currency and probably never was. Instead, PPi hydrolysis is an ancient mechanism that imparts irreversibility, as Kornberg suggested, functioning like a ratchet's pawl to vectorialize the life process toward growth. The two anhydride bonds in nucleoside triphosphates offer ATP-cleaving enzymes an option to impart either thermodynamic control (Pi formation) or kinetic control (PPi formation) upon reactions. This dual capacity explains why nature chose the triphosphate moiety of ATP as biochemistry's universal energy currency.
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Affiliation(s)
- Jessica L. E. Wimmer
- Institute for Molecular Evolution, Department of Biology, Heinrich Heine University Duesseldorf, Duesseldorf, Germany
| | - Karl Kleinermanns
- Institute for Physical Chemistry, Department of Chemistry, Heinrich Heine University Duesseldorf, Duesseldorf, Germany
| | - William F. Martin
- Institute for Molecular Evolution, Department of Biology, Heinrich Heine University Duesseldorf, Duesseldorf, Germany
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6
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Freire MÁ. Short non-coded peptides interacting with cofactors facilitated the integration of early chemical networks. Biosystems 2021; 211:104547. [PMID: 34547425 DOI: 10.1016/j.biosystems.2021.104547] [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: 05/31/2021] [Revised: 08/28/2021] [Accepted: 09/15/2021] [Indexed: 11/02/2022]
Abstract
Independently developed iron-sulphur/thioester- and phosphate-driven chemical reactions would have set up two distinct reaction networks prior to coupling in a proto-metabolic system supporting a minimal organisation closure. Each chemical system assisted initially by simple catalysts and then by more complex cofactors would have provided the precursors of the small metabolites and monomer units along with their respective polymers through dehydrating template-independent assemblies. For example, acylation reactions mediated by activated thioester groups produced peptides, fatty acids and polyhydroxyalkanoates, while phosphorylation reactions by phosphorylating agents allowed the synthesis of polysaccharides, polyribonucleotides and polyphosphates. Here, we address how these independent chemical systems might fit together and shaped a proto-metabolic system, focusing specifically on cofactors as molecular fossils of metabolism. As a result, the proposed overview suggests that non-coded peptides capable of binding a variety of ligands, but in particular with a redox active versatility and/or group transfer potential could have facilitated the chemical connections that led to a minimal closure with a proto-metabolism. Later developments would have made it possible to establish a cellular organisation with more complex and interdependent metabolic pathways.
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Affiliation(s)
- Miguel Ángel Freire
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET, Universidad Nacional de Córdoba (UNC). Facultad de Ciencias Exactas, Físicas y Naturales. Av. Vélez Sarsfield 299, CC 495, 5000, Córdoba, Argentina.
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7
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Chu XY, Zhang HY. Cofactors as Molecular Fossils To Trace the Origin and Evolution of Proteins. Chembiochem 2020; 21:3161-3168. [PMID: 32515532 DOI: 10.1002/cbic.202000027] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 06/03/2020] [Indexed: 12/16/2022]
Abstract
Due to their early origin and extreme conservation, cofactors are valuable molecular fossils for tracing the origin and evolution of proteins. First, as the order of protein folds binding with cofactors roughly coincides with protein-fold chronology, cofactors are considered to have facilitated the origin of primitive proteins by selecting them from pools of random amino acid sequences. Second, in the subsequent evolution of proteins, cofactors still played an important role. More interestingly, as metallic cofactors evolved with geochemical variations, some geochemical events left imprints in the chronology of protein architecture; this provides further evidence supporting the coevolution of biochemistry and geochemistry. In this paper, we attempt to review the molecular fossils used in tracing the origin and evolution of proteins, with a special focus on cofactors.
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Affiliation(s)
- Xin-Yi Chu
- Hubei Key Laboratory of Agricultural Bioinformatics College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hong-Yu Zhang
- Hubei Key Laboratory of Agricultural Bioinformatics College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China
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8
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Martin WF. Older Than Genes: The Acetyl CoA Pathway and Origins. Front Microbiol 2020; 11:817. [PMID: 32655499 PMCID: PMC7325901 DOI: 10.3389/fmicb.2020.00817] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 04/06/2020] [Indexed: 11/13/2022] Open
Abstract
For decades, microbiologists have viewed the acetyl CoA pathway and organisms that use it for H2-dependent carbon and energy metabolism, acetogens and methanogens, as ancient. Classical evidence and newer evidence indicating the antiquity of the acetyl CoA pathway are summarized here. The acetyl CoA pathway requires approximately 10 enzymes, roughly as many organic cofactors, and more than 500 kDa of combined subunit molecular mass to catalyze the conversion of H2 and CO2 to formate, acetate, and pyruvate in acetogens and methanogens. However, a single hydrothermal vent alloy, awaruite (Ni3Fe), can convert H2 and CO2 to formate, acetate, and pyruvate under mild hydrothermal conditions on its own. The chemical reactions of H2 and CO2 to pyruvate thus have a natural tendency to occur without enzymes, given suitable inorganic catalysts. This suggests that the evolution of the enzymatic acetyl CoA pathway was preceded by-and patterned along-a route of naturally occurring exergonic reactions catalyzed by transition metal minerals that could activate H2 and CO2 by chemisorption. The principle of forward (autotrophic) pathway evolution from preexisting non-enzymatic reactions is generalized to the concept of patterned evolution of pathways. In acetogens, exergonic reduction of CO2 by H2 generates acyl phosphates by highly reactive carbonyl groups undergoing attack by inert inorganic phosphate. In that ancient reaction of biochemical energy conservation, the energy behind formation of the acyl phosphate bond resides in the carbonyl, not in phosphate. The antiquity of the acetyl CoA pathway is usually seen in light of CO2 fixation; its role in primordial energy coupling via acyl phosphates and substrate-level phosphorylation is emphasized here.
