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Membrane alternatives in worlds without oxygen: Creation of an azotosome.

Stevenson J, Lunine J, Clancy P - Sci Adv (2015)

Bottom Line: The lipid bilayer membrane, which is the foundation of life on Earth, is not viable outside of biology based on liquid water.Using molecular simulations, we demonstrate that these membranes in cryogenic solvent have an elasticity equal to that of lipid bilayers in water at room temperature.As a proof of concept, we also demonstrate that stable cryogenic membranes could arise from compounds observed in the atmosphere of Saturn's moon, Titan, known for the existence of seas of liquid methane on its surface.

View Article: PubMed Central - PubMed

Affiliation: School of Chemical and Biomolecular Engineering, Cornell University, 365 Olin Hall, Ithaca, NY 14853, USA.

ABSTRACT
The lipid bilayer membrane, which is the foundation of life on Earth, is not viable outside of biology based on liquid water. This fact has caused astronomers who seek conditions suitable for life to search for exoplanets within the "habitable zone," the narrow band in which liquid water can exist. However, can cell membranes be created and function at temperatures far below those at which water is a liquid? We take a step toward answering this question by proposing a new type of membrane, composed of small organic nitrogen compounds, that is capable of forming and functioning in liquid methane at cryogenic temperatures. Using molecular simulations, we demonstrate that these membranes in cryogenic solvent have an elasticity equal to that of lipid bilayers in water at room temperature. As a proof of concept, we also demonstrate that stable cryogenic membranes could arise from compounds observed in the atmosphere of Saturn's moon, Titan, known for the existence of seas of liquid methane on its surface.

No MeSH data available.


Related in: MedlinePlus

Umbrella sampling of the azotosome decomposition process.The test molecule is incrementally withdrawn from the membrane in the z direction.
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Figure 5: Umbrella sampling of the azotosome decomposition process.The test molecule is incrementally withdrawn from the membrane in the z direction.

Mentions: Next, a test molecule (at the location x,y = 3,3) was incrementally withdrawn in the z direction. At each increment, the test molecule was allowed to move freely in the [x,y] directions. In the z direction, it was loosely restrained by a harmonic potential, allowing it to sample nearby z locations, but not to leave the vicinity. This procedure, known as “umbrella sampling,” allows a sampling of all possible configurations and also provides a measure of whether the sampling was adequate—we can simply check whether we have enough samples from each small increment in the z direction. A schematic of this process is shown in Fig. 5.


Membrane alternatives in worlds without oxygen: Creation of an azotosome.

Stevenson J, Lunine J, Clancy P - Sci Adv (2015)

Umbrella sampling of the azotosome decomposition process.The test molecule is incrementally withdrawn from the membrane in the z direction.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4644080&req=5

Figure 5: Umbrella sampling of the azotosome decomposition process.The test molecule is incrementally withdrawn from the membrane in the z direction.
Mentions: Next, a test molecule (at the location x,y = 3,3) was incrementally withdrawn in the z direction. At each increment, the test molecule was allowed to move freely in the [x,y] directions. In the z direction, it was loosely restrained by a harmonic potential, allowing it to sample nearby z locations, but not to leave the vicinity. This procedure, known as “umbrella sampling,” allows a sampling of all possible configurations and also provides a measure of whether the sampling was adequate—we can simply check whether we have enough samples from each small increment in the z direction. A schematic of this process is shown in Fig. 5.

Bottom Line: The lipid bilayer membrane, which is the foundation of life on Earth, is not viable outside of biology based on liquid water.Using molecular simulations, we demonstrate that these membranes in cryogenic solvent have an elasticity equal to that of lipid bilayers in water at room temperature.As a proof of concept, we also demonstrate that stable cryogenic membranes could arise from compounds observed in the atmosphere of Saturn's moon, Titan, known for the existence of seas of liquid methane on its surface.

View Article: PubMed Central - PubMed

Affiliation: School of Chemical and Biomolecular Engineering, Cornell University, 365 Olin Hall, Ithaca, NY 14853, USA.

ABSTRACT
The lipid bilayer membrane, which is the foundation of life on Earth, is not viable outside of biology based on liquid water. This fact has caused astronomers who seek conditions suitable for life to search for exoplanets within the "habitable zone," the narrow band in which liquid water can exist. However, can cell membranes be created and function at temperatures far below those at which water is a liquid? We take a step toward answering this question by proposing a new type of membrane, composed of small organic nitrogen compounds, that is capable of forming and functioning in liquid methane at cryogenic temperatures. Using molecular simulations, we demonstrate that these membranes in cryogenic solvent have an elasticity equal to that of lipid bilayers in water at room temperature. As a proof of concept, we also demonstrate that stable cryogenic membranes could arise from compounds observed in the atmosphere of Saturn's moon, Titan, known for the existence of seas of liquid methane on its surface.

No MeSH data available.


Related in: MedlinePlus