Photosynthetic water oxidation at elevated dioxygen partial pressure monitored by time-resolved X-ray absorption measurements

被引:47
作者
Haumann, Michael [1 ]
Grundmeier, Alexander [1 ]
Zaharieva, Ivelina [1 ]
Dau, Holger [1 ]
机构
[1] Free Univ Berlin, Inst Expt Phys, D-14195 Berlin, Germany
关键词
manganese complex; photosystem II; X-ray spectroscopy; bioinorganic chemistry; oxygen pressure;
D O I
10.1073/pnas.0802596105
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 atmospheric dioxygen (O-2) is produced at a tetramanganese complex bound to the proteins of photosystem II (PSII). To investigate product inhibition at elevated oxygen partial pressure (pO(2) ranging from 0.2 to 16 bar), we monitored specifically the redox reactions of the Mn complex in its catalytic S-state cycle by rapid-scan and time-resolved X-ray absorption near-edge spectroscopy (XANES) at the Mn K-edge. By using a pressure cell for X-ray measurements after laser-flash excitation of PSII particles, we found a clear pO(2) influence on the redox reactions of the Mn complex, with a similar half-effect pressure as determined (2-3 bar). However, XANES spectra and the time courses of the X-ray fluorescence collected with microsecond resolution suggested that the O-2 evolution transition itself (S-3 double right arrow S-0+O-2) was not affected. Additional (nonstandard) oxidation of the Mn complex at high pO(2) explains our experimental findings more readily. Our results suggest that photosynthesis at ambient conditions is not limited by product inhibition of the O-2 formation step.
引用
收藏
页码:17384 / 17389
页数:6
相关论文
共 45 条
[1]  
Beerling D.J., 2007, EMERALD PLANET PLANT
[2]   Impact of a Permo-Carboniferous high O2 event on the terrestrial carbon cycle [J].
Beerling, DJ ;
Berner, RA .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2000, 97 (23) :12428-12432
[3]   Photosynthetic water oxidation at high O2 backpressure monitored by delayed chlorophyll fluorescence [J].
Clausen, J ;
Junge, W ;
Dau, H ;
Haumann, M .
BIOCHEMISTRY, 2005, 44 (38) :12775-12779
[4]   Detection of an intermediate of photosynthetic water oxidation [J].
Clausen, J ;
Junge, W .
NATURE, 2004, 430 (6998) :480-483
[5]   Radiative and non-radiative charge recombination pathways in Photosystem II studied by thermoluminescence and chlorophyll fluorescence in the cyanobacterium Synechocystis 6803 [J].
Cser, Krisztian ;
Vass, Imre .
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS, 2007, 1767 (03) :233-243
[6]  
Dau H, 2006, SCIENCE, V312, P1471
[7]   X-ray absorption spectroscopy to analyze nuclear geometry and electronic structure of biological metal centers - Potential and questions examined with special focus on the tetra-nuclear manganese complex of oxygenic photosynthesis [J].
Dau, H ;
Liebisch, P ;
Haumann, M .
ANALYTICAL AND BIOANALYTICAL CHEMISTRY, 2003, 376 (05) :562-583
[8]   The structure of the manganese complex of Photosystem II in its dark-stable S1-state-EXAFS results in relation to recent crystallographic data [J].
Dau, H ;
Liebisch, P ;
Haumann, M .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2004, 6 (20) :4781-4792
[9]   The tetra-manganese complex of photosystem II during its redox cycle - X-ray absorption results and mechanistic implications [J].
Dau, H ;
Iuzzolino, L ;
Dittmer, J .
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS, 2001, 1503 (1-2) :24-39
[10]   The manganese complex of photosystem II in its reaction cycle - Basic framework and possible realization at the atomic level [J].
Dau, Holger ;
Haumann, Michael .
COORDINATION CHEMISTRY REVIEWS, 2008, 252 (3-4) :273-295