| Ultrafast primary processes in PS I from Synechocystis sp. PCC 6803: roles of P700 and A(0). | |
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MedLine Citation:
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PMID: 10969018 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The excitation transport and trapping kinetics of core antenna-reaction center complexes from photosystem I of wild-type Synechocystis sp. PCC 6803 were investigated under annihilation-free conditions in complexes with open and closed reaction centers. For closed reaction centers, the long-component decay-associated spectrum (DAS) from global analysis of absorption difference spectra excited at 660 nm is essentially flat (maximum amplitude <10(-5) absorbance units). For open reaction centers, the long-time spectrum (which exhibits photobleaching maxima at approximately 680 and 700 nm, and an absorbance feature near 690 nm) resembles one previously attributed to (P700(+) - P700). For photosystem I complexes excited at 660 nm with open reaction centers, the equilibration between the bulk antenna and far-red chlorophylls absorbing at wavelengths >700 nm is well described by a single DAS component with lifetime 2.3 ps. For closed reaction centers, two DAS components (2.0 and 6.5 ps) are required to fit the kinetics. The overall trapping time at P700 ( approximately 24 ps) is very nearly the same in either case. Our results support a scenario in which the time constant for the P700 --> A(0) electron transfer is 9-10 ps, whereas the kinetics of the subsequent A(0) --> A(1) electron transfer are still unknown. |
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Authors:
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S Savikhin; W Xu; P R Chitnis; W S Struve |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Biophysical journal Volume: 79 ISSN: 0006-3495 ISO Abbreviation: Biophys. J. Publication Date: 2000 Sep |
Date Detail:
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Created Date: 2000-10-18 Completed Date: 2000-10-18 Revised Date: 2010-09-14 |
Medline Journal Info:
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Nlm Unique ID: 0370626 Medline TA: Biophys J Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 1573-86 Citation Subset: IM |
Affiliation:
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Ames Laboratory, U. S. Department of Energy, Ames, Iowa 50011, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Chlorophyll
/
chemistry,
metabolism* Cyanobacteria / physiology* Kinetics Models, Molecular Photosynthetic Reaction Center Complex Proteins / chemistry*, metabolism* Protein Conformation Spectrophotometry |
| Chemical | |
Reg. No./Substance:
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0/Photosynthetic Reaction Center Complex Proteins; 1406-65-1/Chlorophyll; 479-61-8/chlorophyll a; 53321-11-2/chlorophyll P 700 |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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