Thermal Effects and Structural Changes of Photosynthetic Reaction Centers Characterized by Wide Frequency Band Hydrophone: Effects of Carotenoids and Terbutryn.
Photothermal characteristics and light-induced structural (volume) changes of carotenoid-containing and noncontaining photosynthetic reaction centers (RCs) were investigated by wide frequency band hydrophone. We found that the presence of carotenoid either does not play considerable role in the light-induced conformational movements, or these rearrangements are too slow for inducing a photoacoustic (PA) signal. The kinetic component with a few tens of microseconds, exhibited by the carotenoid-less RCs, appears to be similar to that of triplet state lifetimes, identified by other methods. The binding of terbutryn to the acceptor side is shown to affect the dynamics of the RC. Our results do not confirm large displacements or volume changes induced by the charge movements and by the charge relaxation processes in the RCs in few hundreds of microseconds time scale that accompanies the electron transfer between the primary and secondary electron acceptor quinones.
Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary.
László
L
Nagy
Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel.
Vladimir
V
Kiss
Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel.
Vlad
V
Brumfeld
Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary.
Károly
K
Osvay
Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary.
Ádám
Á
Börzsönyi
Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary.
Melinda
M
Magyar
Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary.
Tibor
T
Szabó
Biophotonics R&D Ltd, Szeged, Hungary.|Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged, Hungary.
Márta
M
Dorogi
Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel.
Shmuel
S
Malkin
D002338:Carotenoids / Q000737:chemistry*; D008027:Light; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry*; D013696:Temperature; D014227:Triazines / Q000737:chemistry*
D045322:Photosynthetic Reaction Center Complex Proteins; D014227:Triazines; D002338:Carotenoids; C010347:terbutryne