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Piatkevich KD, Boyden ES. Optogenetic control of neural activity: The biophysics of microbial rhodopsins in neuroscience. Q Rev Biophys 2023; 57:e1. [PMID: 37831008 DOI: 10.1017/s0033583523000033] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
Optogenetics, the use of microbial rhodopsins to make the electrical activity of targeted neurons controllable by light, has swept through neuroscience, enabling thousands of scientists to study how specific neuron types contribute to behaviors and pathologies, and how they might serve as novel therapeutic targets. By activating a set of neurons, one can probe what functions they can initiate or sustain, and by silencing a set of neurons, one can probe the functions they are necessary for. We here review the biophysics of these molecules, asking why they became so useful in neuroscience for the study of brain circuitry. We review the history of the field, including early thinking, early experiments, applications of optogenetics, pre-optogenetics targeted neural control tools, and the history of discovering and characterizing microbial rhodopsins. We then review the biophysical attributes of rhodopsins that make them so useful to neuroscience - their classes and structure, their photocycles, their photocurrent magnitudes and kinetics, their action spectra, and their ion selectivity. Our hope is to convey to the reader how specific biophysical properties of these molecules made them especially useful to neuroscientists for a difficult problem - the control of high-speed electrical activity, with great precision and ease, in the brain.
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Affiliation(s)
- Kiryl D Piatkevich
- School of Life Sciences, Westlake University, Hangzhou, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, China
| | - Edward S Boyden
- McGovern Institute and Koch Institute, Departments of Brain and Cognitive Sciences, Media Arts and Sciences, and Biological Engineering, K. Lisa Yang Center for Bionics and Center for Neurobiological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Howard Hughes Medical Institute, Cambridge, MA, USA
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Stauffer M, Hirschi S, Ucurum Z, Harder D, Schlesinger R, Fotiadis D. Engineering and Production of the Light-Driven Proton Pump Bacteriorhodopsin in 2D Crystals for Basic Research and Applied Technologies. Methods Protoc 2020; 3:mps3030051. [PMID: 32707904 PMCID: PMC7563565 DOI: 10.3390/mps3030051] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 07/18/2020] [Accepted: 07/19/2020] [Indexed: 11/16/2022] Open
Abstract
The light-driven proton pump bacteriorhodopsin (BR) from the extreme halophilic archaeon Halobacterium salinarum is a retinal-binding protein, which forms highly ordered and thermally stable 2D crystals in native membranes (termed purple membranes). BR and purple membranes (PMs) have been and are still being intensively studied by numerous researchers from different scientific disciplines. Furthermore, PMs are being successfully used in new, emerging technologies such as bioelectronics and bionanotechnology. Most published studies used the wild-type form of BR, because of the intrinsic difficulty to produce genetically modified versions in purple membranes homologously. However, modification and engineering is crucial for studies in basic research and, in particular, to tailor BR for specific applications in applied sciences. We present an extensive and detailed protocol ranging from the genetic modification and cultivation of H. salinarum to the isolation, and biochemical, biophysical and functional characterization of BR and purple membranes. Pitfalls and problems of the homologous expression of BR versions in H. salinarum are discussed and possible solutions presented. The protocol is intended to facilitate the access to genetically modified BR versions for researchers of different scientific disciplines, thus increasing the application of this versatile biomaterial.
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Affiliation(s)
- Mirko Stauffer
- Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, 3012 Bern, Switzerland; (M.S.); (S.H.); (Z.U.); (D.H.)
| | - Stephan Hirschi
- Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, 3012 Bern, Switzerland; (M.S.); (S.H.); (Z.U.); (D.H.)
| | - Zöhre Ucurum
- Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, 3012 Bern, Switzerland; (M.S.); (S.H.); (Z.U.); (D.H.)
| | - Daniel Harder
- Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, 3012 Bern, Switzerland; (M.S.); (S.H.); (Z.U.); (D.H.)
| | - Ramona Schlesinger
- Department of Physics, Genetic Biophysics, Freie Universität Berlin, 14195 Berlin, Germany
- Correspondence: (R.S.); (D.F.)
| | - Dimitrios Fotiadis
- Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, 3012 Bern, Switzerland; (M.S.); (S.H.); (Z.U.); (D.H.)
- Correspondence: (R.S.); (D.F.)
