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Basuri P, Chakraborty A, Ahuja T, Mondal B, Kumar JS, Pradeep T. Spatial reorganization of analytes in charged aqueous microdroplets. Chem Sci 2022; 13:13321-13329. [PMID: 36507174 PMCID: PMC9682915 DOI: 10.1039/d2sc04589c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 10/11/2022] [Indexed: 12/15/2022] Open
Abstract
Imprinted charged aqueous droplets of micrometer dimensions containing spherical gold and silver nanoparticles, gold nanorods, proteins and simple molecules were visualized using dark-field and transmission electron microscopies. With such studies, we hoped to understand the unusual chemistry exhibited by microdroplets. These droplets with sizes in the range of 1-100 μm were formed using a home-built electrospray source with nitrogen as the nebulization gas. Several remarkable features such as mass/size-selective segregation and spatial localization of solutes in nanometer-thin regions of microdroplets were visualized, along with the formation of micro-nano vacuoles. Electrospray parameters such as distance between the spray tip and surface, voltage and nebulization gas pressure influenced particle distribution within the droplets. We relate these features to unusual phenomena such as the enhancement of rates of chemical reactions in microdroplets.
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Affiliation(s)
- Pallab Basuri
- DST Unit of Nanoscience, Department of Chemistry, Indian Institute of Technology, Madras Chennai 600036 India
| | - Amrita Chakraborty
- DST Unit of Nanoscience, Department of Chemistry, Indian Institute of Technology, Madras Chennai 600036 India
| | - Tripti Ahuja
- DST Unit of Nanoscience, Department of Chemistry, Indian Institute of Technology, Madras Chennai 600036 India
| | - Biswajit Mondal
- DST Unit of Nanoscience, Department of Chemistry, Indian Institute of Technology, Madras Chennai 600036 India
| | - Jenifer Shantha Kumar
- DST Unit of Nanoscience, Department of Chemistry, Indian Institute of Technology, Madras Chennai 600036 India
| | - Thalappil Pradeep
- DST Unit of Nanoscience, Department of Chemistry, Indian Institute of Technology, Madras Chennai 600036 India
- International Centre for Clean Water Chennai Tamil Nadu 600113 India
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2
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La DD, Ngo HH, Nguyen DD, Tran NT, Vo HT, Nguyen XH, Chang SW, Chung WJ, Nguyen MDB. Advances and prospects of porphyrin-based nanomaterials via self-assembly for photocatalytic applications in environmental treatment. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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3
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Damer B, Deamer D. The Hot Spring Hypothesis for an Origin of Life. ASTROBIOLOGY 2020; 20:429-452. [PMID: 31841362 PMCID: PMC7133448 DOI: 10.1089/ast.2019.2045] [Citation(s) in RCA: 178] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 10/23/2019] [Indexed: 05/05/2023]
Abstract
We present a testable hypothesis related to an origin of life on land in which fluctuating volcanic hot spring pools play a central role. The hypothesis is based on experimental evidence that lipid-encapsulated polymers can be synthesized by cycles of hydration and dehydration to form protocells. Drawing on metaphors from the bootstrapping of a simple computer operating system, we show how protocells cycling through wet, dry, and moist phases will subject polymers to combinatorial selection and draw structural and catalytic functions out of initially random sequences, including structural stabilization, pore formation, and primitive metabolic activity. We propose that protocells aggregating into a hydrogel in the intermediate moist phase of wet-dry cycles represent a primitive progenote system. Progenote populations can undergo selection and distribution, construct niches in new environments, and enable a sharing network effect that can collectively evolve them into the first microbial communities. Laboratory and field experiments testing the first steps of the scenario are summarized. The scenario is then placed in a geological setting on the early Earth to suggest a plausible pathway from life's origin in chemically optimal freshwater hot spring pools to the emergence of microbial communities tolerant to more extreme conditions in dilute lakes and salty conditions in marine environments. A continuity is observed for biogenesis beginning with simple protocell aggregates, through the transitional form of the progenote, to robust microbial mats that leave the fossil imprints of stromatolites so representative in the rock record. A roadmap to future testing of the hypothesis is presented. We compare the oceanic vent with land-based pool scenarios for an origin of life and explore their implications for subsequent evolution to multicellular life such as plants. We conclude by utilizing the hypothesis to posit where life might also have emerged in habitats such as Mars or Saturn's icy moon Enceladus. "To postulate one fortuitously catalyzed reaction, perhaps catalyzed by a metal ion, might be reasonable, but to postulate a suite of them is to appeal to magic." -Leslie Orgel.
