Polypeptide formation in clusters of \u03b2-alanine amino acids by single ion impact

Patrick Rousseau,Michael Capron,Manuel Alcamí,Alicja Domaracka,Fernando Martín,Bernd A Huber,Dariusz G Piekarski,Sergio Díaz-Tendero,Lamri Adoui

doi:10.1038/s41467-020-17653-z

Abstract

The formation of peptide bonds by energetic processing of amino acids is an important step towards the formation of biologically relevant molecules. As amino acids are present in space, scenarios have been developed to identify the roots of life on Earth, either by processes occurring in outer space or on Earth itself. We study the formation of peptide bonds in single collisions of low-energy He2+ ions (α-particles) with loosely bound clusters of β-alanine molecules at impact energies typical for solar wind. Experimental fragmentation mass spectra produced by collisions are compared with results of molecular dynamics simulations and an exhaustive exploration of potential energy surfaces. We show that peptide bonds are efficiently formed by water molecule emission, leading to the formation of up to tetrapeptide. The present results show that a plausible route to polypeptides formation in space is the collision of energetic ions with small clusters of amino acids.

Highlights

The formation of peptide bonds by energetic processing of amino acids is an important step towards the formation of biologically relevant molecules
A number of scenarios towards abiotic peptide synthesis focuses on the idea that simple amino acids came down on Earth or exoplanets from outer space[4]
Our work aims to answer a more general and comprehensive question: are there direct gas-phase routes from neutral, cold gasphase ensembles of amino acids toward formation of polypeptides? Recently, several theoretical and experimental studies have been performed in order to answer this question

Summary

Introduction

The formation of peptide bonds by energetic processing of amino acids is an important step towards the formation of biologically relevant molecules. The observed protonation is in very good agreement with the results obtained in the molecular dynamics (MD) calculations, which have been performed using the density functional theory (DFT-based MD) for different cluster sizes, charges, and internal energies (see details in the Supplementary Information).

Results

Conclusion