Structural Stability in Dimer and Tetramer Clusters of l-Alanine in the Gas Phase and the Feasibility of Peptide Bond Formation

E. J. Padma Malar, P. Divya
  • The Journal of Physical Chemistry, June 2018, American Chemical Society (ACS)
  • DOI: 10.1021/acs.jpcb.8b01629

Understanding the feasibility of peptide formation in prebiotic conditions

What is it about?

To understand the feasibility of peptide formation from amino acid aggregates in prebiotic conditions, stability in the dimer and tetramer clusters of l-Alanine in the gas-phase was studied by accurate quantum chemical methods. The different low-energy structures were examined by structural optimization. Analysis of bonding in the tetramer shows that the low-energy tetramer and higher clusters are formed through the OH···NH mode of hydrogen bonding, unlike the dimer which is formed through the OH···OC bond. Feasibility of the amino acid cluster to function as a precursor for polypeptide formation in the prebiotic period is examined because the orientation of the OH···NH mode of hydrogen bonding is suitable for chemical condensation. The propensity of forming coiled structures in higher clusters and thus in the polypeptides is examined based on the conformational stability in the tetramer of alanine.

Why is it important?

It is of considerable interest to examine the feasibility of elongated peptide formation directly from the larger clusters in the gas phase, in order to understand their role in prebiotic chemistry.


E.J. Padma Malar
University of Madras

The study reveals that the larger amino acid clusters are stable primarily due to the strong OH...NH hydrogen bonds between the adjacent amino acids. The orientation of OH...NH hydrogen bonds are favorable for chemical condensation leading to peptide bonds.

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The following have contributed to this page: E.J. Padma Malar