1
|
Mougkogiannis P, Adamatzky A. Proto-neural networks from thermal proteins. Biochem Biophys Res Commun 2024; 709:149725. [PMID: 38579617 DOI: 10.1016/j.bbrc.2024.149725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 02/25/2024] [Indexed: 04/07/2024]
Abstract
Proteinoids are synthetic polymers that have structural similarities to natural proteins, and their formation is achieved through the application of heat to amino acid combinations in a dehydrated environment. The thermal proteins, initially synthesised by Sidney Fox during the 1960s, has the ability to undergo self-assembly, resulting in the formation of microspheres that resemble cells. These microspheres have fascinating biomimetic characteristics. In recent studies, substantial advancements have been made in elucidating the electrical signalling phenomena shown by proteinoids, hence showcasing their promising prospects in the field of neuro-inspired computing. This study demonstrates the advancement of experimental prototypes that employ proteinoids in the construction of fundamental neural network structures. The article provides an overview of significant achievements in proteinoid systems, such as the demonstration of electrical excitability, emulation of synaptic functions, capabilities in pattern recognition, and adaptability of network structures. This study examines the similarities and differences between proteinoid networks and spontaneous neural computation. We examine the persistent challenges associated with deciphering the underlying mechanisms of emergent proteinoid-based intelligence. Additionally, we explore the potential for developing bio-inspired computing systems using synthetic thermal proteins in forthcoming times. The results of this study offer a theoretical foundation for the advancement of adaptive, self-assembling electronic systems that operate using artificial bio-neural principles.
Collapse
|
2
|
Barge LM, Fournier GP. Considerations for Detecting Organic Indicators of Metabolism on Enceladus. ASTROBIOLOGY 2024; 24:328-338. [PMID: 38507694 DOI: 10.1089/ast.2023.0074] [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: 03/22/2024]
Abstract
Enceladus is of interest to astrobiology and the search for life since it is thought to host active hydrothermal activity and habitable conditions. It is also possible that the organics detected on Enceladus may indicate an active prebiotic or biotic system; in particular, the conditions on Enceladus may favor mineral-driven protometabolic reactions. When including metabolism-related biosignatures in Enceladus mission concepts, it is necessary to base these in a clearer understanding of how these signatures could also be produced prebiotically. In addition, postulating which biological metabolisms to look for on Enceladus requires a non-Earth-centric approach since the details of biological metabolic pathways are heavily shaped by adaptation to geochemical conditions over the planet's history. Creating metabolism-related organic detection objectives for Enceladus missions, therefore, requires consideration of how metabolic systems may operate differently on another world, while basing these speculations on observed Earth-specific microbial processes. In addition, advances in origin-of-life research can play a critical role in distinguishing between interpretations of any future organic detections on Enceladus, and the discovery of an extant prebiotic system would be a transformative astrobiological event in its own right.
Collapse
Affiliation(s)
- Laura M Barge
- Planetary Science Section, NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Gregory P Fournier
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| |
Collapse
|
3
|
Sallembien Q, Bouteiller L, Crassous J, Raynal M. Possible chemical and physical scenarios towards biological homochirality. Chem Soc Rev 2022; 51:3436-3476. [PMID: 35377372 DOI: 10.1039/d1cs01179k] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The single chirality of biological molecules in terrestrial biology raises more questions than certitudes about its origin. The emergence of biological homochirality (BH) and its connection with the appearance of life have elicited a large number of theories related to the generation, amplification and preservation of a chiral bias in molecules of life under prebiotically relevant conditions. However, a global scenario is still lacking. Here, the possibility of inducing a significant chiral bias "from scratch", i.e. in the absence of pre-existing enantiomerically-enriched chemical species, will be considered first. It includes phenomena that are inherent to the nature of matter itself, such as the infinitesimal energy difference between enantiomers as a result of violation of parity in certain fundamental interactions, and physicochemical processes related to interactions between chiral organic molecules and physical fields, polarized particles, polarized spins and chiral surfaces. The spontaneous emergence of chirality in the absence of detectable chiral physical and chemical sources has recently undergone significant advances thanks to the deracemization of conglomerates through Viedma ripening and asymmetric auto-catalysis with the Soai reaction. All these phenomena are commonly discussed as plausible sources of asymmetry under prebiotic conditions and are potentially accountable for the primeval chiral bias in molecules of life. Then, several scenarios will be discussed that are aimed to reflect the different debates about the emergence of BH: extra-terrestrial or terrestrial origin (where?), nature of the mechanisms leading to the propagation and enhancement of the primeval chiral bias (how?) and temporal sequence between chemical homochirality, BH and life emergence (when?). Intense and ongoing theories regarding the emergence of optically pure molecules at different moments of the evolution process towards life, i.e. at the levels of building blocks of Life, of the instructed or functional polymers, or even later at the stage of more elaborated chemical systems, will be critically discussed. The underlying principles and the experimental evidence will be commented for each scenario with particular attention on those leading to the induction and enhancement of enantiomeric excesses in proteinogenic amino acids, natural sugars, and their intermediates or derivatives. The aim of this review is to propose an updated and timely synopsis in order to stimulate new efforts in this interdisciplinary field.