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Affiliation(s)
- Bruce Damer
- Department of Biomolecular Engineering, University of California, Santa Cruz, California
| | - David Deamer
- Department of Biomolecular Engineering, University of California, Santa Cruz, California
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4
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Possible Roles of Amphiphilic Molecules in the Origin of Biological Homochirality. Symmetry (Basel) 2019. [DOI: 10.3390/sym11080966] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A review. The question of homochirality is an intriguing problem in the field of chemistry, and is deeply related to the origin of life. Though amphiphiles and their supramolecular assembly have attracted less attention compared to biomacromolecules such as RNA and proteins, the lipid world hypothesis sheds new light on the origin of life. This review describes how amphiphilic molecules are possibly involved in the scenario of homochirality. Some prebiotic conditions relevant to amphiphilic molecules will also be described. It could be said that the chiral properties of amphiphilic molecules have various interesting features such as compositional information, spontaneous formation, the ability to exchange components, fission and fusion, adsorption, and permeation. This review aims to clarify the roles of amphiphiles regarding homochirality, and to determine what kinds of physical properties of amphiphilic molecules could have played a role in the scenario of homochirality.
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5
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Sinai S, Olejarz J, Neagu IA, Nowak MA. Primordial sex facilitates the emergence of evolution. J R Soc Interface 2019; 15:rsif.2018.0003. [PMID: 29491181 DOI: 10.1098/rsif.2018.0003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 02/05/2018] [Indexed: 12/22/2022] Open
Abstract
Compartments are ubiquitous throughout biology, and they have very likely played a crucial role at the origin of life. Here we assume that a protocell, which is a compartment enclosing functional components, requires N such components in order to be evolvable. We calculate the timescale in which a minimal evolvable protocell is produced. We show that when protocells fuse and share information, the timescales polynomially in N By contrast, in the absence of fusion, the worst-case scenario is exponential in N We discuss the implications of this result for the origin of life and other biological processes.
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Affiliation(s)
- Sam Sinai
- Program for Evolutionary Dynamics, Harvard University, Cambridge, MA 02138, USA .,Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Jason Olejarz
- Program for Evolutionary Dynamics, Harvard University, Cambridge, MA 02138, USA
| | - Iulia A Neagu
- Program for Evolutionary Dynamics, Harvard University, Cambridge, MA 02138, USA.,Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Martin A Nowak
- Program for Evolutionary Dynamics, Harvard University, Cambridge, MA 02138, USA .,Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA.,Department of Mathematics, Harvard University, Cambridge, MA 02138, USA
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6
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Martin L, Gurnani P, Zhang J, Hartlieb M, Cameron NR, Eissa AM, Perrier S. Polydimethylsiloxane-Based Giant Glycosylated Polymersomes with Tunable Bacterial Affinity. Biomacromolecules 2019; 20:1297-1307. [PMID: 30694656 DOI: 10.1021/acs.biomac.8b01709] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A synthetic cell mimic in the form of giant glycosylated polymersomes (GGPs) comprised of a novel amphiphilic diblock copolymer is reported. A synthetic approach involving a poly(dimethylsiloxane) (PDMS) macro-chain transfer agent (macroCTA) and postpolymerization modification was used to marry the hydrophobic and highly flexible properties of PDMS with the biological activity of glycopolymers. 2-Bromoethyl acrylate (BEA) was first polymerized using a PDMS macroCTA ( Mn,th ≈ 4900 g·mol-1, Đ = 1.1) to prepare well-defined PDMS- b-pBEA diblock copolymers ( Đ = 1.1) that were then substituted with 1-thio-β-d-glucose or 1-thio-β-d-galactose under facile conditions to yield PDMS- b-glycopolymers. Compositions possessing ≈25% of the glycopolymer block (by mass) were able to adopt a vesicular morphology in aqueous solution (≈210 nm in diameter), as indicated by TEM and light scattering techniques. The resulting carbohydrate-decorated polymersomes exhibited selective binding with the lectin concanavalin A (Con A), as demonstrated by turbidimetric experiments. Self-assembly of the same diblock copolymer compositions using an electroformation method yielded GGPs (ranging from 2-20 μm in diameter). Interaction of these cell-sized polymersomes with fimH positive E. coli was then studied via confocal microscopy. The glucose-decorated GGPs were found to cluster upon addition of the bacteria, while galactose-decorated GGPs could successfully interact with (and possibly immobilize) the bacteria without the onset of clustering. This demonstrates an opportunity to modulate the response of these synthetic cell mimics (protocells) toward biological entities through exploitation of selective ligand-receptor interactions, which may be readily tuned through a considered choice of carbohydrate functionality.
