1
|
Li Z, Duan S, Liu B. Freezing Functional Nucleic Acids: From Molecular Reactions to Surface Immobilization. Chembiochem 2024:e202400416. [PMID: 38979890 DOI: 10.1002/cbic.202400416] [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: 05/07/2024] [Revised: 07/08/2024] [Accepted: 07/08/2024] [Indexed: 07/10/2024]
Abstract
Biochemical reactions are typically slowed down by decreasing temperature. However, accelerated reaction kinetics have been observed for a long time. More recent examples have highlighted the unique role of freezing in fabricating supermaterials, degrading environmental contaminants, and accelerating bioreactions. Functional nucleic acids are DNA or RNA oligonucleotides with versatile properties, including target recognition, catalysis, and molecular co4mputing. In this review, we discuss the current observations and understanding of freezing-facilitated reactions involving functional nucleic acids. Molecular reactions such as ligation/conjugation, cleavage, and hybridization are discussed. Moreover, freezing-induced DNA-nanoparticle conjugations are introduced. Then, we describe our effect in immobilizing DNA on bulk surfaces. Finally, we address some critical questions and research opportunities in the field.
Collapse
Affiliation(s)
- Zhenglian Li
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China
| | - Siyi Duan
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China
| | - Biwu Liu
- Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China
| |
Collapse
|
2
|
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.
Collapse
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.)
| |
Collapse
|
3
|
Song EY, Jiménez EI, Lin H, Le Vay K, Krishnamurthy R, Mutschler H. Prebiotically Plausible RNA Activation Compatible with Ribozyme-Catalyzed Ligation. Angew Chem Int Ed Engl 2021; 60:2952-2957. [PMID: 33128282 PMCID: PMC7898671 DOI: 10.1002/anie.202010918] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 10/29/2020] [Indexed: 01/04/2023]
Abstract
RNA-catalyzed RNA ligation is widely believed to be a key reaction for primordial biology. However, since typical chemical routes towards activating RNA substrates are incompatible with ribozyme catalysis, it remains unclear how prebiotic systems generated and sustained pools of activated building blocks needed to form increasingly larger and complex RNA. Herein, we demonstrate in situ activation of RNA substrates under reaction conditions amenable to catalysis by the hairpin ribozyme. We found that diamidophosphate (DAP) and imidazole drive the formation of 2',3'-cyclic phosphate RNA mono- and oligonucleotides from monophosphorylated precursors in frozen water-ice. This long-lived activation enables iterative enzymatic assembly of long RNAs. Our results provide a plausible scenario for the generation of higher-energy substrates required to fuel ribozyme-catalyzed RNA synthesis in the absence of a highly evolved metabolism.
Collapse
Affiliation(s)
- Emilie Yeonwha Song
- Max Planck Institute of BiochemistryAm Klopferspitz 1882152MartinsriedGermany
| | - Eddy Ivanhoe Jiménez
- Department of ChemistryThe Scripps Research Institute10550 North Torrey Pines RoadLa JollaCA92037USA
| | - Huacan Lin
- Department of ChemistryThe Scripps Research Institute10550 North Torrey Pines RoadLa JollaCA92037USA
| | - Kristian Le Vay
- Max Planck Institute of BiochemistryAm Klopferspitz 1882152MartinsriedGermany
| | | | - Hannes Mutschler
- Max Planck Institute of BiochemistryAm Klopferspitz 1882152MartinsriedGermany
- Technical University DortmundOtto-Hahn-Strasse 4a44227DortmundGermany
| |
Collapse
|
4
|
Song EY, Jiménez EI, Lin H, Le Vay K, Krishnamurthy R, Mutschler H. Präbiotisch plausible RNA‐Aktivierung kompatibel mit ribozymkatalysierter Ligation. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202010918] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Emilie Yeonwha Song
- Max Planck Institute of Biochemistry Am Klopferspitz 18 82152 Martinsried Deutschland
| | - Eddy Ivanhoe Jiménez
- Department of Chemistry The Scripps Research Institute 10550 North Torrey Pines Road La Jolla CA 92037 USA
| | - Huacan Lin
- Department of Chemistry The Scripps Research Institute 10550 North Torrey Pines Road La Jolla CA 92037 USA
| | - Kristian Le Vay
- Max Planck Institute of Biochemistry Am Klopferspitz 18 82152 Martinsried Deutschland
| | | | - Hannes Mutschler
- Max Planck Institute of Biochemistry Am Klopferspitz 18 82152 Martinsried Deutschland
- TU Dortmund University Otto-Hahn-Straße 4a 44227 Dortmund Deutschland
| |
Collapse
|
5
|
Iijima K, Harada M, Fukuhara G, Okada T. Frozen Solution-Mediated Asymmetric Synthesis: Control of Enantiomeric Excess. J Org Chem 2020; 85:4525-4529. [PMID: 32069399 DOI: 10.1021/acs.joc.9b03415] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Asymmetric List-Mannich reactions were carried out in the frozen state to afford optically active adducts in moderate-to-good chemical yields and enantiomeric excesses (ee). The frozen solution exerts critical control of ee via entropy changes, in sharp contrast to the enthalpy-driven asymmetric reactions typically observed in homogeneous solvents. This study provides new perspectives for asymmetric syntheses and an attractive alternative to conventional media.
