Iron-mediated peptide formation in water and liquid sulfur dioxide under early Earth conditions

20 May 2022, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

Peptides have essential structural and catalytic functions in living organisms. The formation of peptides requires the overcoming of thermodynamic and kinetic barriers. In recent years, various formation scenarios that may have occurred during the origin of life have been investigated, including iron(III)-catalyzed condensations. However, iron(III) catalysts require harsh conditions and the catalytic activity in peptide bond forming reactions is low. It is likely that in an anoxic environment such as that of the early Earth, reduced iron compounds were abundant, both on the Earth's surface itself and as a major component of iron meteorites. Here we show, that reduced iron activated by acetic acid mediates efficiently peptide formation. We observed, both in water and liquid sulfur dioxide, up to four amino acid/ peptide coupling steps and the formation of up to decamers. In 21 days 4.1% triglycine G3 and 11.3% tetraglycine G4 were formed. Addition of G3 and dialanine A2 yielded 26.0% G4. Therefore, this is a highly efficient and plausible route for the formation of the first peptides as simple catalysts for further transformations in such environments.

Keywords

amino acids
iron
origin of life
peptides
prebiotic chemistry

Supplementary materials

Title
Description
Actions
Title
Supplementary Information to Iron-mediated peptide formation in water and liquid sulfur dioxide under early Earth conditions
Description
Experimental details, CE-MS, MS, MS/MS analysis
Actions

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.