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Boyden ES. A history of optogenetics: the development of tools for controlling brain circuits with light. F1000 BIOLOGY REPORTS 2011; 3:11. [PMID: 21876722 PMCID: PMC3155186 DOI: 10.3410/b3-11] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Understanding how different kinds of neuron in the brain work together to implement sensations, feelings, thoughts, and movements, and how deficits in specific kinds of neuron result in brain diseases, has long been a priority in basic and clinical neuroscience. “Optogenetic” tools are genetically encoded molecules that, when targeted to specific neurons in the brain, enable their activity to be driven or silenced by light. These molecules are microbial opsins, seven-transmembrane proteins adapted from organisms found throughout the world, which react to light by transporting ions across the lipid membranes of cells in which they are genetically expressed. These tools are enabling the causal assessment of the roles that different sets of neurons play within neural circuits, and are accordingly being used to reveal how different sets of neurons contribute to the emergent computational and behavioral functions of the brain. These tools are also being explored as components of prototype neural control prosthetics capable of correcting neural circuit computations that have gone awry in brain disorders. This review gives an account of the birth of optogenetics and discusses the technology and its applications.
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Affiliation(s)
- Edward S Boyden
- Media Lab, McGovern Institute, Department of Brain and Cognitive Sciences and Department of Biological Engineering MIT, 77 Massachusetts Avenue, Cambridge, MA 02139 USA
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Boyden ES. A history of optogenetics: the development of tools for controlling brain circuits with light. F1000 BIOLOGY REPORTS 2011; 3:11. [PMID: 21876722 DOI: 10.3410/b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Understanding how different kinds of neuron in the brain work together to implement sensations, feelings, thoughts, and movements, and how deficits in specific kinds of neuron result in brain diseases, has long been a priority in basic and clinical neuroscience. "Optogenetic" tools are genetically encoded molecules that, when targeted to specific neurons in the brain, enable their activity to be driven or silenced by light. These molecules are microbial opsins, seven-transmembrane proteins adapted from organisms found throughout the world, which react to light by transporting ions across the lipid membranes of cells in which they are genetically expressed. These tools are enabling the causal assessment of the roles that different sets of neurons play within neural circuits, and are accordingly being used to reveal how different sets of neurons contribute to the emergent computational and behavioral functions of the brain. These tools are also being explored as components of prototype neural control prosthetics capable of correcting neural circuit computations that have gone awry in brain disorders. This review gives an account of the birth of optogenetics and discusses the technology and its applications.
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Affiliation(s)
- Edward S Boyden
- Media Lab, McGovern Institute, Department of Brain and Cognitive Sciences and Department of Biological Engineering MIT, 77 Massachusetts Avenue, Cambridge, MA 02139 USA
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5
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Mutagenic Analysis of Membrane Protein Functional Mechanisms: Bacteriorhodopsin as a Model Example. Methods Cell Biol 2008. [DOI: 10.1016/s0091-679x(07)84016-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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6
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Abstract
This article highlights areas of research at the interface of nanotechnology, the physical sciences, and biology that are related to energy conversion: specifically, those related to photovoltaic applications. Although much ongoing work is seeking to understand basic processes of photosynthesis and chemical conversion, such as light harvesting, electron transfer, and ion transport, application of this knowledge to the development of fully synthetic and/or hybrid devices is still in its infancy. To develop systems that produce energy in an efficient manner, it is important both to understand the biological mechanisms of energy flow for optimization of primary structure and to appreciate the roles of architecture and assembly. Whether devices are completely synthetic and mimic biological processes or devices use natural biomolecules, much of the research for future power systems will happen at the intersection of disciplines.
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Affiliation(s)
- David A. LaVan
- *Department of Mechanical Engineering, Yale University, New Haven, CT 06511; and
- To whom correspondence may be addressed at:
Department of Mechanical Engineering, Yale University, 9 Hillhouse Avenue, Mason Lab Building, Room M3, New Haven, CT 06511. E-mail:
| | - Jennifer N. Cha
- IBM Almaden Research, 650 Harry Road, San Jose, CA 95120
- To whom correspondence may be addressed. E-mail:
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Reiser J, Glumoff V, Kälin M, Ochsner U. Transfer and expression of heterologous genes in yeasts other than Saccharomyces cerevisiae. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2005; 43:75-102. [PMID: 2291442 DOI: 10.1007/bfb0009080] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In the past few years, yeasts other than those belonging to the genus Saccharomyces have become increasingly important for industrial applications. Species such as Pichia pastoris, Hansenula polymorpha, Schizosaccharomyces pombe, Yarrowia lipolytica and Kluyveromyces lactis have been modified genetically and used for the production of heterologous proteins. For a number of additional yeasts such as Schwanniomyces occidentalis, Zygosaccharomyces rouxii, Trichosporon cutaneum, Pachysolen tannophilus, Pichia guilliermondii and members of the genus Candida genetic transformation systems have been worked out. Transformation was achieved using either dominant selection markers based on antibiotic resistance genes or auxotrophic markers in conjunction with cloned biosynthetic genes involved in amino acid or nucleotide metabolism.
