title: Phosphate Activation via Reduced Oxidation State Phosphorus (P). Mild Routes to Condensed-P Energy Currency Molecules.
abstract: The emergence of mechanisms for phosphorylating organic and inorganic molecules is a key step en route to the earliest living systems. At the heart of all contemporary biochemical systems reside reactive phosphorus (P) molecules (such as adenosine triphosphate, ATP) as energy currency molecules to drive endergonic metabolic processes and it has been proposed that a predecessor of such molecules could have been pyrophosphate [P2O74-; PPi(V)]. Arguably the most geologically plausible route to PPi(V) is dehydration of orthophosphate, Pi(V), normally a highly endergonic process in the absence of mechanisms for activating Pi(V). One possible solution to this problem recognizes the presence of reactive-P containing mineral phases, such as schreibersite [(Fe,Ni)3P] within meteorites whose abundance on the early Earth would likely have been significant during a putative Hadean-Archean heavy bombardment. Here, we propose that the reduced oxidation state P-oxyacid, H-phosphite [HPO32-; Pi(III)] could have activated Pi(V) towards condensation via the intermediacy of the condensed oxyacid pyrophosphite [H2P2O52-; PPi(III)]. We provide geologically plausible provenance for PPi(III) along with evidence of its ability to activate Pi(V) towards PPi(V) formation under mild conditions (80 °C) in water.
authors.affiliation: School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK. t.p.kee@leeds.ac.uk.
authors.forename: Terence P
authors.initials: TP
authors.lastname: Kee
authors.affiliation: School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK. d.e.bryant@leeds.ac.uk.
authors.forename: David E
authors.initials: DE
authors.lastname: Bryant
authors.affiliation: School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK. b.herschy@ucl.ac.uk.
authors.forename: Barry
authors.initials: B
authors.lastname: Herschy
authors.affiliation: School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK. katie.marriott@glasgow.ac.uk.
authors.forename: Katie E R
authors.initials: KE
authors.lastname: Marriott
authors.affiliation: School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK. n.e.cosgrove@leeds.ac.uk.
authors.forename: Nichola E
authors.initials: NE
authors.lastname: Cosgrove
authors.affiliation: Department of Geology, University of South Florida, 4202 East Fowler Ave., SCA 528, Tampa, FL 33620, USA. mpasek@usf.edu.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Pasek
authors.affiliation: Department of Geology, University of South Florida, 4202 East Fowler Ave., SCA 528, Tampa, FL 33620, USA. zatlas@usf.edu.
authors.forename: Zachary D
authors.initials: ZD
authors.lastname: Atlas
authors.affiliation: Department of Earth and Planetary Science, Birkbeck College, University of London, Gower Street, London, WC1E 6BT, UK. c.cousins@ucl.ac.uk.
authors.forename: Claire R
authors.initials: CR
authors.lastname: Cousins