Did Nature use Reduced Oxidation State Phosphorus in Prebiotic Chemistry? Strengthening the Case for a Non-Phosphate World prior to the RNA-World
Lead Research Organisation:
University of Bradford
Department Name: Faculty of Life Sciences
Abstract
Phosphate is a key ingredient in all life on Earth. Phosphate is everywhere on Earth, we dig it out of the ground as a calcium salt, we use it to brush our teeth, we consume it in food and drink every day. However, despite it being a rather common chemical, it is by no means certain that Nature chose phosphate for the earliest forms of life on Earth. A large part of the problem is that phosphate chemicals are both extremely insoluble and very unreactive chemically. In 1955, the scientist Addison Gulick proposed that this phosphate problem could have been solved if other forms of phosphorus were available on the early Earth. These chemicals, called phosphonates and phosphinates, are close relatives of phosphate but are both more soluble and chemically reactive in water. The problem is that phosphonates and phosphinates are unknown on Earth today because over the millennia, the chemical environment of Earth has changed to such a degree that only phosphates are now stable. However, we have recently discovered that phosphinates and phosphonates could have been readily available to prebiotic chemistry on the early Earth through chemical reactions of iron-rich meteorites with water in the presence of light. This discovery allows us to explore in detail the potential of phosphonates and phosphinates in the origin-of-life problem for the first time with a degree of confidence that such chemistry could have been available on the early Earth.This project is built in two parts. In Part 1 we will look in detail at how exactly phosphonates and phosphinates were formed from the chemical modification of actual meteorite fragments. In Part 2, we explore potential chemical reactions which could have taken place on an early Earth with these two phosphorus species and which could have an impact in how some key biological molecules, such as prebiotic organic phosphorus polymers, might have emerged.
Publications
Bryant D
(2013)
Hydrothermal modification of the Sikhote-Alin iron meteorite under low pH geothermal environments. A plausibly prebiotic route to activated phosphorus on the early Earth
in Geochimica et Cosmochimica Acta
Carter EA
(2010)
A Raman spectroscopic study of a fulgurite.
in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
Dartnell LR
(2012)
Destruction of Raman biosignatures by ionising radiation and the implications for life detection on Mars.
in Analytical and bioanalytical chemistry
Edwards H
(2011)
Development of oxidative sample preparation for the analysis of forensic soil samples with near-IR Raman spectroscopy
in Journal of Raman Spectroscopy
Edwards HG
(2011)
Raman spectra of biomarkers of relevance to analytical astrobiological exploration: hopanoids, sterols and steranes.
in Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy
| Description | The impact of meteorites on the early earth may have had a crucial influence on the emergence of life. Aside from the potential of extraterrestrial organic species, meteorites infalls are likely to have provided crucial elements in the correct form for subsequent preparation for molecules of life. Of these, how phosphorus became the primary element of the backbone of nucleic acids including DNA and RNA, the molecules encoding life, remains a mystery. These studies have established mechanisms to show meteorites bearing a mineral called Schreibersite, which may have provided phosphorus in the right form to generate molecules that serve as precursors to nucleic acid systems and provide pre-biotic chemical reactions to couple amino acids and hence potentially from primitive proteins. The mechanisms involve two key steps: (i) the corrosion of the Schreibersite bearing meteorite. It appears that this process is driven by the electrochemistry of the meteorite themselves, with a corrosion process that literally unlocks the Schreibersite from the meteorite body (ii) the production of phosphorus species from Fe3P like Schreibersite that have been shown to have the ability to couple amino acids, the first step towards primitive proteins. |
| Exploitation Route | This work will be of interest not only to members of the scientific community but also to the general public. Much has been published on the origin and role of prebiotic chemicals but until recently discussion of phosphorus has been limited to orthophosphate and sources thereof. We envisage this work to provide a step-change in thinking about pre-RNA & prebiotic worlds. Analytical measurements arising from the projects will contribute fundamentally to the wider understanding of the interrelationship between minerals and biologically relevant molecular species and how these interactions may leave 'biomarker' degredant traces. Such information is fundamental to exo-biological prospecting and will underpin new areas of investigation for high-impact projects such as the ESA's ExoMars mission where one of the primary objectives is the 'Search for traces of past and present life' in the Martian environment. In the wider context, progress in in situ analyses and, particularly the development of oxo-phosphorus quantitative models, will contribute to ongoing developments in rapid 'real-time' process information for chemical and pharmaceutical manufacturing industries. |
| Sectors | Agriculture, Food and Drink,Chemicals,Education,Culture, Heritage, Museums and Collections,Pharmaceuticals and Medical Biotechnology |
| Description | This work will be of interest not only to members of the scientific community but also to the general public. Much has been published on the origin and role of prebiotic chemicals but until recently discussion of phosphorus has been limited to orthophosphate and sources thereof. We envisage this work to provide a step-change in thinking about pre-RNA & prebiotic worlds. Analytical measurements arising from the projects will contribute fundamentally to the wider understanding of the interrelationship between minerals and biologically relevant molecular species and how these interactions may leave 'biomarker' degredant traces. Such information is fundamental to exo-biological prospecting and will underpin new areas of investigation for high-impact projects such as the ESA's ExoMars mission where one of the primary objectives is the 'Search for traces of past and present life' in the Martian environment. In the wider context, progress in in situ analyses and, particularly the development of oxo-phosphorus quantitative models, will contribute to ongoing developments in rapid 'real-time' process information for chemical and pharmaceutical manufacturing industries. |
| First Year Of Impact | 2012 |
| Sector | Chemicals,Education,Culture, Heritage, Museums and Collections,Pharmaceuticals and Medical Biotechnology |
| Impact Types | Cultural,Societal |