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Commentaries on Section 1 “Primary processes of photosynthesis”статья
- Авторы: Proskuryakov I.I., Semenov A.Yu
- Журнал: Biophysical Reviews
- Том: 14
- Год издания: 2022
- Издательство: Springer Verlag
- Местоположение издательства: Germany
- Первая страница: 755
- Последняя страница: 756
- DOI: 10.1007/s12551-022-00960-8
- Аннотация: The section “Primary processes of photosynthesis” (Book of Abstracts, 2021) comprised an opening lecture, 12 oral and 4 poster presentations. In his opening lecture Andrei Rubin described the function of enzymes and photosynthetic reaction centers as of molecular machines discussing the importance of strong correlation between electron transfer and protein conformational changes. Much attention was also paid to computer simulations of homogeneous and heterogeneous (biological) systems, including molecular dynamics modelling. The subject of protein influence on photoinduced electron transfer in bacterial RCs was continued in the talk of Lyudmila Vasilieva. She reported on the new results of X-ray structure determination of the Rhodobacter sphaeroides reaction centers with Phe-His aminoacid substitution at the position M197 in the vicinity of the BChl primary donor dimer P. The obtained results enabled explanation of a number of unusual properties of the mutant, and for the first time revealed the existence of hydrogen bond clusters around the primary electron donor. The role of the clusters is yet to be established. Possibly, the combined net of hydrogen bonds close to P stabilize the reaction center structure, and apart from this take part in fine tuning the primary donor redox properties.Three talks were dealing with bacterial light-harvesting complexes, especially in relation to the properties of carotenoids they include. Aleksandr Ashikhmin reported an unusual ability of LH complexes to generate singlet oxygen when carotenoids are excited. Roman Pishchalnikov provided a theoretical approach to energy transfer between carotenoids and bacteriochlorophylls with a special emphasis on the absence of energy transfer from the BChl Qx level to the S2 level of carotenoid. Maksim Bolshakov reported on the assembly of LH complexes of purple bacteria under the conditions of carotenoid synthesis inhibition. Various applications of time-resolved EPR to the studied of primary processes in bacterial RCs and LH complexes were demonstrated by Ivan Proskuryakov. A new mechanism of pigment triplet states quenching was put forward. Several mechanisms of a green alga adaptation to high light intensity were discussed in the talk of Konstantin Chekanov. It was concluded that screening by carotenoids and reduction of photosynthetic apparatus are the main protection mechanisms. As shown in the talk by Natalia Belyaeva, the entire electron-transfer chain of a green alga can be analysed by a theoretical analysis of fluorescence induction curves. Several talks were dealing with the studies of photosystems I (PS I) and II (PS II) of higher plants and cyanobacteria. Mahir Mamedov presented results on the measurements of the photo-induced steady state voltage generation by photosystems I and II adsorbed onto the porous Millipore filter sandwiched between two semiconductor indium-tin oxide coated transparent glass electrodes in the presence of trehalose. It was shown that this system provides stable voltage generation during 50 minutes illumination at room temperature. Alexey Semenov reported on the effect of relative humidity on the flash-induced electron transfer in PS II core complexes embedded into trehalose glassy matrix. Anastasia Petrova talked about the mechanisms of adaptation of photosynthesizing organisms to the illumination conditions on the level of PS I. Victor Nadtochenko presented the results on the effect of point mutations near the second pair of chlorophyll molecules A0 on the formation of primary and secondary ion-radical pairs in PS I. Dmitry Cherepanov et al., using ultrafast pump-probe optical spectroscopy, studied the energy and charge transfer processes in PS I complexes from cyanobacteria Fisherella thermalis containing seven long-wavelength chlorophyll (Chl) f molecules in addition to Chl a. It was shown that Chl f functions solely as an antenna pigment in these complexes. The formation of the secondary ion-radical pair P700+A1− in Chl f-containing PS I is slowed by a factor of 10 compared to the Chl a-containing PS I because the rate-limiting excitation migrates uphill from Chl f in the antenna to the trapping center.References9th Congress of the Russian Society of Photobiology, Book of Abstracts, Pushchino, 2021. http://www.photobiology.ru/files/9RSP-2021.pdf (in Russian)
- Добавил в систему: Семенов Алексей Юрьевич