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Affiliation(s)
- J Reiser
- Institut für Biotechnologie, ETH-Hönggerberg, Zürich, Switzerland
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Hillebrecht JR, Wise KJ, Koscielecki JF, Birge RR. Directed evolution of bacteriorhodopsin for device applications. Methods Enzymol 2004; 388:333-47. [PMID: 15289081 DOI: 10.1016/s0076-6879(04)88026-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
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Opekarová M, Tanner W. Specific lipid requirements of membrane proteins--a putative bottleneck in heterologous expression. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1610:11-22. [PMID: 12586375 DOI: 10.1016/s0005-2736(02)00708-3] [Citation(s) in RCA: 172] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Membrane proteins are mostly protein-lipid complexes. For more than 30 examples of membrane proteins from prokaryotes, yeast, plant and mammals, the importance of phospholipids and sterols for optimal activity is documented. All crystallized membrane protein complexes show defined lipid-protein contacts. In addition, lipid requirements may also be transitory and necessary only for correct folding and intercellular transport. With respect to specific lipid requirements of membrane proteins, the phospholipid and glycolipid as well as the sterol content of the host cell chosen for heterologous expression should be carefully considered. The lipid composition of bacteria, archaea, yeasts, insects,Xenopus oocytes, and typical plant and mammalian cells are given in this review. A few examples of heterologous expression of membrane proteins, where problems of specific lipid requirements have been noticed or should be thought of, have been chosen.
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Affiliation(s)
- M Opekarová
- Institute of Microbiology, Czech Academy of Sciences, 142 20 4 Prague, Czech Republic
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Heymann JB, Pfeiffer M, Hildebrandt V, Kaback HR, Fotiadis D, Groot B, Engel A, Oesterhelt D, Müller DJ. Conformations of the rhodopsin third cytoplasmic loop grafted onto bacteriorhodopsin. Structure 2000; 8:643-53. [PMID: 10873864 DOI: 10.1016/s0969-2126(00)00151-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND The third cytoplasmic loop of rhodopsin (Rho EF) is important in signal transduction from the retinal in rhodopsin to its G protein, transducin. This loop also interacts with rhodopsin kinase, which phosphorylates light-activated rhodopsin, and arrestin, which displaces transducin from light-activated phosphorylated rhodopsin. RESULTS We replaced eight residues of the EF loop of bacteriorhodopsin (BR) with 24 residues from the third cytoplasmic loop of bovine Rho EF. The surfaces of purple membrane containing the mutant BR (called IIIN) were imaged by atomic force microscopy (AFM) under physiological conditions to a resolution of 0.5-0.7 nm. The crystallinity and extracellular surface of IIIN were not perturbed, and the cytoplasmic surface of IIIN increased in height compared with BR, consistent with the larger loop. Ten residues of Rho EF were excised by V8 protease, revealing helices E and F in the AFM topographs. Rho EF was modeled onto the BR structure, and the envelope derived from the AFM data of IIIN was used to select probable models. CONCLUSIONS A likely conformation of Rho EF involves some extension of helices E and F, with the tip of the loop lying over helix C and projecting towards the C terminus. This is consistent with mutagenesis data showing the TTQ transducin-binding motif close to loop CD, and cysteine cross-linking data indicating the C-terminal part of Rho EF to be close to the CD loop.
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Affiliation(s)
- J B Heymann
- M.E. Müller-Institute for Structural Biology, Biozentrum, University of Basel, Basel, CH-4056, Switzerland
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Bieszke JA, Spudich EN, Scott KL, Borkovich KA, Spudich JL. A eukaryotic protein, NOP-1, binds retinal to form an archaeal rhodopsin-like photochemically reactive pigment. Biochemistry 1999; 38:14138-45. [PMID: 10571987 DOI: 10.1021/bi9916170] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The nop-1 gene from Neurospora crassa is predicted to encode a seven-helix protein exhibiting conservation with the rhodopsins of the archaeon Halobacterium salinarum. In the work presented here we have expressed this gene heterologously in the yeast Pichia pastoris, obtaining a relatively high yield of 2.2 mg of NOP-1 protein/L of cell culture. The expressed protein is membrane-associated and forms with all-trans retinal a visible light-absorbing pigment with a 534 nm absorption maximum and approximately 100 nm half-bandwidth typical of retinylidene protein absorption spectra. Its lambda(max) indicates a protonated Schiff base linkage of the retinal. Laser flash kinetic spectroscopy demonstrates that the retinal-reconstituted pigment undergoes a photochemical reaction cycle with a near-UV-absorbing intermediate that is similar to the M intermediates produced by transient Schiff base deprotonation of the chromophore in the photocycles of bacteriorhodopsin and sensory rhodopsins I and II. The slow photocycle (seconds) and long-lived intermediates (M and O) are most similar to those of the phototaxis receptor sensory rhodopsin II. The results demonstrate a photochemically reactive member of the archaeal rhodopsin family in a eukaryotic cell.