Collapse
Affiliation(s)
- Koki Iijima
- Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
| | - Makoto Harada
- Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
| | - Gaku Fukuhara
- Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan.,JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Tetsuo Okada
- Department of Chemistry, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8551, Japan
| |
Collapse
|
6
|
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.
Collapse
|
7
|
Rahman MM, Matsumura S, Ikawa Y. Oligomerization of a Bimolecular Ribozyme Modestly Rescues its Structural Defects that Disturb Interdomain Assembly to Form the Catalytic Site. J Mol Evol 2018; 86:431-442. [DOI: 10.1007/s00239-018-9862-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 08/07/2018] [Indexed: 12/31/2022]
|
8
|
Emergence of native peptide sequences in prebiotic replication networks. Nat Commun 2017; 8:434. [PMID: 28874657 PMCID: PMC5585222 DOI: 10.1038/s41467-017-00463-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 06/30/2017] [Indexed: 12/15/2022] Open
Abstract
Biopolymer syntheses in living cells are perfected by an elaborate error correction machinery, which was not applicable during polymerization on early Earth. Scientists are consequently striving to identify mechanisms by which functional polymers were selected and further amplified from complex prebiotic mixtures. Here we show the instrumental role of non-enzymatic replication in the enrichment of certain product(s). To this end, we analyzed a complex web of reactions in β-sheet peptide networks, focusing on the formation of specific intermediate compounds and template-assisted replication. Remarkably, we find that the formation of several products in a mixture is not critically harmful, since efficient and selective template-assisted reactions serve as a backbone correction mechanism, namely, for keeping the concentration of the peptide containing the native backbone equal to, or even higher than, the concentrations of the other products. We suggest that these findings may shed light on molecular evolution processes that led to current biology.The synthesis of biopolymers in living cells is perfected by complex machinery, however this was not the case on early Earth. Here the authors show the role of non-enzymatic replication in the enrichment of certain products within prebiotically relevant mixtures.
Collapse
|
9
|
Nonenzymatic gluconeogenesis-like formation of fructose 1,6-bisphosphate in ice. Proc Natl Acad Sci U S A 2017; 114:7403-7407. [PMID: 28652321 DOI: 10.1073/pnas.1702274114] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The evolutionary origins of metabolism, in particular the emergence of the sugar phosphates that constitute glycolysis, the pentose phosphate pathway, and the RNA and DNA backbone, are largely unknown. In cells, a major source of glucose and the large sugar phosphates is gluconeogenesis. This ancient anabolic pathway (re-)builds carbon bonds as cleaved in glycolysis in an aldol condensation of the unstable catabolites glyceraldehyde 3-phosphate and dihydroxyacetone phosphate, forming the much more stable fructose 1,6-bisphosphate. We here report the discovery of a nonenzymatic counterpart to this reaction. The in-ice nonenzymatic aldol addition leads to the continuous accumulation of fructose 1,6-bisphosphate in a permanently frozen solution as followed over months. Moreover, the in-ice reaction is accelerated by simple amino acids, in particular glycine and lysine. Revealing that gluconeogenesis may be of nonenzymatic origin, our results shed light on how glucose anabolism could have emerged in early life forms. Furthermore, the amino acid acceleration of a key cellular anabolic reaction may indicate a link between prebiotic chemistry and the nature of the first metabolic enzymes.
Collapse
|
10
|
Wieczorek R, Adamala K, Gasperi T, Polticelli F, Stano P. Small and Random Peptides: An Unexplored Reservoir of Potentially Functional Primitive Organocatalysts. The Case of Seryl-Histidine. Life (Basel) 2017; 7:E19. [PMID: 28397774 PMCID: PMC5492141 DOI: 10.3390/life7020019] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 04/03/2017] [Accepted: 04/05/2017] [Indexed: 12/11/2022] Open
Abstract
Catalysis is an essential feature of living systems biochemistry, and probably, it played a key role in primordial times, helping to produce more complex molecules from simple ones. However, enzymes, the biocatalysts par excellence, were not available in such an ancient context, and so, instead, small molecule catalysis (organocatalysis) may have occurred. The best candidates for the role of primitive organocatalysts are amino acids and short random peptides, which are believed to have been available in an early period on Earth. In this review, we discuss the occurrence of primordial organocatalysts in the form of peptides, in particular commenting on reports about seryl-histidine dipeptide, which have recently been investigated. Starting from this specific case, we also mention a peptide fragment condensation scenario, as well as other potential roles of peptides in primordial times. The review actually aims to stimulate further investigation on an unexplored field of research, namely one that specifically looks at the catalytic activity of small random peptides with respect to reactions relevant to prebiotic chemistry and early chemical evolution.
