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Photo-catalytic oxidation of a di-nuclear manganese centre in an engineered bacterioferritin 'reaction centre'

Conlan, Brendon; Cox, Nicholas; Su, Ji-Hu; Hillier, Warwick; Messinger, Johannes; Lubitz, Wolfgang; Dutton, Peter Leslie; Wydrzynski, Thomas

Description

Photosynthesis involves the conversion of light into chemical energy through a series of electron transfer reactions within membrane-bound pigment/protein complexes. The Photosystem II (PSII) complex in plants, algae and cyanobacteria catalyse the oxidation of water to molecular O2. The complexity of PSII has thus far limited attempts to chemically replicate its function. Here we introduce a reverse engineering approach to build a simple, light-driven photo-catalyst based on the organization...[Show more]

dc.contributor.authorConlan, Brendon
dc.contributor.authorCox, Nicholas
dc.contributor.authorSu, Ji-Hu
dc.contributor.authorHillier, Warwick
dc.contributor.authorMessinger, Johannes
dc.contributor.authorLubitz, Wolfgang
dc.contributor.authorDutton, Peter Leslie
dc.contributor.authorWydrzynski, Thomas
dc.date.accessioned2015-12-10T23:01:29Z
dc.identifier.issn0005-2728
dc.identifier.urihttp://hdl.handle.net/1885/61632
dc.description.abstractPhotosynthesis involves the conversion of light into chemical energy through a series of electron transfer reactions within membrane-bound pigment/protein complexes. The Photosystem II (PSII) complex in plants, algae and cyanobacteria catalyse the oxidation of water to molecular O2. The complexity of PSII has thus far limited attempts to chemically replicate its function. Here we introduce a reverse engineering approach to build a simple, light-driven photo-catalyst based on the organization and function of the donor side of the PSII reaction centre. We have used bacterioferritin (BFR) (cytochrome b1) from Escherichia coli as the protein scaffold since it has several, inherently useful design features for engineering light-driven electron transport. Among these are: (i.) a di-iron binding site; (ii.) a potentially redox-active tyrosine residue; and (iii.) the ability to dimerise and form an inter-protein heme binding pocket within electron tunnelling distance of the di-iron binding site. Upon replacing the heme with the photoactive zinc-chlorin e6 (ZnCe6) molecule and the di-iron binding site with two manganese ions, we show that the two Mn ions bind as a weakly coupled di-nuclear Mn2II,II centre, and that ZnCe6 binds in stoichiometric amounts of 1:2 with respect to the dimeric form of BFR. Upon illumination the bound ZnCe6 initiates electron transfer, followed by oxidation of the di-nuclear Mn centre possibly via one of the inherent tyrosine residues in the vicinity of the Mn cluster. The light dependent loss of the MnII EPR signals and the formation of low field parallel mode Mn EPR signals are attributed to the formation of MnIII species. The formation of the MnIII is concomitant with consumption of oxygen. Our model is the first artificial reaction centre developed for the photo-catalytic oxidation of a di-metal site within a protein matrix which potentially mimics water oxidation centre (WOC) photo-assembly.
dc.publisherElsevier
dc.sourceBiochimica et Biophysica Acta: Bioenergetics
dc.subjectKeywords: bacterioferritin; chlorine; ferritin; hemoprotein; iron; manganese; scaffold protein; unclassified drug; zinc; article; binding site; bioengineering; catalysis; controlled study; electron spin resonance; electron transport; Escherichia coli; human; human Artificial photosynthesis; Bacterioferritin; Electron transfer; EPR; Manganese; Protein engineering; Zinc chlorin e6
dc.titlePhoto-catalytic oxidation of a di-nuclear manganese centre in an engineered bacterioferritin 'reaction centre'
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume1787
dc.date.issued2009
local.identifier.absfor060702 - Plant Cell and Molecular Biology
local.identifier.absfor030699 - Physical Chemistry not elsewhere classified
local.identifier.ariespublicationu9204316xPUB626
local.type.statusPublished Version
local.contributor.affiliationConlan, Brendon, College of Medicine, Biology and Environment, ANU
local.contributor.affiliationCox, Nicholas, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationSu, Ji-Hu, Max-Planck Institute for Bioinorganic Chemistry
local.contributor.affiliationHillier, Warwick, College of Medicine, Biology and Environment, ANU
local.contributor.affiliationMessinger, Johannes, Max Planck Institute for Bioinorganic Chemistry
local.contributor.affiliationLubitz, Wolfgang , Max Planck Institute for Bioinorganic Chemistry
local.contributor.affiliationDutton, Peter Leslie, University of Pennsylvania
local.contributor.affiliationWydrzynski, Thomas, College of Medicine, Biology and Environment, ANU
local.description.embargo2037-12-31
local.bibliographicCitation.issue9
local.bibliographicCitation.startpage1112
local.bibliographicCitation.lastpage1121
local.identifier.doi10.1016/j.bbabio.2009.04.011
dc.date.updated2016-02-24T11:52:46Z
local.identifier.scopusID2-s2.0-67649499951
local.identifier.thomsonID000267926900004
CollectionsANU Research Publications

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