Collapse
Affiliation(s)
- Quentin Sallembien
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, Equipe Chimie des Polymères, 4 Place Jussieu, 75005 Paris, France.
| | - Laurent Bouteiller
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, Equipe Chimie des Polymères, 4 Place Jussieu, 75005 Paris, France.
| | - Jeanne Crassous
- Univ Rennes, CNRS, Institut des Sciences Chimiques de Rennes, ISCR-UMR 6226, F-35000 Rennes, France.
| | - Matthieu Raynal
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, Equipe Chimie des Polymères, 4 Place Jussieu, 75005 Paris, France.
| |
Collapse
|
4
|
Barge LM, Rodriguez LE, Weber JM, Theiling BP. Determining the "Biosignature Threshold" for Life Detection on Biotic, Abiotic, or Prebiotic Worlds. ASTROBIOLOGY 2022; 22:481-493. [PMID: 34898272 DOI: 10.1089/ast.2021.0079] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The field of prebiotic chemistry has demonstrated that complex organic chemical systems that exhibit various life-like properties can be produced abiotically in the laboratory. Understanding these chemical systems is important for astrobiology and life detection since we do not know the extent to which prebiotic chemistry might exist or have existed on other worlds. Nor do we know what signatures are diagnostic of an extant or "failed" prebiotic system. On Earth, biology has suppressed most abiotic organic chemistry and overprints geologic records of prebiotic chemistry; therefore, it is difficult to validate whether chemical signatures from future planetary missions are remnant or extant prebiotic systems. The "biosignature threshold" between whether a chemical signature is more likely to be produced by abiotic versus biotic chemistry on a given world could vary significantly, depending on the particular environment, and could change over time, especially if life were to emerge and diversify on that world. To interpret organic signatures detected during a planetary mission, we advocate for (1) gaining a more complete understanding of prebiotic/abiotic chemical possibilities in diverse planetary environments and (2) involving experimental prebiotic samples as analogues when generating comparison libraries for "life-detection" mission instruments.
Collapse
Affiliation(s)
- Laura M Barge
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Laura E Rodriguez
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Jessica M Weber
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | | |
Collapse
|
5
|
Jia TZ, Nishikawa S, Fujishima K. Sequencing the Origins of Life. BBA ADVANCES 2022; 2:100049. [PMID: 37082609 PMCID: PMC10074849 DOI: 10.1016/j.bbadva.2022.100049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/27/2022] [Accepted: 03/02/2022] [Indexed: 01/10/2023] Open
Abstract
One goal of origins of life research is to understand how primitive informational and catalytic biopolymers emerged and evolved. Recently, a number of sequencing techniques have been applied to analysis of replicating and evolving primitive biopolymer systems, providing a sequence-specific and high-resolution view of primitive chemical processes. Here, we review application of sequencing techniques to analysis of synthetic and primitive nucleic acids and polypeptides. This includes next-generation sequencing of primitive polymerization and evolution processes, followed by discussion of other novel biochemical techniques that could contribute to sequence analysis of primitive biopolymer driven chemical systems. Further application of sequencing to origins of life research, perhaps as a life detection technology, could provide insight into the origin and evolution of informational and catalytic biopolymers on early Earth or elsewhere.