Collapse
Affiliation(s)
- Rafal Wieczorek
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.
| | - Katarzyna Adamala
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Tecla Gasperi
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy.
| | - Fabio Polticelli
- Department of Science, Roma Tre University, Viale G. Marconi 446, 00146 Rome, Italy.
- National Institute of Nuclear Physics, Roma Tre Section, Via della Vasca Navale 84, 00146 Rome, Italy.
| | - Pasquale Stano
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Campus Ecotekne (S.P. 6 Lecce-Monteroni), 73100 Lecce, Italy.
| |
Collapse
|
11
|
Domagal-Goldman SD, Wright KE, Adamala K, Arina de la Rubia L, Bond J, Dartnell LR, Goldman AD, Lynch K, Naud ME, Paulino-Lima IG, Singer K, Walther-Antonio M, Abrevaya XC, Anderson R, Arney G, Atri D, Azúa-Bustos A, Bowman JS, Brazelton WJ, Brennecka GA, Carns R, Chopra A, Colangelo-Lillis J, Crockett CJ, DeMarines J, Frank EA, Frantz C, de la Fuente E, Galante D, Glass J, Gleeson D, Glein CR, Goldblatt C, Horak R, Horodyskyj L, Kaçar B, Kereszturi A, Knowles E, Mayeur P, McGlynn S, Miguel Y, Montgomery M, Neish C, Noack L, Rugheimer S, Stüeken EE, Tamez-Hidalgo P, Imari Walker S, Wong T. The Astrobiology Primer v2.0. ASTROBIOLOGY 2016; 16:561-653. [PMID: 27532777 PMCID: PMC5008114 DOI: 10.1089/ast.2015.1460] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 06/06/2016] [Indexed: 05/09/2023]
Affiliation(s)
- Shawn D Domagal-Goldman
- 1 NASA Goddard Space Flight Center , Greenbelt, Maryland, USA
- 2 Virtual Planetary Laboratory , Seattle, Washington, USA
| | - Katherine E Wright
- 3 University of Colorado at Boulder , Colorado, USA
- 4 Present address: UK Space Agency, UK
| | - Katarzyna Adamala
- 5 Department of Genetics, Cell Biology and Development, University of Minnesota , Minneapolis, Minnesota, USA
| | | | - Jade Bond
- 7 Department of Physics, University of New South Wales , Sydney, Australia
| | | | | | - Kennda Lynch
- 10 Division of Biological Sciences, University of Montana , Missoula, Montana, USA
| | - Marie-Eve Naud
- 11 Institute for research on exoplanets (iREx) , Université de Montréal, Montréal, Canada
| | - Ivan G Paulino-Lima
- 12 Universities Space Research Association , Mountain View, California, USA
- 13 Blue Marble Space Institute of Science , Seattle, Washington, USA
| | - Kelsi Singer
- 14 Southwest Research Institute , Boulder, Colorado, USA
| | | | - Ximena C Abrevaya
- 16 Instituto de Astronomía y Física del Espacio (IAFE) , UBA-CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Rika Anderson
- 17 Department of Biology, Carleton College , Northfield, Minnesota, USA
| | - Giada Arney
- 18 University of Washington Astronomy Department and Astrobiology Program , Seattle, Washington, USA
| | - Dimitra Atri
- 13 Blue Marble Space Institute of Science , Seattle, Washington, USA
| | | | - Jeff S Bowman
- 19 Lamont-Doherty Earth Observatory, Columbia University , Palisades, New York, USA
| | | | | | - Regina Carns
- 22 Polar Science Center, Applied Physics Laboratory, University of Washington , Seattle, Washington, USA
| | - Aditya Chopra
- 23 Planetary Science Institute, Research School of Earth Sciences, Research School of Astronomy and Astrophysics, The Australian National University , Canberra, Australia
| | - Jesse Colangelo-Lillis
- 24 Earth and Planetary Science, McGill University , and the McGill Space Institute, Montréal, Canada
| | | | - Julia DeMarines
- 13 Blue Marble Space Institute of Science , Seattle, Washington, USA
| | | | - Carie Frantz
- 27 Department of Geosciences, Weber State University , Ogden, Utah, USA
| | - Eduardo de la Fuente
- 28 IAM-Departamento de Fisica, CUCEI , Universidad de Guadalajara, Guadalajara, México
| | - Douglas Galante
- 29 Brazilian Synchrotron Light Laboratory , Campinas, Brazil
| | - Jennifer Glass
- 30 School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia , USA
| | | | | | - Colin Goldblatt
- 33 School of Earth and Ocean Sciences, University of Victoria , Victoria, Canada
| | - Rachel Horak
- 34 American Society for Microbiology , Washington, DC, USA
| | | | - Betül Kaçar
- 36 Harvard University , Organismic and Evolutionary Biology, Cambridge, Massachusetts, USA
| | - Akos Kereszturi
- 37 Research Centre for Astronomy and Earth Sciences , Hungarian Academy of Sciences, Budapest, Hungary
