Which Amino Acids Should Be Used in Prebiotic Chemistry Studies?

Abstract

The adsorption of amino acids on minerals and their condensation under conditions that resemble those of prebiotic earth is a well studied subject. However, which amino acids should be used in these experiments is still an open question. The main goal of this review is to attempt to answer this question. There were two sources of amino acids for the prebiotic earth: (1) exogenous -- meaning that the amino acids were synthesized outside the earth and delivered to our planet by interplanetary dust particles (IDPs), meteorites, comets, etc. and (2) endogenous -- meaning that they were synthesized on earth in atmospheric mixtures, hydrothermal vents, etc. For prebiotic chemistry studies, the use of a mixture of amino acids from both endogenous and exogenous sources is suggested. The exogenous contribution of amino acids to this mixture is very different from the average composition of proteins, and contains several non-protein amino acids. On the other hand, the mixture of amino acids from endogenous sources is seems to more closely resemble the amino acid composition of terrestrial proteins.

Concentration of Specific Amino Acids at the Catalytic/Active Centers of Highly-Conserved “Housekeeping” Enzymes of Central Metabolism in Archaea, Bacteria and Eukaryota: Is There a Widely Conserved Chemical Signal of Prebiotic Assembly?

“…We have added our occupancy data and rearranged their table. Our Supplementary File SF-2 (<http:// www.stat.osu.edu/~dkp/ppp/>) compares our data to amino acid abundance-ranking in laboratory syntheses (e.g., Miller 1987), presence in meteorite(s) (Brack 2007), temporal order of appearance (Trifonov 2000(Trifonov , 2004 and literature emphasizing the probable appearance and putative role of these amino acids (Brooks et al 2002, Brooks and Fresco 2003, Lazcano 2006, Zaia et al 2008. Several amino acids newly detected by liquid or gas chromatography-mass spectroscopy in preserved residues of S. Miller's experiments (Johnson et al 2008) and amino acid enantiomers in the Murchison meteorite (Cronin and Pizzarello 1997) were not included in our Supplementary File SF-2.…”

The tautomerization of H2NCH2C(OH)NH to H2NCH2CONH2 in the interstellar medium

“…Considering the huge mass of the Earth by its diameter of 12800 km, it might have the necessary compositions for the origin of amino acids and life. When environments on the early Earth became friendly, such as suitable temperatures and H 2 O sea available, it would start the origin of amino acids and life with Earth's already existing chemical compositions and the newly formed (or transported) ones [77,78].…”

Frozen Accident Pushing 50: Stereochemistry, Expansion and Chance in the Evolution of the Genetic Code

“…Ten amino acids have been consistently identified in prebiotic chemistry experiments as well as in in meteorites, in the following order of abundance: Gly, Ala, Asp, Glu, Val, Ser, Ile, Leu, Pro, Thr [69,70] [71,72]. Notably, the recent, perhaps most promising at this time prebiotic chemistry experiments, based on hydrogen cyanide photochemistry, that yield precursors of ribonucleotides and amino acids, also primarily produce amino acid from the above list, namely, Gly, Ala, Ser, and Thr [73,74] The ranks of amino acids in the 'early' list positively and significantly correlate with the free energy of their synthesis: the amino acids that are on top of the list are the "cheapest" energetically [75].…”