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1. Arabidopsis Mutants Deleted in the Light-Harvesting Protein Lhcb4 Have a Disrupted Photosystem II Macrostructure and Are Defective in Photoprotection

Author

Roberto Bassi, Nico Betterle, Egbert J. Boekema, Roman Kouril, Stefano Cazzaniga, Silvia de Bianchi, Luca Dall'Osto, and Electron Microscopy

Subjects
0106 biological sciences, Chlorophyll, Photoinhibition, Photosystem II, Light, Arabidopsis, Plant Science, 01 natural sciences, Thylakoids, HIGHER-PLANTS, Protein Isoforms, Photosynthesis, Research Articles, IN-VIVO, STATE TRANSITIONS, 0303 health sciences, Cytochrome b6f complex, minor antennae, Temperature, food and beverages, Chloroplast, ENERGY-DISSIPATION, Thylakoid, Gene Knockdown Techniques, PHOTOOXIDATIVE STRESS, Oxidation-Reduction, RESOLVED FLUORESCENCE ANALYSIS, Photosynthetic Reaction Center Complex Proteins, SUBUNIT CP29, macromolecular substances, Biology, Photosystem I, Fluorescence, MINOR ANTENNA PROTEINS, CHLAMYDOMONAS-REINHARDTII, 03 medical and health sciences, Membrane Lipids, chloroplast, Botany, CYCLIC ELECTRON-TRANSPORT, PSII, 030304 developmental biology, Photosystem I Protein Complex, Arabidopsis Proteins, Lhcb4, photoprotection, Photosystem II Protein Complex, Cell Biology, Oxygen, Oxidative Stress, Photoprotection, Biophysics, Lipid Peroxidation, Chlorophyll Binding Proteins, 010606 plant biology & botany
Abstract

The role of the light-harvesting complex Lhcb4 (CP29) in photosynthesis was investigated in Arabidopsis thaliana by characterizing knockout lines for each of the three Lhcb4 isoforms (Lhcb4.1/4.2/4.3). Plants lacking all isoforms (koLhcb4) showed a compensatory increase of Lhcb1 and a slightly reduced photosystem II/I ratio with respect to the wild type. The absence of Lhcb4 did not result in alteration in electron transport rates. However, the kinetic of state transition was faster in the mutant, and nonphotochemical quenching activity was lower in koLhcb4 plants with respect to either wild type or mutants retaining a single Lhcb4 isoform. KoLhcb4 plants were more sensitive to photoinhibition, while this effect was not observed in knockout lines for any other photosystem II antenna subunit. Ultrastructural analysis of thylakoid grana membranes showed a lower density of photosystem II complexes in koLhcb4. Moreover, analysis of isolated supercomplexes showed a different overall shape of the C2S2 particles due to a different binding mode of the S-trimer to the core complex. An empty space was observed within the photosystem II supercomplex at the Lhcb4 position, implying that the missing Lhcb4 was not replaced by other Lhc subunits. This suggests that Lhcb4 is unique among photosystem II antenna proteins and determinant for photosystem II macro-organization and photoprotection.

Published
2011

2. A Novel Photosynthetic Strategy for Adaptation to Low-Iron Aquatic Environments

Author

Felisa Wolfe-Simon, Petra Fromme, Carolyn E. Lubner, Craig Jolley, Devendra Chauhan, Dorota D. Kolber, Egbert J. Boekema, Roman Kouril, I. Mihaela Folea, Su Lin, John H. Golbeck, Groningen Biomolecular Sciences and Biotechnology, and Electron Microscopy

Subjects
Cyanobacteria, Limiting factor, STRESS, Flavodoxin, Operon, Iron, Adaptation, Biological, Trimer, Fresh Water, ISIAB OPERON, Photosynthesis, Photochemistry, CYANOBACTERIUM SYNECHOCYSTIS PCC-6803, Biochemistry, Electron transfer, IMAGE DATA, Bacterial Proteins, OCEAN, PHOTOSYSTEM-I PARTICLES, biology, Photosystem I Protein Complex, SYNECHOCOCCUS-ELONGATUS, ANTENNA RING, biology.organism_classification, CHLOROPHYLL-BINDING PROTEIN, Oxidative Stress, biology.protein, Photosynthetic membrane, ENERGY-TRANSFER
Abstract

Iron (Fe) availability is a major limiting factor for primary production in aquatic environments. Cyanobacteria respond to Fe deficiency by derepressing the isiAB operon, which encodes the antenna protein IsiA and flavodoxin. At nanomolar Fe concentrations, a PSI-IsiA supercomplex forms, comprising a PSI trimer encircled by two complete IsiA rings. This PSI-IsiA supercomplex is the largest photosynthetic membrane protein complex yet isolated. This study presents a detailed characterization of this complex using transmission electron microscopy and ultrafast fluorescence spectroscopy. Excitation trapping and electron transfer are highly efficient, allowing cyanobacteria to avoid oxidative stress. This mechanism may be a major factor used by cyanobacteria to successfully adapt to modern low-Fe environments.

Published
2011
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3. The PsbS protein controls the macro-organisation of photosystem II complexes in the grana membranes of higher plant chloroplasts

Author

Egbert J. Boekema, Roman Kouril, Sami Kereiche, Peter Horton, Anett Z. Kiss, Groningen Biomolecular Sciences and Biotechnology, and Electron Microscopy

Subjects
Chloroplasts, Light, Photosystem II, PH-DEPENDENT DISSIPATION, GREEN PLANTS, Arabidopsis, Light-Harvesting Protein Complexes, Biophysics, RHODOBACTER-SPHAEROIDES, Biology, EXCITATION-ENERGY, Photosynthesis, PHOTOPROTECTIVE ENERGY-DISSIPATION, Thylakoids, Biochemistry, Thylakoid membrane, Light-harvesting complex, Photosystem II supercomplex, Rhodobacter sphaeroides, Structural Biology, Genetics, THYLAKOID MEMBRANES, ANTENNA, Molecular Biology, Arabidopsis Proteins, Non-photochemical quenching, PsbS, LIGHT-HARVESTING COMPLEXES, Photosystem II Protein Complex, food and beverages, Cell Biology, IN-VITRO, biology.organism_classification, Chloroplast, Microscopy, Electron, Membrane, Thylakoid, Mutation, Crystallization, PHOTOSYNTHETIC MEMBRANES
Abstract

The PsbS protein is a critical component in the regulation of non-photochemical quenching (NPQ) in higher plant photosynthesis. Electron microscopy and image analysis of grana membrane fragments from wild type and mutant Arabidopsis plants showed that the semi-crystalline domains of photosystem II supercomplexes were identical in the presence and absence of PsbS. However, the frequency of the domains containing crystalline arrays was increased in the absence of PsbS. Conversely, there was a complete absence of such arrays in the membranes of plants containing elevated amounts of this protein. It is proposed that PsbS controls the macro-organisation of the grana membrane, providing an explanation of its role in NPQ. (C) 2009 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.

Published
2010
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4. Origin of Chlorophyll Fluorescence in Plants at 55-75°C¶

Author

Kazimierz Strzałka, Hana Popelkova, Jerzy Kruk, Petr Ilík, Roman Kouril, Jan Nauš, and Beata Myśliwa-Kurdziel

Subjects
Absorption (pharmacology), Chlorophyll a, Analytical chemistry, food and beverages, macromolecular substances, General Medicine, Photosystem I, Photochemistry, Biochemistry, Fluorescence, Chloroplast, chemistry.chemical_compound, chemistry, Thylakoid, polycyclic compounds, Emission spectrum, Physical and Theoretical Chemistry, Chlorophyll fluorescence
Abstract

The origin of heat-induced chlorophyll fluorescence rise that appears at about 55-60 degrees C during linear heating of leaves, chloroplasts or thylakoids (especially with a reduced content of grana thylakoids) was studied. This fluorescence rise was earlier attributed to photosystem I (PSI) emission. Our data show that the fluorescence rise originates from chlorophyll a (Chl a) molecules released from chlorophyll-containing protein complexes denaturing at 55-60 degrees C. This conclusion results mainly from Chl a fluorescence lifetime measurements with barley leaves of different Chl a content and absorption and emission spectra measurements with barley leaves preheated to selected temperatures. These data, supported by measurements of liposomes with different Chl a/lipid ratios, suggest that the released Chl a is dissolved in lipids of thylakoid membranes and that with increasing Chl a content in the lipid phase, the released Chl a tends to form low-fluorescing aggregates. This is probably the reason for the suppressed fluorescence rise at 55-60 degrees C and the decreasing fluorescence course at 60-75 degrees C, which are observable during linear heating of plant material with a high Chl a/lipid ratio (e.g. green leaves, grana thylakoids, isolated PSII particles).

