TY - JOUR
T1 - Quantifying the extent of amide and peptide bond synthesis across conditions relevant to geologic and planetary environments
AU - Robinson, Kirtland J.
AU - Bockisch, Christiana
AU - Gould, Ian R.
AU - Liao, Yiju
AU - Yang, Ziming
AU - Glein, Christopher R.
AU - Shaver, Garrett D.
AU - Hartnett, Hilairy E.
AU - Williams, Lynda B.
AU - Shock, Everett L.
N1 - Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/5/1
Y1 - 2021/5/1
N2 - Amide bonds are fundamental products in biochemistry, forming peptides critical to protein formation, but amide bonds are also detected in sterile environments and abiotic synthesis experiments. The abiotic formation of amide bonds may represent a prerequisite to the origin of life. Here we report thermodynamic models that predict optimal conditions for amide bond synthesis across geologically relevant ranges of temperature, pressure, and pH. We modeled acetamide formation from acetic acid and ammonia as a simple analog to peptide bond formation, and tested this model with hydrothermal experiments examining analogous reactions of amides including benzanilide and related structures. We also expanded predictions for optimizing diglycine formation, revealing that in addition to synthesis becoming more favorable at near-ambient pressures (Psat) with increasing temperatures, the strongest thermodynamic drive exists at extremely high pressures (>15,000 bar) and decreasing temperatures. Beyond implications for life's origins, the reactants and products involved in simple amide formation reactions can potentially be used as geochemical tracers for planetary exploration of environments that may be habitable.
AB - Amide bonds are fundamental products in biochemistry, forming peptides critical to protein formation, but amide bonds are also detected in sterile environments and abiotic synthesis experiments. The abiotic formation of amide bonds may represent a prerequisite to the origin of life. Here we report thermodynamic models that predict optimal conditions for amide bond synthesis across geologically relevant ranges of temperature, pressure, and pH. We modeled acetamide formation from acetic acid and ammonia as a simple analog to peptide bond formation, and tested this model with hydrothermal experiments examining analogous reactions of amides including benzanilide and related structures. We also expanded predictions for optimizing diglycine formation, revealing that in addition to synthesis becoming more favorable at near-ambient pressures (Psat) with increasing temperatures, the strongest thermodynamic drive exists at extremely high pressures (>15,000 bar) and decreasing temperatures. Beyond implications for life's origins, the reactants and products involved in simple amide formation reactions can potentially be used as geochemical tracers for planetary exploration of environments that may be habitable.
KW - Enceladus
KW - Hydrothermal experiments
KW - Ocean worlds
KW - Origin of life
KW - Prebiotic
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U2 - 10.1016/j.gca.2021.01.038
DO - 10.1016/j.gca.2021.01.038
M3 - Article
AN - SCOPUS:85101886113
SN - 0016-7037
VL - 300
SP - 318
EP - 332
JO - Geochimica et Cosmochimica Acta
JF - Geochimica et Cosmochimica Acta
ER -