May 2022
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32 Reads
Protocells Approximately 4 billion years ago, protocells are thought to have emerged as a precursor to life. In article number 2106624, Irep Gözen and co‐workers introduce protocell concepts, research and laboratory methods.
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May 2022
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32 Reads
Protocells Approximately 4 billion years ago, protocells are thought to have emerged as a precursor to life. In article number 2106624, Irep Gözen and co‐workers introduce protocell concepts, research and laboratory methods.
April 2022
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21 Reads
The front cover artwork is provided by İrep Gözen group at the University of Oslo. The image shows primitive cell‐like compartments which have spontaneously emerged from a crack in rock‐forming mineral oligoclase. Read the full text of the Article at 10.1002/syst.202100040.
April 2022
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20 Reads
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2 Citations
The Front Cover shows primitive cell‐like compartments which have spontaneously emerged from a crack in rock‐forming mineral oligoclase. More information can be found in the Article by Irep Gözen and co‐workers.
March 2022
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517 Reads
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62 Citations
The origin of life is still one of humankind's great mysteries. At the transition between nonliving and living matter, protocells, initially featureless aggregates of abiotic matter, gain the structure and functions necessary to fulfill the criteria of life. Research addressing protocells as a central element in this transition is diverse and increasingly interdisciplinary. The authors review current protocell concepts and research directions, address milestones, challenges and existing hypotheses in the context of conditions on the early Earth, and provide a concise overview of current protocell research methods.
February 2022
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68 Reads
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6 Citations
Prominent among the models for protocells is the spherical biosurfactant shell, freely suspended in aqueous media. This model explains initial, but not subsequent events in the development process towards structured protocells. Taking into consideration the involvement of naturally occurring surfaces, which were abundant on the early Earth, feasible and productive pathways for the development of primitive cells are reported. Surfaces intrinsically possess energy, easily utilized by the interfacing amphiphiles, such as lipids, to attain self‐organization and spontaneous transformations. This work shows that the physical interaction of phospholipid pools with 20 Hadean Earth analogue materials as well as a Martian meteorite composed of fused regolith representing the ancient crust of Mars consistently lead to the shape transformation and autonomous formation of surfactant compartment assemblies. Dense, colony‐like protocell populations grow from these lipid deposits, predominantly at the grain boundaries or cleavages of the investigated natural surfaces, and remain there for several days. The model protocells in this study are able to autonomously develop, transform and pseudo‐divide, and encapsulate RNA as well as DNA. Moreover, they can accommodate non‐enzymatic, DNA strand displacement reactions. These findings suggest a feasible route towards the transformation from non‐living to living entities, and provide fresh support for the ‘Lipid World’ hypothesis.
November 2021
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30 Reads
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5 Citations
Physical Chemistry Chemical Physics
Self-assembled membranes composed of both fatty acids and phospholipids are permeable for solutes and structurally stable, which was likely an advantageous combination for the development of primitive cells on the early Earth. Here we report on the solid surface-assisted formation of primitive mixed-surfactant membrane compartments, i.e. model protocells, from multilamellar lipid reservoirs composed of different ratios of fatty acids and phospholipids. Similar to the previously discovered enhancement of model protocell formation on solid substrates, we achieve spontaneous multi-step self-transformation of mixed surfactant reservoirs into closed surfactant containers, interconnected via nanotube networks. Some of the fatty acid-containing compartments in the networks exhibit colony-like growth. We demonstrate that the compartments generated from fatty acid-containing phospholipid membranes feature increased permeability coefficients for molecules in the ambient solution, for fluorescein up to 7 × 10-6 cm s-1 and for RNA up to 3.5 × 10-6 cm s-1. Our findings indicate that surface-assisted autonomous protocell formation and development, starting from mixed amphiphiles, is a plausible scenario for the early stages of the emergence of primitive cells.
January 2021
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21 Reads
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1 Citation
In article number 2005320, Irep Gözen and co‐workers demonstrate that the spontaneous subcompartmentalization of model protocells is governed by the physicochemical interaction of the protocell membranes with mineral‐like solid interfaces. In the described experiments, several tens of compartments emerge on the basal membrane of each adhered model protocell. They are able to encapsulate small molecules from the external environment and maintain them within. The compartments become isolated daughter protocells when the enveloping membrane ruptures, which can be perceived as a form of primitive division.
November 2020
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51 Reads
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23 Citations
Membrane enclosed intracellular compartments have been exclusively associated with the eukaryotes, represented by the highly compartmentalized last eukaryotic common ancestor. Recent evidence showing the presence of membranous compartments with specific functions in archaea and bacteria makes it conceivable that the last universal common ancestor and its hypothetical precursor, the protocell, may have exhibited compartmentalization. To the authors’ knowledge, there are no experimental studies yet that have tested this hypothesis. They report on an autonomous subcompartmentalization mechanism for protocells which results in the transformation of initial subcompartments to daughter protocells. The process is solely determined by the fundamental materials properties and interfacial events, and does not require biological machinery or chemical energy supply. In the light of the authors’ findings, it is proposed that similar events may have taken place under early Earth conditions, leading to the development of compartmentalized cells and potentially, primitive division.
