1
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Toparlak Ö, Sebastianelli L, Egas Ortuno V, Karki M, Xing Y, Szostak JW, Krishnamurthy R, Mansy SS. Cyclophospholipids Enable a Protocellular Life Cycle. ACS NANO 2023; 17:23772-23783. [PMID: 38038709 PMCID: PMC10722605 DOI: 10.1021/acsnano.3c07706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 12/02/2023]
Abstract
There is currently no plausible path for the emergence of a self-replicating protocell, because prevalent formulations of model protocells are built with fatty acid vesicles that cannot withstand the concentrations of Mg2+ needed for the function and replication of nucleic acids. Although prebiotic chelates increase the survivability of fatty acid vesicles, the resulting model protocells are incapable of growth and division. Here, we show that protocells made of mixtures of cyclophospholipids and fatty acids can grow and divide in the presence of Mg2+-citrate. Importantly, these protocells retain encapsulated nucleic acids during growth and division, can acquire nucleotides from their surroundings, and are compatible with the nonenzymatic extension of an RNA oligonucleotide, chemistry needed for the replication of a primitive genome. Our work shows that prebiotically plausible mixtures of lipids form protocells that are active under the conditions necessary for the emergence of Darwinian evolution.
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Affiliation(s)
- Ö.
Duhan Toparlak
- Department
of Cellular, Computational and Integrative Biology, University of Trento, Via Sommarive 9, 38123 Povo, Trentino, Italy
| | - Lorenzo Sebastianelli
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton Alberta T6G 2G2, Canada
| | - Veronica Egas Ortuno
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Megha Karki
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Yanfeng Xing
- Department
of Biochemistry and Molecular Biology, University
of Chicago, Chicago, Illinois 60637, United States
| | - Jack W. Szostak
- Howard
Hughes Medical Institute, Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Ramanarayanan Krishnamurthy
- Department
of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Sheref S. Mansy
- Department
of Cellular, Computational and Integrative Biology, University of Trento, Via Sommarive 9, 38123 Povo, Trentino, Italy
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton Alberta T6G 2G2, Canada
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2
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Douliez JP. Double Emulsion Droplets as a Plausible Step to Fatty Acid Protocells. SMALL METHODS 2023; 7:e2300530. [PMID: 37574259 DOI: 10.1002/smtd.202300530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 07/07/2023] [Indexed: 08/15/2023]
Abstract
It is assumed that life originated on the Earth from vesicles made of fatty acids. These amphiphiles are the simplest chemicals, which can be present in the prebiotic soup, capable of self-assembling into compartments mimicking modern cells. Production of fatty acid vesicles is widely studied, as their growing and division. However, how prebiotic chemicals require to further yield living cells encapsulated within protocells remains unclear. Here, one suggests a scenario based on recent studies, which shows that phospholipid vesicles can form from double emulsions affording facile encapsulation of cargos. In these works, water-in-oil-in-water droplets are produced by microfluidics, having dispersed lipids in the oil. Dewetting of the oil droplet leaves the internal aqueous droplet covered by a lipid bilayer, entrapping cargos. In this review, formation of fatty acid protocells is briefly reviewed, together with the procedure for preparing double emulsions and vesicles from double emulsion and finally, it is proposed that double emulsion droplets formed in the deep ocean where undersea volcano expulsed materials, with fatty acids (under their carboxylic form) and alkanols as the oily phase, entrapping hydrosoluble prebiotic chemicals in a double emulsion droplet core. Once formed, double emulsion droplets can move up to the surface, where an increase of pH, variation of pressure and/or temperature may have allowed dewetting of the oily droplet, leaving a fatty acid vesicular protocell with encapsulated prebiotic materials.
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Affiliation(s)
- Jean-Paul Douliez
- Biologie du Fruit et Pathologie, UMR 1332, Institut National de Recherche Agronomique (INRAE), Université De Bordeaux, Villenave d'Ornon, F-33140, France
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3
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Santos TCB, Futerman AH. The fats of the matter: Lipids in prebiotic chemistry and in origin of life studies. Prog Lipid Res 2023; 92:101253. [PMID: 37659458 DOI: 10.1016/j.plipres.2023.101253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/30/2023] [Accepted: 08/30/2023] [Indexed: 09/04/2023]
Abstract
The unique biophysical and biochemical properties of lipids render them crucial in most models of the origin of life (OoL). Many studies have attempted to delineate the prebiotic pathways by which lipids were formed, how micelles and vesicles were generated, and how these micelles and vesicles became selectively permeable towards the chemical precursors required to initiate and support biochemistry and inheritance. Our analysis of a number of such studies highlights the extremely narrow and limited range of conditions by which an experiment is considered to have successfully modeled a role for lipids in an OoL experiment. This is in line with a recent proposal that bias is introduced into OoL studies by the extent and the kind of human intervention. It is self-evident that OoL studies can only be performed by human intervention, and we now discuss the possibility that some assumptions and simplifications inherent in such experimental approaches do not permit determination of mechanistic insight into the roles of lipids in the OoL. With these limitations in mind, we suggest that more nuanced experimental approaches than those currently pursued may be required to elucidate the generation and function of lipids, micelles and vesicles in the OoL.
