Emerging studies suggest that alpha amino acids have a superior degree of stability. This stability possibly accounts for why they were important building blocks for proteins in the early days of life on Earth. This joint study led by a team at the Hebrew University focuses on the role that these amino acids might play in producing proteins, the workhorses of all living things known today.
Alpha amino acids, the building blocks of proteins, are used by all forms of life on Earth. It is made out of 20 unique alpha amino acids that are essential to many physiological processes. Fischer Springer’s research confirms that these amino acids were abundant on prebiotic Earth. The widespread presence of amino acids likely made it easier for early proteins to form.
Stability and Self-Assembly of Alpha Amino Acids
The research headed by Dr. Moran Frenkel-Pinter focused on alpha amino acids such as glycine and their proto-peptides’ unique properties. From this perspective, these alpha-based proto-peptides have impressive skills at forming stable compartments. It is possible stepwise development of this capacity has been absolutely key to our early life.
Depsipeptides, which are minimally complex model peptide-like molecules made from alpha amino acids, were able to undergo condensation into these droplet-like assemblies. These assemblies show incredible durability, lasting for weeks even when subjected to repeated freeze-thaw cycles.
Commenting on the significance of these findings, Dr. Frenkel-Pinter noted, “Self-assembly is one of the most crucial underlying requirements for life.” This property enables depsipeptides to functionally reproduce contemporary peptides, demonstrating their possible involvement in the evolutionary origin of proteins.
Comparison with Beta Amino Acids
The study additionally tested alpha amino acids against their beta analogs in terms of their assembly propensity. In that work, researchers discovered that alpha amino acids are particularly adept at assembling stable, complex structures. This talent confers to them an emergency evolutionary edge over their precursors beta and gamma amino acids. It also begs the question of why evolution seemed to prefer the alpha amino acids, a conundrum that has baffled researchers for decades.
Ezerzer, a member of the research team, highlighted the significance of addressing this question: “The question of why evolution handpicked a specific set of amino acids has remained a mystery for a very long time. Just getting even an incremental step closer to addressing this enduring mystery is pretty awesome. I couldn’t be more honored and excited to help inject this enthusiasm into that pursuit!
Implications for Future Research and Industry
This research is more than just an effort to understand what early life was like on Earth. It opens the door for novel innovations beyond the sciences, including in the pharmaceutical industry. The self-assembly properties of depsipeptides could inform innovative drug development and delivery systems.
Fisher, another senior author on the study, enthused, “This is the first time that we demonstrate that depsipeptides can self-assemble—although to do so, they intermolecularly assemble in a way that overlaps with modern peptides. These results represent an important step forward in the process of chemical evolution. They have the potential to change the course of so many other industries, especially the pharmaceutical industry.
Read the full T4 study here, published in the Proceedings of the National Academy of Sciences (PNAS). In doing so, it makes a major contribution to our understanding of chemical evolution and the origins of life.