| | - Emily Knowles
- 38 Johnson & Wales University , Denver, Colorado, USA
| | - Paul Mayeur
- 39 Rensselaer Polytechnic Institute , Troy, New York, USA
| | - Shawn McGlynn
- 40 Earth Life Science Institute, Tokyo Institute of Technology , Tokyo, Japan
| | - Yamila Miguel
- 41 Laboratoire Lagrange, UMR 7293, Université Nice Sophia Antipolis , CNRS, Observatoire de la Côte d'Azur, Nice, France
| | | | - Catherine Neish
- 43 Department of Earth Sciences, The University of Western Ontario , London, Canada
| | - Lena Noack
- 44 Royal Observatory of Belgium , Brussels, Belgium
| | - Sarah Rugheimer
- 45 Department of Astronomy, Harvard University , Cambridge, Massachusetts, USA
- 46 University of St. Andrews , St. Andrews, UK
| | - Eva E Stüeken
- 47 University of Washington , Seattle, Washington, USA
- 48 University of California , Riverside, California, USA
| | | | - Sara Imari Walker
- 13 Blue Marble Space Institute of Science , Seattle, Washington, USA
- 50 School of Earth and Space Exploration and Beyond Center for Fundamental Concepts in Science, Arizona State University , Tempe, Arizona, USA
| | - Teresa Wong
- 51 Department of Earth and Planetary Sciences, Washington University in St. Louis , St. Louis, Missouri, USA
| |
Collapse
|
12
|
Plöger TA, von Kiedrowski G. A self-replicating peptide nucleic acid. Org Biomol Chem 2015; 12:6908-14. [PMID: 25065957 DOI: 10.1039/c4ob01168f] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
While the non-enzymatic ligation and template-directed synthesis of peptide nucleic acids (PNA) have been reported since 1995, a case of self-replication of PNA has not been achieved yet. Here, we present evidence for autocatalytic feedback in a template directed synthesis of a self-complementary hexa-PNA from two trimeric building blocks. The course of the reaction was monitored in the presence of increasing initial concentrations of the product by RP-HPLC. Kinetic modeling with the SimFit program revealed parabolic growth characteristics. The observed template effect, as well as the rate of ligation, was significantly influenced by nucleophilic catalysts, pH value, and uncharged co-solvents. Systematic optimization of the reaction conditions allowed us to increase the autocatalytic efficiency of the system by two orders of magnitude. Our findings contribute to the hypothesis that PNA may have served as a primordial genetic molecule and was involved in a potential precursor of a RNA world.
Collapse
Affiliation(s)
- Tobias A Plöger
- Ruhr-Universität Bochum, Chair of Organic Chemistry I - Bioorganic Chemistry, 44780 Bochum, Germany.
| | | |
Collapse
|
13
|
Ma W, Feng Y. Protocells: at the interface of life and non-life. Life (Basel) 2015; 5:447-58. [PMID: 25809963 PMCID: PMC4390862 DOI: 10.3390/life5010447] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 02/02/2015] [Indexed: 02/07/2023] Open
Abstract
The cellular form, manifesting as a membrane-bounded system (comprising various functional molecules), is essential to life. The ultimate reason for this is that, typically, one functional molecule can only adopt one “correct” structure to perform one special function (e.g., an enzyme), and thus molecular cooperation is inevitable. While this is particularly true for advanced life with complex functions, it should have already been true for life at its outset with only limited functions, which entailed some sort of primitive cellular form—“protocells”. At the very beginning, the protocells may have even been unable to intervene in the growth of their own membrane, which can be called “pseudo-protocells”. Then, the ability to synthesize membrane components (amphiphiles) may have emerged under selective pressure, leading to “true-protocells”. The emergence of a “chromosome” (with genes linked together)—thus avoiding “gene-loss” during the protocell division, was another key event in the evolution of protocells. Such “unitary-protocells”, containing a central genetic molecule, may have appeared as a milestone—in principle, since then life could evolve endlessly, “gaining” more and more functions by introducing new genes. To synthesize in laboratory these different types of protocells, which stand at the interface between life and non-life, would greatly enhance our understanding on the essence of life.
