The mechanism for proton-coupled electron transfer from tyrosine in a model complex and comparisons with Y(Z) oxidation in photosystem II.
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.
Sjödin
Martin
M
Department of Physical Chemistry, Uppsala University, Box 532, S-751 21 Uppsala, Sweden.
Styring
Stenbjörn
S
Akermark
Björn
B
Sun
Licheng
L
Hammarström
Leif
L
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
D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D011522:Protons; D014867:Water; D014443:Tyrosine; D008345:Manganese; D012413:Rubidium; D010100:Oxygen