Naked Science Forum
On the Lighter Side => New Theories => Topic started by: Vladimir Matveev on 13/01/2016 05:31:55
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The great basic question of science: Membrane compartment or non-membrane phase compartment (biophase) is a physical basis for origin of life?
Matveev V.V. 2016. Comparison of fundamental physical properties of the model cells (protocells) and the living cells reveals the need in protophysiology. International Journal of Astrobiology, Page 1-8. DOI:10.1017/S1473550415000476
Comments and critisim are welcome.
External links are not allowed. Sorry.
Abstract
A hypothesis is proposed about potassium ponds being the cradles of life enriches the gamut of ideas about the possible conditions of pre-biological evolution on the primeval Earth, but does not bring us closer to solving the real problem of the origin of life. The gist of the matter lies in the mechanism of making a delimitation between two environments – the intracellular environment and the habitat of protocells. Since the sodium–potassium pump (Na+/K+-ATPase) was discovered, no molecular model has been proposed for a predecessor of the modern sodium pump. This has brought into life the idea of the potassium pond, wherein protocells would not need a sodium pump. However, current notions of the operation of living cells come into conflict with even physical laws when trying to use them to explain the origin and functioning of protocells. Thus, habitual explanations of the physical properties of living cells have become inapplicable to explain the corresponding properties of Sidney Fox's microspheres. Likewise, existing approaches to solving the problem of the origin of life do not see the need for the comparative study of living cells and cell models, assemblies of biological and artificial small molecules and macromolecules under physical conditions conducive to the origin of life. The time has come to conduct comprehensive research into the fundamental physical properties of protocells and create a new discipline – protocell physiology or protophysiology – which should bring us much closer to solving the problem of the origin of life.
Highlights
1. If life originated in seawater, the origin of the first cell inevitably comes down to the origin of the sodium pump and any structure supporting it – the lipid membrane – without which the work of any pump would make little sense.
2. Since the sodium-potassium pump (Na+/K+-ATPase) was discovered, no molecular model has been proposed for a predecessor of the modern sodium pump. Neither Miller’s electrical charges, nor Fox’s amino-acid condensation, nor building ready-made biomolecules into coacervates; none of this has managed to lead to the self-origination of the progenitor of the ion pump even in favourable lab conditions.
3. In 2007, we saw the simultaneous release of two articles, in which it was posited that life originated not in seawater as previously thought, but in smaller bodies of water with a K+/Na+ ratio necessary to sustain life. In this conditions sodium pump is not needed and the pump can originate later. But why the pump is needed if K+/Na+ ratio is good? The origin of the sodium pump in conditions where there is no natural need for it may require the agency of Providence.
4. Potassium Big Bang on Earth instead of potassium ponds.
5. Fox's microspheres do not need potassium ponds.
6. Despite the fact that Fox's microspheres have no fully functional membrane with sodium pumps and specific ion channels, they generate action potentials similar to that by nerve cells and in addition have ion channels which open and close spontaneously. This ability of the microspheres contradicts to the generally accepted ideas about the mechanism of generation of biological electrical potentials.
7. Hodgkin-Huxley model of action potentials is similarly well-compatible with both the nerve cell and Fox’s microsphere.
8. Biophase as the main subject of protophysiology. In the past they considered the living cell as a non-membrane phase compartment with different physical properties in comparison to the surrounding medium, and this physical difference plays a key role in cell function. According to a new take on an old phase, non-membrane phase compartments play an important role in the functioning of the cell nucleus, nuclear envelope and then of cytoplasm. Somebody sees the compartments even as temporary organelles. According to available data, the phase compartments can play a key role in cell signaling. In this historical context, studies in recent years dedicated to non-membrane phase compartments in the living cells sound sensational.
9. It is essentially a Protocell World which weaves known RNA World, DNA World and Protein World into unity.
10. In the view of non-membrane phase approach, the usage of liposomes and other membrane (non-biophase) cell models to solve the issue of the origin of life is a deadlock way of the investigation.
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Congratulations on the publication acceptance.
I assume you have applied for a decent grant to further this as a protophysiology research project?
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I assume you have applied for a decent grant to further this as a protophysiology research project?
Not in my Institute...
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I assume you have applied for a decent grant to further this as a protophysiology research project?
Not in my Institute...
Why not?
I notice that this although published, is not published in Russia. I assume you first tried that and got rejections.
If such is indeed the case, what do you see as your next step?
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I notice that this although published, is not published in Russia. I assume you first tried that and got rejections.
If such is indeed the case, what do you see as your next step?
The first attempt was the journal "Origins of Life and Evolution of Biospheres". They rejected the manuscript with the speed of a bullet. My only hope is to interest professionals obsessed by lipid membranes.
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I see.
So your just going for maximum exposure.
