Photochemically Driven Peptide Formation in Supersaturated Aerosol Droplets.

Autor: Logozzo A; Department of Chemistry, McGill University, Montreal, Quebec, Canada., Vennes B; Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec, Canada., Kaur Kohli R; Department of Chemistry, University of California Riverside, Riverside, California, United States., Davies JF; Department of Chemistry, University of California Riverside, Riverside, California, United States., Castillo-Pazos DJ; Department of Chemistry, McGill University, Montreal, Quebec, Canada., Li CJ; Department of Chemistry, McGill University, Montreal, Quebec, Canada., Neish CD; Department of Earth Sciences, The University of Western Ontario, London, Ontario, Canada., Preston TC; Department of Chemistry, McGill University, Montreal, Quebec, Canada.; Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec, Canada.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2024 Sep 23; Vol. 63 (39), pp. e202409788. Date of Electronic Publication: 2024 Aug 23.
DOI: 10.1002/anie.202409788
Abstrakt: The condensation of amino acids into peptides plays a crucial role in protein synthesis and is thus essential for understanding the origins of life. However, the spontaneous formation of peptides from amino acids in bulk aqueous media is energetically unfavorable, posing a challenge for elucidating plausible abiotic mechanisms. In this study, we investigate the formation of amide bonds between amino acids within highly supersaturated aerosol droplets containing dicyandiamide (DCD), a cyanide derivative potentially present on primordial Earth. Metastable states, i.e. supersaturation, within individual micron-sized droplets are studied using both an optical trap and a linear quadrupole electrodynamic balance. When irradiated with intense visible light, amide bond formation is observed to occur and can be monitored using vibrational bands in Raman spectra. The reaction rate is found to be strongly influenced by droplet size and kinetic modelling suggests that it is driven by the photochemical product of a DCD self-reaction. Our results highlight the potential of atmospheric aerosol particles as reaction environments for peptide synthesis and have potential implications for the prebiotic chemistry of early Earth.
(© 2024 The Author(s). Angewandte Chemie International Edition published by Wiley-VCH GmbH.)
Databáze: MEDLINE
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