Introduction

I started the present theoretical work on the origins of life in 2006. I followed the progress of my thinking by answering, step by step, the most basic questions and taking as postulate the answer to the first question. These questions are entirely separate from those of the workshop which I have read in 2014.

Thus, I feel that my approach would be better understood by hereby exposing the history of my work and current thinking following the workshop. Internet links to the abstracts for my other published articles are included in this paper, for reference purposes.

History of my Work until the Workshop OQOL2014

My research on an open system consisting of a simple network of chemical reactions catalyzed by a group of some amino acids and coenzyme, soon found itself at an impasse.

Issues on the Article “Prebiotic Petroleum”

The way of liposomes appeared to me very quickly especially promising since it would provide delimitation of an interior where organization can progress, and the possibility of abiotic synthesis of their fatty acids. Only this synthesis confronts controversy of abiotic oil.

Thus I proposed the following as a basic postulate for the investigation on the origins of life:

“The class of most complex molecules of life that may have geochemical and abiotic origin is the class of fatty acids with long aliphatic chains”.

From there, much like the abiotic oil seems to be formed deep in the earth’s crust, I sought to establish the state of research on the formation of a prebiotic soup in the deep terrestrial crust as opposed to the surface, as elements N, P and S must be added to fatty acids. This idea seemed counter-intuitive to me in terms of the nitrogen and sulfur, because nitrogen is mainly in the atmosphere and sulfur and its derivatives inhibit the synthesis of oil synthesized by the Fischer- Tropsch process used in the industry. Furthermore, I was against the current theories and their results on the origins of life that stem from the Miller-Urey experiment, which itself would take place in a primitive atmosphere, rich in N2 and no longer exists due to the appearance of oxygen O2.

This prebiotic subterranean soup, which I named “prebiotic petroleum” has a huge advantage over the outcome of the primitive atmosphere, because it is current. It suffices to prove its existence geochemically even indirectly because of the omnipresence of fossil oil. This advantage is also conceptual. Its existence is not due to a unique phenomenon of the past, one that we can no longer reproduce, but it is due to a process that occurs continuously and therefore can be reproduced by ourselves.

Issues on the Article “Prebiotic Chemo-Osmosis”

This article tries to answer the crucial question: can there be an exchange between the inside organized − as highlighted in the literature by “liposome first” theory − and outside the liposome with or without hydrophilic heads? Understanding these exchanges in life-forms implements four basic physical processes: passageways (channels), an electro-chemical potential, the periplasm and the segregation of Na/K. All this is overseen by protein.

Originally, the protein does not exist, there remains the possibility that amino acids of the prebiotic soup cling to the hydrophilic heads and sink into the membrane to form passageways, aided by electric potential differences localized, temporary and of very low power.

It is also necessary that the heads exist! This article raises many questions for a meager result: how will substantial potential differences be established? Why and how will segregation of Na/K will it become established? Is periplasm necessary at the beginning of this molecular evolution?

Issues on the Article “Prebiotic Chirality”

This article tried to solve the problem of the synthesis of hydrophilic heads from glycerol apparently being nonexistent in prebiotic conditions, at least from the literature that I presented in the article “prebiotic oil.”

In fact, the article “prebiotic chirality” began by demonstrating the chirality of sugars and amino acids to solve the problem of cohesion liposome started incorrectly in “chemo-osmosis prebiotic.”

The hypothesis of a DHA-P esterification followed by H2 hydrogenation (prebiotic soup) catalyzed both by polyanionic surface (fatty acids) and in synergy with mechanical cohesion that is due to the chirality of the amino acid, appears consistent with the corresponding enzymatic reactions.

This result seems encouraging, however it is in fact unusual because it violates the principle whereby spontaneous chemical reactions (creation of covalent bond) are generally inconsistent with enzyme activity. Research on the origins of life still advancing spontaneous reactions as early molecular evolution because they depart from the prebiotic soup and hope to solve the problem later.

Anyway I took this result as it is and instead of rejecting it, I tried to answer the following question: Why and how could spontaneous reactions be excluded? And among them, the reactions with H2O are the most numerous and important, but the bacteria is made of 70% water by volume.

It is with this questioning of exchange channels and spontaneous reactions that I addressed the seminar OQOL2014, interested primarily in the oral presentation (No. 04–1) on “Towards coevolution of metabolism and membrane” regarding my 3 articles.

Developments Following the Workshop

It was by listening to the presentation “Towards co-evolution of membranes and metabolism”, which deals with the permeability of peptides through the membrane that I realized that the passageways through the membrane could be formed from the formation of the liposome and could then move towards protein channels.

I published an article just after the seminar under the title “evolution of prebiotic membrane” to demonstrate the physical processes in action (please refer to the summary below).

  1. 1

    Immediate conceptual consequences as a result of this assumption are:

    • No more trying to imagine the establishment of passageways, but rather follow their transformation into protein channels;

    • Segregation of Na/K can be done without understanding why or how;

    • Thanks to this segregation, the electro-chemical potentials can be more powerful, without reaching the power in the presence of a periplasm;

    • Amino acids may be involved in molecular evolution earlier and more easily as they can replace the fatty acids of passageways instead of clinging onto the hydrophilic heads of phospholipids in order to penetrate the membrane.