Collapse
Affiliation(s)
- Tony Z. Jia
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
- Blue Marble Space Institute of Science, 600 1st Ave, Floor 1, Seattle, WA 98104, USA
- Corresponding author
| | - Shota Nishikawa
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8501, Japan
| | - Kosuke Fujishima
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
- Graduate School of Media and Governance, Keio University, 5322 Endo, Fujisawa-shi, Kanagawa 252-0882, Japan
| |
Collapse
|
6
|
Kahana A, Maslov S, Lancet D. Dynamic lipid aptamers: non-polymeric chemical path to early life. Chem Soc Rev 2021; 50:11741-11746. [PMID: 34541591 DOI: 10.1039/d1cs00633a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A widespread dogma asserts that life could not have emerged without biopolymers - RNA and proteins. However, the widely acknowledged implausibility of a spontaneous appearance and proliferation of these complex molecules in primordial messy chemistry casts doubt on this scenario. A proposed alternative is "Lipid-First", based on the evidence that lipid assemblies may spontaneously emerge in heterogeneous environments, and are shown to undergo growth and fission, and to portray autocatalytic self-copying. What seems undecided is whether lipid assemblies have protein-like capacities for stereospecific interactions, a sine qua non of life processes. This Viewpoint aims to alleviate such doubts, pointing to growing experimental evidence that lipid aggregates possess dynamic surface configurations capable of stereospecific molecular recognition. Such findings help support a possible key role of lipids in seeding life's origin.
Collapse
Affiliation(s)
- Amit Kahana
- Dept. of Molecular Genetics, the Weizmann Institute of Science, Rehovot 7610001, Israel.
| | - Svetlana Maslov
- Dept. of Molecular Genetics, the Weizmann Institute of Science, Rehovot 7610001, Israel.
| | - Doron Lancet
- Dept. of Molecular Genetics, the Weizmann Institute of Science, Rehovot 7610001, Israel.
| |
Collapse
|
7
|
Kahana A, Lancet D. Self-reproducing catalytic micelles as nanoscopic protocell precursors. Nat Rev Chem 2021; 5:870-878. [PMID: 37117387 DOI: 10.1038/s41570-021-00329-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2021] [Indexed: 12/31/2022]
Abstract
Protocells at life's origin are often conceived as bilayer-enclosed precursors of life, whose self-reproduction rests on the early advent of replicating catalytic biopolymers. This Perspective describes an alternative scenario, wherein reproducing nanoscopic lipid micelles with catalytic capabilities were forerunners of biopolymer-containing protocells. This postulate gains considerable support from experiments describing micellar catalysis and autocatalytic proliferation, and, more recently, from reports on cross-catalysis in mixed micelles that lead to life-like steady-state dynamics. Such results, along with evidence for micellar prebiotic compatibility, synergize with predictions of our chemically stringent computer-simulated model, illustrating how mutually catalytic lipid networks may enable micellar compositional reproduction that could underlie primal selection and evolution. Finally, we highlight studies on how endogenously catalysed lipid modifications could guide further protocellular complexification, including micelle to vesicle transition and monomer to biopolymer progression. These portrayals substantiate the possibility that protocellular evolution could have been seeded by pre-RNA lipid assemblies.
Collapse
|
8
|
Perl SM, Celestian AJ, Cockell CS, Corsetti FA, Barge LM, Bottjer D, Filiberto J, Baxter BK, Kanik I, Potter-McIntyre S, Weber JM, Rodriguez LE, Melwani Daswani M. A Proposed Geobiology-Driven Nomenclature for Astrobiological In Situ Observations and Sample Analyses. ASTROBIOLOGY 2021; 21:954-967. [PMID: 34357788 PMCID: PMC8403179 DOI: 10.1089/ast.2020.2318] [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: 05/06/2023]
Abstract
As the exploration of Mars and other worlds for signs of life has increased, the need for a common nomenclature and consensus has become significantly important for proper identification of nonterrestrial/non-Earth biology, biogenic structures, and chemical processes generated from biological processes. The fact that Earth is our single data point for all life, diversity, and evolution means that there is an inherent bias toward life as we know it through our own planet's history. The search for life "as we don't know it" then brings this bias forward to decision-making regarding mission instruments and payloads. Understandably, this leads to several top-level scientific, theoretical, and philosophical questions regarding the definition of life and what it means for future life detection missions. How can we decide on how and where to detect known and unknown signs of life with a single biased data point? What features could act as universal biosignatures that support Darwinian evolution in the geological context of nonterrestrial time lines? The purpose of this article is to generate an improved nomenclature for terrestrial features that have mineral/microbial interactions within structures and to confirm which features can only exist from life (biotic), features that are modified by biological processes (biogenic), features that life does not affect (abiotic), and properties that can exist or not regardless of the presence of biology (abiogenic). These four categories are critical in understanding and deciphering future returned samples from Mars, signs of potential extinct/ancient and extant life on Mars, and in situ analyses from ocean worlds to distinguish and separate what physical structures and chemical patterns are due to life and which are not. Moreover, we discuss hypothetical detection and preservation environments for extant and extinct life, respectively. These proposed environments will take into account independent active and ancient in situ detection prospects by using previous planetary exploration studies and discuss the geobiological implications within an astrobiological context.
