Chemical evolution of biomolecule building blocks. Can thermodynamics explain the accumulation of glycine in the prebiotic ocean?

TitleChemical evolution of biomolecule building blocks. Can thermodynamics explain the accumulation of glycine in the prebiotic ocean?
Publication TypeJournal Article
Year of Publication2011
AuthorsSzori M, Jojart B, Izsak R, Szori K, Csizmadia IG, Viskolcz B
JournalPhysical Chemistry Chemical Physics
Volume13
Pagination7449-7458
Date PublishedMAR 22
ISSN1463-9076
Abstract

It has always been a question of considerable scientific interest why amino acids (and other biomolecule building blocks) formed and accumulated in the prebiotic ocean. In this study, we suggest an answer to this question for the simplest amino acid, glycine. We have shown for the first time that classical equilibrium thermodynamics can explain the most likely selection of glycine (and the derivative of its dipeptide) in aqueous media, although glycine is not the lowest free energy structure among all (404) possible constitutional isomers. Species preceding glycine in the free energy order are either supramolecular complexes of small molecules or such molecules likely to dissociate and thus get back to the gas phase. Then, 2-hydroxyacetamide condensates yielding a thermodynamically favored derivative of glycine dipeptide providing an alternative way for peptide formation. It is remarkable that a simple equilibrium thermodynamic model can explain the accumulation of glycine and provide a reason for the importance of water in the formation process.

DOI10.1039/c0cp02687e