-transparent.png){kind=logo}
The electron transfer in photosystem I (PS I) from the secondary acceptor A1 to the iron-sulfur centers is studied by X-band transient EPR with a time resolution of approximately 50 ns. Results are presented for a series of different PS I preparations from the cyanobacterium Synechococcus 6301 ranging from whole cells to core particles in which the iron-sulfur centers have been successively removed. In addition, results from PS I preparations from spinach and the cyanobacterium Synechocystis 6803 are presented. In all samples containing iron-sulfur centers, two consecutive spin-polarized EPR spectra are observed. The two signals have previously been assigned to the charge-separated states P700+.A1-. and P700+.(FeS)-, where (FeS) is one of the three iron-sulfur centers, FX, FA, or FB [Bock, C., van der Est, A., Brettel, K., & Stehlik, D. (1989) FEBS Lett. 247, 91-96]. In agreement with this, the second spectrum is not observed in the sample in which the iron-sulfur centers have been removed. For (P700-FX), core particles which do not contain FA and FB, the second spectrum can unambiguously be assigned to the pair P700+.FX-. In all samples containing FX, the transition from the first to the second spectrum occurs with t1/e approximately 280 ns (t1/2 approximately 190 ns) both in the presence and absence of FA and FB, which strongly suggests that this phase reflects electron transfer from A1-. to FX in intact PS I.(ABSTRACT TRUNCATED AT 250 WORDS)
A van der Est, and
C Bock, and
J Golbeck, and
K Brettel, and
P Sétif, and
D Stehlik
August 1993,
Biochemistry,
A van der Est, and
C Bock, and
J Golbeck, and
K Brettel, and
P Sétif, and
D Stehlik
August 1995,
Biochemistry,
A van der Est, and
C Bock, and
J Golbeck, and
K Brettel, and
P Sétif, and
D Stehlik
April 2005,
The Journal of biological chemistry,
A van der Est, and
C Bock, and
J Golbeck, and
K Brettel, and
P Sétif, and
D Stehlik
July 1997,
Biochemistry,
A van der Est, and
C Bock, and
J Golbeck, and
K Brettel, and
P Sétif, and
D Stehlik
October 1995,
Biochemistry,
A van der Est, and
C Bock, and
J Golbeck, and
K Brettel, and
P Sétif, and
D Stehlik
April 1995,
Proceedings of the National Academy of Sciences of the United States of America,
A van der Est, and
C Bock, and
J Golbeck, and
K Brettel, and
P Sétif, and
D Stehlik
June 1998,
Biochemistry,
A van der Est, and
C Bock, and
J Golbeck, and
K Brettel, and
P Sétif, and
D Stehlik
September 1995,
Photosynthesis research,
A van der Est, and
C Bock, and
J Golbeck, and
K Brettel, and
P Sétif, and
D Stehlik
October 2022,
Biochemistry. Biokhimiia,
A van der Est, and
C Bock, and
J Golbeck, and
K Brettel, and
P Sétif, and
D Stehlik
April 1979,
FEBS letters,