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Affiliation(s)
- William F. Martin
- Institute for Molecular Evolution, University of Düsseldorf, Düsseldorf, Germany
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9
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Xavier JC, Hordijk W, Kauffman S, Steel M, Martin WF. Autocatalytic chemical networks at the origin of metabolism. Proc Biol Sci 2020; 287:20192377. [PMID: 32156207 PMCID: PMC7126077 DOI: 10.1098/rspb.2019.2377] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 02/12/2020] [Indexed: 12/12/2022] Open
Abstract
Modern cells embody metabolic networks containing thousands of elements and form autocatalytic sets of molecules that produce copies of themselves. How the first self-sustaining metabolic networks arose at life's origin is a major open question. Autocatalytic sets smaller than metabolic networks were proposed as transitory intermediates at the origin of life, but evidence for their role in prebiotic evolution is lacking. Here, we identify reflexively autocatalytic food-generated networks (RAFs)-self-sustaining networks that collectively catalyse all their reactions-embedded within microbial metabolism. RAFs in the metabolism of ancient anaerobic autotrophs that live from H2 and CO2 provided with small-molecule catalysts generate acetyl-CoA as well as amino acids and bases, the monomeric components of protein and RNA, but amino acids and bases without organic catalysts do not generate metabolic RAFs. This suggests that RAFs identify attributes of biochemical origins conserved in metabolic networks. RAFs are consistent with an autotrophic origin of metabolism and furthermore indicate that autocatalytic chemical networks preceded proteins and RNA in evolution. RAFs uncover intermediate stages in the emergence of metabolic networks, narrowing the gaps between early Earth chemistry and life.
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Affiliation(s)
- Joana C. Xavier
- Institut für Molekulare Evolution, Heinrich Heine Universität, 40225 Düsseldorf, Germany
| | - Wim Hordijk
- Konrad Lorenz Institute for Evolution and Cognition Research, 3400 Klosterneuburg, Austria
| | | | - Mike Steel
- Biomathematics Research Centre, University of Canterbury, Christchurch 8041, New Zealand
| | - William F. Martin
- Institut für Molekulare Evolution, Heinrich Heine Universität, 40225 Düsseldorf, Germany
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
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10
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A hydrogen-dependent geochemical analogue of primordial carbon and energy metabolism. Nat Ecol Evol 2020; 4:534-542. [PMID: 32123322 DOI: 10.1038/s41559-020-1125-6] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 01/23/2020] [Indexed: 11/08/2022]
Abstract
Hydrogen gas, H2, is generated by alkaline hydrothermal vents through an ancient geochemical process called serpentinization, in which water reacts with iron-containing minerals deep within the Earth's crust. H2 is the electron donor for the most ancient and the only energy-releasing route of biological CO2 fixation, the acetyl-CoA pathway. At the origin of metabolism, CO2 fixation by hydrothermal H2 within serpentinizing systems could have preceded and patterned biotic pathways. Here we show that three hydrothermal minerals-greigite (Fe3S4), magnetite (Fe3O4) and awaruite (Ni3Fe)-catalyse the fixation of CO2 with H2 at 100 °C under alkaline aqueous conditions. The product spectrum includes formate (up to 200 mM), acetate (up to 100 µM), pyruvate (up to 10 µM), methanol (up to 100 µM) and methane. The results shed light on both the geochemical origin of microbial metabolism and the nature of abiotic formate and methane synthesis in modern hydrothermal vents.
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11
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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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12
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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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13
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Preiner M, Xavier JC, Vieira ADN, Kleinermanns K, Allen JF, Martin WF. Catalysts, autocatalysis and the origin of metabolism. Interface Focus 2019; 9:20190072. [PMID: 31641438 PMCID: PMC6802133 DOI: 10.1098/rsfs.2019.0072] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 08/30/2019] [Indexed: 12/24/2022] Open
Abstract
If life on Earth started out in geochemical environments like hydrothermal vents, then it started out from gasses like CO2, N2 and H2. Anaerobic autotrophs still live from these gasses today, and they still inhabit the Earth's crust. In the search for connections between abiotic processes in ancient geological systems and biotic processes in biological systems, it becomes evident that chemical activation (catalysis) of these gasses and a constant source of energy are key. The H2–CO2 redox reaction provides a constant source of energy and anabolic inputs, because the equilibrium lies on the side of reduced carbon compounds. Identifying geochemical catalysts that activate these gasses en route to nitrogenous organic compounds and small autocatalytic networks will be an important step towards understanding prebiotic chemistry that operates only on the basis of chemical energy, without input from solar radiation. So, if life arose in the dark depths of hydrothermal vents, then understanding reactions and catalysts that operate under such conditions is crucial for understanding origins.
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Affiliation(s)
- Martina Preiner
- Institute for Molecular Evolution, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Joana C Xavier
- Institute for Molecular Evolution, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | | | - Karl Kleinermanns
- Institute for Physical Chemistry, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - John F Allen
- Research Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - William F Martin
- Institute for Molecular Evolution, Heinrich-Heine-University, 40225 Düsseldorf, Germany
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