Collapse
Affiliation(s)
- Wentao Ma
- College of Life Sciences, Wuhan University, Wuhan 430072, China.
| | - Yu Feng
- College of Life Sciences, Wuhan University, Wuhan 430072, China.
| |
Collapse
|
14
|
From the RNA world to the RNA/protein world: contribution of some riboswitch-binding species? J Theor Biol 2015; 370:197-201. [PMID: 25571850 DOI: 10.1016/j.jtbi.2014.12.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 12/19/2014] [Accepted: 12/22/2014] [Indexed: 12/16/2022]
Abstract
Some amino acids and their formal derivatives, currently riboswitch-binding species, could have interacted with polyribonucletides in prebiotic environments, leading to the peptide formation. If the resulting compounds had led to a sustainable polymerization of amino acids and the new structures had catalytic activity, such would have been an important contribution to the transition from the RNA world to the RNA/Protein world.
Collapse
|
15
|
Adamala K, Anella F, Wieczorek R, Stano P, Chiarabelli C, Luisi PL. Open questions in origin of life: experimental studies on the origin of nucleic acids and proteins with specific and functional sequences by a chemical synthetic biology approach. Comput Struct Biotechnol J 2014; 9:e201402004. [PMID: 24757502 PMCID: PMC3995231 DOI: 10.5936/csbj.201402004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 02/16/2014] [Accepted: 02/21/2014] [Indexed: 11/22/2022] Open
Abstract
In this mini-review we present some experimental approaches to the important issue in the origin of life, namely the origin of nucleic acids and proteins with specific and functional sequences. The formation of macromolecules on prebiotic Earth faces practical and conceptual difficulties. From the chemical viewpoint, macromolecules are formed by chemical pathways leading to the condensation of building blocks (amino acids, or nucleotides) in long-chain copolymers (proteins and nucleic acids, respectively). The second difficulty deals with a conceptual problem, namely with the emergence of specific sequences among a vast array of possible ones, the huge “sequence space”, leading to the question “why these macromolecules, and not the others?” We have recently addressed these questions by using a chemical synthetic biology approach. In particular, we have tested the catalytic activity of small peptides, like Ser-His, with respect to peptide- and nucleotides-condensation, as a realistic model of primitive organocatalysis. We have also set up a strategy for exploring the sequence space of random proteins and RNAs (the so-called “never born biopolymer” project) with respect to the production of folded structures. Being still far from solved, the main aspects of these “open questions” are discussed here, by commenting on recent results obtained in our groups and by providing a unifying view on the problem and possible solutions. In particular, we propose a general scenario for macromolecule formation via fragment-condensation, as a scheme for the emergence of specific sequences based on molecular growth and selection.
Collapse
Affiliation(s)
- Katarzyna Adamala
- Sciences Department, University of Roma Tre; Viale Guglielmo Marconi 446, 00146 Rome, Italy ; MIT Media Lab, Departments of Brain and Cognitive Sciences and Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA ; These Authors are listed in alphabetic order and contributed equally to the work
| | - Fabrizio Anella
- Sciences Department, University of Roma Tre; Viale Guglielmo Marconi 446, 00146 Rome, Italy ; Department of Bionanoscience, Kavli Institute of Nanoscience Delft University of Technology Lorentzweg 1, 2628 CJ, Delft, The Netherlands ; These Authors are listed in alphabetic order and contributed equally to the work
| | - Rafal Wieczorek
- Sciences Department, University of Roma Tre; Viale Guglielmo Marconi 446, 00146 Rome, Italy ; FLinT Center, Institut for Fysik, Kemi og Farmaci (IFKF), University of Southern Denmark; Campusvej 55, 5230 Odense, Denmark ; These Authors are listed in alphabetic order and contributed equally to the work
| | - Pasquale Stano
- Sciences Department, University of Roma Tre; Viale Guglielmo Marconi 446, 00146 Rome, Italy
| | - Cristiano Chiarabelli
- Sciences Department, University of Roma Tre; Viale Guglielmo Marconi 446, 00146 Rome, Italy
| | - Pier Luigi Luisi
- Sciences Department, University of Roma Tre; Viale Guglielmo Marconi 446, 00146 Rome, Italy
| |
Collapse
|
16
|
Stüeken EE, Anderson RE, Bowman JS, Brazelton WJ, Colangelo-Lillis J, Goldman AD, Som SM, Baross JA. Did life originate from a global chemical reactor? GEOBIOLOGY 2013; 11:101-126. [PMID: 23331348 DOI: 10.1111/gbi.12025] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Accepted: 12/03/2012] [Indexed: 06/01/2023]
Abstract
Many decades of experimental and theoretical research on the origin of life have yielded important discoveries regarding the chemical and physical conditions under which organic compounds can be synthesized and polymerized. However, such conditions often seem mutually exclusive, because they are rarely encountered in a single environmental setting. As such, no convincing models explain how living cells formed from abiotic constituents. Here, we propose a new approach that considers the origin of life within the global context of the Hadean Earth. We review previous ideas and synthesize them in four central hypotheses: (i) Multiple microenvironments contributed to the building blocks of life, and these niches were not necessarily inhabitable by the first organisms; (ii) Mineral catalysts were the backbone of prebiotic reaction networks that led to modern metabolism; (iii) Multiple local and global transport processes were essential for linking reactions occurring in separate locations; (iv) Global diversity and local selection of reactants and products provided mechanisms for the generation of most of the diverse building blocks necessary for life. We conclude that no single environmental setting can offer enough chemical and physical diversity for life to originate. Instead, any plausible model for the origin of life must acknowledge the geological complexity and diversity of the Hadean Earth. Future research may therefore benefit from identifying further linkages between organic precursors, minerals, and fluids in various environmental contexts.