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Affiliation(s)
- J A Bieszke
- Department of Microbiology and Molecular Genetics, The University of Texas Medical School, Houston, Texas 77030, USA
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Haupts U, Tittor J, Oesterhelt D. Closing in on bacteriorhodopsin: progress in understanding the molecule. ANNUAL REVIEW OF BIOPHYSICS AND BIOMOLECULAR STRUCTURE 1999; 28:367-99. [PMID: 10410806 DOI: 10.1146/annurev.biophys.28.1.367] [Citation(s) in RCA: 435] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bacteriorhodopsin is the best understood ion transport protein and has become a paradigm for membrane proteins in general and transporters in particular. Models up to 2.5 A resolution of bacteriorhodopsin's structure have been published during the last three years and are basic for understanding its function. Thus one focus of this review is to summarize and to compare these models in detail. Another focus is to follow the protein through its catalytic cycle in summarizing more recent developments. We focus on literature published since 1995; a comprehensive series of reviews was published in 1995 (112).
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Affiliation(s)
- U Haupts
- Max-Planck-Institut für Biochemie, Martinsried, Germany
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13
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Abstract
Yeasts combine the advantages of fast and easy handling with the potential to perform eukaryotic post-translational modifications and are for this reason interesting hosts for heterologous production of G-protein-coupled receptors. The possibility to connect foreign receptors to a yeast internal MAP kinase pathway was used to establish yeast-based systems for high-throughput screening of compound libraries. In addition, yeasts have the potential for high level production of G-protein-coupled receptors. In this field, non-Saccharomyces yeasts seems to be interesting alternatives to S. cerevisiae, as well as to systems based on higher eukaryotic cells.
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Affiliation(s)
- H Reiländer
- Max-Planck-Institut für Biophysik, Abteilung Molekulare Membranbiologie, Frankfurt/M., Germany.
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Abdulaev NG, Popp MP, Smith WC, Ridge KD. Functional expression of bovine opsin in the methylotrophic yeast Pichia pastoris. Protein Expr Purif 1997; 10:61-9. [PMID: 9179292 DOI: 10.1006/prep.1996.0704] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The methylotrophic yeast Pichia pastoris was examined for functional expression of bovine opsin. An expression plasmid was constructed where the bovine opsin gene was placed downstream from the P. pastoris alcohol oxidase 1 gene promoter and fused at its amino-terminus to the acid phosphatase secretion signal. Quantitative-competitive PCR analysis of a stable yeast transformant showed that one copy of the opsin gene was integrated into the yeast genome. The expression level in this transformant corresponded to approximately 0.3 mg of opsin per liter of cell culture (A600 = 1.0). Sucrose density sedimentation analysis indicated that the opsin was associated exclusively with the membrane fraction. Similar to retinal opsin, P. pastoris-expressed opsin migrated as a single band of approximately 37 kDa on SDS-PAGE and showed high mannose N-glycosylation. A portion of the expressed opsin (approximately 4-15%) reacted with 11-cis-retinal to form the rhodopsin chromophore (lambda max 500 nm), and after purification showed ground and excited state spectral characteristics indistinguishable from those of the native pigment. Further, the metarhodopsin-II-mediated G-protein-activating potential of yeast expressed rhodopsin was similar to that of native rhodopsin. These results show that P. pastoris cells have the capacity to functionally express bovine opsin.
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Affiliation(s)
- N G Abdulaev
- Center for Advanced Research in Biotechnology, National Institute of Standards and Technology, Rockville, Maryland, USA
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Heymann J, Jager R, Subramaniam S. Expression of bacteriorhodopsin in Sf9 and COS-1 cells. J Bioenerg Biomembr 1997; 29:55-9. [PMID: 9067802 DOI: 10.1023/a:1022411806090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We report studies on the expression of the archaebacterial membrane protein bacteriorhodopsin in Sf9 insect cells and in COS-1 mammalian cells. In both cell systems, the apoprotein bacterio-opsin was expressed at levels of approximately 1 microgram/10(6) cells. Immunofluorescence studies showed that the expressed protein was accumulated in the endoplasmic reticulum. However, upon addition of all-trans retinal to membranes isolated from either Sf9 or COS-1 cells expressing bacterio-opsin, the characteristic bacteriorhodopsin chromophore (lambda max at approximately 560 nm) was rapidly generated. This is in contrast to bacterio-opsin expressed in E. coli, which cannot be functionally reconstituted with retinal unless it is first denatured, and then renatured in vitro. These studies demonstrate that the bacterio-opsin expressed is correctly folded and show that localization of a heterologously expressed membrane protein in the endoplasmic reticulum does not necessarily imply that it is misfolded.
