Quantum chemical studies of a model for peptide bond formation: formation of formamide and water from ammonia and formic acid

1982 ◽  
Vol 104 (23) ◽  
pp. 6169-6174 ◽  
Author(s):  
Tetsuro Oie ◽  
Gilda H. Loew ◽  
Stanley K. Burt ◽  
J. Stephen Binkley ◽  
Robert D. MacElroy
Keyword(s):  
Formic Acid ◽  
Quantum Chemical ◽  
Bond Formation ◽  
Peptide Bond ◽  
Peptide Bond Formation ◽  
Chemical Studies ◽  
Quantum Chemical Studies

scholarly journals Prebiotic Peptide Bond Formation Through Amino Acid Phosphorylation. Insights from Quantum Chemical Simulations

Life ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 75 ◽  
Author(s):  
Berta Martínez-Bachs ◽  
Albert Rimola
Keyword(s):  
Free Energy ◽  
Quantum Chemical ◽  
Density Functional ◽  
Bond Formation ◽  
Building Blocks ◽  
Peptide Bond ◽  
High Energy ◽  
Free Energy Barrier ◽  
Peptide Bond Formation ◽  
Condensation Reactions

Condensation reactions between biomolecular building blocks are the main synthetic channels to build biopolymers. However, under highly diluted prebiotic conditions, condensations are thermodynamically hampered since they release water. Moreover, these reactions are also kinetically hindered as, in the absence of any catalyst, they present high activation energies. In living organisms, in the formation of peptides by condensation of amino acids, this issue is overcome by the participation of adenosine triphosphate (ATP), in which, previous to the condensation, phosphorylation of one of the reactants is carried out to convert it as an activated intermediate. In this work, we present for the first time results based on density functional theory (DFT) calculations on the peptide bond formation between two glycine (Gly) molecules adopting this phosphorylation-based mechanism considering a prebiotic context. Here, ATP has been modeled by a triphosphate (TP) component, and different scenarios have been considered: (i) gas-phase conditions, (ii) in the presence of a Mg2+ ion available within the layer of clays, and (iii) in the presence of a Mg2+ ion in watery environments. For all of them, the free energy profiles have been fully characterized. Energetics derived from the quantum chemical calculations indicate that none of the processes seem to be feasible in the prebiotic context. In scenarios (i) and (ii), the reactions are inhibited due to unfavorable thermodynamics associated with the formation of high energy intermediates, while in scenario (iii), the reaction is inhibited due to the high free energy barrier associated with the condensation reactions. As a final consideration, the role of clays in this TP-mediated peptide bond formation route is advocated, since the interaction of the phosphorylated intermediate with the internal clay surfaces could well favor the reaction free energies.

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