Collapse
Affiliation(s)
- E E Stüeken
- Department of Earth and Space Sciences, University of Washington, Seattle, WA, USA.
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Wieczorek R, Dörr M, Chotera A, Luisi PL, Monnard PA. Formation of RNA phosphodiester bond by histidine-containing dipeptides. Chembiochem 2012; 14:217-23. [PMID: 23255284 DOI: 10.1002/cbic.201200643] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Indexed: 11/08/2022]
Abstract
A new scenario for prebiotic formation of nucleic acid oligomers is presented. Peptide catalysis is applied to achieve condensation of activated RNA monomers into short RNA chains. As catalysts, L-dipeptides containing a histidine residue, primarily Ser-His, were used. Reactions were carried out in self-organised environment, a water-ice eutectic phase, with low concentrations of reactants. Incubation periods up to 30 days resulted in the formation of short oligomers of RNA. During the oligomerisation, an active intermediate (dipeptide-mononucleotide) is produced, which is the reactive species. Details of the mechanism and kinetics, which were elucidated with a set of control experiments, further establish that the imidazole side chain of a histidine at the carboxyl end of the dipeptide plays a crucial role in the catalysis. These results suggest that this oligomerisation catalysis occurs by a transamination mechanism. Because peptides are much more likely products of spontaneous condensation than nucleotide chains, their potential as catalysts for the formation of RNA is interesting from the origin-of-life perspective. Finally, the formation of the dipeptide-mononucleotide intermediate and its significance for catalysis might also be viewed as the tell-tale signs of a new example of organocatalysis.
Collapse
Affiliation(s)
- Rafał Wieczorek
- FLinT Center, Institut for Fysik, Kemi og Farmaci (IFKF), University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark
| | | | | | | | | |
Collapse
|
18
|
Kuruvilla E, Schuster GB, Hud NV. Enhanced nonenzymatic ligation of homopurine miniduplexes: support for greater base stacking in a pre-RNA world. Chembiochem 2012; 14:45-8. [PMID: 23225671 DOI: 10.1002/cbic.201200601] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Indexed: 11/07/2022]
Abstract
The ancestors of RNA? There is a long-standing proposal that contemporary nucleic acids might have evolved from RNA-like polymers that utilized only purine-purine base pairs. Here we demonstrate the great advantage that increased nucleobase stacking area provides for nonenzymatic ligation.
Collapse
Affiliation(s)
- Elizabeth Kuruvilla
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA
| | | | | |
Collapse
|
19
|
Cape JL, Edson JB, Spencer LP, DeClue MS, Ziock HJ, Maurer S, Rasmussen S, Monnard PA, Boncella JM. Phototriggered DNA phosphoramidate ligation in a tandem 5'-amine deprotection/3'-imidazole activated phosphate coupling reaction. Bioconjug Chem 2012; 23:2014-9. [PMID: 22985338 DOI: 10.1021/bc300093y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report the preparation and use of an N-methyl picolinium carbamate protecting group for applications in a phototriggered nonenzymatic DNA phosphoramidate ligation reaction. Selective 5'-amino protection of a modified 13-mer oligonucleotide is achieved in aqueous solution by reaction with an N-methyl-4-picolinium carbonyl imidazole triflate protecting group precursor. Deprotection is carried out by photoinduced electron transfer from Ru(bpy)(3)(2+) using visible light photolysis and ascorbic acid as a sacrificial electron donor. Phototriggered 5'- amino oligonucleotide deprotection is used to initiate a nonenzymatic ligation of the 13-mer to an imidazole activated 3'-phospho-hairpin template to generate a ligated product with a phosphoramidate linkage. We demonstrate that this methodology offers a simple way to exert control over reaction initiation and rates in nonenzymatic DNA ligation for potential applications in the study of model protocellular systems and prebiotic nucleic acid synthesis.