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Affiliation(s)
- Tania C B Santos
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
| | - Anthony H Futerman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
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4
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Martín O, Leyva Y, Suárez-Lezcano J, Pérez-Castillo Y, Marrero-Ponce Y. Inducing Homochirality Through Intermediary Catalytic Species: A Stochastic Approach. ASTROBIOLOGY 2023; 23:1083-1089. [PMID: 37651215 DOI: 10.1089/ast.2023.0004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
A new chiral amplification mechanism based on a stochastic approach is proposed. The mechanism includes five different chemical species, an achiral substrate (A), two chiral forms (L, D), and two intermediary species (LA, DA). The process occurs within a small, semipermeable compartment that can be diffusively coupled with the outside environment. The study considers two alternative primary sources for chiral species within the compartment, one chemical and the other diffusive. As a remarkable fact, the chiral amplification process occurs due to stochastic fluctuations of an intermediary catalytic species (LA, DA) produced in situ, given the interaction of the chiral species with the achiral substrate. The net process includes two different steps: the synthesis of the catalyst (LA and DA) and the catalytic production of new chiral species from the substrate. Stochastic simulations show that proper parameterization can induce a robust chiral state within the compartment regardless of whether the system is open or closed. We also show how an increase in the non-catalytic production of chiral species tends to negatively impact the homochirality degree of the system. By its conception, the proposed mechanism suggests a deeper connection with how most biochemical processes occur in living beings, a fact that could open new avenues for studying this fascinating phenomenon.
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Affiliation(s)
- Osmel Martín
- Laboratorio de Ciencia Planetaria. Universidad Central "Marta Abreu" de las Villas, Santa Clara, Cuba
| | - Yoelsy Leyva
- Departamento de Física, Facultad de Ciencias, Universidad de Tarapacá, Arica, Chile
| | - José Suárez-Lezcano
- Escuela de Enfermería, Pontificia Universidad Católica del Ecuador Sede Esmeraldas (PUCESE), Esmeraldas, Ecuador
| | - Yunierkis Pérez-Castillo
- Bio-Cheminformatics Research Group and Escuela de Ciencias Físicas y Matemáticas, Universidad de Las Américas, Quito, Ecuador
| | - Yovani Marrero-Ponce
- Universidad San Francisco de Quito (USFQ), Grupo de Medicina Molecular y Traslacional (MeM&T), Colegio de Ciencias de la Salud (COCSA), Escuela de Medicina, Edificio de Especialidades Médicas, Quito, Ecuador
- Departamento de Ciencias de la Computación, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, Baja California, México
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5
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Mandal R, Ghosh A, Rout NK, Prasad M, Hazra B, Sar S, Das S, Datta A, Tarafdar PK. Self-assembled prebiotic amphiphile-mixture exhibits tunable catalytic properties. Org Biomol Chem 2023; 21:4473-4481. [PMID: 37194351 DOI: 10.1039/d3ob00606a] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Protocellular surface formation via the self-assembly of amphiphiles, and catalysis by simple peptides/proto-RNA are two important pillars in the evolution of protocells. To hunt for prebiotic self-assembly-supported catalytic reactions, we thought that amino-acid-based amphiphiles might play an important role. In this paper, we investigate the formation of histidine-based and serine-based amphiphiles under mild prebiotic conditions from amino acid : fatty alcohol and amino acid : fatty acid mixtures. The histidine-based amphiphiles were able to catalyze hydrolytic reactions at the self-assembled surface (with a rate increase of ∼1000-fold), and the catalytic ability can be tuned by linkage of the fatty carbon part to histidine (N-acylated vs. O-acylated). Moreover, the presence of cationic serine-based amphiphiles on the surface enhances the catalytic efficiency by another ∼2-fold, whereas the presence of anionic aspartic acid-based amphiphiles reduces the catalytic activity. Ester partitioning into the surface, reactivity, and the accumulation of liberated fatty acid explain the substrate selectivity of the catalytic surface, where the hexyl esters were found to be more hydrolytic than other fatty acyl esters. Di-methylation of the -NH2 of OLH increases the catalytic efficacy by a further ∼2-fold, whereas trimethylation reduces the catalytic ability. The self-assembly, charge-charge repulsion, and the H-bonding to the ester carbonyl are likely to be responsible for the superior (∼2500-fold higher rate than the pre-micellar OLH) catalytic efficiency of O-lauryl dimethyl histidine (OLDMH). Thus, prebiotic amino-acid-based surfaces served as an efficient catalyst that exhibits regulation of catalytic function, substrate selectivity, and further adaptability to perform bio-catalysis.
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Affiliation(s)
- Raki Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur-741246, India.
| | - Anupam Ghosh
- Indian Association for the Cultivation of Science, Raja S. C. Mullick Road, Kolkata 700032, India
| | - Nilesh K Rout
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur-741246, India.
| | - Mahesh Prasad
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur-741246, India.
| | - Bibhas Hazra
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur-741246, India.
| | - Sanu Sar
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur-741246, India.
| | - Subrata Das
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur-741246, India.
| | - Ayan Datta
- Indian Association for the Cultivation of Science, Raja S. C. Mullick Road, Kolkata 700032, India
| | - Pradip K Tarafdar
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur-741246, India.
