TY - CHAP
T1 - Towards uncovering the energetics of secondary electron transfer reactions in photosystem I
AU - Santabarbara, Stefano
AU - Rappaport, Fabrice
AU - Redding, Kevin
N1 - Funding Information:
Work in KR’s laboratory was supported by Energy Biosciences grant DE-FG02-08ER15989 from the U.S. Dept. of Energy. FR acknowledges funding by CNRS and UPMC. SS thanks the CNR for funding.
Publisher Copyright:
© Zhejiang University Press, Hangzhou and Springer-Verlag Berlin Heidelberg 2013.
PY - 2013
Y1 - 2013
N2 - Phylloquinone (PhQ) acts as the secondary electron acceptor in the reaction centre of Photosystem I. At room temperature the semiquinone anion is oxidized with complex multiphasic kinetics by electron transfer to the iron-sulphur cluster FX. The two principle phases of the oxidation kinetics are characterized by lifetimes of 20 ns and 250 ns. The 20-ns phase is associated primarily with the oxidation of PhQB, which is bound by the PsaB subunit, and the 250-ns phase is associated with oxidation of PhQA, which is bound by the PsaA subunit. The difference of about one order of magnitude between the two oxidation lifetimes can be explained by considering the difference in the driving force for oxidation of the PhQA (ΔG0 > 0) and PhQB (ΔG0 < 0) semiquinone forms. Such an energetic scenario also promotes a transient electron transfer from PhQA − to PhQB, with FX acting as an intermediary.
AB - Phylloquinone (PhQ) acts as the secondary electron acceptor in the reaction centre of Photosystem I. At room temperature the semiquinone anion is oxidized with complex multiphasic kinetics by electron transfer to the iron-sulphur cluster FX. The two principle phases of the oxidation kinetics are characterized by lifetimes of 20 ns and 250 ns. The 20-ns phase is associated primarily with the oxidation of PhQB, which is bound by the PsaB subunit, and the 250-ns phase is associated with oxidation of PhQA, which is bound by the PsaA subunit. The difference of about one order of magnitude between the two oxidation lifetimes can be explained by considering the difference in the driving force for oxidation of the PhQA (ΔG0 > 0) and PhQB (ΔG0 < 0) semiquinone forms. Such an energetic scenario also promotes a transient electron transfer from PhQA − to PhQB, with FX acting as an intermediary.
KW - Clusters
KW - Electron Transfer (ET)
KW - Iron-sulphur
KW - Photosystem I (PS I)
KW - Phylloquinone
KW - Reaction centre (RC)
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U2 - 10.1007/978-3-642-32034-7_2
DO - 10.1007/978-3-642-32034-7_2
M3 - Chapter
AN - SCOPUS:85060683183
T3 - Advanced Topics in Science and Technology in China
SP - 7
EP - 12
BT - Advanced Topics in Science and Technology in China
PB - Springer
ER -