A 4641Da Polymer of Amino Acids in Acfer 086 And Allende Meteorites

A specific 4641Da amino acid polymer entity is present in two CV3 meteorites Acfer 086 and Allende, together with its breakdown polymer fragments of mass < 2000Da. Previously in Allende and Murchison meteorites we had detected polymer amide of mass < 2000Da using a new method based on Folch extraction of micron meteoritic particles with hydrophilic and hydrophobic phases. Low temperature extraction kept polymer amide intact whereas previous methods had resulted in degradation via boiling the samples. Acfer 086 and Allende polymer amide composition was predominantly glycine with partial content of hydroxy-glycine and alanine. Detection was via matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI/TOF/MS). Amino acid analysis showed that the amino acids present were almost entirely bound in polymers prior to acid hydrolysis. Fragment analysis provided a possible subunit structure for the 4641 species. In the Allende polymer fragment data heavy isotope satellite enhancement confirmed an extraterrestrial origin that could be in the interstellar medium or the protoplanetary disc. The dominance of 4641Da polymer amide suggested a replication or concentration mechanism. Analysis of the infrared modes of a proposed structure showed a peak in collective mode intensity at 20 residue length, giving a possible explanation in terms of optimized energy absorption for the dominance of this size of linear glycine-based structure. Julie E. M. McGeoch, Malcolm W. McGeoch
(Submitted on 28 Jul 2017)

Comments: 40 pages, 12 Tables, 13 Figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1707.09080 [astro-ph.EP] (or arXiv:1707.09080v1 [astro-ph.EP] for this version)
Submission history
From: Julie McGeoch
[v1] Fri, 28 Jul 2017 00:37:10 GMT (7662kb)
https://arxiv.org/abs/1707.09080
Astrobiology