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6
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Martín O, Leyva Y, Suárez-Lezcano J, Pérez-Castillo Y, Marrero-Ponce Y. homFrom a coenzyme-like mechanism to homochirality. Biosystems 2023; 227-228:104904. [PMID: 37088349 DOI: 10.1016/j.biosystems.2023.104904] [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: 02/12/2023] [Revised: 04/15/2023] [Accepted: 04/18/2023] [Indexed: 04/25/2023]
Abstract
Inspired in a coenzyme-like behavior, an alternative mechanism to induce homochirality within a small vesicle is proposed. The system includes six different chemical species: an achiral substrate A, the enantiomeric forms L and D, a coenzyme E and two intermediate catalytic forms LE and DE. Whereas the coenzyme and the intermediate catalytic forms are trapped within the vesicle, the substrate and the two enantiomeric forms are able to diffuse selectively across the vesicle boundary. Instead of using autocatalysis, the production of new enantiomers includes two different steps, the production of intermediate catalytic species (LE, DE) and the catalytic production of new enantiomers from the substrate. Using a suitable parameterization, we found that the chiral evolution of the system is highly dependent on the total amount of coenzyme within the vesicle, regardless of whether the surrounding membrane is permeable or not. However, the existence of large flows from the outside can destabilize the homochiral state inside the vesicle. In general, homochiral states tend to arise when the amount of coenzyme is quite low, a value that can vary according to the parametrization. On the other hand, the system tends to decrease the enantiomeric excess when the coenzyme levels are high enough. In general, the appearance of homochirality is conditioned by stochastic fluctuations in coenzyme levels within the vesicle, an effect that is gradually amplified throughout the entire process of enantiomer synthesis.
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Affiliation(s)
- Osmel Martín
- Laboratorio de Ciencia Planetaria, Universidad Central "Marta Abreu" de Las Villas, Santa Clara, Cuba.
| | - Yoelsy Leyva
- Departamento de Física, Facultad de Ciencias, Universidad de Tarapacá, Casilla 7-D, Arica, Chile
| | - José Suárez-Lezcano
- Escuela de Enfermería, Pontificia Universidad Católica Del Ecuador Sede Esmeraldas (PUCESE), Esmeraldas, Ecuador
| | - Yunierkis Pérez-Castillo
- Bio-Cheminformatics Research Group and Escuela de Ciencias Físicas y Matemáticas, Universidad de Las Américas, Quito, 170504, Ecuador
| | - Yovani Marrero-Ponce
- Universidad San Francisco de Quito (USFQ), Grupo de Medicina Molecular y Traslacional (MeM&T), Colegio de Ciencias de La Salud (COCSA), Escuela de Medicina, Edificio de Especialidades Médicas, Av. Interoceánica Km 12 ½, Cumbayá, Quito, 170157, Ecuador
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7
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Akbari A, Palsson BO. Positively charged mineral surfaces promoted the accumulation of organic intermediates at the origin of metabolism. PLoS Comput Biol 2022; 18:e1010377. [PMID: 35976973 PMCID: PMC9423644 DOI: 10.1371/journal.pcbi.1010377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 08/29/2022] [Accepted: 07/11/2022] [Indexed: 11/23/2022] Open
Abstract
Identifying plausible mechanisms for compartmentalization and accumulation of the organic intermediates of early metabolic cycles in primitive cells has been a major challenge in theories of life's origins. Here, we propose a mechanism, where positive membrane potentials elevate the concentration of the organic intermediates. Positive membrane potentials are generated by positively charged surfaces of protocell membranes due to accumulation of transition metals. We find that (i) positive membrane potentials comparable in magnitude to those of modern cells can increase the concentration of the organic intermediates by several orders of magnitude; (ii) generation of large membrane potentials destabilize ion distributions; (iii) violation of electroneutrality is necessary to induce nonzero membrane potentials; and (iv) violation of electroneutrality enhances osmotic pressure and diminishes reaction efficiency, resulting in an evolutionary driving force for the formation of lipid membranes, specialized ion channels, and active transport systems.
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Affiliation(s)
- Amir Akbari
- Department of Bioengineering, University of California, San Diego, California, United States of America
| | - Bernhard O. Palsson
- Department of Bioengineering, University of California, San Diego, California, United States of America
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
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8
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Nader S, Sebastianelli L, Mansy SS. Protometabolism as out-of-equilibrium chemistry. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2022; 380:20200423. [PMID: 35599565 PMCID: PMC9125230 DOI: 10.1098/rsta.2020.0423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/24/2021] [Indexed: 05/06/2023]
Abstract
It is common to compare life with machines. Both consume fuel and release waste to run. In biology, the engine that drives the living system is referred to as metabolism. However, attempts at deciphering the origins of metabolism do not focus on this energetic relationship that sustains life but rather concentrate on nonenzymatic reactions that produce all the intermediates of an extant metabolic pathway. Such an approach is akin to studying the molecules produced from the burning of coal instead of deciphering how the released energy drives the movement of pistons and ultimately the train when investigating the mechanisms behind locomotion. Theories that do explicitly invoke geological chemical gradients to drive metabolism most frequently feature hydrothermal vent conditions, but hydrothermal vents are not the only regions of the early Earth that could have provided the fuel necessary to sustain the Earth's first (proto)cells. Here, we give examples of prior reports on protometabolism and highlight how more recent investigations of out-of-equilibrium systems may point to alternative scenarios more consistent with the majority of prebiotic chemistry data accumulated thus far. This article is part of the theme issue 'Emergent phenomena in complex physical and socio-technical systems: from cells to societies'.
