Kinetics and mechanism of electron transfer in intact photosystem II and in the isolated reaction center:: Pheophytin is the primary electron acceptor

被引:252
作者
Holzwarth, AR
Müller, MG
Reus, M
Nowaczyk, M
Sander, J
Rögner, M
机构
[1] Max Planck Inst Bioanorgan Chem, D-45470 Mulheim, Germany
[2] Ruhr Univ Bochum, Lehrstuhl Biochem & Pflanzen, D-44801 Bochum, Germany
关键词
charge separation; photosynthesis; ultrafast spectroscopy; D1/D2-cyt(b559); femtosecond absorption;
D O I
10.1073/pnas.0505371103
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
The mechanism and kinetics of electron transfer in isolated D1/D2-cyt(b559) photosystem (PS) II reaction centers (RCs) and in intact PSII cores have been studied by femtosecond transient absorption and kinetic compartment modeling. For intact PSII, a component of approximate to 1.5 ps reflects the dominant energy-trapping kinetics from the antenna by the RC. A 5.5-ps component reflects the apparent lifetime of primary charge separation, which is faster by a factor of 8-12 than assumed so far. The 35-ps component represents the apparent lifetime of formation of a secondary radical pair, and the approximate to 200-ps component represents the electron transfer to the Q(A) acceptor. In isolated RCs, the apparent lifetimes of primary and secondary charge separation are approximate to 3 and 11 ps, respectively. It is shown (i) that pheophytin is reduced in the first step, and (ii) that the rate constants of electron transfer in the RC are identical for PSII cores and for isolated RCs. We interpret the first electron transfer step as electron donation from the primary electron donor Chl(acc) (D1). Thus, this mechanism, suggested earlier for isolated RCs at cryogenic temperatures, is also operative in intact PSII cores and in isolated RCs at ambient temperature. The effective rate constant of primary electron transfer from the equilibrated RC* excited state is 170-180 ns(-1), and the rate constant of secondary electron transfer is 120-130 ns(-1).
引用
收藏
页码:6895 / 6900
页数:6
相关论文
共 58 条
[1]   LIGHT-INDUCED FOURIER-TRANSFORM INFRARED-SPECTRUM OF THE CATION-RADICAL P680+ [J].
ALLAKHVERDIEV, SI ;
AHMED, A ;
TAJMIRRIAHI, HA ;
KLIMOV, VV ;
CARPENTIER, R .
FEBS LETTERS, 1994, 339 (1-2) :151-154
[2]   On the role of the CP47 core antenna in the energy transfer and trapping dynamics of Photosystem II [J].
Andrizhiyevskaya, EG ;
Frolov, D ;
van Grondelle, R ;
Dekker, JP .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2004, 6 (20) :4810-4819
[3]  
[Anonymous], MOL GLOBAL PHOTOSYNT
[4]   Low-temperature spectroscopy of fully active PSII cores.: Comparisons with CP43, CP47, D1/D2/cyt b559 fragments [J].
Årsköld, SP ;
Prince, BJ ;
Krausz, E ;
Smith, PJ ;
Pace, RJ ;
Picorel, R ;
Seibert, M .
JOURNAL OF LUMINESCENCE, 2004, 108 (1-4) :97-100
[5]   Structural model of the oxygen-evolving centre of photosystem II with mechanistic implications [J].
Barber, J ;
Ferreira, K ;
Maghlaoui, K ;
Iwata, S .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2004, 6 (20) :4737-4742
[6]   A quantitative structure-function relationship for the Photosystern II reaction center: Supermolecular behavior in natural photosynthesis [J].
Barter, LMC ;
Durrant, JR ;
Klug, DR .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2003, 100 (03) :946-951
[7]   Crystal structure of cyanobacterial photosystem II at 3.2 Å resolution:: a closer look at the Mn-cluster [J].
Biesiadka, J ;
Loll, B ;
Kern, J ;
Irrgang, KD ;
Zouni, A .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2004, 6 (20) :4733-4736
[8]   Pathways for energy transfer in the core light-harvesting complexes CP43 and CP47 of photosystem II [J].
de Weerd, FL ;
van Stokkum, IHM ;
van Amerongen, H ;
Dekker, JP ;
van Grondelle, R .
BIOPHYSICAL JOURNAL, 2002, 82 (03) :1586-1597
[9]   Primary charge separation in Photosystem II [J].
Dekker, JP ;
Van Grondelle, R .
PHOTOSYNTHESIS RESEARCH, 2000, 63 (03) :195-208
[10]   Structure, dynamics, and energetics of the primary photochemistry of photosystem II of oxygenic photosynthesis [J].
Diner, BA ;
Rappaport, F .
ANNUAL REVIEW OF PLANT BIOLOGY, 2002, 53 :551-580