Collapse
Affiliation(s)
- Scott M. Perl
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- Mineral Sciences, Natural History Museum of Los Angeles County, Los Angeles, California, USA
- Blue Marble Space Institute for Science, Seattle, Washington, USA
- Address correspondence to: Scott M. Perl, NASA Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, +USA
| | - Aaron J. Celestian
- Mineral Sciences, Natural History Museum of Los Angeles County, Los Angeles, California, USA
| | - Charles S. Cockell
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, Scotland
| | - Frank A. Corsetti
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
| | - Laura M. Barge
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
- Blue Marble Space Institute for Science, Seattle, Washington, USA
| | - David Bottjer
- Department of Earth Sciences, University of Southern California, Los Angeles, California, USA
| | | | - Bonnie K. Baxter
- Great Salt Lake Institute, Westminster College, Salt Lake City, Utah, USA
| | - Isik Kanik
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Sally Potter-McIntyre
- School of Earth Systems and Sustainability, Southern Illinois University Carbondale, Carbondale, Illinois, USA
| | - Jessica M. Weber
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Laura E. Rodriguez
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - Mohit Melwani Daswani
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| |
Collapse
|
9
|
Abstract
Astrobiology is focused on the study of life in the universe. However, lifeless planetary environments yield biological information on the variety of ways in which physical and chemical conditions in the universe preclude the possibility of the origin or persistence of life, and in turn this will help explain the distribution and abundance of life, or lack of it, in the universe. Furthermore, many places that humans wish to explore and settle in space are lifeless, and studying the fate of life in these environments will aid our own success in thriving in them. In this synthetic review, I have three objectives, as follows: (1) To discuss the biological value and use of lifeless environments, (2) To explore the diverse planetary bodies and environments that can be lifeless and to categorize them, and (3) To propose sets of biological experiments that can be undertaken in different categories of lifeless worlds and environments and suggest concepts for mission ideas to realize these goals. They include origin of life and microbial inoculation experiments in lifeless but habitable environments. I suggest that the biological study of lifelessness is an underappreciated area in planetary sciences.
Collapse
Affiliation(s)
- Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
10
|
Chirumbolo S, Vella A. Molecules, Information and the Origin of Life: What Is Next? Molecules 2021; 26:molecules26041003. [PMID: 33672848 PMCID: PMC7917628 DOI: 10.3390/molecules26041003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 12/20/2022] Open
Abstract
How life did originate and what is life, in its deepest foundation? The texture of life is known to be held by molecules and their chemical-physical laws, yet a thorough elucidation of the aforementioned questions still stands as a puzzling challenge for science. Focusing solely on molecules and their laws has indirectly consolidated, in the scientific knowledge, a mechanistic (reductionist) perspective of biology and medicine. This occurred throughout the long historical path of experimental science, affecting subsequently the onset of the many theses and speculations about the origin of life and its maintenance. Actually, defining what is life, asks for a novel epistemology, a ground on which living systems’ organization, whose origin is still questioned via chemistry, physics and even philosophy, may provide a new key to focus onto the complex nature of the human being. In this scenario, many issues, such as the role of information and water structure, have been long time neglected from the theoretical basis on the origin of life and marginalized as a kind of scenic backstage. On the contrary, applied science and technology went ahead on considering molecules as the sole leading components in the scenery. Water physics and information dynamics may have a role in living systems much more fundamental than ever expected. Can an organism be simply explained by a mechanistic view of its nature or we need “something else”? Probably, we can earn sound foundations about life by simply changing our prejudicial view about living systems simply as complex, highly ordered machines. In this manuscript we would like to reappraise many fundamental aspects of molecular and chemical biology and reading them through a new paradigm, which includes Prigogine’s dissipative structures and informational dissipation (Shannon dissipation). This would provide readers with insightful clues about how biology and chemistry may be thoroughly revised, referring to new models, such as informational dissipation. We trust they are enabled to address a straightforward contribution in elucidating what life is for science. This overview is not simply a philosophical speculation, but it would like to affect deeply our way to conceive and describe the foundations of organisms’ life, providing intriguing suggestions for readers in the field.