Published
2007
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5. Contributory presentations/posters

Author

N. Manoj, V. R. Srinivas, A. Surolia, M. Vijayan, K. Suguna, R. Ravishankar, R. Schwarzenbacher, K. Zeth, null Diederichs, G. M. Kostner, A. Gries, P. Laggner, R. Prassl, null Madhusudan, Pearl Akamine, Nguyen-huu Xuong, Susan S. Taylor, M. Bidva Sagar, K. Saikrishnan, S. Roy, K. Purnapatre, P. Handa, U. Varshney, B. K. Biswal, N. Sukumar, J. K. Mohana Rao, A. Johnson, Vasantha Pattabhi, S. Sri Krishna, Mira Sastri, H. S. Savithri, M. R. N. Murthy, Bindu Pillai, null Kannan, M. V. Hosur, Mukesh Kumar, Swati Patwardhan, K. K. Kannan, B. Padmanabhaa, S. Sasaki-Sugio, M. Nukaga, T. Matsuzaki, S. Karthikevan, S. Sharma, A. K. Sharma, M. Paramasivam, P. Kumar, J. A. Khan, S. Yadav, A. Srinivasan, T. P. Singh, S. Gourinath, Neelima Alam, A. Srintvasan, Vikas Chandra, Punit Kaur, Ch. Betzel, S. Ghosh, A. K. Bera, S. Bhattacharya, S. Chakraborty, A. K. Pal, B. P. Mukhopadhyay, I. Dey, U. Haldar, Asok Baneriee, Jozef Sevcik, Adriana Solovicova, K. Sekar, M. Sundaralingam, N. Genov, Dong-cai Liang, Tao Jiang, Ji-ping Zhang, Wen-rui Chang, Wolfgang Jahnke, Marcel Blommers, S. C. Panchal, R. V. Hosur, Bindu Pillay, Puniti Mathur, S. Srivatsun, Ratan Mani Joshi, N. R. Jaganathan, V. S. Chauhan, H. S. Atreya, S. C. Sahu, K. V. R. Chary, Girjesh Govil, Elisabeth Adjadj, Éric Quinjou, Nadia Izadi-Pruneyre, Yves Blouquit, Joël Mispelter, Bernadette Heyd, Guilhem Lerat, Philippe Milnard, Michel Desmadreil, Y. Lin, B. D. Nageswara Rao, Vidva Raghunathan, Mei H. Chau, Prashant Pesais, Sudha Srivastava, Evans Coutinho, Anil Saran, Leizl F. Sapico, Jayson Gesme, Herbert Lijima, Raymond Paxton, Thamarapu Srikrishnan, C. R. Grace, G. Nagenagowda, A. M. Lynn, Sudha M. Cowsik, Sarata C. Sahu, S. Chauhan, A. Bhattacharya, G. Govil, Anil Kumar, Maurizio Pellecchia, Erik R. P. Zuiderweg, Keiichi Kawano, Tomoyasu Aizawa, Naoki Fujitani, Yoichi Hayakawa, Atsushi Ohnishi, Tadayasu Ohkubo, Yasuhiro Kumaki, Kunio Hikichi, Katsutoshi Nitta, V. Rani Parvathy, R. M. Kini, Takumi Koshiba, Yoshihiro Kobashigawa, Min Yao, Makoto Demura, Astushi Nakagawa, Isao Tanaka, Kunihiro Kuwajima, Jens Linge, Seán O. Donoghue, Michael Nilges, G. Chakshusmathi, Girish S. Ratnaparkhi, P. K. Madhu, R. Varadarajan, C. Tetreau, M. Tourbez, D. Lavalette, M. Manno, P. L. San Biagio, V. Martorana, A. Emanuele, S. M. Vaiana, D. Bulone, M. B. Palma-Vittorelli, M. U. Palma, V. D. Trivedi, S. F. Cheng, W. J. Chien, S. H. Yang, S. Francis, D. K. Chang, Renn Batra, Michael A. Geeves, Dietmar J. Manstein, Joanna Trvlska, Pawel Grochowski, Maciej Geller, K. Ginalski, P. Grochowski, B. Lesyng, P. Lavalette, Y. Blouquit, D. Roccatano, A. Amadei, A. Di Nola, H. J. C. Berendsen, Bosco Ho, P. M. G. Curmi, H. Berry, D. Lairez, E. Pauthe, J. Pelta, V. Kothekar, Shakti Sahi, M. Srinivasan, Anil K. Singh, Kartha S. Madhusudnan, Fateh S. Nandel, Harpreet Kaur, Balwinder Singh, D. V. S. Jain, K. Anton Feenstra, Herman J. C. Berendsen, F. Tama, Y. -H. Sanejouand, N. Go, Deepak Sharma, Sunita Sharma, Santosh Pasha, Samir K. Brahmachari, R. Viiavaraghavan, Jyoti Makker, Sharmisllia Dey, S. Kumar, G. S. Lakshmikanth, G. Krishnamoorthy, V. M. Mazhul, E. M. Zaitseva, Borys Kierdaszuk, J. Widengren, B. Terry, Ü. Mets, R. Rigler, R. Swaminathan, S. Thamotharan, N. Yathindra, Y. Shibata, H. Chosrowjan, N. Mataga, I. Morisima, Tania Chakraharty, Ming Xiao, Roger Cooke, Paul Selvin, C. Branca, A. Faraone, S. Magazù, G. Maisano, P. Migliardo, V. Villari, Digambar V. Behere, M. Sharique Zahida Waheed Deva, M. Brunori, F. Cutruzzolà, Q. H. Gibson, C. Savino, C. Travaglini-Allocatelli, B. Vallone, Swati Prasad, Shyamalava Mazumdar, Samaresh Mitra, P. Soto, R. Fayad, I. E. Sukovataya, N. A. Tyulkova, Sh. V. Mamedov, B. Aktas, M. Canturk, B. Aksakal, R. Yilgin, K. I. Bogutska, N. S. Miroshnichenko, S. Chacko, M. DiSanto, J. A. Hypolite, Y-M. Zheng, A. J. Wein, M. Wojciechowski, T. Grycuk, J. Antosiewicz, Marc A. Ceruso, Alfredo Di Nola, Subhasis Bandvopadhvay, Bishnu P. Chatterjee, Devapriva Choudhury, Andrew Thompson, Vivian Stojanoff, Jerome Pinkner, Scott Hultgren, Stefan Khight, Delphine Flatters, Julia Goodfellow, Fumi Takazawatt, Minoru Kanehisa, Masaki Sasai, Hironori Nakamura, Wang Bao Han, Yuan Zheng, Wang Zhi Xin, Pan xin Min, Vlnod Bhakuni, Sangeeta Kulkarni, Atta Ahmad, Koodathingal Prakash, Shashi Prajapati, Alexey Surin, Tomoharu Matsumoto, Li Yang, Yuki Nakagawa, Kazumoto Kimura, Yoshiyuki Amemiya, Gennady V. Semisotnov, Hiroshi Kihara, Saad Tayyab, Salman Muzammil, Yogesh Kumar, Vinod Bhakuni, Monica Sundd, Suman Kundu, M. V. Jagannadham, Medicherla V. Jagannadham, Bina Chandani, Ruby Dhar, Lalankumar Sinha, Deepti Warrier, Sonam Mehrotra, Purnima Khandelwal, Subhendu Seth, Y. U. Sasidhar, C. Ratna Prabha, Arun Gidwani, K. P. Madhusudan, Akira R. Kinjo, Ken Nishikawa, Suvobrata Chakravarty, Raghavan Varadarajan, K. Noyelle, P. Haezebrouck, M. Joniau, H. Van Dael, Sheffali Dash, Indra Brata Jha, Rajiv Bhat, Prasanna Mohanty, A. K. Bandyopadhyay, H. M. Sonawat, Ch. Mohan Rao, Siddhartha Datta, K. Rajaraman, B. Raman, T. Ramakrishna, A. Pande, J. Pande, S. Betts, N. Asherie, O. Ogun, J. King, G. Benedek, I. V. Sokolova, G. S. Kalacheva, Masashi Sonoyama, Yasunori Yokoyama, Kunihiro Taira, Shigeki Mitaku, Chicko Nakazawal, Takanori Sasakil, Yuri