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Affiliation(s)
- Serge Nader
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AB, Canada T6G 2G2
| | - Lorenzo Sebastianelli
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AB, Canada T6G 2G2
| | - Sheref S. Mansy
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AB, Canada T6G 2G2
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9
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Fiore M, Chieffo C, Lopez A, Fayolle D, Ruiz J, Soulère L, Oger P, Altamura E, Popowycz F, Buchet R. Synthesis of Phospholipids Under Plausible Prebiotic Conditions and Analogies with Phospholipid Biochemistry for Origin of Life Studies. ASTROBIOLOGY 2022; 22:598-627. [PMID: 35196460 DOI: 10.1089/ast.2021.0059] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Phospholipids are essential components of biological membranes and are involved in cell signalization, in several enzymatic reactions, and in energy metabolism. In addition, phospholipids represent an evolutionary and non-negligible step in life emergence. Progress in the past decades has led to a deeper understanding of these unique hydrophobic molecules and their most pertinent functions in cell biology. Today, a growing interest in "prebiotic lipidomics" calls for a new assessment of these relevant biomolecules.
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Affiliation(s)
- Michele Fiore
- Université de Lyon, Université Claude Bernard Lyon 1, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires, UMR 5246, CNRS, CPE, Villeurbanne, France
| | - Carolina Chieffo
- Université de Lyon, Université Claude Bernard Lyon 1, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires, UMR 5246, CNRS, CPE, Villeurbanne, France
| | - Augustin Lopez
- Université de Lyon, Université Claude Bernard Lyon 1, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires, UMR 5246, CNRS, CPE, Villeurbanne, France
| | - Dimitri Fayolle
- Université de Lyon, Université Claude Bernard Lyon 1, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires, UMR 5246, CNRS, CPE, Villeurbanne, France
| | - Johal Ruiz
- Université de Lyon, Université Claude Bernard Lyon 1, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires, UMR 5246, CNRS, CPE, Villeurbanne, France
- Institut National Des Sciences Appliquées, INSA Lyon, Villeurbanne, France
| | - Laurent Soulère
- Université de Lyon, Université Claude Bernard Lyon 1, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires, UMR 5246, CNRS, CPE, Villeurbanne, France
- Institut National Des Sciences Appliquées, INSA Lyon, Villeurbanne, France
| | - Philippe Oger
- Microbiologie, Adaptation et Pathogénie, UMR 5240, Université de Lyon, Claude Bernard Lyon 1, Villeurbanne, France
| | - Emiliano Altamura
- Chemistry Department, Università degli studi di Bari "Aldo Moro," Bari, Italy
| | - Florence Popowycz
- Université de Lyon, Université Claude Bernard Lyon 1, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires, UMR 5246, CNRS, CPE, Villeurbanne, France
- Institut National Des Sciences Appliquées, INSA Lyon, Villeurbanne, France
| | - René Buchet
- Université de Lyon, Université Claude Bernard Lyon 1, Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires, UMR 5246, CNRS, CPE, Villeurbanne, France
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10
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Piedrafita G, Varma SJ, Castro C, Messner CB, Szyrwiel L, Griffin JL, Ralser M. Cysteine and iron accelerate the formation of ribose-5-phosphate, providing insights into the evolutionary origins of the metabolic network structure. PLoS Biol 2021; 19:e3001468. [PMID: 34860829 PMCID: PMC8673631 DOI: 10.1371/journal.pbio.3001468] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 12/15/2021] [Accepted: 11/04/2021] [Indexed: 12/21/2022] Open
Abstract
The structure of the metabolic network is highly conserved, but we know little about its evolutionary origins. Key for explaining the early evolution of metabolism is solving a chicken–egg dilemma, which describes that enzymes are made from the very same molecules they produce. The recent discovery of several nonenzymatic reaction sequences that topologically resemble central metabolism has provided experimental support for a “metabolism first” theory, in which at least part of the extant metabolic network emerged on the basis of nonenzymatic reactions. But how could evolution kick-start on the basis of a metal catalyzed reaction sequence, and how could the structure of nonenzymatic reaction sequences be imprinted on the metabolic network to remain conserved for billions of years? We performed an in vitro screening where we add the simplest components of metabolic enzymes, proteinogenic amino acids, to a nonenzymatic, iron-driven reaction network that resembles glycolysis and the pentose phosphate pathway (PPP). We observe that the presence of the amino acids enhanced several of the nonenzymatic reactions. Particular attention was triggered by a reaction that resembles a rate-limiting step in the oxidative PPP. A prebiotically available, proteinogenic amino acid cysteine accelerated the formation of RNA nucleoside precursor ribose-5-phosphate from 6-phosphogluconate. We report that iron and cysteine interact and have additive effects on the reaction rate so that ribose-5-phosphate forms at high specificity under mild, metabolism typical temperature and environmental conditions. We speculate that accelerating effects of amino acids on rate-limiting nonenzymatic reactions could have facilitated a stepwise enzymatization of nonenzymatic reaction sequences, imprinting their structure on the evolving metabolic network. The evolutionary origins of metabolism are largely unknown. This study shows that the prebiotically available proteinogenic amino acid cysteine can promote the metabolism-like rate-limiting formation of ribose-5-phosphate, suggesting that early metabolic pathways could have emerged thought the stepwise enzymatization of non-enzymatic reaction sequences.
