Publication of the LGL-TPE in the Journal of Physical Chemistry A on January 11, 2023. Press realease of the Claude Bernard Lyon 1 University on February 10, 2023.
A team of Lyon-based scientists from the Institute of Physics of the 2 Infinities (IP2I - Claude Bernard Lyon 1 University /CNRS) and the Laboratory of Geology of Lyon: Earth, Planets, Environment (LGL-TPE - Claude Bernard Lyon 1 University/CNRS/ENS de Lyon), together with a team from the Grenoble Interdisciplinary Laboratory of Physics (LIPhy - Grenoble Alpes University/CNRS), discovered a new abiotic pathway for the formation of peptide chains from amino acids - a key chemical step in the origin of life - with scientists from the Innsbruck University in Austria. The study, published in the Journal of Physical Chemistry A, provided strong evidence that this crucial step for the emergence of life can indeed occur even in the very inhospitable conditions of space.
Peptide chain formation from amino acids such as glycine is a key step in the emergence of life. Unlike their synthesis by living systems, how peptide chains grow under abiotic conditions is an open question given the variety of organic compounds discovered in various astrophysical environments, comets and meteorites. We propose a new abiotic route in the presence of protonated molecular dimers of glycine in a cold gaseous atmosphere without further need for a solid catalytic substrate. The results provide evidence for the preferential formation of mixed protonated dimers of glycine consisting of a dipeptide and a glycine molecule instead of pure protonated glycine dimers. Additional measurements mimicking a cosmic-ray impact in terms of internal excitation show that a single gas-phase collision induces polymerization via dehydration in both the mixed and pure dimer ions. Peptide chain growth is thus demonstrated to occur via a unimolecular gas-phase reaction in an excited cluster ion.
Reference : Glycine Peptide Chain Formation in the Gas Phase via Unimolecular Reactions . Denis Comte, Léo Lavy, Paul Bertier, Florent Calvo, Isabelle Daniel, Bernadette Farizon, Michel Farizon and Tilmann D. Märk. DOI : doi.org/10.1021/acs.jpca.2c08248