title: The mechanism for proton-coupled electron transfer from tyrosine in a model complex and comparisons with Y(Z) oxidation in photosystem II.
abstract: In the water-oxidizing reactions of photosystem II (PSII), a tyrosine residue plays a key part as an intermediate electron-transfer reactant between the primary donor chlorophylls (the pigment P(680)) and the water-oxidizing Mn cluster. The tyrosine is deprotonated upon oxidation, and the coupling between the proton reaction and electron transfer is of great mechanistic importance for the understanding of the water-oxidation mechanism. Within a programme on artificial photosynthesis, we have made and studied the proton-coupled tyrosine oxidation in a model system and been able to draw mechanistic conclusions that we use to interpret the analogous reactions in PSII.
authors.affiliation: Department of Physical Chemistry, Uppsala University, Box 532, S-751 21 Uppsala, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Sjödin
authors.forename: Stenbjörn
authors.initials: S
authors.lastname: Styring
authors.forename: Björn
authors.initials: B
authors.lastname: Akermark
authors.forename: Licheng
authors.initials: L
authors.lastname: Sun
authors.forename: Leif
authors.initials: L
authors.lastname: Hammarström
mesh_terms: D004579:Electron Transport; D006860:Hydrogen Bonding; D007700:Kinetics; D008027:Light; D008345:Manganese / Q000378:metabolism; D008954:Models, Biological; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000378:metabolism*; D045332:Photosystem II Protein Complex; D011522:Protons; D012413:Rubidium / Q000737:chemistry; D014443:Tyrosine / Q000737:chemistry* / Q000378:metabolism*; D014867:Water / Q000378:metabolism
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D011522:Protons; D014867:Water; D014443:Tyrosine; D008345:Manganese; D012413:Rubidium; D010100:Oxygen