Mukai, Naoki Kamo, Seema Dalal, Lynne Regan, Shigeki Mituku, Mihir Roychoudhury, Devesh Kumar, Dénes Lőrinczv, Franciska Könczöl, László Farkas, Joseph Belagyi, Christoph Schick, Christy A. Thomson, Vettai S. Ananthanarayanan, E. G. Alirzayeva, S. N. Baba-Zade, M. Michael Gromiha, M. Oobatake, H. Kono, J. An, H. Uedaira, A. Sarai, Kazufumi Takano, Yuriko Yamagata, Katsuhide Yutani, Gouri S. Jas, Victor Muñoz, James Hofrichter, William A. Eaton, Jonathan Penoyar, Philip T. Lo Verde, J. Kardos, Á. Bódi, I. Venekei, P. Závodszky, L. Gráf, András Szilágyi, Péter Závodszky, R. D. Allan, J. Walshaw, D. N. Woolfson, Jun Funahashi, Savan Gupta, M. Mangoni, P. Roccatano, Gosu Ramachandraiah, Nagasuma R. Chandra, Barbara Ciani, Derek N. Woolfson, Usha B. Nair, Kanwal J. Kaur, Dinakar M. Salunke, Chittoor P. Swaminathan, Avadhesha Surolia, A. Pramanik, P. Jonasson, G. Kratz, O. T. Jansson, P. -Å. Nygren, S. Ståhl, K. Ekberg, B. -L. Johansson, S. Uhlén, M. Uhlén, H. Jörnvall, J. Wahren, Karin Welfle, Rolf Misselwitz, Wolfgang Höhne, Heinz Welfle, L. G. Mitskevich, N. V. Fedurkina, B. I. Kurganov, Gotam K. Jarori, Haripada Maity, J. Guharay, B. Sengupta, P. K. Sengupta, K. Sridevi, S. R. Kasturi, S. P. Gupta, Gunjan Agarwal, Suzanne Kwong, Robin W. Briehl, O. I. Ismailova, N, A. Tyulkova, C. Hariharan, D. Pines, E. Pines, M. Zamai, R. Cohen-Luria, A. Yayon, A. H. Parola, M. J. Padya, G. A. Spooner, D. N. Woolfeon, Panchan Bakshi, D. K. Bharadwaj, U. Sharma, N. Srivastava, R. Barthwal, N. R. Jagannathan, Keiko Matsuda, Takaaki Nishioka, Nobuhiro Go, T. Aita, S. Urata, Y. Husimi, Mainak Majumder, Nicola G. A. Abrescia, Lucy Malinina, Juan A. Subirana, Juan Aymami, Ramón Eritxa, Miquel Coll, B. J. Premraj, R. Thenmalarchelvi, P. Satheesh Kumar, N. Gautham, Lou -Sing Kan, null Ming-Hou, Shwu-Bin Lin, Tapas Sana, Kanal B. Roy, N. Bruant, D. Flatters, R. Lavery, D. Genest, Remo Rons, Heinz Sklenar, Richard Lavery, Sudip Kundu, Dhananjay Bhattacharyya, Debashree Bandyopadhyay, Ashoke Ranjan Thakur, Rabi Majumdar, F. Barceló, J. Portugal, Sunita Ramanathan, B. J. Rao, Mahua Gliosli, N. Vinay Kumar, Umesh Varshney, Shashank S. Pataskar, R. Sarojini, S. Selvasekarapandian, P. Kolandaivel, S. Sukumar, P. Kolmdaivel, Motilal Maiti, Anjana Sen, Suman Das, Elisa Del Terra, Chiara Suraci, Silvia Diviacco, Franco Quadrifoglio, Luigi Xodo, Arghya Ray, G. Karthikeyan, Kandala V. R. Chary, Basuthkar J. Rao, Anwer Mujeeb, Thomas L. James, N. Kasyanenko, E. E. F. Haya, A. Bogdanov, A. Zanina, M. R. Bugs, M. L. Cornélio, M. Ye. Tolstorukov, Nitish K. Sanval, S. N. Tiwari, Nitish K. Sanyal, Mihir Roy Choudhury, P. K. Patel, Neel S. Bhavesh, Anna Gabrielian, Stefan Wennmalm, Lars Edman, Rudolf Rigler, B. Constantinescu, L. Radu, I. Radulcscu, D. Gazdaru, Sebastian Wärmländer, Mikael Leijon, Setsuyuki Aoki, Takao Kondo, Masahiro Ishiura, V. A. Pashinskaya, M. V. Kosevich, V. S. Shelkovsky, Yu. P. Blagoy, Ji-hua Wang, R. Malathi, K. Chandrasekhar, E. R. Kandimalla, S. Agrawal, V. K. Rastogi, M. Alcolea Palafox, Chatar Singh, A. D. Beniaminov, S. A. Bondarenko, E. M. Zdobnov, E. E. Minyat, N. B. Ulyanov, V. I. Ivanov, J. S. Singh, Kailas D. Sonawane, Henri Grosjean, Ravindra Tewari, Uddhavesh B. Sonavane, Annie Morin, Elizabeth A. Doherty, Jennifer A. Doudna, H. Tochio, S. Sato, H. Matsuo, M. Shirakawa, Y. Kyogoku, B. Javaram, Surjit B. Dixit, Piyush Shukla, Parul Kalra, Achintya Das, Kevin McConnell, David L. Beveridge, W. H. Sawyer, R. Y. S. Chan, J. F. Eccelston, Yuling Yan, B. E. Davidson, Eimer Tuite, Bengt Norden, Peter Nielsen, Masayuki Takahashi, Anirban Ghosh, Manju Bansal, Frauke Christ, Hubert Thole, Wolfgang Wende, Alfred Pingoud, Vera Pingoud, Pratibha Mehta Luthra, Ramesh Chandra, Ranjan Sen, Rodney King, Robert Weisberg, Olaf F. A. Larsen, Jos Berends, Hans A. Heus, Cornelis W. Hilbers, Ivo H. M. van Stokkum, Bas Gobets, Rienk van Grondelle, Herbert van Amerongen, HE. Sngrvan, Yu. S. Babayan, N. V. Khudaverdian, M. Gromiha, F. Pichierri, M. Aida, P. Prabakaran, K. Sayano, Saulius Serva, Eglė Merkienė, Giedrius Vilkaitis, Elmar Weinhold, Saulius Klimašauskas, Eleonora Marsich, Antonella Bandiera, Giorgio Manzini, G. Potikyan, V. Arakelyan, Yu. Babayan, Alex Ninaber, Julia M. Goodfellow, Yoichiro Ito, Shigeru Ohta, Yuzuru Husimi, J. Usukura, H. Tagami, H. Aiba, Mougli Suarez, Elia Nunes, Deborah Keszenman, E. Carmen Candreva, Per Thyberg, Zeno Földes-Papp, Amita Joshi, Dinesh Singh, M. R. Rajeswari, null Ira, M. Pregetter, H. Amenitsch, J. Chapman, B. N. Pandev, K. P. Mishra, E. E. Pohl, J. Sun, I. I. Agapov, A. G. Tonevitsky, P. Pohl, S. M. Dennison, G. P. Gorbeako, T. S. Dynbko, N. Pappavee, A. K. Mishra, Prieto Manuel, Almeida Rodrigo, Loura Luis, L. Ya. Gendel, S. Przestalski, J. Kuczera, H. Kleszczyńska, T. Kral, E. A. Chernitsky, O. A. Senkovich, V. V. Rosin, Y. M. Allakhverdieva, G. C. Papageorgiou, R. A. Gasanov, Calin Apetrei, Tudor Savopol, Marius Balea, D. Cucu, D. Mihailescu, K. V. Ramanathan, Goran Bačić, Nicolas Sajot, Norbert Garnier, Serge Crouzy, Monique Genest, Z. S. Várkonyi, O. Zsiros, T. Farkas, Z. Combos, Sophie Cribier, I. F. Fraceto, S. Schreier, A. Spisni, F. de Paula, F. Sevšek, G. Gomišček, V. Arrigler, S. Svetina, B. Žekš, Fumimasa Nomura, Miki Nagata, Kingo Takiguchi, Hirokazu Hotani, Lata Panicker, P. S. Parvathanathan, A. Ishino, A. Saitoh, H. Hotani, K. Takiguchi, S. Afonin, A. Takahashi, Y. Nakato, T. Takizawa, Dipti