Research Team Explores Water Droplet Interfaces, Uncovering the Key Element for Life Formation

R. Graham Cooks, the Henry B. Hass Distinguished Professor of Chemistry, along with his postdoctoral researcher Lingqi Qiu, have conducted experiments that provide evidence for a significant step in protein formation occurring in droplets of pure water. These findings have been recently published in the Proceedings of the National Academy of Sciences.

During this crucial step, amino acids undergo dehydration, despite being in a water solution. This paradox is resolved by the fact that the surfaces of these droplets are remarkably dry and highly acidic. Under these unique conditions, amino acids connect with each other to form peptides, which is a fundamental process in the formation of proteins and eventually, living organisms.

One important aspect of this discovery is that the natural “left-handed” structure of amino acids is preserved throughout the process. This results in the formation of pure chiral peptides with the same “L” handedness. The researchers have identified a specific compound called oxazolidinone, which plays a crucial role as an intermediate in this reaction.

Furthermore, the researchers have found that this dehydration reaction is not limited to microscopic droplets. It also occurs on a larger scale, up to centimeter-sized droplets, as demonstrated in laboratory experiments starting from the oxazolidinone intermediate. This larger-scale reaction mirrors the chemistry observed in microdroplets and is analogous to the well-studied wet-dry cycles that are believed to take place in hydrothermal pools and seashores. This connection establishes a link between peptide formation in aerosols and in more extensive prebiotic environments.

This study contributes to the growing body of evidence that the surfaces of water droplets represent a uniquely active physical and chemical system. These droplets exhibit high electric fields and extreme acidity, which drive the dehydration of amino acids and the formation of peptides. Exploring the chemistry at water droplet interfaces provides valuable insights into the early stages of life’s chemical evolution.

The authors express their gratitude for the valuable discussions they had with Purdue research associates Dylan T. Holden and Nicolás M. Morato.

This article is republished from PhysORG under a Creative Commons license. Read the original article.