title: Polymer amide as an early topology.
abstract: 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.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: Julie E M
authors.initials: JE
authors.lastname: McGeoch
authors.affiliation: PLEX LLC, Fall River, Massachusetts, United States of America.
authors.forename: Malcolm W
authors.initials: MW
authors.lastname: McGeoch
mesh_terms: D000577:Amides; D000596:Amino Acids; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D011108:Polymers
chemical_list: D000577:Amides; D000596:Amino Acids; D011108:Polymers