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Affiliation(s)
- J Heymann
- Department of Biological Chemistry, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21205, USA
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Abstract
▪ Abstract Plant and fungal membrane proteins catalyzing the transmembrane translocation of small molecules without directly using ATP or acting as channels are discussed in this review. Facilitators, ion-cotransporters, and exchange translocators mainly for sugars, amino acids, and ions that have been cloned and characterized from Saccharomyces cerevisiae and from various plant sources have been tabulated. The membrane topology and structure of the most extensively studied carriers (lac permease of Escherichia coli, Glut1 of man, HUP1 of Chlorella) are discussed in detail as well as the kinetic analysis of specific Na+ and H+ cotransporters. Finally, the knowledge concerning regulatory phenomena of carriers—mainly of S. cerevisiae—is summarized.
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Affiliation(s)
- W. Tanner
- Lehrstuhl fur Zellbiologie und Pflanzenphysiologie, Universitat Regensburg, Regensburg, 93040 Germany
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Abstract
Determination of the structure of integral membrane proteins is a challenging task that is essential to understand how fundamental biological processes (such as photosynthesis, respiration and solute translocation) function at the atomic level. Crystallisation of membrane proteins in 3D has led to the determination of four atomic resolution structures [photosynthetic reaction centres (Allenet al. 1987; Changet al. 1991; Deisenhofer & Michel, 1989; Ermleret al. 1994); porins (Cowanet al. 1992; Schirmeret al. 1995; Weisset al. 1991); prostaglandin H2synthase (Picotet al. 1994); light harvesting complex (McDermottet al. 1995)], and crystals of membrane proteins formed in the plane of the lipid bilayer (2D crystals) have produced two more structures [bacteriorhodopsin (Hendersonet al. 1990); light harvesting complex (Kühlbrandtet al. 1994)].
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Affiliation(s)
- R Grisshammer
- Centre for Protein Engineering, MRC Centre, Cambridge, UK
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Hoffmann A, Hildebrandt V, Heberle J, Büldt G. Photoactive mitochondria: in vivo transfer of a light-driven proton pump into the inner mitochondrial membrane of Schizosaccharomyces pombe. Proc Natl Acad Sci U S A 1994; 91:9367-71. [PMID: 7937771 PMCID: PMC44813 DOI: 10.1073/pnas.91.20.9367] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The light-driven proton pump bacteriorhodopsin (bR) from Halobacterium salinarium has been genetically transferred into the inner mitochondrial membrane (IM) of the eukaryotic cell Schizosaccharomyces pombe, where the archaebacterial proton pump replaces or increases the proton gradient usually formed by the respiratory chain. For targeting and integration, as well as for the correct orientation of bR in the IM, the bacterioopsin gene (bop) was fused to signal sequences of IM proteins. Northern and Western blot analysis proved that all hybrid gene constructs containing the bop gene and a mitochondrial signal sequence were expressed and processed to mature bR. Fast transient absorption spectroscopy showed photocycle activity of bR integrated in the IM by formation of the M intermediate. Experiments with the pH-sensitive fluorescence dye 2',7'-bis(2-carboxyethyl)-5 (and -6)-carboxyfluorescein revealed bR-mediated proton pumping from the mitochondrial matrix into the intermembrane space. Glucose uptake measurements under anaerobic conditions showed that yeast cells containing photoactive mitochondria need less sugar under illumination. In summary, our experiments demonstrate the functional genetic transfer of a light energy converter to a naturally nonphotoactive eukaryotic organism.