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Affiliation(s)
| | | | | | | | - Neil R Cameron
- Department of Materials Science and Engineering , Monash University , Clayton , VIC 3800 , Australia
| | - Ahmed M Eissa
- Department of Polymers, Chemical Industries Research Division , National Research Centre (NRC) , El-Bohouth Street , Dokki , 12622 , Cairo , Egypt
| | - Sébastien Perrier
- Faculty of Pharmacy and Pharmaceutical Sciences , Monash University , Clayton , VIC 3052 , Australia
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Sakhno Y, Battistella A, Mezzetti A, Jaber M, Georgelin T, Michot L, Lambert JF. One Step up the Ladder of Prebiotic Complexity: Formation of Nonrandom Linear Polypeptides from Binary Systems of Amino Acids on Silica. Chemistry 2019; 25:1275-1285. [PMID: 30284764 DOI: 10.1002/chem.201803845] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Indexed: 12/17/2022]
Abstract
Evidence for the formation of linear oligopeptides with nonrandom sequences from mixtures of amino acids coadsorbed on silica and submitted to a simple thermal activation is presented. The amino acid couples (glutamic acid+leucine) and (aspartic acid+valine) were deposited on a fumed silica and submitted to a single heating step at moderate temperature. The evolution of the systems was characterized by X-ray diffraction, infrared spectroscopy, thermosgravimetric analysis, HPLC, and electrospray ionization mass spectrometry (ESI-MS). Evidence for the formation of amide bonds was found in all systems studied. While the products of single amino acids activation on silica could be considered as evolutionary dead ends, (glutamic acid+leucine) and, at to some extent, (aspartic acid+valine) gave rise to the high yield formation of linear peptides up to the hexamers. Oligopeptides of such length have not been observed before in surface polymerization scenarios (unless the amino acids had been deposited by chemical vapor deposition, which is not realistic in a prebiotic environment). Furthermore, not all possible amino acid sequences were present in the activation products, which is indicative of polymerization selectivity. These results are promising for origins of life studies because they suggest the emergence of nonrandom biopolymers in a simple prebiotic scenario.
