Scientists discover new “origins of life” chemical reactions

Amazing stuff! Discovering the origins of life on this planet! Much maligned carbon dioxide might have been a crucial ingredient to early life!

"... scientists ... have discovered a new set of chemical reactions that use cyanide, ammonia and carbon dioxide—all thought to be common on the early earth—to generate amino acids and orotic acid, the building blocks of proteins and DNA. ...
a new paradigm to explain this shift from prebiotic to biotic chemistry ...
In addition to giving researchers insight into the chemistry of the early earth, the newly discovered chemical reactions are also useful in certain manufacturing processes, such as the generation of custom labeled biomolecules from inexpensive starting materials. ...
Earlier this year ... group showed how cyanide can enable the chemical reactions that turn prebiotic molecules and water into basic organic compounds required for life. Unlike previously proposed reactions, this one worked at room temperature and in a wide pH range. ...
After their success using cyanide to drive other chemical reactions, ... suspected that cyanide, even without enzymes, might also help turn α-keto acids into amino acids. Because they knew nitrogen would be required in some form, they added ammonia—a form of nitrogen that would have been present on the early earth. Then, through trial and error, they discovered a third key ingredient: carbon dioxide. With this mixture, they quickly started seeing amino acids form. ...
“If you mix only the keto acid, cyanide and ammonia, it just sits there. As soon as you add carbon dioxide, even trace amounts, the reaction picks up speed.” ...

Because the new reaction is relatively similar to what occurs today inside cells—except for being driven by cyanide instead of a protein—it seems more likely to be the source of early life, rather than drastically different reactions, the researchers say. The research also helps bring together two sides of a long-standing debate about the importance of carbon dioxide to early life, concluding that carbon dioxide was key, but only in combination with other molecules. ..."

From the abstract:

"The Strecker reaction of aldehydes is the pre-eminent pathway to explain the prebiotic origins of α-amino acids. However, biology employs transamination of α-ketoacids to synthesize amino acids which are then transformed to nucleobases, implying an evolutionary switch—abiotically or biotically—of a prebiotic pathway involving the Strecker reaction into today’s biosynthetic pathways. Here we show that α-ketoacids react with cyanide and ammonia sources to form the corresponding α-amino acids through the Bucherer–Bergs pathway. An efficient prebiotic transformation of oxaloacetate to aspartate via N-carbamoyl aspartate enables the simultaneous formation of dihydroorotate, paralleling the biochemical synthesis of orotate as the precursor to pyrimidine nucleobases. Glyoxylate forms both glycine and orotate and reacts with malonate and urea to form aspartate and dihydroorotate. These results, along with the previously demonstrated protometabolic analogues of the Krebs cycle, suggest that there can be a natural emergence of congruent forerunners of biological pathways with the potential for seamless transition from prebiotic chemistry to modern metabolism."

Scripps Research scientists discover new “origins of life” chemical reactions | Scripps Research The reaction generates amino acids and orotic acid, the building blocks of proteins and DNA.

Prebiotic synthesis of α-amino acids and orotate from α-ketoacids potentiates transition to extant metabolic pathways (no public access)