Collapse
Affiliation(s)
- Salvatore Chirumbolo
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37134 Verona, Italy
- Correspondence: ; Tel.: +39-0458027645
| | - Antonio Vella
- Verona-Unit of Immunology, Azienda Ospedaliera Universitaria Integrata, 37134 Verona, Italy;
| |
Collapse
|
11
|
Angelis G, Kordopati GG, Zingkou E, Karioti A, Sotiropoulou G, Pampalakis G. Plausible Emergence of Biochemistry in Enceladus Based on Chemobrionics. Chemistry 2021; 27:600-604. [PMID: 33108005 DOI: 10.1002/chem.202004018] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/18/2020] [Indexed: 11/11/2022]
Abstract
Saturn's satellite Enceladus is proposed to have a soda-type subsurface ocean with temperature able to support life and an iron ore-based core. Here, it was demonstrated that ocean chemistry related to Enceladus can support the development of Fe-based hydrothermal vents, one of the places suggested to be the cradle of life. The Fe-based chemical gardens were characterized with Fourier-transform (FT)IR spectroscopy and XRD. The developed chemobrionic structures catalyzed the condensation polymerization of simple organic prebiotic molecules to kerogens. Further, they could passively catalyze the condensation of the prebiotic molecule formamide to larger polymers, suggesting that elementary biochemical precursors could have emerged in Enceladus.
Collapse
Affiliation(s)
- Georgios Angelis
- Department of Pharmacognosy-Pharmacology, School of Pharmacy, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece
| | - Golfo G Kordopati
- Department of Pharmacy, School of Health Sciences, University of Patras, 26504, Rion-Patras, Greece
| | - Eleni Zingkou
- Department of Pharmacy, School of Health Sciences, University of Patras, 26504, Rion-Patras, Greece
| | - Anastasia Karioti
- Department of Pharmacognosy-Pharmacology, School of Pharmacy, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece
| | - Georgia Sotiropoulou
- Department of Pharmacy, School of Health Sciences, University of Patras, 26504, Rion-Patras, Greece
| | - Georgios Pampalakis
- Department of Pharmacognosy-Pharmacology, School of Pharmacy, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece
| |
Collapse
|
12
|
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.
Collapse
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.
| |
Collapse
|
13
|
Post EAJ, Fletcher SP. Dissipative self-assembly, competition and inhibition in a self-reproducing protocell model. Chem Sci 2020; 11:9434-9442. [PMID: 34094210 PMCID: PMC8162124 DOI: 10.1039/d0sc02768e] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 08/07/2020] [Indexed: 12/14/2022] Open
Abstract
The bottom-up synthesis of artificial, life-like systems promises to enable the study of emergent properties distinctive to life. Here, we report protocell systems generated from phase-separated building blocks. Vesicle protocells self-reproduce through a phase-transfer mechanism, catalysing their own formation. Dissipative self-assembly by the protocells is achieved when a hydrolysis step to destroy the surfactant is introduced. Competition between micelle and vesicle based replicators for a common feedstock shows that environmental conditions can control what species predominates: under basic conditions vesicles predominate, but in a neutral medium micelles are selected for via a mechanism which inhibits vesicle formation. Finally, the protocells enable orthogonal reactivity by catalysing in situ formation of an amphiphilic organocatalyst, which after incorporation into the vesicle bilayer enantioselectively forms a secondary product.
Collapse
Affiliation(s)
- Elias A J Post
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford 12 Mansfield Road Oxford OX1 3TA UK
| | - Stephen P Fletcher
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford 12 Mansfield Road Oxford OX1 3TA UK
| |
Collapse
|
14
|
Polyesters as a Model System for Building Primitive Biologies from Non-Biological Prebiotic Chemistry. Life (Basel) 2020; 10:life10010006. [PMID: 31963928 PMCID: PMC7175156 DOI: 10.3390/life10010006] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/22/2019] [Accepted: 01/10/2020] [Indexed: 12/14/2022] Open
Abstract
A variety of organic chemicals were likely available on prebiotic Earth. These derived from diverse processes including atmospheric and geochemical synthesis and extraterrestrial input, and were delivered to environments including oceans, lakes, and subaerial hot springs. Prebiotic chemistry generates both molecules used by modern organisms, such as proteinaceous amino acids, as well as many molecule types not used in biochemistry. As prebiotic chemical diversity was likely high, and the core of biochemistry uses a rather small set of common building blocks, the majority of prebiotically available organic compounds may not have been those used in modern biochemistry. Chemical evolution was unlikely to have been able to discriminate which molecules would eventually be used in biology, and instead, interactions among compounds were governed simply by abundance and chemical reactivity. Previous work has shown that likely prebiotically available α-hydroxy acids can combinatorially polymerize into polyesters that self-assemble to create new phases which are able to compartmentalize other molecule types. The unexpectedly rich complexity of hydroxy acid chemistry and the likely enormous structural diversity of prebiotic organic chemistry suggests chemical evolution could have been heavily influenced by molecules not used in contemporary biochemistry, and that there is a considerable amount of prebiotic chemistry which remains unexplored.