Marathe, Kent Jørgensen, Satinder S. Rawat, R. Rukmini, Amitabha Chattopadhyay, M. Šentiurc, J. Štrancar, Z. Stolič, K. Filipin, S. Pečar, S. C. Biswas, Satyen Sana, Anunay Samanta, Koji Kinoshita, Masahito Yamazaki, Tetsuhiko Ohba, Tai Kiuchi, null Yoshitoshi, null Kamakura, Akira Goto, Takaaki Kumeta, Kazuo Ohki, I. P. Sugar, T. E. Thompson, K. K. Thompson, R. L. Biltonen, Y. Suezaki, H. Ichinose, M. Akivama, S. Matuoka, K. Tsuchihashi, S. Gasa, P. Mattjus, J. G. Molotkovsky, H. M. Pike, R. E. Brown, Ashish Arora, Jörg H. Kleinschmidt, Lukas K. Tamm, O. G. Luneva, K. E. Kruglyakova, V. A. Fedin, O. S. Kuptsoya, J. W. Borst, N. V. Visser, A. J. W. G. Visser, T. S. Dyubko, Toshihiko Ogihara, Kiyoshi Mishima, A. L. Shvaleva, N. Č. Radenović, P. M. Minić, M. G. Jeremić, Č. N. Radenović, T. F. Aripov, E. T. Tadjibaeva, O. N. Vagina, M. V. Zamaraeva, B. A. Salakhutdinov, A. Cole, M. Poppofl, C. Naylor, R. Titball, A. K. Basak, J. T. Eaton, C. E. Naylor, N. Justin, D. S. Moss, R. W. Titball, F. Nomura, M. Nagata, S. Ishjkawa, S. Takahashi, Kaoru Obuchi, Erich Staudegger, Manfred Kriechbaum, Robert I. Lehrer, Alan J. Waring, Karl Lohner, Susanne Gangl, Bernd Mayer, Gottfried Köhler, J. Shobini, Z. Guttenberg, B. Lortz, B. Hu, E. Sackmann, N. M. Kozlova, L. M. Lukyanenko, A. N. Antonovich, E. I. Slobozhanina, Andrey V. Krylov, Yuri N. Antonenko, Elena A. Kotova, Alexander A. Yaroslavov, Subhendu Ghosh, Amal K. Bera, Sudipto Das, Eva Urbánková, Masood Jelokhani-Niaraki, Karl Freeman, Petr Jezek, P. B. Usmanov, A. Ongarbaev, A. K. Tonkikh, Peter Pohl, Sapar M. Saparov, P. Harikumar, J. P. Reeves, S. Rao, S. K. Sikdar, A. S. Ghatpande, C. Corsso, A. C. Campos de Carvalho, W. A. Varanda, C. ElHamel, E. Dé, N. Saint, G. Molle, Anurae Varshney, M. K. Mathew, E. Loots, E. Y. Isacoff, Michiki Kasai, Naohiro Yamaguchi, Paramita Ghosh, Joseph Tigyi, Gabor Tigyi, Karoly Liliom, Ricardo Miledi, Maja R. Djurisic, Pavle R. Andjus, Indira H. Shrivastava, M. S. P. Sansom, C. Barrias, P. F. Oliveira, A. C. Mauricio, A. M. Rebelo da Costa, I. A. Lopes, S. V. Fedorovich, V. S. Chubanov, M. V. Sholukh, S. V. Konev, N. Fedirko, V. Manko, M. Klevets, N. Shvinka, B. S. Prabhananda, Mamata H. Kombrabail, S. Aravamudhan, Berenice Venegas-Cotero, Ivan Ortega Blake, Zhi-hong Zhang, Xiao-jian Hu, Han-qing Zhou, Wei-ying Cheng, Hang-fang Feng, L. O. Dubitsky, L. S. Vovkanvch, I. A. Zalyvsky, E. Savio-Galimberti, P. Bonazzola, J. E. Ponce-Homos, Mario Parisi, Claudia Capurro, Roxana Toriano, Laxma G. Ready, Larry R. Jones, David D. Thomas, B. A. Tashmukhamedov, B. T. Sagdullaev, D. Heitzmann, R. Warth, M. Bleich, R. Greger, K. T. G. Ferreira, H. G. Ferreira, Orna Zagoory, Essa Alfahel, Abraham H. Parola, Zvi Priel, H. Hama-Inaba, R. Wang, K. Choi, T. Nakajima, K. Haginoya, M. Mori, H. Ohyama, O. Yukawa, I. Hayata, Nanda B. Joshi, Sridhar K. Kannurpatti, Preeti G. Joshi, Mau Sinha, Xun Shen, Tianhui Hu, Ling Bei, Menno L. W. Knetsch, Nicole Schäfers, John Sandblom, Juris Galvanovskis, Roxana Pologea-Moraru, Eugenia Kovacs, Alexandra Dinu, S. H. Sanghvi, V. Jazbinšek, G. Thiel, W. Müller, G. Wübeller, Z. Tronteli, Leš Fajmut, Marko Marhl, Milan Brumen, I. D. Volotovski, S. G. Sokolovski, M. R. Knight, Alexei N. Vasil’ev, Alexander V. Chalyi, P. Sharma, P. J. Steinbach, M. Sharma, N. D. Amin, J. Barchir, R. W. Albers, H. C. Pant, M. Balasubramanyam, M. Condrescu, J. P. Gardner, Shamci Monajembashi, Gotz Pilarczyk, K. O. Greulich, F. M. El-Refaei, M. M. Talaat, A. I. El-Awadi, F. M. Ali, Ivan Tahradník, Jana Pavelková, Alexandra Zahradniková, Boris S. Zhorov, Vettai S. Ananthanaravanan, M. Ch. Michailov, E. Neu, W. Seidenbusch, E. Gornik, D. Martin, U. Welscher, D. G. Weiss, B. R. Pattnaik, A. Jellali, V. Forster, D. Hicks, J. Sahel, H. Dreyfus, S. Picaud, Hong-Wei Wang, Sen-fang Sui, Pradeep K. Luther, John Barry, Ed Morris, John Squire, C. Sivakama Sundari, D. Balasubramanian, K. Veluraia, T. Hema Thanka Christlet, M. Xavier Suresh, V. Laretta-Garde, Dubravka Krilov, Nataša Stojanović, Janko N. Herak, Ravi Jasuja, Maria Ivanova, Rossen Mirchev, Frank A. Ferrone, David Stopar, Ruud B. Spruijt, Cor J. A. M. Wolfs, Marcus A. Hemminga, G. Arcovito, M. De Spirito, Rajendra K. Agrawal, Amy B. Heagle, Pawel Penczek, Robert Grassucci, Joachim Frank, Manjuli R. Sharma, Loice H. Jeyakumar, Sidney Fleischer, Terence Wagenknecht, Carlo Knupp, Peter M. G. Munro, Eric Ezra, John M. Squire, Koji Ichihara, Hidefumi Kitazawa, Yusuke Iguchi, Tomohiko J. Itoh, Greta Pifat, Marina Kveder, Slavko Pečar, Milan Schara, Deepak Nair, Kavita Singh, Kanury V. S. Rao, Kanwaljeet Kaur, Deepti Jain, B. Sundaravadivel, Manisha Goel, D. M. Salunke, E. I. Kovalenko, G. N. Semenkova, S. N. Cherenkevich, T. Lakshmanan, D. Sriram, S. Srinivasan, D. Loganathan, T. S. Ramalingam, J. A. Lebrón, P. J. Bjorkman, A. K. Singh, T. N. Gayatri, Ernesto R. Caffarena, J. Raul Grigera, Paulo M. Bisch, V. Kiessling, P. Fromherz, K. N. Rao, S. M. Gaikwad, M. I. Khan, C. G. Suresh, P. Kaliannan, M. Elanthiraiyan, K. Chadha, J. Payne, J. L. Ambrus, M. P. N. Nair, Madhavan P. N. Nair, S. Mahajan, K. C. Chadha, R. Hewitt, S. A. Schwartz, J. Bourguignon, M. Faure, C. Cohen-Addad, M. Neuburger, R. Ober, L. Sieker, D. Macherel, R. Douce, D. S. Gurumurthy, S. Velmurugan, Z. Lobo, Ratna S. Phadke, Prashant