    • And this, while maintaining the evolutionary potentials of polyanionic surfaces of reverses vesicles (in oil), then those of zwitterionic surfaces of forming liposomes, and those of the synergy of mechanical cohesion due to amino acids (see prebiotic chirality).

  2. 2

    Secondly, the fact that segregation of Na /K can be achieved prompted me to look at

    • These developments have allowed me to glimpse into the molecular evolution of metabolism after initialization:

    • how can it be established? The hydration of Li and Na slows down their movement between two electrodes than for K. This makes it so that they have several layers of hydration, the latter layer with more free H2O molecules. Thus the assembly may move more easily.

    • Why are there segregation? K salts hydration is relatively small compared to those of Na and Li. Therefore K and mineral ions go together. That’s why the Na/K ratio is much larger in seawater than in the Earth’s crust. In the liposome, ion mineral types are inorganic phosphate and ammonium radical, so K stuck with them.

    • Consequently I have a better understanding of the eviction of spontaneous reactions in metabolism, at least those using H2O. The hydrolysis could no longer use the H2O adsorbed on surfaces and on proteins, and H2O produced by the reverse reactions are eliminated by the Na exiting the liposome. This shifts the equilibrium of these reverse reactions toward metastable molecules, “energy-rich” (phosphate anhydrides), or to molecules with stronger covalent bond (peptide bond). He there synergy between segregation and esterification of fatty acids.

  3. 3

    These developments have allowed me to glimpse into the molecular evolution of metabolism after initialization:

    • One can say that the initialization step of metabolism is completed when the surface of fatty acids is completely esterified, at this point the system will reach a steady-state far from equilibrium. The spontaneous reactions no longer exist: hydrolyses are prohibited and those that produce H2O are blocked by the stabilization of the Na/K segregation. These reactions are mainly phosphorylations in direct connection with the esterification of fatty acids and therefore with the segregation of Na/K.

    • From this point of view, the synthesis of monophosphate nucleotides as described in ‘chirality prebiotic’ appears to be a spontaneous reaction unrelated to the catalysis effected by the surface of fatty acids. At the stabilization of the Na/K segregation this synthesis will be present, which is not compatible with the biotic metabolism.

    • One minimalist hypothesis would be that synthesis of monophosphate nucleotides iscatalyzed by the surface of the fatty acids in the same way that the esterification of carboxylic heads (hydrogenation by H2, then esterification by DHA-P). The nucleobases are hydrophobic, and would incorporate themselves into the membrane and present their reactive nitrogen, alongside carboxylic heads. This reactive nitrogen will attach a D- glyceraldehyde-3P and, acetaldehyde for giving deoxynucleotide or glycolaldehyde for giving nucleotide.

    • The continuation of molecular evolution is made by amino acids. With the disappearance of mobile H2O, amino acids will tend to assemble more strongly by hydrogen bonds between their zwitterions. In some places − at pores, at the level of hydrophilic heads or simply amino acids surrounded by a thick layer of hydration − amino acids will form structures similar to peptides, developing physical forces (electric dipoles of alpha-helices, for example). These forces are much lower and less specific (not depending on the amino acid sequence), but still supporting the creation of covalent bonds. These reactions are not spontaneous, they are directed by the constraints imposed by Na/K segregation, and they are localized: transfer reactions of phosphorylated groups requiring no H2O, and hydrolysis of anhydride bonds using adsorbed H2O paired with reactions without H2O, can then be performed.

Presentation of articles in chronological order:

  • Prebiotic Petroleum

The theoretical and bibliographical work on the geochemical origin of life, which I hereby present, works on the assumption that:

“The class of most complex molecules of life that can have a geochemical and abiotic origin is the class of fatty acids with a long aliphatic chain”.

This idea comes from the controversy over the abiotic oil industry, and the first measurements of abiotic oil at mid-ocean ridges (Charlou J.L. et al. 2002, Proskurowski G. et al. 2008). To go further and propose a comprehensive experimentation on the origin of life, I propose in this article the idea that the prebiotic soup or prebiotic petroleum would stem from the diagenesis of the gas clathrates/sediments mixture. The gases H2S H2 N2 CH4 CO2, are produced in mid-ocean ridges, and in large-scale in the sea-floor, by serpentinization. Sediments contain hydrogenphosphates as a source of phosphate and minerals for the surface catalysis.

Extreme conditions experienced by some prokaryotes and pressures and temperatures of submarine oilfields of fossil petroleum are comparable. The hydrostatic pressure is around 1.5 kbar and the temperature is below 150 °C.

This experiment I propose is quite feasible today since these conditions are used

  • in research and exploration of fossil petroleum;

  • in the field of organic chemistry called “green chemistry” and where temperatures remain low and the pressure can reach 10 kbar (RV Eldik et al. 2008);

  • to study the biology of prokaryotes living in the fossil petroleum of industrial interest. These studies are quite comparable to experiment with prebiotic oil;

  • Finally, this experiment can be based on research on abiotic CH4 on Mars and abiotic hydrocarbons on Titan.