Collapse
|
15
|
Lancet D, Segrè D, Kahana A. Twenty Years of "Lipid World": A Fertile Partnership with David Deamer. Life (Basel) 2019; 9:E77. [PMID: 31547028 PMCID: PMC6958426 DOI: 10.3390/life9040077] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 09/08/2019] [Accepted: 09/10/2019] [Indexed: 12/17/2022] Open
Abstract
"The Lipid World" was published in 2001, stemming from a highly effective collaboration with David Deamer during a sabbatical year 20 years ago at the Weizmann Institute of Science in Israel. The present review paper highlights the benefits of this scientific interaction and assesses the impact of the lipid world paper on the present understanding of the possible roles of amphiphiles and their assemblies in the origin of life. The lipid world is defined as a putative stage in the progression towards life's origin, during which diverse amphiphiles or other spontaneously aggregating small molecules could have concurrently played multiple key roles, including compartment formation, the appearance of mutually catalytic networks, molecular information processing, and the rise of collective self-reproduction and compositional inheritance. This review brings back into a broader perspective some key points originally made in the lipid world paper, stressing the distinction between the widely accepted role of lipids in forming compartments and their expanded capacities as delineated above. In the light of recent advancements, we discussed the topical relevance of the lipid worldview as an alternative to broadly accepted scenarios, and the need for further experimental and computer-based validation of the feasibility and implications of the individual attributes of this point of view. Finally, we point to possible avenues for exploring transition paths from small molecule-based noncovalent structures to more complex biopolymer-containing proto-cellular systems.
Collapse
Affiliation(s)
- Doron Lancet
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610010, Israel.
| | - Daniel Segrè
- Bioinformatics Program, Department of Biology, Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
| | - Amit Kahana
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610010, Israel.
| |
Collapse
|
16
|
Kahana A, Lancet D. Protobiotic Systems Chemistry Analyzed by Molecular Dynamics. Life (Basel) 2019; 9:E38. [PMID: 31083329 PMCID: PMC6617412 DOI: 10.3390/life9020038] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/06/2019] [Accepted: 05/08/2019] [Indexed: 12/16/2022] Open
Abstract
Systems chemistry has been a key component of origin of life research, invoking models of life's inception based on evolving molecular networks. One such model is the graded autocatalysis replication domain (GARD) formalism embodied in a lipid world scenario, which offers rigorous computer simulation based on defined chemical kinetics equations. GARD suggests that the first pre-RNA life-like entities could have been homeostatically-growing assemblies of amphiphiles, undergoing compositional replication and mutations, as well as rudimentary selection and evolution. Recent progress in molecular dynamics has provided an experimental tool to study complex biological phenomena such as protein folding, ligand-receptor interactions, and micellar formation, growth, and fission. The detailed molecular definition of GARD and its inter-molecular catalytic interactions make it highly compatible with molecular dynamics analyses. We present a roadmap for simulating GARD's kinetic and thermodynamic behavior using various molecular dynamics methodologies. We review different approaches for testing the validity of the GARD model by following micellar accretion and fission events and examining compositional changes over time. Near-future computational advances could provide empirical delineation for further system complexification, from simple compositional non-covalent assemblies towards more life-like protocellular entities with covalent chemistry that underlies metabolism and genetic encoding.
Collapse
Affiliation(s)
- Amit Kahana
- Dept. Molecular Genetics, The Weizmann Institute of Science, Rehovot 7610010, Israel.
| | - Doron Lancet
- Dept. Molecular Genetics, The Weizmann Institute of Science, Rehovot 7610010, Israel.
| |
Collapse
|