PhosphorusChemistryintheOriginofLIfe

Ma7hewPasekAssistantProfessor

UniversityofSouthFlorida

TerryKeeUniversityofLeeds

DNA

WhyP?

•  Charged•  Capableofformingtwobridges

•  Achiral•  StableofrangeofredoxcondiHons

Phosphorus&Biochemistry

Metabolic molecules (ATP)

Structure(phospholipids)

Limiting reagent for life!

PhosphorusMineralogy

•  PhosphorusissynonymouswithPhosphates

•  ApaHte‐Ca5(PO4)3X

•  OxidaHonstateP5+•  Insoluble,inert•  ThisdominatesEarth’ssurfaceandmantle

PhosphorylaHon

www.wrightsrockshop.com

www.wtsmith.com

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TheEarlyEarth

Caveatswithminerals

•  MineralshaveevolvedoverHmeasearthenvironmenthaschanged(Hazenetal.2008)

?

Name Formula

Beusite (Mn2+,Fe2+,Ca,Mg)3(PO4)2

Childrenite Fe2+AlPO4(OH)2·H2O

Chlorapatite Ca5(PO4)3Cl

Farringtonite Mg3(PO4)2

Fluorapatite Ca5(PO4)3F

Galileiite Na(Fe2+,Mn2+)4(PO4)3

Graftonite (Fe2+,Mn2+,Ca)3(PO4)2

Hydroxylapatite Ca5(PO4)3OH

Johnsomervilleite Na2Ca(Fe2+,Mg,Mn2+)7(PO4)6

Merrillite Ca9NaMg(PO4)7

Monazite-Ce (Ce,La,Nd,Th)PO4

Sarcopside (Fe2+,Mn2+,Mg)3(PO4)2

Stanfieldite Ca4Mg5(PO4)6

Triplite (Mn2+,Fe2+)2PO4(F,OH)

Wagnerite Mg2PO4F

Wavellite Al3(PO4)2(OH)3·5H2O

Whitlockite Ca9Mg(PO4)6(PO3OH)

Name Formula

Chlorapatite Ca5(PO4)3Cl

Fluorapatite Ca5(PO4)3F

Hydroxylapatite Ca5(PO4)3OH

Monazite-Ce (Ce,La,Nd,Th)PO4

Whitlockite Ca9Mg(PO4)6(PO3OH)

ACaseforSchreibersite

•  OriginofphosphorylatedbiomoleculesbestexampleofmineralsinprebioHcchemistry?

•  ReducedP:Fe2NiP•  Fe3P+H2OFe2++H2PO4

‐+H2

Seymchan meteorite (pallasite / IIE)

P 2O64-

P 2O74-

PO43-

HPO32- With CH3COOH

AqueousCorrosionofPhosphidePowder(underAr)

PasekandLaure0a2005

PRedoxstatesandinorganicspecies

PasekandLaure7a,Astrobiology2005

V.

BryantandKee2006Pechetal.2011

VI. Phosphine

PH3

Hypothesis•  PhosphorylaHonontheearlyearthrequiredmeteoriHcphosphorustomakeprebioHcandearlybioHcmaterials– Corrosionofschreibersitegeneratespyrophosphite(Bryantetal.2013)

– PyrophosphiteisaphosphorylaHngagent(Bryantetal.PNASinreview)

– Schreibersiteimportantpartofearlyearth(Paseketal.PNASinreview)

– Schreibersitephosphorylatesorganics(Gulletal.,inprep)

Pyrophosphitefrommeteorites

Corrosionofschreibersiteinhydrothermalsystems

GeneraHonofpyrophosphite

PyrophosphiteinprebioHcchemistry

TransiHonalSpecies

•  Varyingdegreesofstability,andofphosphorylaHngpower

Schreibersiteontheearlyearth

•  Presenceofpyrophosphitedependentofpresenceofphosphiteonearlyearth

•  Wasitthere?

•  Whatwasitsorigin?

DetecHngreducedP

DetecHngreducedP

SearchforreducedPRockLocality RockType Age(Ma)

CoucalFm.,Coonterunah,Australia Limestone(2samplesites)

3,520

“ Hydrothermalchert “

GoldmanMeadowsFm.,SouthPass,Wyoming

BandedIronFormaHon

2,870

CheshireFm.,Belingwe,Zimbabwe Carbonate 2,700

BrockmanIronFm.,HamersleyBasin,Australia

BandedIronFormaHon

2,500

MillboroFm.,CharlesTownWestVirginia,USA

Shale 400‐380

GreenRiverFm.,Kemmerer,Wyoming,USA

Shale 50

AvonParkFm.,CitrusCounty,Florida,USA Limestone 35

•  MagneHte+calcite±dolomite•  Bothoutcropandcoresamplesanalyzed

Analysis

No phosphite in rocks 2.9 Ga and younger

Results

•  Phosphitepresentinextractat~30‐60%oftotalPextracted

•  CaHPO3about1000×moresolublethanCaHPO4underequal[Ca2+]

•  Archeanoceansmayhavecontained10‐3‐10‐4Mofphosphite

•  DominantPspeciesintheArcheanoceans?

Whatisthesource?•  HighenergyorlowfO2arenecessary

•  Phosphiteisknownfrom:Ricepaddies(Tsubota1959),phosphidecorrosion(Mortonetal.2002,PasekandLaure7a2005),lightning(PasekandBlock2009),Geothermalfluids(Pechetal.2009,2011),eutrophiclakes(Hanetal.2012)

Schreibersitephosphorylatesorganics

•  Noother“prebioHcphosphate”candothis

Glycerol

PrebioHcrelevance

•  Ifphosphitewasformedfromphosphides

•  ThisallowsnewprebioHcchemistry

•  Schreibersitereactswithorganicstomakeorganophosphates

•  EarliestsourceofPforlife?

Conclusions

•  ArcheanphosphorusgeochemistryincludesredoxofP

•  Possiblesourceismeteorites

•  MayhaveencouragedphosphorylaHon+phosphonylaHon

•  A“philosopher’sstone”?

Thanks

•  NASAExobiology&EvoluHonaryBiology,NASAEarlyCareerFellowship,NSFCCICenterforChemicalEvoluHon

•  RogerBuick,JelteHarnmeijer,ZacAtlas,MaheenGull,VirginiaPasek,JackieSampson,KrishnaFoster,DaveBryant,TerryKee,ThomOrlando,FacundoFernandez,ManshuiZhou