Prebiotic Evolution of Amino Acids and Peptides

Recent research on the prebiotic formation of precursor molecules of biomolecules relevant for the origin of life on earth has revealed that amino acids and their polymers, i.e. peptides and proteins, have probably played the primary role in the beginning of chemical evolution on the primordial earth. Based on previous work by the applicant the present project aims at a detailed investigation of the 2 main steps of peptide evolution, the production of amino acids from atmospheric compounds under various conditions, and the formation of their polymers under the environmental conditions assumed for the primitive earth on the basis of recent geochemical research. First experiments of the applicant have proven that amino acids can be produced by electrical discharges from a neutral atmosphere consisting of nitrogen, carbon dioxide and water vapour, which is the composition generally assumed nowadays for the secondary earth atmosphere 4 billion years ago. In a series of experiments, the composition of this atmosphere will be varied, including also other compounds assumed to have been present, in particular suphur dioxide, and the aqueous phase under this atmosphere, mimicking the primordial sea, will also be varied with respect to its content of inorganic conpounds such as salts and minerals. Further, the possible formation of precursor molecules for proteins under different atmospheric conditions, e.g. nitrogen-methane atmosphere over ice as found on Titan under electric discharges will be investigated. The analysis of amino acids thus formed under varying conditions should deliver conclusive data, which `spectrum` of amino acids could be expected as the foundation of chemical evolution of an emerging `amino acid world`, either under terrestric or extraterrestric conditions. Following up the numerous aspects of the Salt-Induced Peptide Formation (SIPF) reaction and recent discoveries related to this reaction providing the most plausible way for prebiotic peptide evolution, the possible role of this reaction in the origin of bio-homochirality and the catalytic influence of some prebiotically available compounds on peptide formation will be another focus of the investigations in this project. The stability of formed peptides under various environmental conditions such as temperature and the presence of inorganic materials, in particular of clay minerals, will be studied to evaluate the sustainability of the evolutionary processes and mechanisms of chain elongation leading to higher polymers. Finally, quantum mechanical calculations at ab initio level will be employed to study the relative stability of fragment structures in the gas phase and of the Cu(II) complexes central to the peptide formation in the SIPF reaction.

Recent research on the prebiotic formation of precursor molecules of biomolecules relevant for the origin of life on earth has revealed that amino acids and their polymers, i.e. peptides and proteins, have probably played the primary role in the beginning of chemical evolution on the primordial earth. Based on previous work by the applicant the present project aims at a detailed investigation of the 2 main steps of peptide evolution, the production of amino acids from atmospheric compounds under various conditions, and the formation of their polymers under the environmental conditions assumed for the primitive earth on the basis of recent geochemical research. First experiments of the applicant have proven that amino acids can be produced by electrical discharges from a neutral atmosphere consisting of nitrogen, carbon dioxide and water vapour, which is the composition generally assumed nowadays for the secondary earth atmosphere 4 billion years ago. In a series of experiments, the composition of this atmosphere will be varied, including also other compounds assumed to have been present, in particular suphur dioxide, and the aqueous phase under this atmosphere, mimicking the primordial sea, will also be varied with respect to its content of inorganic conpounds such as salts and minerals. Further, the possible formation of precursor molecules for proteins under different atmospheric conditions, e.g. nitrogen-methane atmosphere over ice as found on Titan under electric discharges will be investigated. The analysis of amino acids thus formed under varying conditions should deliver conclusive data, which `spectrum` of amino acids could be expected as the foundation of chemical evolution of an emerging `amino acid world`, either under terrestric or extraterrestric conditions. Following up the numerous aspects of the Salt-Induced Peptide Formation (SIPF) reaction and recent discoveries related to this reaction providing the most plausible way for prebiotic peptide evolution, the possible role of this reaction in the origin of bio-homochirality and the catalytic influence of some prebiotically available compounds on peptide formation will be another focus of the investigations in this project. The stability of formed peptides under various environmental conditions such as temperature and the presence of inorganic materials, in particular of clay minerals, will be studied to evaluate the sustainability of the evolutionary processes and mechanisms of chain elongation leading to higher polymers. Finally, quantum mechanical calculations at ab initio level will be employed to study the relative stability of fragment structures in the gas phase and of the Cu(II) complexes central to the peptide formation in the SIPF reaction.