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Affiliation(s)
- Gabriel Piedrafita
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, United Kingdom
| | - Sreejith J. Varma
- Department of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Cecilia Castro
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, United Kingdom
| | - Christoph B. Messner
- The Molecular Biology of Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Lukasz Szyrwiel
- Department of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
- The Molecular Biology of Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
| | - Julian L. Griffin
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, United Kingdom
- The Rowett Institute, The University of Aberdeen, Aberdeen, United Kingdom
| | - Markus Ralser
- Department of Biochemistry and Cambridge Systems Biology Centre, University of Cambridge, United Kingdom
- Department of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
- The Molecular Biology of Metabolism Laboratory, The Francis Crick Institute, London, United Kingdom
- * E-mail:
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11
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Higgs PG. When Is a Reaction Network a Metabolism? Criteria for Simple Metabolisms That Support Growth and Division of Protocells. Life (Basel) 2021; 11:life11090966. [PMID: 34575115 PMCID: PMC8469938 DOI: 10.3390/life11090966] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/08/2021] [Accepted: 09/08/2021] [Indexed: 11/16/2022] Open
Abstract
With the aim of better understanding the nature of metabolism in the first cells and the relationship between the origin of life and the origin of metabolism, we propose three criteria that a chemical reaction system must satisfy in order to constitute a metabolism that would be capable of sustaining growth and division of a protocell. (1) Biomolecules produced by the reaction system must be maintained at high concentration inside the cell while they remain at low or zero concentration outside. (2) The total solute concentration inside the cell must be higher than outside, so there is a positive osmotic pressure that drives cell growth. (3) The metabolic rate (i.e., the rate of mass throughput) must be higher inside the cell than outside. We give examples of small-molecule reaction systems that satisfy these criteria, and others which do not, firstly considering fixed-volume compartments, and secondly, lipid vesicles that can grow and divide. If the criteria are satisfied, and if a supply of lipid is available outside the cell, then continued growth of membrane surface area occurs alongside the increase in volume of the cell. If the metabolism synthesizes more lipid inside the cell, then the membrane surface area can increase proportionately faster than the cell volume, in which case cell division is possible. The three criteria can be satisfied if the reaction system is bistable, because different concentrations can exist inside and out while the rate constants of all the reactions are the same. If the reaction system is monostable, the criteria can only be satisfied if there is a reason why the rate constants are different inside and out (for example, the decay rates of biomolecules are faster outside, or the formation rates of biomolecules are slower outside). If this difference between inside and outside does not exist, a monostable reaction system cannot sustain cell growth and division. We show that a reaction system for template-directed RNA polymerization can satisfy the requirements for a metabolism, even if the small-molecule reactions that make the single nucleotides do not.
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Affiliation(s)
- Paul G Higgs
- Department of Physics and Astronomy, Origins Institute, McMaster University, Hamilton, ON L8S 4M1, Canada
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12
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Toparlak Ö, Wang A, Mansy SS. Population-Level Membrane Diversity Triggers Growth and Division of Protocells. JACS AU 2021; 1:560-568. [PMID: 34467319 PMCID: PMC8395648 DOI: 10.1021/jacsau.0c00079] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Indexed: 06/01/2023]
Abstract
To date, multiple mechanisms have been described for the growth and division of model protocells, all of which exploit the lipid dynamics of fatty acids. In some examples, the more heterogeneous aggregate consisting of fatty acid and diacyl phospholipid or fatty acid and peptide grows at the expense of the more homogeneous aggregate containing a restricted set of lipids with similar dynamics. Imbalances between surface area and volume during growth can generate filamentous vesicles, which are typically divided by shear forces. Here, we describe another pathway for growth and division that depends simply on differences in the compositions of fatty acid membranes without additional components. Growth is driven by the thermodynamically favorable mixing of lipids between two populations, i.e., the system as a whole proceeds toward equilibrium. Division is the result of growth-induced curvature. Importantly, growth and division do not require a specific composition of lipids. For example, vesicles made from one type of lipid, e.g., short-chain fatty acids, grow and divide when fed with vesicles consisting of another type of lipid, e.g., long-chain fatty acids, and vice versa. After equilibration, additional rounds of growth and division could potentially proceed by the introduction of compositionally distinct aggregates. Since prebiotic synthesis likely gave rise to mixtures of lipids, the data are consistent with the presence of growing and dividing protocells on the prebiotic Earth.
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Affiliation(s)
- Ö.
Duhan Toparlak
- Department
of Cellular, Computational and Integrative Biology (D-CIBIO), University of Trento, Via Sommarive 9, 38123 Povo, TN, Italy
| | - Anna Wang
- School
of Chemistry and Australian Centre for Astrobiology, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Sheref S. Mansy
- Department
of Cellular, Computational and Integrative Biology (D-CIBIO), University of Trento, Via Sommarive 9, 38123 Povo, TN, Italy
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AB T6G
2G2, Canada
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13
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Sarkar S, Das S, Dagar S, Joshi MP, Mungi CV, Sawant AA, Patki GM, Rajamani S. Prebiological Membranes and Their Role in the Emergence of Early Cellular Life. J Membr Biol 2020; 253:589-608. [PMID: 33200235 DOI: 10.1007/s00232-020-00155-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 11/08/2020] [Indexed: 01/30/2023]
Abstract
Membrane compartmentalization is a fundamental feature of contemporary cellular life. Given this, it is rational to assume that at some stage in the early origins of life, membrane compartments would have potentially emerged to form a dynamic semipermeable barrier in primitive cells (protocells), protecting them from their surrounding environment. It is thought that such prebiological membranes would likely have played a crucial role in the emergence and evolution of life on the early Earth. Extant biological membranes are highly organized and complex, which is a consequence of a protracted evolutionary history. On the other hand, prebiotic membrane assemblies, which are thought to have preceded sophisticated contemporary membranes, are hypothesized to have been relatively simple and composed of single chain amphiphiles. Recent studies indicate that the evolution of prebiotic membranes potentially resulted from interactions between the membrane and its physicochemical environment. These studies have also speculated on the origin, composition, function and influence of environmental conditions on protocellular membranes as the niche parameters would have directly influenced their composition and biophysical properties. Nonetheless, the evolutionary pathways involved in the transition from prebiological membranes to contemporary membranes are largely unknown. This review critically evaluates existing research on prebiotic membranes in terms of their probable origin, composition, energetics, function and evolution. Notably, we outline new approaches that can further our understanding about how prebiotic membranes might have evolved in response to relevant physicochemical parameters that would have acted as pertinent selection pressures on the early Earth.