Collapse
Affiliation(s)
- Jonathan L Cape
- Material, Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Domenech M, García E, Prieto A, Moscoso M. Insight into the composition of the intercellular matrix of Streptococcus pneumoniae biofilms. Environ Microbiol 2012; 15:502-16. [PMID: 22913814 DOI: 10.1111/j.1462-2920.2012.02853.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 07/21/2012] [Indexed: 12/01/2022]
Abstract
Biofilm matrices consist of a mixture of extracellular polymeric substances synthesized in large part by the biofilm-producing microorganisms themselves. These matrices are responsible for the cohesion and three-dimensional architecture of biofilms. The present study demonstrates the existence of a matrix composed of extracellular DNA, proteins and polysaccharides in the biofilm formed by the human pathogen Streptococcus pneumoniae. Extracellular DNA, visualized by fluorescent labelling, was an important component of this matrix. The existence of DNA-protein complexes associated with bacterial aggregates and other polymers was hypothesized based on the unexpected DNA binding activity of lysozyme LytC, a novel moonlighting protein. Actually, a 25-amino-acid-long peptide derived from LytC (positions 408 and 432 of the mature LytC) was also capable of efficiently binding to DNA. Moreover, the presence of intercellular DNA-LytC protein complexes in pneumococcal biofilms was demonstrated by confocal laser scanning microscopy. Evidence of extracellular polysaccharide different from the capsule was obtained by staining with Calcofluor dye and four types of lectin conjugated to Alexa fluorophores, and by incubation with glycoside hydrolases. The presence of residues of Glcp(1→4) and GlcNAc(1→4) (in its deacetylated form) in the pneumococcal biofilm was confirmed by GC-MS techniques.
Collapse
Affiliation(s)
- Mirian Domenech
- Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | | | | | | |
Collapse
|
21
|
Menor-Salván C, Marín-Yaseli MR. Prebiotic chemistry in eutectic solutions at the water-ice matrix. Chem Soc Rev 2012; 41:5404-15. [PMID: 22660387 DOI: 10.1039/c2cs35060b] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A crystalline ice matrix at subzero temperatures can maintain a liquid phase where organic solutes and salts concentrate to form eutectic solutions. This concentration effect converts the confined reactant solutions in the ice matrix, sometimes making condensation and polymerisation reactions occur more favourably. These reactions occur at significantly high rates from a prebiotic chemistry standpoint, and the labile products can be protected from degradation. The experimental study of the synthesis of nitrogen heterocycles at the ice-water system showed the efficiency of this scenario and could explain the origin of nucleobases in the inner Solar System bodies, including meteorites and extra-terrestrial ices, and on the early Earth. The same conditions can also favour the condensation of monomers to form ribonucleic acid and peptides. Together with the synthesis of these monomers, the ice world (i.e., the chemical evolution in the range between the freezing point of water and the limit of stability of liquid brines, 273 to 210 K) is an under-explored experimental model in prebiotic chemistry.
Collapse
Affiliation(s)
- César Menor-Salván
- Centro de Astrobiología (INTA-CSIC), INTA, E-28850 Torrejón de Ardoz, Spain.
| | | |
Collapse
|
22
|
Ma W, Hu J. Computer simulation on the cooperation of functional molecules during the early stages of evolution. PLoS One 2012; 7:e35454. [PMID: 22514745 PMCID: PMC3325964 DOI: 10.1371/journal.pone.0035454] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Accepted: 03/16/2012] [Indexed: 12/21/2022] Open
Abstract
It is very likely that life began with some RNA (or RNA-like) molecules, self-replicating by base-pairing and exhibiting enzyme-like functions that favored the self-replication. Different functional molecules may have emerged by favoring their own self-replication at different aspects. Then, a direct route towards complexity/efficiency may have been through the coexistence/cooperation of these molecules. However, the likelihood of this route remains quite unclear, especially because the molecules would be competing for limited common resources. By computer simulation using a Monte-Carlo model (with “micro-resolution” at the level of nucleotides and membrane components), we show that the coexistence/cooperation of these molecules can occur naturally, both in a naked form and in a protocell form. The results of the computer simulation also lead to quite a few deductions concerning the environment and history in the scenario. First, a naked stage (with functional molecules catalyzing template-replication and metabolism) may have occurred early in evolution but required high concentration and limited dispersal of the system (e.g., on some mineral surface); the emergence of protocells enabled a “habitat-shift” into bulk water. Second, the protocell stage started with a substage of “pseudo-protocells”, with functional molecules catalyzing template-replication and metabolism, but still missing the function involved in the synthesis of membrane components, the emergence of which would lead to a subsequent “true-protocell” substage. Third, the initial unstable membrane, composed of prebiotically available fatty acids, should have been superseded quite early by a more stable membrane (e.g., composed of phospholipids, like modern cells). Additionally, the membrane-takeover probably occurred at the transition of the two substages of the protocells. The scenario described in the present study should correspond to an episode in early evolution, after the emergence of single “genes”, but before the appearance of a “chromosome” with linked genes.
