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Nagy G, Garab G. Neutron scattering in photosynthesis research: recent advances and perspectives for testing crop plants. PHOTOSYNTHESIS RESEARCH 2021; 150:41-49. [PMID: 32488447 PMCID: PMC8556207 DOI: 10.1007/s11120-020-00763-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/25/2020] [Indexed: 05/05/2023]
Abstract
The photosynthetic performance of crop plants under a variety of environmental factors and stress conditions, at the fundamental level, depends largely on the organization and structural flexibility of thylakoid membranes. These highly organized membranes accommodate virtually all protein complexes and additional compounds carrying out the light reactions of photosynthesis. Most regulatory mechanisms fine-tuning the photosynthetic functions affect the organization of thylakoid membranes at different levels of the structural complexity. In order to monitor these reorganizations, non-invasive techniques are of special value. On the mesoscopic scale, small-angle neutron scattering (SANS) has been shown to deliver statistically and spatially averaged information on the periodic organization of the thylakoid membranes in vivo and/or, in isolated thylakoids, under physiologically relevant conditions, without fixation or staining. More importantly, SANS investigations have revealed rapid reversible reorganizations on the timescale of several seconds and minutes. In this paper, we give a short introduction into the basics of SANS technique, advantages and limitations, and briefly overview recent advances and potential applications of this technique in the physiology and biotechnology of crop plants. We also discuss future perspectives of neutron crystallography and different neutron scattering techniques, which are anticipated to become more accessible and of more use in photosynthesis research at new facilities with higher fluxes and innovative instrumentation.
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Affiliation(s)
- Gergely Nagy
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, POB 49, 1525, Budapest, Hungary.
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, POB 521, 6701, Szeged, Hungary.
- Department of Physics, Faculty of Science, Ostrava University, Chittussiho 10, Ostrava - Slezská, 710 0, Ostrava, Czech Republic.
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Dynamics Properties of Photosynthetic Microorganisms Probed by Incoherent Neutron Scattering. Biophys J 2019; 116:1759-1768. [PMID: 31003761 DOI: 10.1016/j.bpj.2019.03.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 03/18/2019] [Accepted: 03/20/2019] [Indexed: 01/06/2023] Open
Abstract
Studies on the dynamical properties of photosynthetic membranes of land plants and purple bacteria have been previously performed by neutron spectroscopy, revealing a tight coupling between specific photochemical reactions and macromolecular dynamics. Here, we probed the intrinsic dynamics of biotechnologically useful mutants of the green alga Chlamydomonas reinhardtii by incoherent neutron scattering coupled with prompt chlorophyll fluorescence experiments. We brought to light that single amino acid replacements in the plastoquinone (PQ)-binding niche of the photosystem II D1 protein impair electron transport (ET) efficiency between quinones and confer increased flexibility to the host membranes, expanding to the entire cells. Hence, a more flexible environment in the PQ-binding niche has been associated to a less efficient ET. A similar function/dynamics relationship was also demonstrated in Rhodobacter sphaeroides reaction centers having inhibited ET, indicating that flexibility at the quinones region plays a crucial role in evolutionarily distant organisms. Instead, a different functional/dynamical correlation was observed in algal mutants hosting a single amino acid replacement residing in a D1 domain far from the PQ-binding niche. Noteworthy, this mutant displayed the highest degree of flexibility, and besides having a nativelike ET efficiency in physiological conditions, it acquired novel, to our knowledge, phenotypic traits enabling it to preserve a high maximal quantum yield of photosystem II photochemistry in extreme habitats. Overall, in the nanosecond timescale, the degree of the observed flexibility is related to the mutation site; in the picosecond timescale, we highlighted the presence of a more pronounced dynamic heterogeneity in all mutants compared to the native cells, which could be related to a marked chemically heterogeneous environment.
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Siggel U, Schmitt FJ, Messinger J. Gernot Renger (1937-2013): his life, Max-Volmer Laboratory, and photosynthesis research. PHOTOSYNTHESIS RESEARCH 2016; 129:109-127. [PMID: 27312337 DOI: 10.1007/s11120-016-0280-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/02/2016] [Indexed: 06/06/2023]
Abstract
Gernot Renger (October 23, 1937-January 12, 2013), one of the leading biophysicists in the field of photosynthesis research, studied and worked at the Max-Volmer-Institute (MVI) of the Technische Universität Berlin, Germany, for more than 50 years, and thus witnessed the rise and decline of photosynthesis research at this institute, which at its prime was one of the leading centers in this field. We present a tribute to Gernot Renger's work and life in the context of the history of photosynthesis research of that period, with special focus on the MVI. Gernot will be remembered for his thought-provoking questions and his boundless enthusiasm for science.
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Affiliation(s)
- Ulrich Siggel
- Max-Volmer-Laboratorium, TU Berlin, Strasse des 17. Juni 135, 10623, Berlin, Germany.
| | - Franz-Josef Schmitt
- Max-Volmer-Laboratorium, TU Berlin, Strasse des 17. Juni 135, 10623, Berlin, Germany
| | - Johannes Messinger
- Departmant of Chemistry, Umeå University, Linnaeus väg 6 (KBC huset), 90187, Umeå, Sweden.