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Affiliation(s)
- Susovan Sarkar
- Department of Biology, Indian Institute of Science Education and Research, Pune, 411008, India
| | - Souradeep Das
- Department of Biology, Indian Institute of Science Education and Research, Pune, 411008, India
| | - Shikha Dagar
- Department of Biology, Indian Institute of Science Education and Research, Pune, 411008, India
| | - Manesh Prakash Joshi
- Department of Biology, Indian Institute of Science Education and Research, Pune, 411008, India
| | - Chaitanya V Mungi
- Department of Biology, Indian Institute of Science Education and Research, Pune, 411008, India
| | - Anupam A Sawant
- Department of Biology, Indian Institute of Science Education and Research, Pune, 411008, India
| | - Gauri M Patki
- Department of Biology, Indian Institute of Science Education and Research, Pune, 411008, India
| | - Sudha Rajamani
- Department of Biology, Indian Institute of Science Education and Research, Pune, 411008, India.
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14
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Kundu N, Mondal D, Sarkar N. Dynamics of the vesicles composed of fatty acids and other amphiphile mixtures: unveiling the role of fatty acids as a model protocell membrane. Biophys Rev 2020; 12:1117-1131. [PMID: 32926295 PMCID: PMC7575682 DOI: 10.1007/s12551-020-00753-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 09/03/2020] [Indexed: 01/31/2023] Open
Abstract
Fundamental research at the interface of chemistry and biology has the potential to shine light on the question of how living cells can be synthesized from inanimate matter thereby providing plausible pathways for the emergence of cellular life. Compartmentalization of different biochemical reactions within a membrane bound water environment is considered an essential first step in any origin of life pathway. It has been suggested that fatty acid-based vesicles can be considered a model protocell having the potential for change via Darwinian evolution. As such, protocell models have the potential to assist in furthering our understanding of the origin of life in the laboratory. Fatty acids, both by themselves and in mixtures with other amphiphiles, can form different self-assembled structures depending on their surroundings. Recent studies of fatty acid-based membranes have suggested likely pathways of protocell growth, division and membrane permeabilisation for the transport of different nutrients, such as nucleotides across the membrane. In this review, different dynamic processes related to the growth and division of the protocell membrane are discussed and possible pathways for transition of the protocell to the modern cell are explored. These areas of research may lead to a better understanding of the synthesis of artificial cell-like entities and thus herald the possibility of creating new form of life distinct from existing biology. Graphical Abstract Table of Content (TOC) only.
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Affiliation(s)
- Niloy Kundu
- Environment Research Group, R&D Department, Tata Steel Ltd, Jamshedpur, 831007, India.
| | - Dipankar Mondal
- Institute for System Genetics and Department of Cell Biology, New York University, Langone Medical Center, New York, 10016, USA
- Department of Chemistry, Indian Institute of Technology, Kharagpur, WB, 721302, India
| | - Nilmoni Sarkar
- Department of Chemistry, Indian Institute of Technology, Kharagpur, WB, 721302, India
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15
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Yun-Cárcamo S, Carrasco S, Rogan J, Correa-Burrows P, Valdivia JA. Stability and robustness of asymptotic autocatalytic systems. Sci Rep 2020; 10:15498. [PMID: 32968157 PMCID: PMC7511346 DOI: 10.1038/s41598-020-72580-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 08/21/2020] [Indexed: 11/09/2022] Open
Abstract
Here, we address the consequences of the extension in the space of a simple model of a system that is closed to efficient causation: the (M,R)-system model. To do so, we use a diffusion term to describe the collective motion of the nutrients’ concentration across the compartmentalized space that defines the organism. We show that the non-trivial stable steady state remains despite such generalization, as long as the system is small enough to deal with the transport of the precursors to feed the entire protocell and dispose of a sufficient concentration of it in its surroundings. Such consideration explains the emergence of a bifurcation with two parameters that we characterize. Finally, we show that the robustness of the system under catastrophic losses of catalysts also remains, preserving the original’s model character.