Collapse
Affiliation(s)
- Wentao Ma
- College of Life Sciences, Wuhan University, Wuhan, Hubei, China
- * E-mail:
| | - Jiming Hu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei, China
| |
Collapse
|
23
|
Universal sequence replication, reversible polymerization and early functional biopolymers: a model for the initiation of prebiotic sequence evolution. PLoS One 2012; 7:e34166. [PMID: 22493682 PMCID: PMC3320909 DOI: 10.1371/journal.pone.0034166] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 02/23/2012] [Indexed: 02/05/2023] Open
Abstract
Many models for the origin of life have focused on understanding how evolution can drive the refinement of a preexisting enzyme, such as the evolution of efficient replicase activity. Here we present a model for what was, arguably, an even earlier stage of chemical evolution, when polymer sequence diversity was generated and sustained before, and during, the onset of functional selection. The model includes regular environmental cycles (e.g. hydration-dehydration cycles) that drive polymers between times of replication and functional activity, which coincide with times of different monomer and polymer diffusivity. Template-directed replication of informational polymers, which takes place during the dehydration stage of each cycle, is considered to be sequence-independent. New sequences are generated by spontaneous polymer formation, and all sequences compete for a finite monomer resource that is recycled via reversible polymerization. Kinetic Monte Carlo simulations demonstrate that this proposed prebiotic scenario provides a robust mechanism for the exploration of sequence space. Introduction of a polymer sequence with monomer synthetase activity illustrates that functional sequences can become established in a preexisting pool of otherwise non-functional sequences. Functional selection does not dominate system dynamics and sequence diversity remains high, permitting the emergence and spread of more than one functional sequence. It is also observed that polymers spontaneously form clusters in simulations where polymers diffuse more slowly than monomers, a feature that is reminiscent of a previous proposal that the earliest stages of life could have been defined by the collective evolution of a system-wide cooperation of polymer aggregates. Overall, the results presented demonstrate the merits of considering plausible prebiotic polymer chemistries and environments that would have allowed for the rapid turnover of monomer resources and for regularly varying monomer/polymer diffusivities.
Collapse
|
24
|
Lehman N, Hayden EJ. Template-directed RNA polymerization: the taming of the milieu. Chembiochem 2011; 12:2727-8. [PMID: 22028272 DOI: 10.1002/cbic.201100611] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Indexed: 11/11/2022]
Abstract
No-bias binding: The abiotic template-directed synthesis of RNA could have been a key process in the origins of life on Earth. Recreating this process in the laboratory has been challenging, yet a combination of strategies has given rise to a synthesis that is both efficient and unbiased against any of the four nucleotides.
Collapse
Affiliation(s)
- Niles Lehman
- Department of Chemistry, Portland State University, P. O. Box 751, Portland, OR 97207, USA.
| | | |
Collapse
|
25
|
Attwater J, Wochner A, Pinheiro VB, Coulson A, Holliger P. Ice as a protocellular medium for RNA replication. Nat Commun 2010; 1:76. [PMID: 20865803 DOI: 10.1038/ncomms1076] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Accepted: 08/23/2010] [Indexed: 11/09/2022] Open
Abstract
A crucial transition in the origin of life was the emergence of an informational polymer capable of self-replication and its compartmentalization within protocellular structures. We show that the physicochemical properties of ice, a simple medium widespread on a temperate early Earth, could have mediated this transition prior to the advent of membraneous protocells. Ice not only promotes the activity of an RNA polymerase ribozyme but also protects it from hydrolytic degradation, enabling the synthesis of exceptionally long replication products. Ice furthermore relieves the dependence of RNA replication on prebiotically implausible substrate concentrations, while providing quasicellular compartmentalization within the intricate microstructure of the eutectic phase. Eutectic ice phases had previously been shown to promote the de novo synthesis of nucleotide precursors, as well as the condensation of activated nucleotides into random RNA oligomers. Our results support a wider role for ice as a predisposed environment, promoting all the steps from prebiotic synthesis to the emergence of RNA self-replication and precellular Darwinian evolution.
Collapse
Affiliation(s)
- James Attwater
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
| | | | | | | | | |
Collapse
|
26
|
Precambrian lunar volcanic protolife. Int J Mol Sci 2009; 10:2681-2721. [PMID: 19582224 PMCID: PMC2705511 DOI: 10.3390/ijms10062681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 05/28/2009] [Accepted: 06/03/2009] [Indexed: 11/20/2022] Open
Abstract
Five representative terrestrial analogs of lunar craters are detailed relevant to Precambrian fumarolic activity. Fumarolic fluids contain the ingredients for protolife. Energy sources to derive formaldehyde, amino acids and related compounds could be by flow charging, charge separation and volcanic shock. With no photodecomposition in shadow, most fumarolic fluids at 40 K would persist over geologically long time periods. Relatively abundant tungsten would permit creation of critical enzymes, Fischer-Tropsch reactions could form polycyclic aromatic hydrocarbons and soluble volcanic polyphosphates would enable assembly of nucleic acids. Fumarolic stimuli factors are described. Orbital and lander sensors specific to protolife exploration including combined Raman/laser-induced breakdown spectrocsopy are evaluated.
Collapse
|