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Fujiwara S, Araki K, Matsuo T, Yagi H, Yamada T, Shibata K, Mochizuki H. Dynamical Behavior of Human α-Synuclein Studied by Quasielastic Neutron Scattering. PLoS One 2016; 11:e0151447. [PMID: 27097022 PMCID: PMC4838215 DOI: 10.1371/journal.pone.0151447] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 02/29/2016] [Indexed: 12/02/2022] Open
Abstract
α-synuclein (αSyn) is a protein consisting of 140 amino acid residues and is abundant in the presynaptic nerve terminals in the brain. Although its precise function is unknown, the filamentous aggregates (amyloid fibrils) of αSyn have been shown to be involved in the pathogenesis of Parkinson's disease, which is a progressive neurodegenerative disorder. To understand the pathogenesis mechanism of this disease, the mechanism of the amyloid fibril formation of αSyn must be elucidated. Purified αSyn from bacterial expression is monomeric but intrinsically disordered in solution and forms amyloid fibrils under various conditions. As a first step toward elucidating the mechanism of the fibril formation of αSyn, we investigated dynamical behavior of the purified αSyn in the monomeric state and the fibril state using quasielastic neutron scattering (QENS). We prepared the solution sample of 9.5 mg/ml purified αSyn, and that of 46 mg/ml αSyn in the fibril state, both at pD 7.4 in D2O. The QENS experiments on these samples were performed using the near-backscattering spectrometer, BL02 (DNA), at the Materials and Life Science Facility at the Japan Accelerator Research Complex, Japan. Analysis of the QENS spectra obtained shows that diffusive global motions are observed in the monomeric state but largely suppressed in the fibril state. However, the amplitude of the side chain motion is shown to be larger in the fibril state than in the monomeric state. This implies that significant solvent space exists within the fibrils, which is attributed to the αSyn molecules within the fibrils having a distribution of conformations. The larger amplitude of the side chain motion in the fibril state than in the monomeric state implies that the fibril state is entropically favorable.
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Affiliation(s)
- Satoru Fujiwara
- Quantum Beam Science Center, Japan Atomic Energy Agency, Tokai, Ibaraki, Japan
- * E-mail:
| | - Katsuya Araki
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Tatsuhito Matsuo
- Quantum Beam Science Center, Japan Atomic Energy Agency, Tokai, Ibaraki, Japan
| | - Hisashi Yagi
- Center for Research on Green Sustainable Chemistry, Tottori University, Tottori, Japan
| | - Takeshi Yamada
- Research Center for Neutron Science and Technology, CROSS-Tokai, Tokai, Ibaraki, Japan
| | - Kaoru Shibata
- Neutron Science Section, J-PARC Center, Tokai, Ibaraki, Japan
| | - Hideki Mochizuki
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
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Lambreva MD, Russo D, Polticelli F, Scognamiglio V, Antonacci A, Zobnina V, Campi G, Rea G. Structure/function/dynamics of photosystem II plastoquinone binding sites. Curr Protein Pept Sci 2015; 15:285-95. [PMID: 24678671 PMCID: PMC4030317 DOI: 10.2174/1389203715666140327104802] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 11/22/2013] [Accepted: 03/16/2014] [Indexed: 11/22/2022]
Abstract
Photosystem II (PSII)
continuously attracts the attention of researchers aiming to unravel the riddle
of its functioning and efficiency fundamental for all life on Earth. Besides, an
increasing number of biotechnological applications have been envisaged
exploiting and mimicking the unique properties of this macromolecular
pigment-protein complex. The PSII organization and working principles have
inspired the design of electrochemical water splitting schemes and charge
separating triads in energy storage systems as well as biochips and sensors for
environmental, agricultural and industrial screening of toxic compounds. An
intriguing opportunity is the development of sensor devices, exploiting native
or manipulated PSII complexes or ad hoc synthesized polypeptides
mimicking the PSII reaction centre proteins as bio-sensing elements. This review
offers a concise overview of the recent improvements in the understanding of
structure and function of PSII donor side, with focus on the interactions of the
plastoquinone cofactors with the surrounding environment and operational
features. Furthermore, studies focused on photosynthetic proteins
structure/function/dynamics and computational analyses aimed at rational design
of high-quality bio-recognition elements in biosensor devices are discussed.
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Affiliation(s)
| | | | | | | | | | | | | | - Giuseppina Rea
- Institute of Crystallography, National Research Council, Monterotondo, Italy.
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Pieper J. The functional role of protein dynamics in photosynthetic reaction centers investigated by elastic and quasielastic neutron scattering. EPJ WEB OF CONFERENCES 2015. [DOI: 10.1051/epjconf/20158302013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Pan Y, Brown L, Konermann L. Hydrogen exchange mass spectrometry of bacteriorhodopsin reveals light-induced changes in the structural dynamics of a biomolecular machine. J Am Chem Soc 2011; 133:20237-44. [PMID: 22043856 DOI: 10.1021/ja206197h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Many proteins act as molecular machines that are fuelled by a nonthermal energy source. Examples include transmembrane pumps and stator-rotor complexes. These systems undergo cyclic motions (CMs) that are being driven along a well-defined conformational trajectory. Superimposed on these CMs are thermal fluctuations (TFs) that are coupled to stochastic motions of the solvent. Here we explore whether the TFs of a molecular machine are affected by the occurrence of CMs. Bacteriorhodopsin (BR) is a light-driven proton pump that serves as a model system in this study. The function of BR is based on a photocycle that involves trans/cis isomerization of a retinal chromophore, as well as motions of transmembrane helices. Hydrogen/deuterium exchange (HDX) mass spectrometry was used to monitor the TFs of BR, focusing on the monomeric form of the protein. Comparative HDX studies were conducted under illumination and in the dark. The HDX kinetics of BR are dramatically accelerated in the presence of light. The isotope exchange rates and the number of backbone amides involved in EX2 opening transitions increase roughly 2-fold upon illumination. In contrast, light/dark control experiments on retinal-free protein produced no discernible differences. It can be concluded that the extent of TFs in BR strongly depends on photon-driven CMs. The light-induced differences in HDX behavior are ascribed to protein destabilization. Specifically, the thermodynamic stability of the dark-adapted protein is estimated to be 5.5 kJ mol(-1) under the conditions of our work. This value represents the free energy difference between the folded state F and a significantly unfolded conformer U. Illumination reduces the stability of F by 2.2 kJ mol(-1). Mechanical agitation caused by isomerization of the chromophore is transferred to the surrounding protein scaffold, and subsequently, the energy dissipates into the solvent. Light-induced retinal motions therefore act analogously to an internal heat source that promotes the occurrence of TFs. Overall, our data highlight the potential of HDX methods for probing the structural dynamics of molecular machines under "engine on" and "engine off" conditions.
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Affiliation(s)
- Yan Pan
- Department of Chemistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7
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Pieper J, Renger G. Protein dynamics investigated by neutron scattering. PHOTOSYNTHESIS RESEARCH 2009; 102:281-293. [PMID: 19763874 DOI: 10.1007/s11120-009-9480-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Accepted: 07/19/2009] [Indexed: 05/28/2023]
Abstract
This contribution describes incoherent quasielastic neutron scattering (QENS) as a suitable tool for investigations of protein dynamics with special emphasis on applications in photosynthesis research. QENS characterizes protein dynamics via the measurement of energy and momentum exchange between sample system and incident low-energy neutrons (1 meV<E<20 meV). This method is especially sensitive for picosecond motions of hydrogen atoms because it makes use of the exceptionally large incoherent neutron scattering cross section of protons and their almost homogeneous distribution in proteins. After a short introduction into the basic principles of neutron scattering, a more detailed description of QENS will be presented including a short overview on instrumentation and theory. Recent QENS results will be discussed for the antenna complex LHC II and PS II membrane fragments. It is shown that diffusive protein dynamics is indispensable for enabling Q(A)(-·) reoxidation by Q(B) at temperatures above 240 K, which explains the strong dependence of this electron transfer step on temperature and hydration level of the sample. Finally, a new laser-QENS pump-probe technique will be introduced which permits in situ monitoring of protein dynamics correlated with a change of the functional state of the sample, i.e. a direct observation of structure-dynamics-function relationships in real time.
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Affiliation(s)
- Jörg Pieper
- Max-Volmer-Laboratorium für Biophysikalische Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, 10623, Berlin, Germany.
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Pieper J. Time-resolved quasielastic neutron scattering studies of native photosystems. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1804:83-8. [PMID: 19782773 DOI: 10.1016/j.bbapap.2009.09.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 09/14/2009] [Accepted: 09/16/2009] [Indexed: 10/20/2022]
Abstract
The internal molecular dynamics of proteins plays an important role in a number of functional processes in native photosystems. Prominent examples include the photocycle of bacteriorhodopsin and electron transfer in the reaction center of plant photosystem II. In this regard, the recently developed technique of time-resolved quasielastic neutron scattering with laser excitation opens up new perspectives for the study of protein/membrane dynamics in specific functional states of even complex systems. The first direct observation of a functionally modulated protein dynamics has just recently been reported for the model system bacteriorhodopsin (Pieper et al., Phys. Rev. Lett. 100, 2008, 228103.), where a transient softening of the protein was observed on a timescale of approximately 1 ms along with the large-scale structural change in the M-intermediate of bacteriorhodopsin. In contrast, photosystem II membrane fragments with inhibited electron transfer show a suppression of protein dynamics approximately 160 mus after the actinic laser flash (Pieper and Renger, Biochemistry 48, 2009, 6111). This effect may reflect aggregation-like conformational changes capable of dissipation of excess excitation energy to prevent photodamage in the absence of Q(A)-->Q(B) electron transfer. These findings indicate that proteins exhibit a remarkable flexibility to accommodate different functional processes. This contribution will discuss methodical aspects, challenges, and recent applications of laser-excited, time-resolved quasielastic neutron scattering.
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Affiliation(s)
- Jörg Pieper
- Max-Volmer-Laboratories for Biophysical Chemistry, Technische Universität Berlin, 10623 Berlin, Germany.
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