Dynamic Studies on the Primary Photochemical Reaction in the Isolated Photosystem II Reaction Center by Time-Resolved Absorption and Fluorescence Spectroscopy

1995 ◽  
pp. 523-526
Author(s):  
Jian-Min Hou ◽  
Ting-Yun Kuang ◽  
Zhen-Bao Yu ◽  
Chong-Qin Tang ◽  
Kun-Yun Yang ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Fluorescence Spectroscopy ◽  
Reaction Center ◽  
Photochemical Reaction ◽  
Time Resolved ◽  
Absorption And Fluorescence Spectroscopy ◽  
Dynamic Studies ◽  
Primary Photochemical Reaction

Polypeptides with pendant porphyrins of defined sequence of chromophores: towards artificial photosynthetic systems

2008 ◽  
Vol 12 (12) ◽  
pp. 1232-1241 ◽  
Author(s):  
Farid Aziat ◽  
Régis Rein ◽  
Jorge Peón ◽  
Ernesto Rivera ◽  
Nathalie Solladié
Keyword(s):  
Energy Transfer ◽  
Excited State ◽  
Amino Acid ◽  
Fluorescence Spectroscopy ◽  
Photophysical Properties ◽  
Free Base ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Absorption And Fluorescence Spectroscopy ◽  
Artificial Photosynthetic

In this paper we now report our ongoing progress in the preparation of artificial photosynthetic systems through the preparation of light harvesting multi-porphyrins. A tetramer, constituted of a central dipeptide functionalized by two free-base porphyrins and surrounded by one amino-acid bearing a pendant Zn ( II ) porphyrin on each side, has been chosen. The optical and photophysical properties of this tetramer have been studied by absorption and fluorescence spectroscopy. In addition, the energy transfer phenomenon has been studied and monitored by femtosecond time-resolved fluorescence. Our results indicate that the excited state dynamics redounding in the excitation being localized in the inner free-base porphyrins takes place in the time scale of approximately 1 ps.

scholarly journals Early Archean origin of Photosystem II

2017 ◽  
Author(s):  
Tanai Cardona ◽  
Patricia Sánchez-Baracaldo ◽  
A. William Rutherford ◽  
Anthony W. D. Larkum
Keyword(s):  
Photosystem Ii ◽  
Reaction Center ◽  
Water Oxidation ◽  
Photochemical Reaction ◽  
Early Stage ◽  
Oxygenic Photosynthesis ◽  
Recent Common Ancestor ◽  
Molecular Clocks ◽  
Most Recent Common Ancestor ◽  
History Of

AbstractPhotosystem II is a photochemical reaction center that catalyzes the light-driven oxidation of water to molecular oxygen. Water oxidation is the distinctive photochemical reaction that permitted the evolution of oxygenic photosynthesis and the eventual rise of Eukaryotes. At what point during the history of life an ancestral photosystem evolved the capacity to oxidize water still remains unknown. Here we study the evolution of the core reaction center proteins of Photosystem II using sequence and structural comparisons in combination with Bayesian relaxed molecular clocks. Our results indicate that a homodimeric photosystem with sufficient oxidizing power to split water had already appeared in the early Archean about a billion years before the most recent common ancestor of all described Cyanobacteria capable of oxygenic photosynthesis, and well before the diversification of some of the known groups of anoxygenic photosynthetic bacteria. Based on a structural and functional rationale we hypothesize that this early Archean photosystem was capable of water oxidation and had already evolved some level of protection against the formation of reactive oxygen species, which would place primordial forms of oxygenic photosynthesis at a very early stage in the evolutionary history of life.

Two-Step Mechanism of Photodamage to Photosystem II:  Step 1 Occurs at the Oxygen-Evolving Complex and Step 2 Occurs at the Photochemical Reaction Center†

Biochemistry ◽  
2005 ◽  
Vol 44 (23) ◽  
pp. 8494-8499 ◽  
Author(s):  
Norikazu Ohnishi ◽  
Suleyman I. Allakhverdiev ◽  
Shunichi Takahashi ◽  
Shoichi Higashi ◽  
Masakatsu Watanabe ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Reaction Center ◽  
Photochemical Reaction ◽  
Oxygen Evolving Complex ◽  
Oxygen Evolving ◽  
Step Mechanism

Paraquat (Methylviologen): Its Interference with Primary Photochemical Reactions

1993 ◽  
Vol 48 (3-4) ◽  
pp. 374-378 ◽  
Author(s):  
Tetsuo Hiyama ◽  
Akira Ohinata ◽  
Shin-ichi Kobayashi
Keyword(s):  
Reaction Center ◽  
Electron Donor ◽  
Photosystem I ◽  
Photochemical Reaction ◽  
Photochemical Reactions ◽  
The Other ◽  
Primary Photochemical Reaction

Paraquat(methylviologen), a widely used nonspecific herbicide, is ptoreduced in the primary photochemical reaction of photosystemI. Using two types of the photosystem I reaction center preparations, i.e. one with FeSA/FeSB and the other without, the immediate electron donor to methylviologen was determined to be FeSx (P430) rather than FeSA/FeSB.

scholarly journals Chlorophyll and cytochrome b -559 content of the photochemical reaction center of photosystem II

FEBS Letters ◽  
1989 ◽  
Vol 254 (1-2) ◽  
pp. 150-154 ◽  
Author(s):  
Jan P. Dekker ◽  
Neil R. Bowlby ◽  
Charles F. Yocum
Keyword(s):  
Photosystem Ii ◽  
Reaction Center ◽  
Cytochrome B ◽  
Photochemical Reaction
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