The next step in the theoretical research of the origin of life is the abiotic synthesis of liposomes. Abiotic synthesis liposomes just requires synthesis of glycerol and ethanol-amine (or serine) esterifying the phosphate and fatty acid. The state of research on the abiotic synthesis of these molecules shows that those of the serine, and of ethanol-amine as well as the first stage of the formose reaction (Glyceraldehyde, dihydroxyacetone and glycolaldehyde) are quite possible in prebiotic soup after diagenesis of gas clathrates, mainly due to the presence of H2. Whereas, the synthesis of glycerol in the laboratory and in the industrial process are so drastic and complex that I proposed to initialize the metabolism in fatty acid vesicles, hydrogenation by H2 of glyceraldehyde-P or DHA-P (dihydroxyacetone phosphate) glycerol-3P after esterification to the fatty acid, when the hydrogenation is facilitated by the catalyst power of the multi-anionic surface of these vesicles.

This idea I explore in detail in the article “prebiotic chirality”, where I show that the mechanical cohesion of the liposome is at the origin of homochirality of sugars and amino acids, and it accelerates metabolism initialization . In this article I have explored a dozen initial steps in the evolution of prebiotic metabolism.

I also wrote a third article, “chemo-osmosis prebiotic”, in wich I outline the implementation of ion channels, essential to liposome communication with its environment. Initialization of ion channels is based on the zwitterionic nature of the phospholipids, the mechanical cohesion of the liposome and the electrical potential across the bilayer. This electric potential is at the origin of prebiotic chemo-osmosis, motor continuity of molecular evolution.

This article on prebiotic oil is at the base of all my work.

  • Prebiotic chemo-osmosis

Applying the theory of chemo-osmosis of Peter Mitchell (1961), to a system of liposomes and ionophores in abiotic environment, the reflections in this work, claims to the formation of functional membrane proteins and the initialization of metabolism within the liposome by this system.

The metabolism can’t be conceived as being a set of chemical reactions in a synchronous network, subject to the laws of thermodynamics, but rather as two coupled networks of protons and electrons subject to electromagnetic laws and whose structures are located in the membrane created and maintained by the chemiosmotic process.

The concomitant changes in metabolism, structure and chemiosmotic process mutually reinforcing and should result in an organism that evolves consistently.

In earlier molecular evolution each part of the system can reproduce independently of one another. Liposomes can incorporate abiotic phospholipids or those synthesized by the new metabolism and split in half without damaging the islets of membrane proteins.

Oligo-nucleotides can self-duplicate by matching nucleics acids bases.

Two copies of oligo-nucleotides can bind by hydrogen bonds to two groups of amino acids almost identical, integrated into the membrane, on the inner surface of the liposome and positioned by the chemiosmotic process. This reproduction of groups of amino acids, through copies of oligonucleotides, initiates the translation process that we know in living organisms.

Reproduction of these three processes in a coordinated manner should be considered further in depth study of ribosomes and translation.

The hypothesis of the geochemical formation of abiotic pocket oil is considered in this work as a prebiotic environment for prebiotic chemo-osmosis. This hypothesis follows works both in laboratory and in real conditions, on the origins of life at hydrothermal vents on mid-ocean ridges.

Evolution of Prebiotic Membrane

I propose in this letter a new way to conceive the formation of a liposome with pores. It is a physical process that is the logical consequence of the formation of a liposome in a pocket of prebiotic petroleum as described in the article “prebiotic petroleum”. The pores appear during liposome formation and the following molecular evolution serves to strengthen and make more and more functional overall.

Indeed the lipid layers, from the prebiotic soup, consist of heterogeneous phospholipids or fatty acids which are grouped, by mechanical cohesion, into sets of aliphatic chain of approximately identical lengths. This grouping is growing with enormous surface forces that occur during this formation process.

When two groups with short aliphatic chains are facing each other, the repulsion of their electric dipole forces them to adopt a minimum energy configuration, pipe-shaped membrane-spanning, aliphatic chains penetrating the hydrophobic region and the hydrophilic heads by contacting with water that may then flow between the inside and outside of the liposome.

Additional to the breakdown in strength of the lipid layers due to surface forces and electrical repulsion of the dipoles we must be add the osmotic pressure difference on either side of the membrane that forces water to pass through. This pressure difference is due to the fact that the main phase is composed of water content of the vesicles having aborted which may be different from that of the liposomes formed.

Links to publications:

https://en.wikiversity.org/wiki/Prebiotic_Petroleum

https://en.wikiversity.org/wiki/Prebiotic_chemo-osmosis

https://en.wikiversity.org/wiki/Prebiotic_chirality

https://en.wikiversity.org/wiki/Evolution_of_prebiotic_membrane

Posters: https://commons.wikimedia.org/wiki/File:Prebitotic-chirality.pdf

https://commons.wikimedia.org/wiki/File:Prebiotic-Petroleum.pdf