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Affiliation(s)
- Yuriy Sakhno
- Laboratoire de Réactivité de Surface, UMR 7197, Sorbonne Université, Case Courrier 178, 4 Pl. Jussieu, 75252, Paris CEDEX 05, France
| | - Alice Battistella
- Laboratoire de Réactivité de Surface, UMR 7197, Sorbonne Université, Case Courrier 178, 4 Pl. Jussieu, 75252, Paris CEDEX 05, France
| | - Alberto Mezzetti
- Laboratoire de Réactivité de Surface, UMR 7197, Sorbonne Université, Case Courrier 178, 4 Pl. Jussieu, 75252, Paris CEDEX 05, France
| | - Maguy Jaber
- Laboratoire d'Archéologie Moléculaire et Structurale, UMR 8220, Sorbonne Université, Case Courrier 178, 4 Pl. Jussieu, 75252, Paris CEDEX 05, France
| | - Thomas Georgelin
- Laboratoire de Réactivité de Surface, UMR 7197, Sorbonne Université, Case Courrier 178, 4 Pl. Jussieu, 75252, Paris CEDEX 05, France.,Temporary address: Centre de Biophysique Moléculaire, UPR 4301, CNRS, Rue Charles Sadron CS 80054, 45071, Orléans CEDEX 2, France
| | - Laurent Michot
- Laboratoire de Physicochimie des Electrolytes et Nanosystèmes Interfaciaux, UMR 8234, Sorbonne Université, Case Courrier 178, 4 Pl. Jussieu, 75252, Paris CEDEX 05, France
| | - Jean-François Lambert
- Laboratoire de Réactivité de Surface, UMR 7197, Sorbonne Université, Case Courrier 178, 4 Pl. Jussieu, 75252, Paris CEDEX 05, France
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8
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Prebiotic selection for motifs in a model of template-free elongation of polymers within compartments. PLoS One 2017; 12:e0180208. [PMID: 28723913 PMCID: PMC5516967 DOI: 10.1371/journal.pone.0180208] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 06/12/2017] [Indexed: 01/08/2023] Open
Abstract
The transition from prelife where self-replication does not occur, to life which exhibits self-replication and evolution, has been a subject of interest for many decades. Membranes, forming compartments, seem to be a critical component of this transition as they provide several concurrent benefits. They maintain localized interactions, generate electro-chemical gradients, and help in selecting cooperative functions as they arise. These functions pave the way for the emergence and maintenance of simple metabolic cycles and polymers. In the context of origin of life, evolution of information-carrying molecules and RNA based enzymes within compartments has been subject to intensive theoretical and experimental research. Hence, many experimental efforts aim to produce compartments that contain elongating polynucleotides (also referred to as protocells), which store information and perform catalysis. Despite impressive experimental progress, we are still relatively ignorant about the dynamics by which elongating polynucleotides can produce more sophisticated behaviors. Here we perform computer simulations to couple information production through template-free elongation of polymers with dividing compartments. We find that polymers with a simple ability—biasing the concentration of monomers within their own compartment—can acquire a selective advantage in prelife. We further investigate whether such a mechanism allows for cooperative dynamics to dominate over purely competitive ones. We show that under this system of biased monomer addition, even without template-directed self-replication, genetic motifs can emerge, compete, cooperate, and ultimately survive within the population.
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9
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Current Ideas about Prebiological Compartmentalization. Life (Basel) 2015; 5:1239-63. [PMID: 25867709 PMCID: PMC4500137 DOI: 10.3390/life5021239] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/01/2015] [Accepted: 04/02/2015] [Indexed: 01/17/2023] Open
Abstract
Contemporary biological cells are highly sophisticated dynamic compartment systems which separate an internal volume from the external medium through a boundary, which controls, in complex ways, the exchange of matter and energy between the cell's interior and the environment. Since such compartmentalization is a fundamental principle of all forms of life, scenarios have been elaborated about the emergence of prebiological compartments on early Earth, in particular about their likely structural characteristics and dynamic features. Chemical systems that consist of potentially prebiological compartments and chemical reaction networks have been designed to model pre-cellular systems. These systems are often referred to as "protocells". Past and current protocell model systems are presented and compared. Since the prebiotic formation of cell-like compartments is directly linked to the prebiotic availability of compartment building blocks, a few aspects on the likely chemical inventory on the early Earth are also summarized.
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10
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Berdugo C, Miravet JF, Escuder B. Substrate selective catalytic molecular hydrogels: the role of the hydrophobic effect. Chem Commun (Camb) 2014; 49:10608-10. [PMID: 24098889 DOI: 10.1039/c3cc45623d] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A catalytic hydrogel is reported for the substrate selective direct aldol reaction of aliphatic ketones based on their hydrophobicity and on the emergence of catalytic activity only after self-assembly of the catalyst.
