Let us explain the mechanism by which proteins are produced even without genes!

This is the most important concept underlying the GADV theory!

Immature GADV-protein could be produced through a random process.

It is important to consider, how the first mature protein was created through random processes or without genes on the primitive Earth. Both structure and function of the first protein cannot be designed in advance. The evolutionary pathways from an immature protein to a mature protein can be explained by protein 0^th-orders structure. A protein’s 0^th-orders structure, made of GADV-amino acids, satisfies the four conditions for the formation of water-soluble globular proteins in the absence of genes. GADV-proteins with a weak catalytic activity could be produced by random joining of GADV-amino acids under the protein 0^th-orders structure with a high probability.

Source: Towards Revealing the Origin of Life, P.38, Fig. 3.9

＊Formation of an immature protein with some flexibility in the absence of genetic function.

The reason,- why peptides synthesized by random joining of [GADV]-amino acids could aggregate to form immature but water-soluble globular protein,- is because the protein containing [GADV]-amino acids in roughly equal amounts can satisfy the four minimum conditions (hydropathy, α-helix, β-sheet and turn/coil formabilities), which are necessary to form a water-soluble globular structure.

Let us explain about a protein 0^th-orders structure!

One of the protein 0^th-orders structures is the amino acid composition containing GADV-amino acids in roughly equal amounts. It satisfies the average indexes of four fundamental properties of water-soluble globular proteins, (hydrophobicity/hydrophilicity(hydropathy), three secondary structure formabilities(α-helix, β-sheet, turn/coil)).

Dr.Ikehara describes the process to the emergence of life as follows.

“The first meaningful chemical compounds, which could be produced through a random process, were only the immature water-soluble globular GADV-proteins. The process of the emergence of life could be initiated by formation of the immature GADV-proteins. Life might not emerge on the primitive Earth,-if GADV-proteins or GADV-amino acids did not exist in this world. Another reason,-why a meaningful protein or immature protein could be produced by random joining of amino acids,-is because amino acids themselves are the respective functional units. This is different from the case of genes where codons composed of triplet bases are the functional units.”

Dr. Ikehara also discusses the issue of homochirality of biomolecules, which is very important when considering the origin of life.

“There is another serious problem in the origin of life research. That is the problem of why only L-amino acids and D-sugars such as D-ribose have been used in extant organisms or how the homochirality of biomolecules could be attained on the primitive Earth. The problem remains unsolved until now, although the homochirality is indispensable to form regular structures of protein or α-helix and β-sheet and of right-handed ds-DNA and RNA. However, I consider that homochirality may be achieved during comparatively simple events on this planet.”

The following 1 to 5 are detailed.

1. Large amounts of simple organic compounds with a small number of carbon atoms such as GADV-amino acids could be produced by prebiotic means with an electric discharge into a reducing or even neutral primitive atmosphere (Miller and Orgel 1974; Cleaves et al.2008). Thus, racemic GADV-amino acids first gradually accumulated on the primitive Earth for many years.
2. Successively, ([G]+L-[ADV])-amino acids might be preferentially but accidentally crystallized during concentration of the amino acids in depressions of rocks on seashores under sunshine on the primitive Earth. L-form excess [(G)ADV]-amino acids might remain in a depression after a large part of water was blown away from the depression by winds.

Some experimental results were previously reported, showing that differential crystallization could accidentally occur between racemic amino acid mixtures during concentration of the amino acid in aqueous solution (Kojo 2010; Breslow and Levine 2006). Kojo has published the results showing that L-form amino acids inracemic amino acids could be co-crystallized with L-Asn (Kojo2010). Therefore, it can be supposed that homochiral [(G)ADV]-amino acids could be obtained by co-crystallization with L-Asp ammonium salt, which could exhibit a similar effect to L-Asn.

Dr. Ikehara describes that such important experimental results for solving the homochirality problem of biomolecules have been curiously unnoticed until now.

3. Thereafter, homochiral immature [(G)ADV]-proteins as aggregates of GADV-peptides could be formed by repeated wet-dry cycles.
4. D-sugars as D-ribose could be synthesized preferentially by catalytic reactions on active site of the immature but homochiral L-form [(G)ADV]-proteins, because a high reactivity for synthesis of D-sugars could be expressed on the GADV-proteins composed of homochiral L-form [(G)ADV]-amino acids. Formation of homochiral L-[(G)ADV]-proteins determined the preferential usage of D-sugars as D-ribose.
5. Thus, the appearance of homochiral L-form [(G)ADV]-amino acids upon differential crystallization between racemic amino acids determined all homochiralities of biomolecules, although , of course, L-form excess amino acids, which were introduced from space (Pizzarello and Weber 2004; Pizzarello 2006), and the circularly polarized light in space (Bonner 1991) might also contribute to the formation of homochiral biomolecules.

On this site, GADV-amino acids and GADV-proteins usually refer to homochiral L-amino acids and L-proteins unless otherwise specified.

Living organisms synthesize proteins through the expression of genes. We argue that if we go back to the origins of life, it is theoretically possible for water-soluble globular proteins to be produced in the absence of genes. By setting the starting point of the origins of life there, all the mysteries of life phenomena can be solved.

Dr. Ikehara describes the origin of proteins as follows.

”I noticed that the mechanism of how proteins can be produced in the absence of genes and I was released from the curse of the “chicken-egg” relationship between gene and protein.”

Reference: Ikehara K(2021) Towards Revealing the Origin of Life. Springer Nature