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Polymer Amide as an Early Topology

Hydrophobic polymer amide (HPA) could have been one of the first normal density materials to accrete in space. We present ab initio calculations of the energetics of amino acid polymerization via gas phase collisions. The initial hydrogen-bonded di-peptide is sufficiently stable to proceed in many c...

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Detalles Bibliográficos
Autores principales: McGeoch, Julie E. M., McGeoch, Malcolm W.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4105422/
https://www.ncbi.nlm.nih.gov/pubmed/25048204
http://dx.doi.org/10.1371/journal.pone.0103036
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author McGeoch, Julie E. M.
McGeoch, Malcolm W.
author_facet McGeoch, Julie E. M.
McGeoch, Malcolm W.
author_sort McGeoch, Julie E. M.
collection PubMed
description Hydrophobic polymer amide (HPA) could have been one of the first normal density materials to accrete in space. We present ab initio calculations of the energetics of amino acid polymerization via gas phase collisions. The initial hydrogen-bonded di-peptide is sufficiently stable to proceed in many cases via a transition state into a di-peptide with an associated bound water molecule of condensation. The energetics of polymerization are only favorable when the water remains bound. Further polymerization leads to a hydrophobic surface that is phase-separated from, but hydrogen bonded to, a small bulk water complex. The kinetics of the collision and subsequent polymerization are discussed for the low-density conditions of a molecular cloud. This polymer in the gas phase has the properties to make a topology, viz. hydrophobicity allowing phase separation from bulk water, capability to withstand large temperature ranges, versatility of form and charge separation. Its flexible tetrahedral carbon atoms that alternate with more rigid amide groups allow it to deform and reform in hazardous conditions and its density of hydrogen bonds provides adhesion that would support accretion to it of silicon and metal elements to form a stellar dust material.
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spelling pubmed-41054222014-07-23 Polymer Amide as an Early Topology McGeoch, Julie E. M. McGeoch, Malcolm W. PLoS One Research Article Hydrophobic polymer amide (HPA) could have been one of the first normal density materials to accrete in space. We present ab initio calculations of the energetics of amino acid polymerization via gas phase collisions. The initial hydrogen-bonded di-peptide is sufficiently stable to proceed in many cases via a transition state into a di-peptide with an associated bound water molecule of condensation. The energetics of polymerization are only favorable when the water remains bound. Further polymerization leads to a hydrophobic surface that is phase-separated from, but hydrogen bonded to, a small bulk water complex. The kinetics of the collision and subsequent polymerization are discussed for the low-density conditions of a molecular cloud. This polymer in the gas phase has the properties to make a topology, viz. hydrophobicity allowing phase separation from bulk water, capability to withstand large temperature ranges, versatility of form and charge separation. Its flexible tetrahedral carbon atoms that alternate with more rigid amide groups allow it to deform and reform in hazardous conditions and its density of hydrogen bonds provides adhesion that would support accretion to it of silicon and metal elements to form a stellar dust material. Public Library of Science 2014-07-21 /pmc/articles/PMC4105422/ /pubmed/25048204 http://dx.doi.org/10.1371/journal.pone.0103036 Text en © 2014 McGeoch, McGeoch http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
McGeoch, Julie E. M.
McGeoch, Malcolm W.
Polymer Amide as an Early Topology
title Polymer Amide as an Early Topology
title_full Polymer Amide as an Early Topology
title_fullStr Polymer Amide as an Early Topology
title_full_unstemmed Polymer Amide as an Early Topology
title_short Polymer Amide as an Early Topology
title_sort polymer amide as an early topology
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4105422/
https://www.ncbi.nlm.nih.gov/pubmed/25048204
http://dx.doi.org/10.1371/journal.pone.0103036
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