A Possible Path to Prebiotic Peptides Involving Silica and Hydroxy Acid‐Mediated Amide Bond Formation

Abstract

The formation of alanine and glycine oligomers in films produced by drying aqueous mixtures of lactic acid and silica nanoparticles has been studied as a model prebiotic reaction. The addition of silica results in alanine or glycine enrichment in the polymers. Oligomerization proceeds through ester-mediated peptide bond formation in an acidic and evaporative environment at temperatures as low as 85 °C. For both amino acids, the dominant species produced in the presence of silica and lactic acid are rich in amide bonds and deficient in ester linkages. At higher temperatures, glycine and alanine oligomers contain only a single hydroxy acid residue conjugated to the peptide N terminus. Similar product distributions occur with silica particles prereacted with lactic acid, which suggests the catalytic role of a functionalized surface. This work highlights the role minerals might have served in transitioning from oligomers with both ester and amide linkages (depsipeptides) to peptides in a prebiotic context.

Emergence of Function and Selection from Recursively Programmed Polymerisation Reactions in Mineral Environments

“…In previous work, we had examined the ability of minerals and salts to influence the product distribution of similar uncontrolled condensation reactions . Minerals and other solid substrates have been studied extensively for their ability to concentrate amino acids on their surface, catalyse aqueous peptide polymerisation, and enrich depsipeptides for peptide bonds . Products were characterised in a functional assay and by mass spectrometry at the end of each reaction cycle (Figure ).…”

Emergence of Function and Selection from Recursively Programmed Polymerisation Reactions in Mineral Environments

“…[18] Minerals and other solid substrates have been studied extensively for their ability to concentrate amino acids on their surface,c atalyse aqueous peptide polymerisation, [19,20] and enrich depsipeptides for peptide bonds. [21] Products were characterised in afunctional assay and by mass spectrometry at the end of each reaction cycle ( Figure 1). Because of the vast number of potential products,a ne xtensive mass library of over 19 000 linear, cyclic, and branched singly charged species,each corresponding to aunique depsipeptide composition of up to eight-unit length, was used to screen the mass spectrometry data.…”

A Constructive Way to Think about Different Hydrothermal Environments for the Origins of Life

“…Hydrothermal environments, both submarine and on dry land, are very appealing to the study of the emergence of life. Geyser systems exhibit wet-dry cycling that is arguably the best method for forming biopolymers before life could do it on its own [5,9,10]. It is a classic idea related to Darwin's conjecture and ideas like the primordial soup [2].…”

“…Since then, Darwin's prescient guess has become synonymous with desert ponds and hydrothermal fields on dry land, and many dry land-based pooling systems have been proposed [3][4][5][7][8][9][10][11]. For this modern idea, fresh water accumulated in hydrothermal fields, that underwent In this brief commentary, we wish to lay out the following understanding: hydrothermal environments are energetically robust locations for the origins and early evolution of life as we know it.…”

“…Products would accumulate in pools when it rained or rehydrated otherwise [5,11]. This wet-dry cycling is one of the most effective methods of polymerizing simple bio-monomers into biopolymers on a lifeless planet [3][4][5]9,10]. These environments would have inputs of water, elements associated with life, and wet-dry cycling; therefore, they should not be rejected from the study of life's emergence.…”