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Coupled phases and combinatorial selection in fluctuating hydrothermal pools: a scenario to guide experimental approaches to the origin of cellular life.

Damer B, Deamer D - Life (Basel) (2015)

Bottom Line: Two kinds of selective processes can then occur.The second is a chemical process in which rare combinations of encapsulated polymers form systems capable of capturing energy and nutrients to undergo growth by catalyzed polymerization.Given continued cycling over extended time spans, such combinatorial processes will give rise to molecular systems having the fundamental properties of life.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomolecular Engineering. bdamer@ucsc.edu.

ABSTRACT
Hydrothermal fields on the prebiotic Earth are candidate environments for biogenesis. We propose a model in which molecular systems driven by cycles of hydration and dehydration in such sites undergo chemical evolution in dehydrated films on mineral surfaces followed by encapsulation and combinatorial selection in a hydrated bulk phase. The dehydrated phase can consist of concentrated eutectic mixtures or multilamellar liquid crystalline matrices. Both conditions organize and concentrate potential monomers and thereby promote polymerization reactions that are driven by reduced water activity in the dehydrated phase. In the case of multilamellar lipid matrices, polymers that have been synthesized are captured in lipid vesicles upon rehydration to produce a variety of molecular systems. Each vesicle represents a protocell, an "experiment" in a natural version of combinatorial chemistry. Two kinds of selective processes can then occur. The first is a physical process in which relatively stable molecular systems will be preferentially selected. The second is a chemical process in which rare combinations of encapsulated polymers form systems capable of capturing energy and nutrients to undergo growth by catalyzed polymerization. Given continued cycling over extended time spans, such combinatorial processes will give rise to molecular systems having the fundamental properties of life.

No MeSH data available.


Related in: MedlinePlus

Survival and disruption of protocells. Single-stranded amphiphiles are shown as a monolayer at the atmosphere-water interface and as bilayer vesicles in the aqueous phase. A vesicle may be stabilized if it encapsulates a polymer that interacts with the bilayer surface, as shown in red.
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life-05-00872-f006: Survival and disruption of protocells. Single-stranded amphiphiles are shown as a monolayer at the atmosphere-water interface and as bilayer vesicles in the aqueous phase. A vesicle may be stabilized if it encapsulates a polymer that interacts with the bilayer surface, as shown in red.

Mentions: Selection begins during the hydrated phase when some vesicles are lost to the bulk or disrupted while others survive (Figure 6). Survival is promoted by the encapsulated contents of the vesicles. For instance, if a vesicle happens to contain a polymer that stabilizes the membrane, analogous to cytoskeletal proteins of cells today, it will resist disruptive forces such as mechanical shear caused by turbulence.


Coupled phases and combinatorial selection in fluctuating hydrothermal pools: a scenario to guide experimental approaches to the origin of cellular life.

Damer B, Deamer D - Life (Basel) (2015)

Survival and disruption of protocells. Single-stranded amphiphiles are shown as a monolayer at the atmosphere-water interface and as bilayer vesicles in the aqueous phase. A vesicle may be stabilized if it encapsulates a polymer that interacts with the bilayer surface, as shown in red.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390883&req=5

life-05-00872-f006: Survival and disruption of protocells. Single-stranded amphiphiles are shown as a monolayer at the atmosphere-water interface and as bilayer vesicles in the aqueous phase. A vesicle may be stabilized if it encapsulates a polymer that interacts with the bilayer surface, as shown in red.
Mentions: Selection begins during the hydrated phase when some vesicles are lost to the bulk or disrupted while others survive (Figure 6). Survival is promoted by the encapsulated contents of the vesicles. For instance, if a vesicle happens to contain a polymer that stabilizes the membrane, analogous to cytoskeletal proteins of cells today, it will resist disruptive forces such as mechanical shear caused by turbulence.

Bottom Line: Two kinds of selective processes can then occur.The second is a chemical process in which rare combinations of encapsulated polymers form systems capable of capturing energy and nutrients to undergo growth by catalyzed polymerization.Given continued cycling over extended time spans, such combinatorial processes will give rise to molecular systems having the fundamental properties of life.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomolecular Engineering. bdamer@ucsc.edu.

ABSTRACT
Hydrothermal fields on the prebiotic Earth are candidate environments for biogenesis. We propose a model in which molecular systems driven by cycles of hydration and dehydration in such sites undergo chemical evolution in dehydrated films on mineral surfaces followed by encapsulation and combinatorial selection in a hydrated bulk phase. The dehydrated phase can consist of concentrated eutectic mixtures or multilamellar liquid crystalline matrices. Both conditions organize and concentrate potential monomers and thereby promote polymerization reactions that are driven by reduced water activity in the dehydrated phase. In the case of multilamellar lipid matrices, polymers that have been synthesized are captured in lipid vesicles upon rehydration to produce a variety of molecular systems. Each vesicle represents a protocell, an "experiment" in a natural version of combinatorial chemistry. Two kinds of selective processes can then occur. The first is a physical process in which relatively stable molecular systems will be preferentially selected. The second is a chemical process in which rare combinations of encapsulated polymers form systems capable of capturing energy and nutrients to undergo growth by catalyzed polymerization. Given continued cycling over extended time spans, such combinatorial processes will give rise to molecular systems having the fundamental properties of life.

No MeSH data available.


Related in: MedlinePlus