TY - JOUR
T1 - Kinetics of phyllosemiquinone oxidation in the Photosystem i reaction centre of Acaryochloris marina
AU - Santabarbara, Stefano
AU - Bailleul, Benjamin
AU - Redding, Kevin
AU - Barber, James
AU - Rappaport, Fabrice
AU - Telfer, Alison
N1 - Funding Information:
J.B. acknowledges the support of the Biotechnology and Biological Science Research Council (BBSRC) . K.R. acknowledges support from DOE grant DE-FG02-08ER15989 and NSF award MCB-1052573 . F.R. and B.B. acknowledge support from CNRS and Univ. P. et M. Curie .
PY - 2012/2
Y1 - 2012/2
N2 - Light-induced electron transfer reactions in the chlorophyll a/d-binding Photosystem I reaction centre of Acaryochloris marina were investigated in whole cells by pump-probe optical spectroscopy with a temporal resolution of ~ 5 ns at room temperature. It is shown that phyllosemiquinone, the secondary electron transfer acceptor anion, is oxidised with bi-phasic kinetics characterised by lifetimes of 88 ± 6 ns and 345 ± 10 ns. These lifetimes, particularly the former, are significantly slower than those reported for chlorophyll a-binding Photosystem I, which typically range in the 5-30 ns and 200-300 ns intervals. The possible mechanism of electron transfer reactions in the chlorophyll a/d-binding Photosystem I and the slower oxidation kinetics of the secondary acceptors are discussed.
AB - Light-induced electron transfer reactions in the chlorophyll a/d-binding Photosystem I reaction centre of Acaryochloris marina were investigated in whole cells by pump-probe optical spectroscopy with a temporal resolution of ~ 5 ns at room temperature. It is shown that phyllosemiquinone, the secondary electron transfer acceptor anion, is oxidised with bi-phasic kinetics characterised by lifetimes of 88 ± 6 ns and 345 ± 10 ns. These lifetimes, particularly the former, are significantly slower than those reported for chlorophyll a-binding Photosystem I, which typically range in the 5-30 ns and 200-300 ns intervals. The possible mechanism of electron transfer reactions in the chlorophyll a/d-binding Photosystem I and the slower oxidation kinetics of the secondary acceptors are discussed.
KW - Acaryochloris marina
KW - Bidirectional electron transfer
KW - Chlorophyll d
KW - Photosystem I
KW - Phylloquinone
KW - Radical pair
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U2 - 10.1016/j.bbabio.2011.10.003
DO - 10.1016/j.bbabio.2011.10.003
M3 - Article
C2 - 22037394
AN - SCOPUS:84655167548
SN - 0005-2728
VL - 1817
SP - 328
EP - 335
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
IS - 2
ER -