September 2020
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17 Reads
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1 Citation
In article number 2002529, Irep Gozen and co‐workers present experimental evidence that nucleation and growth of protocell‐like membrane compartments from surface‐adhered lipid nanotube networks are significantly enhanced at temperatures between 40 and 70 °C, and fusion can be initiated at ≈90 °C. They show that the microcontainers (5–15 μm) formed in this manner encapsulate and redistribute RNA, and corroborate that lipid nanotube–interconnected neighboring vesicles join and fuse more rapidly than in bulk suspensions.
August 2020
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55 Reads
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12 Citations
Elevated temperatures might have promoted the nucleation, growth, and replication of protocells on the early Earth. Recent reports have shown evidence that moderately high temperatures not only permit protocell assembly at the origin of life, but can have actively supported it. Here, the fast nucleation and growth of vesicular compartments from autonomously formed lipid networks on solid surfaces, induced by a moderate increase in temperature, are shown. Branches of the networks, initially consisting of self‐assembled interconnected nanotubes, rapidly swell into microcompartments which can spontaneously encapsulate RNA fragments. The increase in temperature further causes fusion of adjacent network‐connected compartments, resulting in the redistribution of the RNA. The experimental observations and the mathematical model indicate that the presence of nanotubular interconnections between protocells facilitates the fusion process.
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... A spectacular presence was reported in the Murchison meteorite, estimated 7 billion years old, which contains particles of SiC [16]. The transition of abiotic compartments to primitive biological cells is currently an unanswered scientific question; a possible involvement of natural solid surfaces in this transition has been suggested [17,18]. ...
April 2022
... [166][167][168][169][170] These division processes can be used for self-reproduction in protocells. [171][172][173] In molecular simulations, reactions can be treated by force fields and MC methods. For atomistic molecular dynamics simulations, a force field called ReaxFF (reactive force field) has been developed to simulate bond breaking/formation based on quantum me-chanics calculations. ...
March 2022
... 14 Most recently, we showed the formation of colony-like model protocells emerging from the molecular lipid films on early Earth minerals and a Martian meteorite. 15 Here we report the stepwise formation and growth of protocell superstructures containing tens to thousands of membranous compartments, originating from a single onionshell lipid reservoir. Inside a lipid compartment, several layers of smaller vesicles grow from the surface up, leading to a densely packed pool of compartments of similar shape and size, reminiscent of bacterial colonies. ...
Reference:
Colony-like Protocell Superstructures
February 2022
... membrane composition, lipid phase, chain length, sterol type. Permeability coefficients of different lipid membranes have been reported [9][10][11][12] . across a DMPC:DPPC (50:50) bilayer was calculated as 0.2 × 10 −9 / for ATP. of fluorescein through GUVs composed of DPPC, DOPC and cholesterol (1:1:1) was determined as 19.4 ± 1.8 × 10 −6 / by Li et al. 12 . ...
November 2021
Physical Chemistry Chemical Physics
... The supplied cargo molecules were ATTO 488 (Fig. 2a), a 10-base RNA labeled with fluorescein amidite (FAM), or a 20-base single stranded DNA, also labeled with FAM. During superfusion, these molecules passed the membrane and entered the protocellnanotube networks through transient nano-pores 10,20 . The concentration of FAM-RNA and FAM-ssDNA inside the compartments after 4 min. of superfusion was observed to be lower compared to ATTO 488 (Fig. S1). ...
January 2021
... This indicates that another adhesion-controlling factor influences the transformation, which we attribute to differences in the number of pinning sites in each patch. Reduction of the adhesion strength by a temperature increase, as reported in references [13,32] is therefore only partly decisive of the transformation outcome. The availability of the pinning sites, evident through the occurrence of fractal ruptures, which we earlier associated with strong inter-bilayer pinning by divalent ions [33,34], prevents excessive de-wetting and transformation into vesicles. ...
November 2020
... Despite their proximity, spontaneous fusion between the compartments is not likely, as energy input is required to create pores in initially isolated bilayers. Fusion in PNNs induced by external cues was previously observed, and characterized with a mathematical model 13 . It is expected that if the two compartments fuse at their equator, they will rapidly form a larger compartment containing a stable circular pore (Fig. S7b-d). ...
September 2020
... In order to exert control over the wetting and de-wetting behavior of the lipid films, we utilized temperature regulation by means of a focused IR-B laser integrated into the laser-induced fluorescence imaging setup. Heating as an effective means of adhesion control has been established earlier [13,26,27]. Depending on the nature (A, B). ...
August 2020
... Previous studies have demonstrated that even small quantities of polymer can lead to pore formation in lipid bilayers. These pores may subsequently compromise the stability of the formed vesicles [42,43], potentially contributing to the observed irregularities and deformations during the cryo-TEM sample preparation processes and explain the poor GUV release efficiency at high SMALP concentrations. Additionally, the reduced vesicle stability was observed by centrifugation (1000 g for 10 min) of the vesicles, which SMALP formed vesicles could not withstand but electroformed vesicles can. ...
September 2019
Soft Matter
... Preparation of Lipid Vesicles. The dehydration and rehydration method 79,80 was used to prepare the lipid suspensions. Briefly, lipids (99 wt %) and lipid-conjugated fluorophores (1 wt %) were dissolved in chloroform to a final concentration of 10 mg/mL (cf . ...
Reference:
Colony-like Protocell Superstructures
January 2019
Journal of Visualized Experiments