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Affiliation(s)
- A Hoffmann
- Forschungszentrum Jülich, Institut für Biologische Informationsverarbeitung, Germany
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Lang-Hinrichs C, Queck I, Büldt G, Stahl U, Hildebrandt V. The archaebacterial membrane protein bacterio-opsin is expressed and N-terminally processed in the yeast Saccharomyces cerevisiae. MOLECULAR & GENERAL GENETICS : MGG 1994; 244:183-8. [PMID: 8052237 DOI: 10.1007/bf00283521] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The bop gene codes for the membrane protein bacterio-opsin (BO), which on binding all-trans-retinal, constitutes the light-driven proton pump bacteriorhodopsin (BR) in the archaebacterium Halobacterium salinarium. This gene was cloned in a yeast multi-copy vector and expressed in Saccharomyces cerevisiae under the control of the constitutive ADH1 promoter. Both the authentic gene and a modified form lacking the precursor sequence were expressed in yeast. Both proteins are incorporated into the membrane in S. cerevisiae. The presequence is thus not required for membrane targeting and insertion of the archaebacterial protein in budding yeast, or in the fission yeast Schizosaccharomyces pombe, as has been shown previously. However, in contrast to S. pombe transformants, which take on a reddish colour when all-trans-retinal is added to the culture medium as a result of the in vivo regeneration of the pigment, S. cerevisiae cells expressing BO do not take on a red colour. The precursor of BO is processed to a protein identical in size to the mature BO found in the purple membrane of Halobacterium. The efficiency of processing in S. cerevisiae is dependent on growth phase, as well as on the composition of the medium and on the strain used. The efficiency of processing of BR is reduced in S. pombe and in a retinal-deficient strain of H. salinarium, when retinal is present in the medium.
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Affiliation(s)
- C Lang-Hinrichs
- Technische Universität Berlin, FG Mikrobiologie und Genetik, Germany
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Tuffery P, Etchebest C, Popot JL, Lavery R. Prediction of the positioning of the seven transmembrane alpha-helices of bacteriorhodopsin. A molecular simulation study. J Mol Biol 1994; 236:1105-22. [PMID: 8120890 DOI: 10.1016/0022-2836(94)90015-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have applied a search strategy for determining the optimal packing of protein secondary structure elements to the rotational positioning of the seven transmembrane helices of bacteriorhodopsin. The search is based on the assumption that the relative orientations of the helices within the bundle are conditioned principally by inter-helix side-chain interactions and that the extra-helical parts of the protein have only a minor influence on the bundle conformation. Our approach performs conformational energy optimization using a predetermined set of side-chain rotamers and appropriate methods for sampling the conformational space of peptide fragments with fixed backbone geometries. The final solution obtained for bacteriorhodopsin places each of the seven helices to a precision of a few degrees in rotation around the helical axis and to a few tenths of an ångström in translation along the helical axis with respect to the best experimental structure obtained by electron diffraction, except for helix D, where our results support the suggestion that this helix should be displaced along its axis toward its N terminus. The perspectives of such an approach for the determination of the structures of other transmembrane helical bundles are discussed.
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Affiliation(s)
- P Tuffery
- CNRS URA 77, Institut de Biologie Physico-Chimique, Paris, France
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Hildebrandt V, Fendler K, Heberle J, Hoffmann A, Bamberg E, Büldt G. Bacteriorhodopsin expressed in Schizosaccharomyces pombe pumps protons through the plasma membrane. Proc Natl Acad Sci U S A 1993; 90:3578-82. [PMID: 8386375 PMCID: PMC46344 DOI: 10.1073/pnas.90.8.3578] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Bacterioopsin (bO) from Halobacterium salinarium ("Halobacterium halobium") has been functionally expressed in a heterologous system, the fission yeast Schizosaccharomyces pombe. Regeneration of bO to bacteriorhodopsin (bR) in S. pombe has been achieved in vivo by addition of the chromophore retinal to the culture medium, as shown for a retinal-negative mutant of H. salinarium (JW5). Western blot analysis revealed that bR is more stable than bO against proteolysis in fission yeast and also in JW5. The light-driven proton pump is expressed in the eukaryotic organism and incorporated into the plasma membrane. Illumination of intact yeast cells leads to acidification of the external medium due to the translocation of H+ from inside to outside of the cell, indicating the same orientation of bR in the yeast plasma membrane as in H. salinarium. The kinetics of proton release into the water phase was observed with the optical pH indicator pyranine. Time-resolved absorbance changes of isolated plasma membrane measured by flash spectroscopy showed rise and decay of the M intermediate during the photocycle similar to those in the homologous system. Photocurrents and photovoltages were recorded with yeast plasma membrane attached to a planar lipid membrane and to a polytetrafluoroethylene (Teflon) film, respectively. Stationary currents measured in the presence of a protonophore showed continuous pumping activity of bR. The action spectrum of the photocurrent and the kinetics of the photovoltage were analyzed and compared with signals obtained from purple membranes. From all these different investigations we conclude that the integral membrane protein bR is correctly folded in vivo into the cytoplasmic membrane of the fission yeast S. pombe.