Fair enough. Pity I'would have to pay to read it.
It would have been of interest.
Good luck..
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Pity I'would have to pay to read it.
Personal request is not forbidden. In addition, you may ask you librarian.
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Personal request is not forbidden.
Consider this a personal request.
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Consider this a personal request.
Please use my e-mail for personal request.
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Abstract
A hypothesis is proposed about potassium ponds being the cradles of life enriches the gamut of ideas about the possible conditions of pre-biological evolution on the primeval Earth, but does not bring us closer to solving the real problem of the origin of life. The gist of the matter lies in the mechanism of making a delimitation between two environments – the intracellular environment and the habitat of protocells. Since the sodium–potassium pump (Na+/K+-ATPase) was discovered, no molecular model has been proposed for a predecessor of the modern sodium pump. This has brought into life the idea of the potassium pond, wherein protocells would not need a sodium pump. However, current notions of the operation of living cells come into conflict with even physical laws when trying to use them to explain the origin and functioning of protocells. Thus, habitual explanations of the physical properties of living cells have become inapplicable to explain the corresponding properties of Sidney Fox's microspheres. Likewise, existing approaches to solving the problem of the origin of life do not see the need for the comparative study of living cells and cell models, assemblies of biological and artificial small molecules and macromolecules under physical conditions conducive to the origin of life. The time has come to conduct comprehensive research into the fundamental physical properties of protocells and create a new discipline – protocell physiology or protophysiology – which should bring us much closer to solving the problem of the origin of life.
Sodium and potassium ions have different impacts on water. Sodium cations are kosmotropic and will create order in water. While potassium cations are chaotropic and will create chaos/disorder in water. Although they both have a single positive charge, this difference will appear because sodium cations bind to water stronger than water hydrogen bonds to itself. While potassium cations bind to water weaker than water binds to itself.
This difference in the water, is why potassium cations has an easier time diffusing through the membrane, compared to the sodium ions. The sodium cations, by making order in water becomes bloated with a strongly attached water shell. Potassium by creating disorder in water, is skinnier in water.
Experiments have shown that if we remove the membranes of cells, so there is no cation pumps, the naked cells will still accumulate potassium ions. What this suggests is the constant accumulation of potassium cations, due to the cationic pumping action, have resulted in an equilibrium selection of proteins, tuned to the chaotropic nature of the potassium cations in the water. If we get rid of the membrane, the proteins that have been selected, over eons, by the chaotropic nature of potassium in water, will now select potassium cations; work as a team. Cationic pumping made a huge difference in terms of the selection.
If we had a membrane bound volume of potassium cation friendly protein, they would establish the cationic gradient, even before cationic pumping appears. Your theory provides a reasonable basis for this. The precursors of the cation pumps, even before they work, will also under aqueous equilibrium, which mean that one end will be in equilibrium with the potassium, while the other end will be out of equilibrium in that pond.
Your theory of the potassium ponds suggests to me that if random protein were to appear in the pond, the potassium excess will be forcing a favorable equilibrium with certain proteins, and an unfavorable equilibrium with other protein. Some will be pushed out to the shore, with the precursors of the cationic pumps, somewhere in the middle between the two, orientated properly. We have the frame but still need the motor and drive train.
Once the cationic pumps do appear, they will force the internal protein equilibrium; selection process. Water acts as the intermediate between the ions and the organics. Modern theories suggests that the cationic pumps are no longer needed but act as a failsafe. This makes little sense, since these can still be used to push the envelope to assure mutation protein define equilibrium, whether they need to be discarded via recycle, or pushed to the membrane, or be expelled from the cell.
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Experiments have shown that if we remove the membranes of cells, so there is no cation pumps, the naked cells will still accumulate potassium ions.
puppypower, Let me explain my position with the following statements:
(1) Since the sodium-potassium pump (Na+/K+-ATPase) was discovered, no molecular model has been proposed for a predecessor of the modern sodium pump. Neither Miller's electrical charges, nor Fox's amino-acid condensation, nor building ready-made biomolecules into coacervates; none of this has managed to lead to the self-origination of the progenitor of the ion pump even in favourable lab conditions.
(2) It is impossible to explain the properties of well-studied cellular model (Fox's microspheres) on the basis of fudamental ideas of membrane physiology (lipid membrane, ion channels, sodium pump).
(3) According to recent studies, non-membrane phase compartments play an important role in the functioning of the cell nucleus, nuclear envelope and then of cytoplasm. Somebody sees the compartments even as temporary organelles. According to available data, the phase compartments can play a key role in cell signaling.
(4) In the view of non-membrane phase approach, the usage of liposomes and other membrane (non-biophase) cell models to solve the issue of the origin of life is a deadlock way of the investigation.
Thanks for your comments. I go to sleep.