Desai, I. M. Guseinova, S. Yu. Suleimanov, I. S. Zulfugarov, S. N. Novruzova, J. A. Aliev, M. A. Ismayilov, T. V. Savchenko, D. R. Alieva, Petr Ilík, Roman Kouřil, Hana Bartošková, Jan Nauš, Jvoti U. Gaikwad, Sarah Thomas, P. B. Vidyasagar, G. Garab, I. Simidjiev, S. Rajagopal, Zs. Várkonyi, S. Stoylova, Z. Cseh, E. Papp, L. Mustárdy, A. Holzenburg, R. Bruder, U. K. Genick, T. T. Woo, D. P. Millar, K. Gerwert, E. D. Getzoff, Tamás Jávorfí, Győző Garab, K. Razi Naqvi, Md. Kalimullah, Jyoti Gaikwad, Manoj Semwal, Roman Kouril, Petr Ilik, Man Naus, István Pomozi, Gábor Horváth, Rüdiger Wehner, Gary D. Bernard, Ana Damjanović, Thorsten Ritz, Klaus Schulten, Wang Jushuo, Shan Jixiu, Gong Yandao, Kuang Tingyun, Zhao Nanming, Arvi Freiberg, Kõu Timpmann, Rein Ruus, Neal W. Woodbury, E. V. Nemtseva, N. S. Kudryasheva, A. G. Sizykh, V. N. Shikhov, T. V. Nesterenko, A. A. Tikhomirov, Giorgio Forti, Giovanni Finazzi, Alberto Furia, Romina Paola Barbagallo, S. Iskenderova, R. Agalarov, R. Gasanov, Miyashita Osamu, G. O. Nobuhiro, R. K. Soni, M. Ramrakhiani, Hiromasa Yagi, Kacko Tozawa, Nobuaki Sekino, Tomoyuki Iwabuchi, Masasuke Yoshida, Hideo Akutsu, A. V. Avetisyan, A. D. Kaulen, V. P. Skulachev, B. A. Feniouk, Cécile Breyton, Werner Kühlbrandt, Maria Assarsson, Astrid Gräslund, G. Horváth, B. Libisch, Z. Gombos, N. V. Budagovskaya, N. Kudryasheva, Erisa Harada, Yuki Fukuoka, Tomoaki Ohmura, Arima Fukunishi, Gota Kawai, Kimitsuna Watanabe, Jure Derganc, Bojan Božič, Saša Svetina, Boštjan Žekš, J. F. Y. Hoh, Z. B. Li, G. H. Rossmanith, E. L. de Beer, B. W. Treijtel, P. L. T. M. Frederix, T. Blangè, S. Hénon, F. Galtet, V. Laurent, E. Planus, D. Isabey, L. S. Rath, P. K. Dash, M. K. Raval, C. Ramakrishnan, R. Balaram, Milan Randic, Subhash C. Basak, Marjan Vracko, Ashesh Nandy, Dragan Amic, Drago Beslo, Sonja Nikolic, Nenad Trinajstic, J. Walahaw, Marc F. J. Lensink, Boojala V. B. Reddy, Ilya N. Shindylov, Philip E. Bourne, M. C. Donnamaria, J. de Xammar Oro, J. R. Grigera, Monica Neagu, Adrian Neagu, Matej Praprotnik, Dušanka Janežič, Pekka Mark, Lennart Nilsson, L. La Fata, Laurent E. Dardenne, Araken S. Werneck, Marçal de O. Neto, N. Kannan, S. Vishveshwara, K. Veluraja, Gregory D. Grunwald, Alexandra T. Balaban, Kanika Basak, Brian D. Gute, Denise Mills, David Opitz, Krishnan Balasubramanian, G. I. Mihalas, Diana Lungeanu, G. Macovievici, Raluca Gruia, C. Cortez-Maghelly, B. Dalcin, E. P. Passos, S. Blesic, M. Ljubisavljevic, S. Milosevic, D. J. Stratimirovic, Nandita Bachhawat, Shekhar C. Mande, A. Nandy, Ayumu Saito, Koichi Nishigaki, Mohammed Naimuddin, Takatsugu Hirokawa, Mitsuo Ono, Hirotomo Takaesu, M. I. El Gohary, Abdalla S. Ahmed, A. M. Eissa, Hiroshi Nakashima, G. P. S. Raghava, N. Kurgalvuk, O. Goryn, Bernard S. Gerstman, E. V. Gritsenko, N. N. Remmel, O. M. Maznyak, V. A. Kratasyuk, E. N. Esimbekova, D. Tchitchkan, S. Koulchitsky, A. Tikhonov, A. German, Y. Pesotskaya, S. Pashkevich, S. Pletnev, V. Kulchitsky, Umamaheswar Duvvuri, Sridhar Charagundla, Rahim Rizi, John S. Leigh, Ravinder Reddy, Mahesh Kumar, O. Coshic, P. K. Julka, O. K. Rath, NR. Jagannathan, Karina Roxana Iliescu, Maria Sajin, Nicolcta Moisoi, Ileana Petcu, A. I. Kuzmenko, R. P. Morozova, I. A. Nikolenko, G. V. Donchenko, M. K. Rahman, M. M. Ahmed, Takehiro Watanabe, Y. Rubin, H. Gilboa, R. Sharony, R. Ammar, G. Uretzky, M. Khubchandani, H. N. Mallick, V. Mohan Kumar, Arijitt Borthakur, Erik M. Shapiro, M. Gulnaz Begum, Mahaveer N. Degaonkar, S. Govindasamy, Ivan Dimitrov, T. A. Kumosani, W. Bild, I. Stefanescu, G. Titescu, R. Iliescu, C. Lupusoru, V. Nastasa, I. Haulica, Gopal Khetawat, N. Faraday, M. Nealen, S. Noga, P. F. Bray, T. V. Ananieva, E. A. Lycholat, MV. Kosevich, S. G. Stepanyan, S. V. Antonyuk, R. Khachatryan, H. Arakelian, A. Kumar, S. Ayrapetyan, V. Mkheyan, S. Agadjanyan, A. Khachatryan, S. S. Rajan, V. Kabaleeswaran, Geetha Gopalakrishnan, T. R. Govindachari, Meera Ramrakhiani, Phillip Lowe, Andrew Badley, David C. Cullen, H. Hermel, W. Schmahl, H. Möhwald, Nirmalya Majumdar, Joydip Das, András Dér, Loránd Kelemen, László Oroszi, András Hámori, Jeremy J. Ramsden, Pál Ormos, D. Savitri, Chanchal K. Mitra, Toshio Yanagida, Seiji Esaki, Yuji Kimura, Tomoyuki Nishida, Yosiyuki Sowa, M. Radu, V. K. Koltover, Ya. I. Estrin, L. A. Kasumova, V. P. Bubnov, E. E. Laukhina, Rajiv Dotta, M. Degaonkar, P. Raghunathan, Rama Jayasundar, Pavel Novák, Milan Marko, Ivan Zahradník, Hiroaki Hirata, Hidetake Miyata, J. Balaji, P. Sengupta, S. Maiti, M. Gonsalves, A. L. Barker, J. V. Macpherson, D. O’Hare, C. P. Winlove, P. R. Unwin, R. Phillip, S. Banerjee, G. Ravindra Kumar, K. Nagayaka, R. Danev, S. Sugitani, K. Murata, Michael Gősch, H. Blom, P. Thyberg, Z. Földes-Papp, G. Björk, J. Holm, T. Heino, Masashi Yokochi, Fuyuhiko Inagaki, Masami Kusunoki, E. K. Matthews, J. Pines, Yu. P. Chukova, Vitaly K. Koltover, Geetanjali Bansal, Uma Singh, M. P. Bansal, Kotoko Nakata, Tastuya Nakano, Tsuguchika Kaminuma, B. P. S. Kang, U. Singh, Bonn Kirn, Neja Potocnik, Vito Stare, Latal Shukla, V. Natarajan, T. P. A. Devasagayam, M. D. Sastry, P. C. Kesavan, R. Sayfutdinov, V. V. Adamovich, D. Yu. Rogozin, A. G. Degermendzhy, C. L. Khetrapal, G. A. Nagana Gowda, Kedar Nath Ghimire, Ishida Masaru, H. Fujita, S. Ishiwata, Y. Kishimoto, S. Kawahara, M. Suzuki, H. Mori, M. Mishina, Y. Kirino, H. Ohshima, A. S. Dukhin, V. N. Shilov, P. J. Goetz, and R. K. Mishra

