P053-0008
Exploring potential origins of life on Earth and Mars by determining ribose stability in the presence of borate and borate-bearing clays
Monday, 14 December 2020
Poster
Shelbie Annette Legett1, Chris M Yeager1, Patrick James Gasda1, Matthew Nellessen2, Laura J Crossey2, Eric Peterson3, Nina Lanza1, Adriana Newell1, Dorothea Delapp1, Andrea Labouriau4, Roger C Wiens5, Samuel M Clegg1 and Debarati Das6, (1)Los Alamos National Laboratory, Los Alamos, NM, United States, (2)University of New Mexico Main Campus, Albuquerque, NM, United States, (3)University of New Mexico, Albuquerque, NM, United States, (4)Los Alamoas Natioanl Laboratory, Los Alamos, NM, United States, (5)Space Science and Applications, Los Alamos, NM, United States, (6)McGill University, Montreal, Canada
Abstract:
Ribose, as a prebiotic molecule necessary for RNA development, has been recognized as a likely major player in the origins of life on early Earth. However, because ribose quickly degrades in water, it must be stabilized before it can form the more complex molecules needed for early life. Because ribose complexation with borates has been shown to considerably slow the degradation of ribose in solution as well as promote phosphorylation (needed to create nucleotides for RNA), the presence of borates in prebiotic environments may provide the stability needed for RNA formation [1,2,3]. On early Earth, boron (as a trace element) likely weathered out of major minerals before concentrating and sorbing to available clay minerals in groundwater [3,4,5]; while on Mars, boron was recently found in a similarly clay-rich, lacustrine environment [6]. Because of this, we hypothesize that clays could function as a borate-concentrating scaffold for ribose stabilization and phosphorylation.
The goals of this study are to: 1) define the stability of ribose in solution with borates and Earth- and Mars-relevant, borate-bearing clays under various conditions; 2) analyze the products of ribose-borate-clay reactions; and 3) determine the structure of any clay-sorbed ribose-borate complexes. To reach these goals, we mix ribose with varying concentrations of borate and borate-bearing clays in aqueous solutions containing various dissolved ions at pH 8-10 and temperatures from 25-80°C under air or nitrogen atmospheres. Aliquots of the solutions are taken at various intervals over 24 hours to be analyzed by GC-HRMS, and the final clay products are analyzed via XRD and solid-state, high-resolution magic angle spinning 1H, 13C, and 11B NMR. The results of this study will lead to a better understanding of prebiotic reactions on early Earth and will give us new insight into how to best search for signs of life on Mars with the Perseverance rover and future sample return missions.
[1] Furukawa et al. 2013, Orig. Life Evol. Bio., 43, 353-361. [2] Becker et al. 2019, Science, 366, 76-82. [3] Scorei, 2012, Orig. Life Evol. Bio., 42, 3-17. [4] Pedreira-Segade et al. 2016, Geo. et Cosmo. Acta, 176, 81-95. [5] Morrison et al. 2018, Life, 8, 4, 64. [6] Gasda et al. 2017, Geo. Res. Let., 44, 8739-8748.