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Affiliation(s)
- V Hildebrandt
- Department of Physics/Biophysics, Freie Universität Berlin, Germany
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23
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Heymann JA, Havelka WA, Oesterhelt D. Homologous overexpression of a light-driven anion pump in an archaebacterium. Mol Microbiol 1993; 7:623-30. [PMID: 8384688 DOI: 10.1111/j.1365-2958.1993.tb01153.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The retinal protein halorhodopsin (HR), a light-driven chloride pump from Halobacterium halobium, was homologously overexpressed in this archaebacterium. Two DNA expression systems differing in their promoter region were investigated. The halopsin, hop, promoter coupled to the hop gene gave an increased level of HR synthesis. However, the extent of expression was driven by the copy number of the shuttle vector and did not reach the magnitude of the bacterio-opsin, bop, promoter system. Employing a gene fusion approach, the promoter for the bop gene was used to drive expression of the hop gene. A shuttle vector containing a bop-hop-cartridge was transformed into a HR-deficient strain and blueish-coloured transformants were obtained. The bop promoter expressed HR to an extent where a specific membrane fraction resembled the crystalline purple membrane of BR in terms of the lipid to protein ratio. HR could, therefore, be easily isolated in a natural membrane-bound state. This allows for direct use in biophysical studies without the application of detergents. This was the first successful overexpression of a 7-helical transmembrane protein and may be extended to other proteins of this family.
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Affiliation(s)
- J A Heymann
- Max-Planck-Institut für Biochemie, Martinsried, Germany
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24
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Pompejus M, Friedrich K, Teufel M, Fritz HJ. High-yield production of bacteriorhodopsin via expression of a synthetic gene in Escherichia coli. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 211:27-35. [PMID: 7916683 DOI: 10.1111/j.1432-1033.1993.tb19866.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A gene (bos) coding for bacterioopsin (BO), the apoprotein of bacteriorhodopsin was assembled from chemically synthesized oligonucleotides by a new method of repeated rounds of insertion mutagenesis. The gene sequence was designed for convenient manipulation in future protein engineering experiments. In-frame fusion of bos to the lacZ454 gene allowed high-yield production in Escherichia coli of a beta-Gal454/BO fusion protein, deposited as intracellular inclusion bodies. These were enriched by virtue of their insolubility in 0.5% Triton X-100 and cleaved in aqueous suspension with IgA protease at a specific site provided at the beta-Gal454/BO boundary. Pure BO could be obtained from the mixture of water-insoluble cleavage products by selective extraction into organic solvent. The yield was in the range 30-50 mg pure protein/l culture medium, depending on individual preparation. This material could be used for reconstitution of fully functional bacteriorhodopsin. Taken together, the procedure constitutes a practical basis for the production of genetically engineered bacteriorhodopsins.
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Affiliation(s)
- M Pompejus
- Institute für Molekulare Genetik, Georg-August-Universität Göttingen, Federal Republic of Germany
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25
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Bauer U, Hildebrandt V, Dencher NA, Wrede P. In vitro synthesis of bacterio-opsin: integration into microsomal membranes. Biochem Biophys Res Commun 1992; 187:1480-5. [PMID: 1384471 DOI: 10.1016/0006-291x(92)90469-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The translation and membrane integration of bacterio-opsin from Halobacterium salinarium were investigated. Plasmids containing the bacterio-opsin-gene with or without its original presequence were transcribed with the T7-RNA-polymerase and translated in vitro in a wheat germ system. The integration of the expressed bacterio-opsin into dog pancreas microsomes was studied. Both precursor bacterio-opsin and mature bacterio-opsin integrate into the eukaryotic membrane.
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Affiliation(s)
- U Bauer
- Freie Universität Berlin, FB Physik, AG Biophysik, Germany
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26
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27
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Villalba J, Palmgren M, Berberián G, Ferguson C, Serrano R. Functional expression of plant plasma membrane H(+)-ATPase in yeast endoplasmic reticulum. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)49845-1] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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28
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Affiliation(s)
- M A Romanos
- Department of Cell Biology, Wellcome Research Laboratories, Beckenham, Kent, U.K
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29
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Moracci M, La Volpe A, Pulitzer JF, Rossi M, Ciaramella M. Expression of the thermostable beta-galactosidase gene from the archaebacterium Sulfolobus solfataricus in Saccharomyces cerevisiae and characterization of a new inducible promoter for heterologous expression. J Bacteriol 1992; 174:873-82. [PMID: 1732221 PMCID: PMC206165 DOI: 10.1128/jb.174.3.873-882.1992] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The lacS gene from the extremely thermoacidophilic archaebacterium Sulfolobus solfataricus encodes an enzyme with beta-galactosidase activity that, like other enzymes from this organism, is exceptionally thermophilic (optimal activity above 90 degrees C), thermostable, and resistant to common protein denaturants and proteases. Expression of the gene in mesophilic hosts is needed to uncover the molecular nature of these features. We have obtained expression of beta-galactosidase in Saccharomyces cerevisiae under the control of the galactose-inducible upstream activating sequence of the yeast genes GAL1 and GAL10. The expressed enzyme is identical in molecular mass, thermostability, and thermophilicity to the native enzyme, showing that these features are intrinsic to the primary structure of the enzyme. We also present a new promoter for the expression of thermostable proteins in S. cerevisiae. This promoter contains a sequence isolated from the nematode Caenorhabditis elegans that works as a strong, heat-inducible upstream activating sequence in S. cerevisiae. Transcription of the lacS gene under the control of this sequence is rapidly and efficiently induced by heat shock. The availability of a plate assay for monitoring beta-galactosidase activity in S. cerevisiae may allow screening for mutants affecting the efficiency and activity of the enzyme.