Subjects
0303 health sciences, biology, General Medicine, 010402 general chemistry, 01 natural sciences, Horseradish peroxidase, General Biochemistry, Genetics and Molecular Biology, 0104 chemical sciences, 03 medical and health sciences, Biochemistry, Manganese porphyrin, biology.protein, Enzyme reconstitution, General Agricultural and Biological Sciences, 030304 developmental biology
Published
1999
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6. [Untitled]

Author

Benoît Schoefs, Jan Nauš, Petr Ilík, and Roman Kouril

Subjects
Chlorophyll b, Chlorophyll a, medicine.diagnostic_test, Chemistry, Analytical chemistry, food and beverages, macromolecular substances, Cell Biology, Plant Science, General Medicine, Biochemistry, Fluorescence, chemistry.chemical_compound, Pigment, Chlorophyll, visual_art, Spectrophotometry, polycyclic compounds, visual_art.visual_art_medium, medicine, Absorption (electromagnetic radiation), Chlorophyll fluorescence
Abstract

The concentration limits for spectrophotometric and spectrofluorimetric determinations of the chlorophyll (Chl) a/b ratio in barley leaves were studied using 80% acetone extracts at room temperature. The optimum sample absorbances (at 663.2 nm – maximum of the QY) band of Chl a) for the Chl a/b determination were determined. For given spectrometers and sample positions, these absorbances ranged between 0.2 and 1.0 and 0.008–0.1 for the absorption and fluorescence methods, respectively. Precision of the measurements and the distorting effects are discussed. The lower limits of both absorption and fluorescence methods depend on sensitivity of the spectrometers for the Chl b detection. The spectrophotometric determination of Chl a/b ratio at higher Chl concentrations can be distorted by the chlorophyll fluorescence signal. The extent of this distortion depends on sample-detector geometry in any given type of the spectrometer. The effect of inner filter of Chl molecules and the detection instrumental function affect the value of the upper limit for the spectrofluorimetric method. Both methods were applied to estimate the Chl a/b ratio in pigment extracts from greening barley leaves, which are characterized by a low Chl concentration and a high Chl a/b ratio at the beginning of greening process.

Published
1999
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7. Organization of oxidative phosphorylation supercomplexes in intact mitochondria

Author

Natalya V. Dudkina, Hans-Peter Braun, Jelle B. Bultema, Egbert J. Boekema, Roman Kouril, and Electron Microscopy

Subjects
Chemistry, Biophysics, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Oxidative phosphorylation, Cell Biology, Mitochondrion, Biochemistry, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Cell biology
Published
2010

8. Structure and function of mitochondrial supercomplexes

Author

Natalya V. Dudkina, Katrin Peters, Egbert J. Boekema, Roman Kouril, Hans-Peter Braun, Electron Microscopy, and Groningen Biomolecular Sciences and Biotechnology

Subjects
Models, Molecular, MAMMALIAN MITOCHONDRIA, Electron Microscope Tomography, Supercomplex, CYTOCHROME-C-OXIDASE, RESPIRATORY-CHAIN SUPERCOMPLEXES, Respirasome, Biophysics, OXIDOREDUCTASE COMPLEX-I, Oxidative phosphorylation, DIMERIC ATP SYNTHASE, Biology, Mitochondrion, Biochemistry, law.invention, chemistry.chemical_compound, BOVINE HEART-MITOCHONDRIA, Imaging, Three-Dimensional, law, Chlorophyta, OXIDATIVE-PHOSPHORYLATION, Electron microscopy, INNER MEMBRANES, Cytochrome c oxidase, 3-DIMENSIONAL STRUCTURE, Plant Proteins, ATP synthase, Cell Biology, Structure and function, Mitochondria, Microscopy, Electron, Monomer, chemistry, Electron Transport Chain Complex Proteins, PLANT-MITOCHONDRIA, biology.protein, Electron microscope, Protein Multimerization
Abstract

The five complexes (complexes I-V) of the oxidative phosphorylation (OXPHOS) system of mitochondria can be extracted in the form of active supercomplexes. Single-particle electron microscopy has provided 2D and 3D data describing the interaction between complexes I and III, among I. Ill and IV and in a dimeric form of complex V. between two ATP synthase monomers. The stable interactions are called supercomplexes which also form higher-ordered oligomers. Cryo-electron tomography provides new insights on how these supercomplexes are arranged within intact mitochondria. The structure and function of OXPHOS supercomplexes are discussed. (C) 2009 Elsevier B.V. All rights reserved.