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Affiliation(s)
- Cristina Berdugo
- Departament de Química Inorgànica i Orgànica, Universitat Jaume I, 12071 Castelló, Spain.
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11
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Zou Q, Zhang L, Yan X, Wang A, Ma G, Li J, Möhwald H, Mann S. Multifunctional Porous Microspheres Based on Peptide-Porphyrin Hierarchical Co-Assembly. Angew Chem Int Ed Engl 2014; 53:2366-70. [DOI: 10.1002/anie.201308792] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 11/29/2013] [Indexed: 11/06/2022]
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12
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Zou Q, Zhang L, Yan X, Wang A, Ma G, Li J, Möhwald H, Mann S. Multifunctional Porous Microspheres Based on Peptide-Porphyrin Hierarchical Co-Assembly. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201308792] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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13
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Egel R. Primal eukaryogenesis: on the communal nature of precellular States, ancestral to modern life. Life (Basel) 2012; 2:170-212. [PMID: 25382122 PMCID: PMC4187143 DOI: 10.3390/life2010170] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 12/29/2011] [Accepted: 01/11/2012] [Indexed: 02/08/2023] Open
Abstract
This problem-oriented, exploratory and hypothesis-driven discourse toward the unknown combines several basic tenets: (i) a photo-active metal sulfide scenario of primal biogenesis in the porespace of shallow sedimentary flats, in contrast to hot deep-sea hydrothermal vent conditions; (ii) an inherently complex communal system at the common root of present life forms; (iii) a high degree of internal compartmentalization at this communal root, progressively resembling coenocytic (syncytial) super-cells; (iv) a direct connection from such communal super-cells to proto-eukaryotic macro-cell organization; and (v) multiple rounds of micro-cellular escape with streamlined reductive evolution-leading to the major prokaryotic cell lines, as well as to megaviruses and other viral lineages. Hopefully, such nontraditional concepts and approaches will contribute to coherent and plausible views about the origins and early life on Earth. In particular, the coevolutionary emergence from a communal system at the common root can most naturally explain the vast discrepancy in subcellular organization between modern eukaryotes on the one hand and both archaea and bacteria on the other.
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Affiliation(s)
- Richard Egel
- Department of Biology, University of Copenhagen Biocenter, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark.
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14
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Mutuality in Discrete and Compositional Information: Perspectives for Synthetic Genetic Codes. Cognit Comput 2011. [DOI: 10.1007/s12559-011-9116-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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15
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Fishkis M. Emergence of self-reproduction in cooperative chemical evolution of prebiological molecules. ORIGINS LIFE EVOL B 2011; 41:261-75. [PMID: 20811777 DOI: 10.1007/s11084-010-9220-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2010] [Accepted: 07/07/2010] [Indexed: 01/19/2023]
Abstract
The paper presents a model of coevolution of short peptides (P) and short oligonucleotides (N) at an early stage of chemical evolution leading to the origin of life. The model describes polymerization of both P and N types of molecules on mineral surfaces in aqueous solution at moderate temperatures. It is assumed that amino acid and nucleotide monomers were available in a prebiotic milieu, that periodic variation in environmental conditions between dry/warm and wet/cool took place and that energy sources were available for the polymerization. An artificial chemistry approach in combination with agent-based modeling was used to explore chemical evolution from an initially random mixture of monomers. It was assumed that the oligonucleotides could serve as templates for self-replication and for translation of peptide compositional sequences, and that certain peptides could serve as weak catalysts. Important features of the model are the short lengths of the peptide and oligonucleotide molecules that prevent an error catastrophe caused by copying errors and a finite diffusion rate of the molecules on a mineral surface that prevents excessive development of parasitism. The result of the simulation was the emergence of self-replicating molecular systems consisting of peptide catalysts and oligonucleotide templates. In addition, a smaller but significant number of molecules with alternative compositions also survived due to imprecise reproduction and translation of templates providing variability for further evolution. In a more general context, the model describes not only peptide-oligonucleotide molecular systems, but any molecular system containing two types of polymer molecules: one of which serves as templates and the other as catalysts.The presented coevolutionary system suggests a possible direction towards finding the origin of molecular functionality in a prebiotic environment.
