Abstract
A negatively charged region on the surface of photosystem II (PSII) near Q A has been identified as a docking site for cationic exogenous electron acceptors. Oxygen evolution activity, which is inhibited in the presence of the herbicide 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), is recovered by adding Co III complexes. Thus, a new electron-transfer pathway is created with Co III as the new terminal electron acceptor from Q A -. This binding site is saturated at ∼2.5 mM [Co III], which is consistent with the existence of low-affinity interactions with a solvent-exposed surface. This is the first example of a higher plant PSII in which the electron-transfer pathway has been redirected from the normal membrane-associated quinone electron acceptors to water-soluble electron acceptors. The proposed Co III binding site may enable efficient collection of electrons generated from photochemical water oxidation by PSII immobilized on an electrode surface.
Original language | English |
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Pages (from-to) | 13260-13263 |
Number of pages | 4 |
Journal | Journal of the American Chemical Society |
Volume | 133 |
Issue number | 34 |
DOIs | |
Publication status | Published - Aug 31 2011 |
ASJC Scopus subject areas
- Catalysis
- Chemistry(all)
- Biochemistry
- Colloid and Surface Chemistry