Insights into the Behaviour of Biomolecules on the Early Earth: The Concentration of Aspartate by Layered Double Hydroxide Minerals

Grégoire, Brian; Erastova, Valentina; Geatches, Dawn L.; Clark, Stewart J.; Greenwell, H. Christopher; Fraser, Donald G.

Abstract

The role of mineral surfaces in concentrating and facilitating the polymerisation of simple protobiomolecules during the Hadean and Archean has been the subject of much research in order to constrain the conditions that may have led to the origin of life on early Earth. Here we examine the adsorption of the amino acid aspartate on layered double hydroxide minerals, and use a combined computer simulation – experimental spectroscopy approach to gain insight into the resulting structures of the host-aspartate material. We show that the uptake of aspartate occurs in alkaline solution by anion exchange of the dianion form of aspartate, rather than by surface adsorption. Anion exchange only occurs at values of pH where a significant population of aspartate has the amino group deprotonated, and is then highly efficient up to the mineral anion exchange capacity.

Citation

Grégoire, B., Erastova, V., Geatches, D. L., Clark, S. J., Greenwell, H. C., & Fraser, D. G. (2016). Insights into the Behaviour of Biomolecules on the Early Earth: The Concentration of Aspartate by Layered Double Hydroxide Minerals. Geochimica et Cosmochimica Acta, 176, 239-258. https://doi.org/10.1016/j.gca.2015.12.026

• Journal Article Type: Article
• Acceptance Date: Dec 22, 2015
• Online Publication Date: Dec 28, 2015
• Publication Date: Mar 1, 2016
• Deposit Date: Jan 9, 2016
• Publicly Available Date: Feb 24, 2017
• Journal: Geochimica et Cosmochimica Acta
• Print ISSN: 0016-7037
• Electronic ISSN: 1872-9533
• Publisher: Meteoritical Society
• Peer Reviewed: Peer Reviewed
• Volume: 176
• Pages: 239-258
• DOI: https://doi.org/10.1016/j.gca.2015.12.026
• Public URL: https://durham-repository.worktribe.com/output/1392185