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Affiliation(s)
- Maya Fishkis
- Evolving Systems Technology, 95 Hawkfield Crescent, Calgary, Alberta, Canada.
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16
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Balleza D. Toward understanding protocell mechanosensation. ORIGINS LIFE EVOL B 2011; 41:281-304. [PMID: 21080073 DOI: 10.1007/s11084-010-9225-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Accepted: 10/20/2010] [Indexed: 01/11/2023]
Abstract
Mechanosensitive (MS) channels can prevent bacterial bursting during hypo-osmotic shocks by responding to increases in lateral tension at the membrane level through an integrated and coordinated opening mechanism. Mechanical regulation in protocells could have been one of the first mechanisms to evolve in order to preserve their integrity against changing environmental conditions. How has the rich functional diversity found in present cells been created throughout evolution, and what did the primordial MS channels look like? This review has been written with the aim of identifying which factors may have been important for the appearance of the first osmotic valve in a prebiotic context, and what this valve may have been like. It highlights the mechanical properties of lipid bilayers, the association of peptides as aggregates in membranes, and the conservation of sequence motifs as central aspects to understand the evolution of proteins that gate below the tension required for spontaneous pore formation and membrane rupture. The arguments developed here apply to both MscL and MscS homologs, but could be valid to mechano-susceptible proteins in general.
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Affiliation(s)
- Daniel Balleza
- Unidad de Biofísica, CSIC-UPV/EHU, Universidad del País Vasco, Barrio Sarriena s/n, Leioa, Spain.
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17
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Carny O, Gazit E. Creating prebiotic sanctuary: self-assembling supramolecular Peptide structures bind and stabilize RNA. ORIGINS LIFE EVOL B 2011; 41:121-32. [PMID: 20585856 DOI: 10.1007/s11084-010-9219-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 06/13/2010] [Indexed: 12/15/2022]
Abstract
Any attempt to uncover the origins of life must tackle the known 'blind watchmaker problem'. That is to demonstrate the likelihood of the emergence of a prebiotic system simple enough to be formed spontaneously and yet complex enough to allow natural selection that will lead to Darwinistic evolution. Studies of short aromatic peptides revealed their ability to self-assemble into ordered and stable structures. The unique physical and chemical characteristics of these peptide assemblies point out to their possible role in the origins of life. We have explored mechanisms by which self-assembling short peptides and RNA fragments could interact together and go through a molecular co-evolution, using diphenylalanine supramolecular assemblies as a model system. The spontaneous formation of these self-assembling peptides under prebiotic conditions, through the salt-induced peptide formation (SIPF) pathway was demonstrated. These peptide assemblies possess the ability to bind and stabilize ribonucleotides in a sequence-depended manner, thus increase their relative fitness. The formation of these peptide assemblies is dependent on the homochirality of the peptide monomers: while homochiral peptides (L-Phe-L-Phe and D-Phe-D-Phe) self-assemble rapidly in aqueous environment, heterochiral diastereoisomers (L-Phe-D-Phe and D-Phe-L-Phe) do not tend to self-assemble. This characteristic consists with the homochirality of all living matter. Finally, based on these findings, we propose a model for the role of short self-assembling peptides in the prebiotic molecular evolution and the origin of life.
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Affiliation(s)
- Ohad Carny
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
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18
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Mishra A, Chauhan VS. Probing the role of aromaticity in the design of dipeptide based nanostructures. NANOSCALE 2011; 3:945-949. [PMID: 21221462 DOI: 10.1039/c0nr00691b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Self-assembly of peptide into nanostructures is believed to be stabilized primarily by aromatic interactions. Using a minimalistic approach, we probed the importance of aromatic interactions in the self-assembly of simple model dipeptides. Our results suggest that aromaticity may not be absolutely essential for self-assembly, even though it tends to provide directionality to the assembly. We found that peptides containing cyclic/linear side chain hydrophobic residues were also capable of forming stable self-assemblies that are stabilized by hydrophobic interactions. Our observations will find relevance in the design of small peptide based nanoparticles.
