What does it take to begin life on primitive Earth? A chemical called diamidophosphate (DAP) may be the missing link, a new study suggests.
How life began on Earth has always been a source of contention in religion, science, and history. While no one knows the answer, scientists try to replicate the possible environment during these prehistoric times. Each time, it feels there's always something missing — until today.
In a study published in Nature Chemistry on Nov. 6, The Scripps Research Institute (TSRI) chemists discovered that DAP may be the prebiotic agent everyone's been looking for.
The Crack The Scientists Need
To create Earth's most primitive life-forms, three ingredients are essential. These are lipids to build the structure, peptides or amino acids for cells to function, and nucleotides that keep the genetic information passed across generations.
Scientists then posited a process called phosphorylation, or the addition of phosphate to an organic compound, ties up all these ingredients. The problem was they didn't have the catalyst to it.
The different hypothesized chemical reactions ended up either uncommon during that time or had produced various prebiotic agents that didn't make these biological processes feel more cohesive.
Could This Be The Proof?
Researchers led by Ramanarayanan Krishnamurthy, TSRI's chemistry associate professor, have worked with DAP for some time. They even learned it could work with sugars relevant to sustaining prebiotic life.
Based on this, they wanted to know if the agent has a much bigger role in the formation of earliest life. In the experiment, they combined DAP with two more components, which are water and imidazole, another organic compound that could be present in early Earth.
With water and DAP, researchers were able to trigger the phosphorylation of RNA's building blocks even if factors such as temperature were changed. In fact, mixing DAP and water and placing it at room temperature added phosphates to amino acids and helped form peptide chains.
Water, DAP, and imidazole replicated the earliest forms of cells called vesicles, which are sacs or cysts filled with either fluid or air, through phosphorylation of fatty acids and glycerol. In other words, this combination helped build the extracellular structure. Imidazole and DAP, meanwhile, produced RNA-like chains.
"It reminds me of the Fairy Godmother in Cinderella, who waves a wand and 'poof,' 'poof,' 'poof,' everything simple is transformed into something more complex and interesting," Krishnamurthy said.
Taking It Further
Whether DAP is the kick-starter to early life on Earth remains a theory. The researchers, therefore, want to corroborate this newfound evidence by working with geochemists. Together, they may know if there are sources of DAP during the earliest years of the planet.