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Affiliation(s)
- Sohyoun Yun-Cárcamo
- Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, 7800024, Santiago, Chile.
| | - Sebastián Carrasco
- Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, 7800024, Santiago, Chile
| | - José Rogan
- Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, 7800024, Santiago, Chile
| | - Paulina Correa-Burrows
- Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, 7840390, Santiago, Chile
| | - Juan Alejandro Valdivia
- Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, 7800024, Santiago, Chile
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16
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Boundary versus enabling conditions for the origins of life: Comment on "Mineral self-organization on a lifeless planet" by García-Ruiz et al. Phys Life Rev 2020; 34-35:96-98. [PMID: 32536537 DOI: 10.1016/j.plrev.2020.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 06/04/2020] [Indexed: 11/22/2022]
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17
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Ruiz-Mirazo K, Shirt-Ediss B, Escribano-Cabeza M, Moreno A. The Construction of Biological 'Inter-Identity' as the Outcome of a Complex Process of Protocell Development in Prebiotic Evolution. Front Physiol 2020; 11:530. [PMID: 32547413 PMCID: PMC7269143 DOI: 10.3389/fphys.2020.00530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 04/29/2020] [Indexed: 11/25/2022] Open
Abstract
The concept of identity is used both (i) to distinguish a system as a particular material entity that is conserved as such in a given environment (token-identity: i.e., identity as permanence or endurance over time), and (ii) to relate a system with other members of a set (type-identity: i.e., identity as an equivalence relationship). Biological systems are characterized, in a minimal and universal sense, by a highly complex and dynamic, far-from-equilibrium organization of very diverse molecular components and transformation processes (i.e., 'genetically instructed cellular metabolisms') that maintain themselves in constant interaction with their corresponding environments, including other systems of similar nature. More precisely, all living entities depend on a deeply convoluted organization of molecules and processes (a naturalized von Neumann constructor architecture) that subsumes, in the form of current individuals (autonomous cells), a history of ecological and evolutionary interactions (across cell populations). So one can defend, on those grounds, that living beings have an identity of their own from both approximations: (i) and (ii). These transversal and trans-generational dimensions of biological phenomena, which unfold together with the actual process of biogenesis, must be carefully considered in order to understand the intricacies and metabolic robustness of the first living cells, their underlying uniformity (i.e., their common biochemical core) and the eradication of previous -or alternative- forms of complex natural phenomena. Therefore, a comprehensive approach to the origins of life requires conjugating the actual properties of the developing complex individuals (fusing and dividing protocells, at various stages) with other, population-level features, linked to their collective-evolutionary behavior, under much wider and longer-term parameters. On these lines, we will argue that life, in its most basic sense, here on Earth or anywhere else, demands crossing a high complexity threshold and that the concept of 'inter-identity' can help us realize the different aspects involved in the process. The article concludes by pointing out some of the challenges ahead if we are to integrate the corresponding explanatory frameworks, physiological and evolutionary, in the hope that a more general theory of biology is on its way.
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Affiliation(s)
- Kepa Ruiz-Mirazo
- Department of Logic and Philosophy of Science, University of the Basque Country, San Sebastian, Spain
- Biofisika Institute (CSIC, UPV-EHU), Leioa, Spain
| | - Ben Shirt-Ediss
- Interdisciplinary Computing and Complex BioSystems Group, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Miguel Escribano-Cabeza
- Department of Logic and Philosophy of Science, University of the Basque Country, San Sebastian, Spain
| | - Alvaro Moreno
- Department of Logic and Philosophy of Science, University of the Basque Country, San Sebastian, Spain
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18
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de la Escosura A. The Informational Substrate of Chemical Evolution: Implications for Abiogenesis. Life (Basel) 2019; 9:E66. [PMID: 31398942 PMCID: PMC6789672 DOI: 10.3390/life9030066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/26/2019] [Accepted: 08/05/2019] [Indexed: 12/11/2022] Open
Abstract
A key aspect of biological evolution is the capacity of living systems to process information, coded in deoxyribonucleic acid (DNA), and used to direct how the cell works. The overall picture that emerges today from fields such as developmental, synthetic, and systems biology indicates that information processing in cells occurs through a hierarchy of genes regulating the activity of other genes through complex metabolic networks. There is an implicit semiotic character in this way of dealing with information, based on functional molecules that act as signs to achieve self-regulation of the whole network. In contrast to cells, chemical systems are not thought of being able to process information, yet they must have preceded biological organisms, and evolved into them. Hence, there must have been prebiotic molecular assemblies that could somehow process information, in order to regulate their own constituent reactions and supramolecular organization processes. The purpose of this essay is then to reflect about the distinctive features of information in living and non-living matter, and on how the capacity of biological organisms for information processing was possibly rooted in a particular type of chemical systems (here referred to as autonomous chemical systems), which could self-sustain and reproduce through organizational closure of their molecular building blocks.
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Affiliation(s)
- Andrés de la Escosura
- Department of Organic Chemistry, Universidad Autónoma of Madrid, Cantoblanco Campus, 28049 Madrid, Spain.
- Department of Organic Chemistry, Institute for Advanced Research in Chemistry (IAdChem), Cantoblanco Campus, 28049 Madrid, Spain.