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Affiliation(s)
- M Moracci
- Institute of Protein Biochemistry and Enzymology, Naples, Italy
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30
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Hildebrandt V, Polakowski F, Büldt G. PURPLE FISSION YEAST: OVEREXPRESSION and PROCESSING OF THE PIGMENT BACTERIORHODOPSIN IN Schizosaccharomyces pombe. Photochem Photobiol 1991. [DOI: 10.1111/j.1751-1097.1991.tb02123.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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Sauer N, Caspari T, Klebl F, Tanner W. Functional expression of the Chlorella hexose transporter in Schizosaccharomyces pombe. Proc Natl Acad Sci U S A 1990; 87:7949-52. [PMID: 11607110 PMCID: PMC54869 DOI: 10.1073/pnas.87.20.7949] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Schizosaccharomyces pombe cells were transformed with an S. pombe expression vector containing a full-length cDNA of the Chlorella hexose transporter. The transformed cells accumulated 3-O-methylglucose up to 10-fold, whereas wild-type S. pombe and control transformants could only equilibrate this sugar analogue. In a pH-jump experiment, in which extracellular pH was lowered by 1.9 units, the accumulation ratio was increased in transformed cells but not in control cells. This result indicates that the gene product, Chlorella H+/glucose-symporter protein, and a pH gradient suffice for active sugar uptake. Km values for glucose, 6-deoxyglucose, and 3-O-methylglucose of 1.5 x 10(-5) M, 2.7 x 10(-4) M, and 1.0 x 10(-3) M, respectively, were identical in Chlorella and in S. pombe cells transformed with Chlorella cDNA and approximately 100-fold lower than those of the endogenous transport system of S. pombe.
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Affiliation(s)
- N Sauer
- Lehstuhl für Zellbiologische und Pflanzenphysiologie, Universität Regensburg, Regensburg, Federal Republic of Germany
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32
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Ni BF, Chang M, Duschl A, Lanyi J, Needleman R. An efficient system for the synthesis of bacteriorhodopsin in Halobacterium halobium. Gene 1990; 90:169-72. [PMID: 2379834 DOI: 10.1016/0378-1119(90)90456-2] [Citation(s) in RCA: 100] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The mechanism by which bacteriorhodopsin (BR) transports protons across the cell membrane of Halobacterium halobium is actively studied in many laboratories. Currently available systems for the synthesis of mutant proteins obtained by site-directed mutagenesis of the gene encoding BR (bop) require reconstitution of the denatured polypeptide after its synthesis Escherichia coli or yeast; this approach is technically difficult and labor intensive, and raises questions about possible differences between in vivo and in vitro folding. Using a newly described transformation system and a halobacterial plasmid vector, we show that it is possible to reintroduce the bop gene into BR- strains of H. halobium. The bop-carrying plasmid expresses native BR in amounts similar to those obtained in several wild type strains. This system allows facile site-directed mutagenesis in halophilic archaebacteria.
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Affiliation(s)
- B F Ni
- Wayne State University School of Medicine, Department of Biochemistry, Detroit, MI 48201
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33
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Hildebrandt V. Regeneration and functional incorporation of bacteriorhodopsin in membranes of fission yeast but not in E. coli. JOURNAL OF PROTEIN CHEMISTRY 1989; 8:345-6. [PMID: 2675898 DOI: 10.1007/bf01674272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- V Hildebrandt
- FB Physik, Abt. Biophysik, Freie Universität Berlin, FRG
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34
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Wrede P, Lange M, Büldt G, Frevert U. Biogenesis of bacteriorhodopsin. JOURNAL OF PROTEIN CHEMISTRY 1989; 8:343-4. [PMID: 2675897 DOI: 10.1007/bf01674271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- P Wrede
- Freie Universität Berlin, FB Physik, AG Biophysik Arnimallee 14, Berlin-Dahlem, FRG
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