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Affiliation(s)
- Aseem Mishra
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
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19
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Rodríguez-Llansola F, Miravet JF, Escuder B. Supramolecular catalysis with extended aggregates and gels: inversion of stereoselectivity caused by self-assembly. Chemistry 2010; 16:8480-6. [PMID: 20540050 DOI: 10.1002/chem.201000654] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
L-Proline-L-valine dipeptide derivatives, which self-assemble in toluene, have been studied as stereoselective catalysts in the conjugate addition of cyclohexanone to trans-beta-nitrostyrene. Remarkable effects on the stereoselectivity are observed associated to the aggregation of the catalyst. Outstanding differences were observed between the catalytic activity of compound 1, which forms supramolecular gels in toluene, and compound 2, which is not a gelator. In the former case, the enantioselectivity of the reaction was almost insensitive to changes in catalyst concentration and temperature, but in the case of compound 2, the catalytic activity was very much affected by those variables. Structural studies indicate that the results can be rationalized by taking into account significant conformational changes experienced by the catalytic L-proline derivatives associated with the aggregation process. The results highlight that catalyst self-assembly is a very important issue to consider in the stereoselective outcome of organocatalytic reactions. Especially relevant is the fact that the use of supramolecular gels as organocatalysts emerges as a technique that affords reliable and constant stereoselectivity in different conditions with the added value of easy catalyst recovery.
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Escuder B, Rodríguez-Llansola F, Miravet JF. Supramolecular gels as active media for organic reactions and catalysis. NEW J CHEM 2010. [DOI: 10.1039/b9nj00764d] [Citation(s) in RCA: 237] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Egel R. Peptide-dominated membranes preceding the genetic takeover by RNA: latest thinking on a classic controversy. Bioessays 2009; 31:1100-9. [PMID: 19708018 DOI: 10.1002/bies.200800226] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
It is commonly presumed that abiotic membranes were colonized by proteins later on. Yet, hydrophobic peptides could have formed primordial protein-dominated membranes on their own. In a metabolism-first context, "autocatalytically closed" sets of statistical peptides could organize a self-maintaining protometabolism, assisted by an unfolding set of ribotide-related cofactors. Pairwise complementary ribotide cofactors may have formed docking guides for stochastic peptide formation, before replicating RNA emerged from this subset. Tidally recurring wet-drying cycles and an early onset of photosynthetic activities are considered most likely to meet the thermodynamic requirements. Conceivably, the earliest peptide-dominated vesicles were engaged in light harvesting, together with isoprenoid-tethered pigments, rather than providing an external boundary. Early on, the bulk of prebiotic organic matter can have formed a contiguous layer covering the mineral sediment, held in place by colloidal coherence of a hydrogel matrix. This unconventional scenario assumes a late onset of cellular individualization - perhaps from within, resembling endosporogenesis.
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Affiliation(s)
- Richard Egel
- Department of Biology, University of Copenhagen Biocenter, Copenhagen, Denmark.
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Gleiser M, Walker SI. Toward homochiral protocells in noncatalytic peptide systems. ORIGINS LIFE EVOL B 2009; 39:479-93. [PMID: 19370399 DOI: 10.1007/s11084-009-9166-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Accepted: 03/20/2009] [Indexed: 10/20/2022]
Abstract
The activation-polymerization-epimerization-depolymerization (APED) model of Plasson et al. has recently been proposed as a mechanism for the evolution of homochirality on prebiotic Earth. The dynamics of the APED model in two-dimensional spatially-extended systems is investigated for various realistic reaction parameters. It is found that the APED system allows for the formation of isolated homochiral proto-domains surrounded by a racemate. A diffusive slowdown of the APED network induced, for example, through tidal motion or evaporating pools and lagoons leads to the stabilization of homochiral bounded structures as expected in the first self-assembled protocells.
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Affiliation(s)
- Marcelo Gleiser
- Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755, USA.
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