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19
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Affiliation(s)
- Kilian Vogele
- Physik-DepartmentTechnische Universitat Munchen, TU München Garching Germany
| | - Tobias Pirzer
- Physik-DepartmentTechnische Universitat Munchen, TU München Garching Germany
| | - Friedrich C. Simmel
- Physik-DepartmentTechnische Universitat Munchen, TU München Garching Germany
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20
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Leyva Y, Martin O, Perez N, Suarez-Lezcano J, Fundora-Pozo M. The optimal size of protocells from simple entropic considerations. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2019; 48:277-283. [PMID: 30899982 DOI: 10.1007/s00249-019-01359-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 12/11/2018] [Accepted: 03/12/2019] [Indexed: 01/29/2023]
Abstract
Potential constraints on protocell size are developed from simple entropic considerations. To do that, two new different indexes as measures of their structural and dynamic order were developed and applied to an elemental model of the heterotrophic protocell. According to our results, cell size should be a key factor determining the potential of these primitive systems to evolve and consequently to support life. Our analyses also suggest that the size of the optimal vesicles could be constrained to have radii in the interval [Formula: see text], where the two extreme limits [Formula: see text] and [Formula: see text] represent the states of maximum structural order (largest accumulation of substrate inside the vesicle) and the maximum flux of entropy production, respectively. According to the above criteria, the size of the optimum vesicles falls, approximately, in the same spatial range estimated for biological living cells assuming plausible values for the second-order rate constant involved in the catabolic process. Furthermore, the existence of very small vesicles could be seriously affected by the limited efficiency, far from the theoretical limits, with which these catabolic processes may proceed in a prebiotic system.
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Affiliation(s)
- Yoelsy Leyva
- Departamento de Física, Facultad de Ciencias, Universidad de Tarapacá, Casilla 7-D, Arica, Chile.
| | - Osmel Martin
- Laboratorio de Ciencia Planetaria, Universidad Central "Marta Abreu" de las Villas, Santa Clara, Cuba
| | - Noel Perez
- Laboratorio de Ciencia Planetaria, Universidad Central "Marta Abreu" de las Villas, Santa Clara, Cuba
| | - José Suarez-Lezcano
- Escuela de Enfermería, Pontificia Universidad Católica del Ecuador Sede Esmeraldas (PUCESE), Esmeraldas, Ecuador
| | - Manuel Fundora-Pozo
- Laboratorio de Ciencia Planetaria, Universidad Central "Marta Abreu" de las Villas, Santa Clara, Cuba
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Abstract
IMPACT STATEMENT Advances in the understanding of the biophysics of membranes, the nonenzymatic and enzymatic polymerization of RNA, and in the design of complex chemical reaction networks have led to a new, integrated way of viewing the shared chemistry needed to sustain life. Although a protocell capable of Darwinian evolution has yet to be built, the seemingly disparate pieces are beginning to fit together. At the very least, better cellular mimics are on the horizon that will likely teach us much about the physicochemical underpinnings of cellular life.
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22
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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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23
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Leyva Y, Martín O, García-Jacas CR. Constraining the Prebiotic Cell Size Limits in Extremely Hostile Environments: A Dynamical Perspective. ASTROBIOLOGY 2018; 18:403-411. [PMID: 29672138 DOI: 10.1089/ast.2017.1696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The ability to support a replicator population in an extremely hostile environment is considered in a simple model of a prebiotic cell. We explore from a classical approach how the replicator viability changes as a function of the cell radius. The model includes the interaction between two different species: a substrate that flows from the exterior and a replicator that feeds on the substrate and is readily destroyed in the environment outside the cell. According to our results, replicators in the cell only exist when the radius exceeds some critical value [Formula: see text] being, in general, a function of the substrate concentration, the diffusion constant of the replicator species, and the reproduction rate coefficient. Additionally, the influence of other parameters on the replicator population is also considered. The viability of chemical replicators under such drastic conditions could be crucial in understanding the origin of the first primitive cells and the ulterior development of life on our planet. Key Words: Prebiotic cell-Chemical replicator-Environment-Reproduction rate. Astrobiology 18, 403-411.
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Affiliation(s)
- Yoelsy Leyva
- 1 Departamento de Física, Facultad de Ciencias, Universidad de Tarapacá , Arica, Chile
| | - Osmel Martín
- 2 Laboratorio de Ciencia Planetaria, Universidad Central "Marta Abreu" de las Villas , Santa Clara, Cuba
| | - César R García-Jacas
- 3 Escuela de Sistemas y Computación, Pontificia Universidad Católica del Ecuador Sede Esmeraldas (PUCESE) , Esmeraldas, Ecuador
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Parrilla-Gutierrez JM, Tsuda S, Grizou J, Taylor J, Henson A, Cronin L. Adaptive artificial evolution of droplet protocells in a 3D-printed fluidic chemorobotic platform with configurable environments. Nat Commun 2017; 8:1144. [PMID: 29074987 PMCID: PMC5658334 DOI: 10.1038/s41467-017-01161-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 08/23/2017] [Indexed: 11/09/2022] Open
Abstract
Evolution via natural selection is governed by the persistence and propagation of living things in an environment. The environment is important since it enabled life to emerge, and shapes evolution today. Although evolution has been widely studied in a variety of fields from biology to computer science, still little is known about the impact of environmental changes on an artificial chemical evolving system outside of computer simulations. Here we develop a fully automated 3D-printed chemorobotic fluidic system that is able to generate and select droplet protocells in real time while changing the surroundings where they undergo artificial evolution. The system is produced using rapid prototyping and explicitly introduces programmable environments as an experimental variable. Our results show that the environment not only acts as an active selector over the genotypes, but also enhances the capacity for individual genotypes to undergo adaptation in response to environmental pressures.
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Affiliation(s)
| | - Soichiro Tsuda
- WestCHEM, School of Chemistry, The University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK
| | - Jonathan Grizou
- WestCHEM, School of Chemistry, The University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK
| | - James Taylor
- WestCHEM, School of Chemistry, The University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK
| | - Alon Henson
- WestCHEM, School of Chemistry, The University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK
| | - Leroy Cronin
- WestCHEM, School of Chemistry, The University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK.
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