American chemists have shown that diamidophosphate, which was available on the young Earth, could participate in reactions that led to the formation of nucleotides and membranes of future cells.
DNA and RNA chains are made up of nucleosides attached to phosphate units. It is also needed for the formation of a double layer of phospholipids - the basis of cell membranes, and for the reactions of peptide formation from individual amino acids. However, while the appearance of most of the compounds that fold biological macromolecules has already been established, with phosphorylation - reactions that could lead to the addition of phosphates - the situation is still difficult.
A number of scenarios have been proposed that could be realized in the conditions of the early Earth, but so far they do not differ in clarity and simplicity. So, it is assumed that different types of phosphates could react with different molecules, and each time - in its own, special, conditions. All this is too difficult to implement, especially within the framework of a single environment, in which, apparently, there were reactions that led to the emergence of life.
A new - and much simpler - version was put forward by a team of chemists at the Scripps Research Institute (TSRI), led by Ramanarayanan Krishnamurthy. In an article published in the journal Nature Chemistry, they put forward diamidophosphate (DAP) as a universal phosphorylating agent in prebiological chemical evolution. In the laboratory, scientists have shown that in aqueous solution, DAP is able to interact with all RNA precursor nucleosides over a wide range of temperatures and other conditions.
In the presence of an imidazole catalyst (which, apparently, was quite widespread on the early Earth), DAP reacts with both glycerol and fatty acids - the basis of cell membrane phospholipids, which immediately form hollow vesicles in water. And already at room temperature, DAP reacts with amino acids - asparagine, glutamine, glycine - participating in the formation of short peptide chains from them.
Phosphorylation of three types of organic compounds - nucleosides, amino acids and fatty acids - with DAP yields ready-made oligonucleotides, peptides and membrane vesicles / Krishnamurthy Lab, TSRI
Previously, Krishnamurti and his colleagues have shown the ability of DAP to phosphorylate simple sugars by participating in the synthesis of many other molecules important for life. Given that all these reactions took place in the laboratory under the most ordinary conditions, they could well have proceeded on the young Earth. Moreover, the phosphorylation mechanism that is realized in interactions with DAP is the same as that used today by more efficient protein kinases, which may serve as another indirect argument in favor of the great role that this phosphate played in the origin of life.
Sergey Vasiliev
Promotional video: