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Tran QH, Eder OM, Winkler A. Dynamics-driven allosteric stimulation of diguanylate cyclase activity in a red light-regulated phytochrome. J Biol Chem 2024; 300:107217. [PMID: 38522512 PMCID: PMC11035067 DOI: 10.1016/j.jbc.2024.107217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 03/26/2024] Open
Abstract
Sensor-effector proteins integrate information from different stimuli and transform this into cellular responses. Some sensory domains, like red-light responsive bacteriophytochromes, show remarkable modularity regulating a variety of effectors. One effector domain is the GGDEF diguanylate cyclase catalyzing the formation of the bacterial second messenger cyclic-dimeric-guanosine monophosphate. While critical signal integration elements have been described for different phytochromes, a generalized understanding of signal processing and communication over large distances, roughly 100 Å in phytochrome diguanylate cyclases, is missing. Here we show that dynamics-driven allostery is key to understanding signal integration on a molecular level. We generated protein variants stabilized in their far-red-absorbing Pfr state and demonstrated by analysis of conformational dynamics using hydrogen-deuterium exchange coupled to mass spectrometry that single amino acid replacements are accompanied by altered dynamics of functional elements throughout the protein. We show that the conformational dynamics correlate with the enzymatic activity of these variants, explaining also the increased activity of a non-photochromic variant. In addition, we demonstrate the functional importance of mixed Pfr/intermediate state dimers using a fast-reverting variant that still enables wild-type-like fold-changes of enzymatic stimulation by red light. This supports the functional role of single protomer activation in phytochromes, a property that might correlate with the non-canonical mixed Pfr/intermediate-state spectra observed for many phytochrome systems. We anticipate our results to stimulate research in the direction of dynamics-driven allosteric regulation of different bacteriophytochrome-based sensor-effectors. This will eventually impact design strategies for the creation of novel sensor-effector systems for enriching the optogenetic toolbox.
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Affiliation(s)
- Quang Hieu Tran
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | | | - Andreas Winkler
- Institute of Biochemistry, Graz University of Technology, Graz, Austria; BioTechMed Graz, Graz, Austria.
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2
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Huber C, Strack M, Schultheiß I, Pielage J, Mechler X, Hornbogen J, Diller R, Frankenberg-Dinkel N. Darkness inhibits autokinase activity of bacterial bathy phytochromes. J Biol Chem 2024; 300:107148. [PMID: 38462162 PMCID: PMC11021371 DOI: 10.1016/j.jbc.2024.107148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 03/12/2024] Open
Abstract
Bathy phytochromes are a subclass of bacterial biliprotein photoreceptors that carry a biliverdin IXα chromophore. In contrast to prototypical phytochromes that adopt a red-light-absorbing Pr ground state, the far-red light-absorbing Pfr-form is the thermally stable ground state of bathy phytochromes. Although the photobiology of bacterial phytochromes has been extensively studied since their discovery in the late 1990s, our understanding of the signal transduction process to the connected transmitter domains, which are often histidine kinases, remains insufficient. Initiated by the analysis of the bathy phytochrome PaBphP from Pseudomonas aeruginosa, we performed a systematic analysis of five different bathy phytochromes with the aim to derive a general statement on the correlation of photostate and autokinase output. While all proteins adopt different Pr/Pfr-fractions in response to red, blue, and far-red light, only darkness leads to a pure or highly enriched Pfr-form, directly correlated with the lowest level of autokinase activity. Using this information, we developed a method to quantitatively correlate the autokinase activity of phytochrome samples with well-defined stationary Pr/Pfr-fractions. We demonstrate that the off-state of the phytochromes is the Pfr-form and that different Pr/Pfr-fractions enable the organisms to fine-tune their kinase output in response to a certain light environment. Furthermore, the output response is regulated by the rate of dark reversion, which differs significantly from 5 s to 50 min half-life. Overall, our study indicates that bathy phytochromes function as sensors of light and darkness, rather than red and far-red light, as originally postulated.
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Affiliation(s)
- Christina Huber
- Department of Microbiology, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Merle Strack
- Department of Physics, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Isabel Schultheiß
- Department of Microbiology, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Julia Pielage
- Department of Microbiology, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Xenia Mechler
- Department of Physics, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Justin Hornbogen
- Department of Physics, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Rolf Diller
- Department of Physics, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Nicole Frankenberg-Dinkel
- Department of Microbiology, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Kaiserslautern, Germany.
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3
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Xu Q, Vogt A, Frechen F, Yi C, Küçükerden M, Ngum N, Sitjà-Roqueta L, Greiner A, Parri R, Masana M, Wenger N, Wachten D, Möglich A. Engineering Bacteriophytochrome-coupled Photoactivated Adenylyl Cyclases for Enhanced Optogenetic cAMP Modulation. J Mol Biol 2024; 436:168257. [PMID: 37657609 DOI: 10.1016/j.jmb.2023.168257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 08/27/2023] [Accepted: 08/28/2023] [Indexed: 09/03/2023]
Abstract
Sensory photoreceptors abound in nature and enable organisms to adapt behavior, development, and physiology to environmental light. In optogenetics, photoreceptors allow spatiotemporally precise, reversible, and non-invasive control by light of cellular processes. Notwithstanding the development of numerous optogenetic circuits, an unmet demand exists for efficient systems sensitive to red light, given its superior penetration of biological tissue. Bacteriophytochrome photoreceptors sense the ratio of red and far-red light to regulate the activity of enzymatic effector modules. The recombination of bacteriophytochrome photosensor modules with cyclase effectors underlies photoactivated adenylyl cyclases (PAC) that catalyze the synthesis of the ubiquitous second messenger 3', 5'-cyclic adenosine monophosphate (cAMP). Via homologous exchanges of the photosensor unit, we devised novel PACs, with the variant DmPAC exhibiting 40-fold activation of cyclase activity under red light, thus surpassing previous red-light-responsive PACs. Modifications of the PHY tongue modulated the responses to red and far-red light. Exchanges of the cyclase effector offer an avenue to further enhancing PACs but require optimization of the linker to the photosensor. DmPAC and a derivative for 3', 5'-cyclic guanosine monophosphate allow the manipulation of cyclic-nucleotide-dependent processes in mammalian cells by red light. Taken together, we advance the optogenetic control of second-messenger signaling and provide insight into the signaling and design of bacteriophytochrome receptors.
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Affiliation(s)
- Qianzhao Xu
- Department of Biochemistry, University of Bayreuth, 95447 Bayreuth, Germany
| | - Arend Vogt
- Charité - University Medicine Berlin, Department of Neurology with Experimental Neurology, 10117 Berlin, Germany. https://twitter.com/ArendVogt
| | - Fabian Frechen
- Institute of Innate Immunity, University of Bonn, 53127 Bonn, Germany
| | - Chengwei Yi
- Department of Biochemistry, University of Bayreuth, 95447 Bayreuth, Germany
| | - Melike Küçükerden
- Department of Biomedical Sciences, Institute of Neurosciences, University of Barcelona, 08036 Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Neville Ngum
- College of Health and Life Sciences, Aston University, Birmingham B4 7ET, United Kingdom
| | - Laia Sitjà-Roqueta
- Department of Biomedical Sciences, Institute of Neurosciences, University of Barcelona, 08036 Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Andreas Greiner
- Macromolecular Chemistry and Bavarian Polymer Institute, University of Bayreuth, Bayreuth 95440, Germany
| | - Rhein Parri
- College of Health and Life Sciences, Aston University, Birmingham B4 7ET, United Kingdom
| | - Mercè Masana
- Department of Biomedical Sciences, Institute of Neurosciences, University of Barcelona, 08036 Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain. https://twitter.com/mercemasana
| | - Nikolaus Wenger
- Charité - University Medicine Berlin, Department of Neurology with Experimental Neurology, 10117 Berlin, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, University of Bonn, 53127 Bonn, Germany. https://twitter.com/DagmarWachten
| | - Andreas Möglich
- Department of Biochemistry, University of Bayreuth, 95447 Bayreuth, Germany; Bayreuth Center for Biochemistry & Molecular Biology, Universität Bayreuth, 95447 Bayreuth, Germany; North-Bavarian NMR Center, Universität Bayreuth, 95447 Bayreuth, Germany.
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4
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Do TN, Menendez D, Bizhga D, Stojković EA, Kennis JTM. Two-photon Absorption and Photoionization of a Bacterial Phytochrome. J Mol Biol 2024; 436:168357. [PMID: 37944794 DOI: 10.1016/j.jmb.2023.168357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 10/19/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023]
Abstract
Phytochromes constitute a family of photosensory proteins that are utilized by various organisms to regulate several physiological processes. Phytochromes bind a bilin pigment that switches its isomeric state upon absorption of red or far-red photons, resulting in protein conformational changes that are sensed by the organism. Previously, the ultrafast dynamics in bacterial phytochrome was resolved to atomic resolution by time-resolved serial femtosecond X-ray diffraction (TR-SFX), showing extensive changes in its molecular conformation at 1 picosecond delay time. However, the large excitation fluence of mJ/mm2 used in TR-SFX questions the validity of the observed dynamics. In this work, we present an excitation-dependent ultrafast transient absorption study to test the response of a related bacterial phytochrome to excitation fluence. We observe excitation power-dependent sub-picosecond dynamics, assigned to the population of high-lying excited state Sn through resonantly enhanced two-photon absorption, followed by rapid internal conversion to the low-lying S1 state. Inspection of the long-lived spectrum under high fluence shows that in addition to the primary intermediate Lumi-R, spectroscopic signatures of solvated electrons and ionized chromophore radicals are observed. Supported by numerical modelling, we propose that under excitation fluences of tens of μJ/mm2 and higher, bacterial phytochrome partly undergoes photoionization from the Sn state in competition with internal conversion to the S1 state in 300 fs. We suggest that the extensive structural changes of related, shorter bacterial phytochrome, lacking the PHY domain, resolved from TR-SFX may have been affected by the ionized species. We propose approaches to minimize the two-photon absorption process by tuning the excitation spectrum away from the S1 absorption or using phytochromes exhibiting minimized or shifted S1 absorption.
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Affiliation(s)
- Thanh Nhut Do
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - David Menendez
- Department of Biology, Northeastern Illinois University, 5500 N. St. Louis Ave., Chicago, IL 60625, USA
| | - Dorina Bizhga
- Department of Biology, Northeastern Illinois University, 5500 N. St. Louis Ave., Chicago, IL 60625, USA
| | - Emina A Stojković
- Department of Biology, Northeastern Illinois University, 5500 N. St. Louis Ave., Chicago, IL 60625, USA
| | - John T M Kennis
- Department of Physics and Astronomy, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
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Schmidt M, Stojković EA. Blue and red in the protein world: Photoactive yellow protein and phytochromes as revealed by time-resolved crystallography. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:014701. [PMID: 38304445 PMCID: PMC10834066 DOI: 10.1063/4.0000233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 01/10/2024] [Indexed: 02/03/2024]
Abstract
Time-resolved crystallography (TRX) is a method designed to investigate functional motions of biological macromolecules on all time scales. Originally a synchrotron-based method, TRX is enabled by the development of TR Laue crystallography (TRLX). TR serial crystallography (TR-SX) is an extension of TRLX. As the foundations of TRLX were evolving from the late 1980s to the turn of the millennium, TR-SX has been inspired by the development of Free Electron Lasers for hard X-rays. Extremely intense, ultrashort x-ray pulses could probe micro and nanocrystals, but at the same time, they inflicted radiation damage that necessitated the replacement by a new crystal. Consequently, a large number of microcrystals are exposed to X-rays one by one in a serial fashion. With TR-SX methods, one of the largest obstacles of previous approaches, namely, the unsurmountable challenges associated with the investigation of non-cyclic (irreversible) reactions, can be overcome. This article describes successes and transformative contributions to the TRX field by Keith Moffat and his collaborators, highlighting two major projects on protein photoreceptors initiated in the Moffat lab at the turn of the millennium.
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Affiliation(s)
- Marius Schmidt
- Physics Department, University of Wisconsin-Milwaukee, 3135 N. Maryland Ave., Milwaukee, Wisconsin 53211, USA
| | - Emina A. Stojković
- Department of Biology, Northeastern Illinois University, 5500 N. St. Louis Ave., Chicago, Illinois 60625, USA
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6
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Kaeser G, Krauß N, Roughan C, Sauthof L, Scheerer P, Lamparter T. Phytochrome-Interacting Proteins. Biomolecules 2023; 14:9. [PMID: 38275750 PMCID: PMC10813442 DOI: 10.3390/biom14010009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 01/27/2024] Open
Abstract
Phytochromes are photoreceptors of plants, fungi, slime molds bacteria and heterokonts. These biliproteins sense red and far-red light and undergo light-induced changes between the two spectral forms, Pr and Pfr. Photoconversion triggered by light induces conformational changes in the bilin chromophore around the ring C-D-connecting methine bridge and is followed by conformational changes in the protein. For plant phytochromes, multiple phytochrome interacting proteins that mediate signal transduction, nuclear translocation or protein degradation have been identified. Few interacting proteins are known as bacterial or fungal phytochromes. Here, we describe how the interacting partners were identified, what is known about the different interactions and in which context of signal transduction these interactions are to be seen. The three-dimensional arrangement of these interacting partners is not known. Using an artificial intelligence system-based modeling software, a few predicted and modulated examples of interactions of bacterial phytochromes with their interaction partners are interpreted.
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Affiliation(s)
- Gero Kaeser
- Karlsruhe Institute of Technology (KIT), Joseph Gottlieb Kölreuter Institut für Pflanzenwissenschaften (JKIP), Fritz-Haber-Weg 4, D-76131 Karlsruhe, Germany; (G.K.); (N.K.); (C.R.)
| | - Norbert Krauß
- Karlsruhe Institute of Technology (KIT), Joseph Gottlieb Kölreuter Institut für Pflanzenwissenschaften (JKIP), Fritz-Haber-Weg 4, D-76131 Karlsruhe, Germany; (G.K.); (N.K.); (C.R.)
| | - Clare Roughan
- Karlsruhe Institute of Technology (KIT), Joseph Gottlieb Kölreuter Institut für Pflanzenwissenschaften (JKIP), Fritz-Haber-Weg 4, D-76131 Karlsruhe, Germany; (G.K.); (N.K.); (C.R.)
| | - Luisa Sauthof
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Group Structural Biology of Cellular Signaling, Charitéplatz 1, D-10117 Berlin, Germany; (L.S.); (P.S.)
| | - Patrick Scheerer
- Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Group Structural Biology of Cellular Signaling, Charitéplatz 1, D-10117 Berlin, Germany; (L.S.); (P.S.)
| | - Tilman Lamparter
- Karlsruhe Institute of Technology (KIT), Joseph Gottlieb Kölreuter Institut für Pflanzenwissenschaften (JKIP), Fritz-Haber-Weg 4, D-76131 Karlsruhe, Germany; (G.K.); (N.K.); (C.R.)
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7
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Malla TN, Hernandez C, Menendez D, Bizhga D, Mendez JH, Muniyappan S, Schwander P, Stojković EA, Schmidt M. Signal Transduction in an Enzymatic Photoreceptor Revealed by Cryo-Electron Microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.08.566274. [PMID: 37986774 PMCID: PMC10659365 DOI: 10.1101/2023.11.08.566274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Phytochromes are essential photoreceptor proteins in plants with homologs in bacteria and fungi that regulate a variety of important environmental responses. They display a reversible photocycle between two distinct states, the red-light absorbing Pr and the far-red light absorbing Pfr, each with its own structure. The reversible Pr to Pfr photoconversion requires covalently bound bilin chromophore and regulates the activity of a C-terminal enzymatic domain, which is usually a histidine kinase (HK). In plants, phytochromes translocate to nucleus where the C-terminal effector domain interacts with protein interaction factors (PIFs) to induce gene expression. In bacteria, the HK phosphorylates a response-regulator (RR) protein triggering downstream gene expression through a two-component signaling pathway. Although plant and bacterial phytochromes share similar structural composition, they have contrasting activity in the presence of light with most BphPs being active in the dark. The molecular mechanism that explains bacterial and plant phytochrome signaling has not been well understood due to limited structures of full-length phytochromes with enzymatic domain resolved at or near atomic resolution in both Pr and Pfr states. Here, we report the first Cryo-EM structures of a wild-type bacterial phytochrome with a HK enzymatic domain, determined in both Pr and Pfr states, between 3.75 and 4.13 Å resolution, respectively. Furthermore, we capture a distinct Pr/Pfr heterodimer of the same protein as potential signal transduction intermediate at 3.75 Å resolution. Our three Cryo-EM structures of the distinct signaling states of BphPs are further reinforced by Cryo-EM structures of the truncated PCM of the same protein determined for the Pr/Pfr heterodimer as well as Pfr state. These structures provide insight into the different light-signaling mechanisms that could explain how bacteria and plants see the light.
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Kurttila M, Rumfeldt J, Takala H, Ihalainen JA. The interconnecting hairpin extension "arm": An essential allosteric element of phytochrome activity. Structure 2023; 31:1100-1108.e4. [PMID: 37392739 DOI: 10.1016/j.str.2023.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/23/2023] [Accepted: 06/06/2023] [Indexed: 07/03/2023]
Abstract
In red-light sensing phytochromes, isomerization of the bilin chromophore triggers structural and dynamic changes across multiple domains, ultimately leading to control of the output module (OPM) activity. In between, a hairpin structure, "arm", extends from an interconnecting domain to the chromophore region. Here, by removing this protein segment in a bacteriophytochrome from Deinococcus radiodurans (DrBphP), we show that the arm is crucial for signal transduction. Crystallographic, spectroscopic, and biochemical data indicate that this variant maintains the properties of DrBphP in the resting state. Spectroscopic data also reveal that the armless systems maintain the ability to respond to light. However, there is no subsequent regulation of OPM activity without the arms. Thermal denaturation reveals that the arms stabilize the DrBphP structure. Our results underline the importance of the structurally flexible interconnecting hairpin extensions and describe their central role in the allosteric coupling of phytochromes.
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Affiliation(s)
- Moona Kurttila
- University of Jyvaskyla, Nanoscience Center, Department of Biological and Environmental Science, 40014 Jyvaskyla, Finland
| | - Jessica Rumfeldt
- University of Jyvaskyla, Nanoscience Center, Department of Biological and Environmental Science, 40014 Jyvaskyla, Finland
| | - Heikki Takala
- University of Jyvaskyla, Nanoscience Center, Department of Biological and Environmental Science, 40014 Jyvaskyla, Finland.
| | - Janne A Ihalainen
- University of Jyvaskyla, Nanoscience Center, Department of Biological and Environmental Science, 40014 Jyvaskyla, Finland.
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