Published
2010

9. Chapter 10 Purification of the cytochrome C reductase/cytochrome C oxidase super complex of yeast mitochondria

Author

Hans-Peter, Braun, Stephanie, Sunderhaus, Egbert J, Boekema, and Roman, Kouril

Subjects
Electron Transport Complex IV, Electrophoresis, Polyacrylamide Gel, Saccharomyces cerevisiae, Oxidoreductases, Ultracentrifugation, Culture Media, Mitochondria
Abstract

The protein complexes of the respiratory chain interact by forming large protein particles called respiratory supercomplexes or "respirasomes". Biochemical characterization of these particles proved to be difficult because of their instability. Here we describe a strategy to isolate and characterize the cytochrome c reductase/cytochrome c oxidase supercomplex of yeast, also termed the III + IV supercomplex, which is based on lactate cultivation of yeast, gentle isolation of mitochondria, membrane solubilization by digitonin, sucrose gradient ultracentrifugation, and native gel electrophoresis. The procedure yields pure forms of two varieties of the III + IV supercomplex composed of dimeric complex III and one or two copies of monomeric complex IV. Supercomplex preparations can be used for physiological or structural investigations.

Published
2009

10. Chapter 10 Purification of the Cytochrome c Reductase/Cytochrome c Oxidase Super Complex of Yeast Mitochondria

Author

Hans-Peter Braun, Stephanie Sunderhaus, Egbert J. Boekema, and Roman Kouril

Subjects
chemistry.chemical_compound, biology, Biochemistry, chemistry, Cytochrome C1, Cytochrome b, Coenzyme Q – cytochrome c reductase, Cytochrome c, biology.protein, Cardiolipin, Respiratory chain, Cytochrome c oxidase, Electron Transport Complex IV
Abstract

The protein complexes of the respiratory chain interact by forming large protein particles called respiratory supercomplexes or "respirasomes". Biochemical characterization of these particles proved to be difficult because of their instability. Here we describe a strategy to isolate and characterize the cytochrome c reductase/cytochrome c oxidase supercomplex of yeast, also termed the III + IV supercomplex, which is based on lactate cultivation of yeast, gentle isolation of mitochondria, membrane solubilization by digitonin, sucrose gradient ultracentrifugation, and native gel electrophoresis. The procedure yields pure forms of two varieties of the III + IV supercomplex composed of dimeric complex III and one or two copies of monomeric complex IV. Supercomplex preparations can be used for physiological or structural investigations.

Published
2009
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11. Association of chlorophyll a/c(2) complexes to photosystem I and photosystem II in the cryptophyte Rhodomonas CS24

Author

Roman Kouril, Jan P. Dekker, Sami Kereiche, Alexander B. Doust, Fabrizia Fusetti, Gert T. Oostergetel, Chantal D. van der Weij-de Wit, Egbert J. Boekema, Biophysics Photosynthesis/Energy, Electron Microscopy, and Enzymology

Subjects
STRUCTURAL-CHARACTERIZATION, Chlorophyll, Chlorophyll a, Photosystem II, photosystem I, Dimer, Biophysics, Chlamydomonas reinhardtii, ANGSTROM RESOLUTION, macromolecular substances, Photosynthesis, Photosystem I, Biochemistry, SUPERCOMPLEX, CHLAMYDOMONAS-REINHARDTII, Mass Spectrometry, Light-harvesting complex, chemistry.chemical_compound, CRYSTAL-STRUCTURE, LIGHT-HARVESTING COMPLEX, biology, electron microscopy, Photosystem I Protein Complex, MEMBRANE-PROTEINS, Chlorophyll A, Spectrum Analysis, Temperature, photosystem II, Photosystem II Protein Complex, Cell Biology, PLASTID GENOME, biology.organism_classification, antenna protein, ALGA RHODOMONAS, Rhodomonas CS24, Crystallography, Microscopy, Electron, chemistry, Chromatography, Gel, Rhodomonas, SUPRAMOLECULAR ORGANIZATION, Electrophoresis, Polyacrylamide Gel, cryptophytes, SDG 6 - Clean Water and Sanitation, Cryptophyta, Dimerization
Abstract

Photosynthetic supercomplexes from the cryptophyte Rhodomonas CS24 were isolated by a short detergent treatment of membranes from the cryptophyte Rhodomonas CS24 and studied by electron microscopy and low-temperature absorption and fluorescence spectroscopy. At least three different types of supercomplexes of photosystem I (PSI) monomers and peripheral Chl a/c(2) proteins were found. The most common complexes have Chl a/c(2) complexes at both sides of the PSI core monomer and have dimensions of about 17 x 24 nm. The peripheral antenna in these supercomplexes shows no obvious similarities in size and/or shape with that of the PSI-LHCI supercomplexes from the green plant Arabidopsis thaliana and the green alga Chlamydomonas reinhardtii, and may be comprised of about 6-8 monomers of Chl a/c(2) light-harvesting complexes. In addition, two different types of supercomplexes of photosystem II (PSII) dimers and peripheral Chl a/c(2) proteins were found. The detected complexes consist of a PSII core dimer and three or four monomeric Chl a/c(2) proteins on one side of the PSII core at positions that in the largest complex are similar to those of Lhcb5, a monomer of the S-trimer of LHCII, Lhcb4 and Lhcb6 in green plants. (C) 2008 Elsevier B.V. All rights reserved.

Published
2008
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12. Supercomplexes of IsiA and Photosystem I in a mutant lacking subunit PsaL

Author

Hans C. P. Matthijs, Egbert J. Boekema, Roman Kouril, Gert T. Oostergetel, Sandrine D'Haene, Nataliya Yeremenko, Jan P. Dekker, Aquatic Microbiology (IBED, FNWI), Other departments, Biophysics Photosynthesis/Energy, Electron Microscopy, Faculty of Science and Engineering, and Groningen Biomolecular Sciences and Biotechnology

Subjects
Photosystem I, Photosystem I Protein Complex, Protein subunit, Synechocystis, Mutant, Light-Harvesting Protein Complexes, Biophysics, Wild type, Structural component, Cell Biology, Biology, biology.organism_classification, Biochemistry, PsaL, Microscopy, Electron, Crystallography, Bacterial Proteins, Mutation, Electron microscopy, IsiA
Abstract

Functional flexibility of light harvesting in cyanobacteria Nataliya Yeremenko 1, Roman Kouril 2, Janne A. Ihalainen 3, Sandrine D¿Haene 3, Martin Hagemann 4, Egbert J. Boekema 2, Hans C.P. Matthijs 1 and Jan P. Dekker 31 Universiteit van Amsterdam, Amsterdam, The Netherlands; 2 University of Groningen, Groningen, The Netherlands; 3 Vrije Universiteit, Amsterdam, The Netherlands; 4 Universität Rostock, Rostock, Germany Regulation of light harvesting is a matter of high importance in photosynthetic organisms. High plants and algae involve mechanism of state transitions which is regulated by the redox state of the plastoquinone pool and leads to the reversible redistribution of excitation energy between the two photosystems through a reorganization of the antennae and to an overall increase in photosynthetic quantum yield by decreasing the delivery of excess excitation energy to PSII while increasing delivery of excitation energy to PSI (or vice-versa) [1]. Cyanobacteria balance energy input and consumption differently. Under iron-deficient conditions, the content of PSI decreases substantially more than that of PSII [2]. Cyanobacteria respond to this condition by accumulation of IsiA protein which may occurs in two different types of complexes (associated and not associated with PSI) and correspondingly serve different functions [3]. The PSI-IsiA supercomplexes show increasingly larger amounts of bound IsiA proteins with increasing iron starvation. The largest particles consist of double IsiA ring around monomeric PSI and contain about 560 chlorophylls, which together with 96 chlorophylls of the PSI core complex would give a total number of 656 chlorophylls. PSI particles with such large antenna sizes have not been observed before. Fluorescence excitation spectra indicate an efficient light-harvesting function for all PSI-bound chlorophylls. With continious iron starvation the further decline of PSI makes PSII increasingly vulnerable to photooxidation and the surplus synthesis of IsiA not associated with PSI shields PSII from excess light.

