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Updated: Jun 29, 2026

In Vitro Reconstitution of Light-harvesting Complexes of Plants and Green Algae
Published on: October 10, 2014
Spectrally silent light induced conformation change in photosynthetic reaction centers
László Nagy1, Péter Maróti, Masahide Terazima
1Institute of Medical Physics and Biophysics, University of Szeged, 6720 Szeged, Rerrich B. tér. 1., Hungary. lnagy@sol.cc.u-szeged.hu
Abstract:
Spectrally silent conformation change after photoexcitation of photosynthetic reaction centers isolated from Rhodobacter sphaeroides R-26 was observed by the optical heterodyne transient grating technique. The signal showed spectrally silent structural change in photosynthetic reaction centers followed by the primary P+BPh- charge separation and this change remains even after the charge recombination. Without bound quinone to the RC, the conformation change relaxes with about 28micros lifetime. The presence of quinone at the primary quinone (QA) site may suppress this conformation change. However, a weak relaxation with 30-40micros lifetime is still observed under the presence of QA, which increases up to 40micros as a function of the occupancy of the secondary quinone (QB) site.
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