Published
2005
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13. Structural characterization of a complex of photosystem I and light-harvesting complex II of Arabidopsis thaliana

Author

Ana A. Arteni, Poul Erik Jensen, A. Zygadlo, Henrik Vibe Scheller, Jan P. Dekker, C.D. de Wit, Egbert J. Boekema, Roman Kouril, Biophysics Photosynthesis/Energy, Faculty of Science and Engineering, Elektronenmicroscopie, Enzymologie, and Groningen Biomolecular Sciences and Biotechnology

Subjects
Microscopy, Electron, Scanning Transmission, Photosystem II, CHLAMYDOMONAS, Arabidopsis, Light-Harvesting Protein Complexes, Biology, Photochemistry, Photosystem I, Thylakoids, Biochemistry, TRANSDUCTION, KINASE, CRYSTAL-STRUCTURE, Protein Structure, Quaternary, PHOSPHORYLATION, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Photosystem, STATE TRANSITIONS, Photosystem I Protein Complex, Arabidopsis Proteins, Plant Leaves, Chloroplast, Transduction (biophysics), Membrane, RESOLUTION, Thylakoid, SUBUNIT, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, THYLAKOID MEMBRANE, Photosynthetic membrane, SUPRAMOLECULAR ORGANIZATION, Energy Metabolism, SDG 6 - Clean Water and Sanitation
Abstract

Chloroplasts are central to the provision of energy for green plants. Their photosynthetic membrane consists of two major complexes converting sunlight: photosystem I (PSI) and photosystem II (PSII). The energy flow toward both photosystems is regulated by light-harvesting complex II (LHCII), which after phosphorylation can move from PSII to PSI in the so-called state 1 to state 2 transition and can move back to PSII after dephosphorylation. To investigate the changes of PSI and PSII during state transitions, we studied the structures and frequencies of all major membrane complexes from Arabidopsis thaliana chloroplasts at conditions favoring either state 1 or state 2. We solubilized thylakoid membranes with digitonin and analyzed the complete set of complexes immediately after solubilization by electron microscopy and image analysis. Classification indicated the presence of a PSI-LHCII supercomplex consisting of one PSI-LHCI complex and one LHCII trimer, which was more abundant in state 2 conditions. The presence of LHCII was confirmed by excitation spectra of the PSI emission of membranes in state 1 or state 2. The PSI-LHCII complex could be averaged with a resolution of 16 Å, showing that LHCII has a specific binding site at the PSI-A, -H, -L, and -K subunits. © 2005 American Chemical Society.

Published
2005
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14. Single particle electron microscopy in combination with mass spectrometry to investigate novel complexes of membrane proteins

Author

M. Rogner, Matthias Rögner, Ana A. Arteni, Marc M. Nowaczyk, Egbert J. Boekema, Roman Kouril, Julia Lax, Electron Microscopy, Enzymology, Faculty of Science and Engineering, and Groningen Biomolecular Sciences and Biotechnology

Subjects
Thermosynechococcus elongatus, Photosystem I, Photosystem II, Photosystem I Protein Complex, Chemistry, Protein subunit, Photosystem II Protein Complex, Mass spectrometry, Cyanobacteria, Mass Spectrometry, Crystallography, Microscopy, Electron, Membrane, Membrane protein, Bacterial Proteins, Structural Biology, Multiprotein Complexes, Complex I, Protein purification, Electron microscopy, Particle
Abstract

Large data sets of molecular projections of the membrane proteins Photosystem I and Photosystem II from cyanobacteria were analyzed by single particle electron microscopy (EM). Analysis resulted in the averaging of 2D projections from the purified complexes but also in the simultaneous detection and averaging of 2D projections from large contaminating complexes, which were present in frequencies as low as 0.1%. Among them T-shaped and L-shaped contaminants were found. The L-shaped particles could be assigned to Complex I just from the shape, although no Complex I from a cyanobacterium has been structurally characterized. A systematic comparison by single particle EM and mass spectrometry of two differently purified Photosystem II complexes resulted in the assignment of PsbZ, a small peripheral subunit of 6.8 kDa, within the structure. Together these data suggest that screening for membrane protein structures by single particle EM and mass spectrometry may be a new approach to find novel structures of such proteins. We propose here a scheme for searching for novel membrane protein structures in specific types of membranes. In this approach single particle EM and mass spectrometry, after pre-fractionation using one- or multidimensional protein separation techniques, are applied to characterize all its larger components.

Published
2004

15. Origin of chlorophyll fluorescence in plants at 55-75 degrees C

Author

Petr, Ilík, Roman, Kouril, Jerzy, Kruk, Beata, Myśliwa-Kurdziel, Hana, Popelková, Kazimierz, Strzałka, and Jan, Naus

Subjects
Chlorophyll, Plant Leaves, Hot Temperature, Spectrophotometry, Atomic, Liposomes, Spectrometry, X-Ray Emission, Hordeum, Lipids, Fluorescence
Abstract

The origin of heat-induced chlorophyll fluorescence rise that appears at about 55-60 degrees C during linear heating of leaves, chloroplasts or thylakoids (especially with a reduced content of grana thylakoids) was studied. This fluorescence rise was earlier attributed to photosystem I (PSI) emission. Our data show that the fluorescence rise originates from chlorophyll a (Chl a) molecules released from chlorophyll-containing protein complexes denaturing at 55-60 degrees C. This conclusion results mainly from Chl a fluorescence lifetime measurements with barley leaves of different Chl a content and absorption and emission spectra measurements with barley leaves preheated to selected temperatures. These data, supported by measurements of liposomes with different Chl a/lipid ratios, suggest that the released Chl a is dissolved in lipids of thylakoid membranes and that with increasing Chl a content in the lipid phase, the released Chl a tends to form low-fluorescing aggregates. This is probably the reason for the suppressed fluorescence rise at 55-60 degrees C and the decreasing fluorescence course at 60-75 degrees C, which are observable during linear heating of plant material with a high Chl a/lipid ratio (e.g. green leaves, grana thylakoids, isolated PSII particles).

Published
2003

16. Lipid Polymorphism of the Subchloroplast—Granum and Stroma Thylakoid Membrane–Particles. II. Structure and Functions

Author

Ondřej Dlouhý, Václav Karlický, Rameez Arshad, Ottó Zsiros, Ildikó Domonkos, Irena Kurasová, András F. Wacha, Tomas Morosinotto, Attila Bóta, Roman Kouřil, Vladimír Špunda, and Győző Garab

Subjects
bilayer, chlorophyll fluorescence, cryo-electron-tomography, electron microscopy, membrane energization, membrane networks, Cytology, QH573-671
Abstract

In Part I, by using 31P-NMR spectroscopy, we have shown that isolated granum and stroma thylakoid membranes (TMs), in addition to the bilayer, display two isotropic phases and an inverted hexagonal (HII) phase; saturation transfer experiments and selective effects of lipase and thermal treatments have shown that these phases arise from distinct, yet interconnectable structural entities. To obtain information on the functional roles and origin of the different lipid phases, here we performed spectroscopic measurements and inspected the ultrastructure of these TM fragments. Circular dichroism, 77 K fluorescence emission spectroscopy, and variable chlorophyll-a fluorescence measurements revealed only minor lipase- or thermally induced changes in the photosynthetic machinery. Electrochromic absorbance transients showed that the TM fragments were re-sealed, and the vesicles largely retained their impermeabilities after lipase treatments—in line with the low susceptibility of the bilayer against the same treatment, as reflected by our 31P-NMR spectroscopy. Signatures of HII-phase could not be discerned with small-angle X-ray scattering—but traces of HII structures, without long-range order, were found by freeze-fracture electron microscopy (FF-EM) and cryo-electron tomography (CET). EM and CET images also revealed the presence of small vesicles and fusion of membrane particles, which might account for one of the isotropic phases. Interaction of VDE (violaxanthin de-epoxidase, detected by Western blot technique in both membrane fragments) with TM lipids might account for the other isotropic phase. In general, non-bilayer lipids are proposed to play role in the self-assembly of the highly organized yet dynamic TM network in chloroplasts.

Published
2021
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