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de Grip WJ, Ganapathy S. Rhodopsins: An Excitingly Versatile Protein Species for Research, Development and Creative Engineering. Front Chem 2022; 10:879609. [PMID: 35815212 PMCID: PMC9257189 DOI: 10.3389/fchem.2022.879609] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 05/16/2022] [Indexed: 01/17/2023] Open
Abstract
The first member and eponym of the rhodopsin family was identified in the 1930s as the visual pigment of the rod photoreceptor cell in the animal retina. It was found to be a membrane protein, owing its photosensitivity to the presence of a covalently bound chromophoric group. This group, derived from vitamin A, was appropriately dubbed retinal. In the 1970s a microbial counterpart of this species was discovered in an archaeon, being a membrane protein also harbouring retinal as a chromophore, and named bacteriorhodopsin. Since their discovery a photogenic panorama unfolded, where up to date new members and subspecies with a variety of light-driven functionality have been added to this family. The animal branch, meanwhile categorized as type-2 rhodopsins, turned out to form a large subclass in the superfamily of G protein-coupled receptors and are essential to multiple elements of light-dependent animal sensory physiology. The microbial branch, the type-1 rhodopsins, largely function as light-driven ion pumps or channels, but also contain sensory-active and enzyme-sustaining subspecies. In this review we will follow the development of this exciting membrane protein panorama in a representative number of highlights and will present a prospect of their extraordinary future potential.
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Affiliation(s)
- Willem J. de Grip
- Leiden Institute of Chemistry, Department of Biophysical Organic Chemistry, Leiden University, Leiden, Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Srividya Ganapathy
- Department of Imaging Physics, Delft University of Technology, Netherlands
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Brinkmann A, Sternberg U, Bovee-Geurts PHM, Fernández Fernández I, Lugtenburg J, Kentgens APM, DeGrip WJ. Insight into the chromophore of rhodopsin and its Meta-II photointermediate by 19F solid-state NMR and chemical shift tensor calculations. Phys Chem Chem Phys 2018; 20:30174-30188. [PMID: 30484791 DOI: 10.1039/c8cp05886e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
19F nuclei are useful labels in solid-state NMR studies, since their chemical shift and tensor elements are very sensitive to the electrostatic and space-filling properties of their local environment. In this study we have exploited a fluorine substituent, strategically placed at the C-12-position of 11-cis retinal, the chromophore of visual rhodopsins. This label was used to explore the local environment of the chromophore in the ground state of bovine rhodopsin and its active photo-intermediate Meta II. In addition, the chemical shift and tensor elements of the chromophore in the free state in a membrane environment and the bound state in the protein were determined. Upon binding of the chromophore into rhodopsin and Meta II, the isotropic chemical shift changes in the opposite direction by +9.7 and -8.4 ppm, respectively. An unusually large isotropic shift difference of 35.9 ppm was observed between rhodopsin and Meta II. This partly originates in the light-triggered 11-cis to all-trans isomerization of the chromophore. The other part reflects the local conformational rearrangements in the chromophore and the binding pocket. These NMR data were correlated with the available X-ray structures of rhodopsin and Meta II using bond polarization theory. For this purpose hydrogen atoms have to be inserted and hereto a family of structures were derived that best correlated with the well-established 13C chemical shifts. Based upon these structures, a 12-F derivative was obtained that best corresponded with the experimentally determined 19F chemical shifts and tensor elements. The combined data indicate strong changes in the local environment of the C-12 position and a substantially different interaction pattern with the protein in Meta II as compared to rhodopsin.
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Affiliation(s)
- Andreas Brinkmann
- Metrology, National Research Council Canada, 1200 Montreal Road, Ottawa, Ontario K1A 0R6, Canada.
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Farag MH, Jansen TLC, Knoester J. The origin of absorptive features in the two-dimensional electronic spectra of rhodopsin. Phys Chem Chem Phys 2018; 20:12746-12754. [DOI: 10.1039/c8cp00638e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A three-state three-mode model Hamiltonian reveals the origin of the absorptive features in the two-dimensional electronic spectra of rhodopsin.
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Affiliation(s)
- Marwa H. Farag
- University of Groningen
- Zernike Institute for Advanced Materials
- 9747 AG Groningen
- The Netherlands
| | - Thomas L. C. Jansen
- University of Groningen
- Zernike Institute for Advanced Materials
- 9747 AG Groningen
- The Netherlands
| | - Jasper Knoester
- University of Groningen
- Zernike Institute for Advanced Materials
- 9747 AG Groningen
- The Netherlands
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Johnson PJM, Farag MH, Halpin A, Morizumi T, Prokhorenko VI, Knoester J, Jansen TLC, Ernst OP, Miller RJD. The Primary Photochemistry of Vision Occurs at the Molecular Speed Limit. J Phys Chem B 2017; 121:4040-4047. [PMID: 28358485 DOI: 10.1021/acs.jpcb.7b02329] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ultrafast photochemical reactions are initiated by vibronic transitions from the reactant ground state to the excited potential energy surface, directly populating excited-state vibrational modes. The primary photochemical reaction of vision, the isomerization of retinal in the protein rhodopsin, is known to be a vibrationally coherent reaction, but the Franck-Condon factors responsible for initiating the process have been difficult to resolve with conventional time-resolved spectroscopies. Here we employ experimental and theoretical 2D photon echo spectroscopy to directly resolve for the first time the Franck-Condon factors that initiate isomerization on the excited potential energy surface and track the reaction dynamics. The spectral dynamics reveal vibrationally coherent isomerization occurring on the fastest possible time scale, that of a single period of the local torsional reaction coordinate. We successfully model this process as coherent wavepacket motion through a conical intersection on a ∼30 fs time scale, confirming the reaction coordinate as a local torsional coordinate with a frequency of ∼570 cm-1. As a result of spectral features being spread out along two frequency coordinates, we unambiguously assign reactant and product states following passage through the conical intersection, which reveal the key vibronic transitions that initiate the vibrationally coherent photochemistry of vision.
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Affiliation(s)
- Philip J M Johnson
- Departments of Chemistry & Physics, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Marwa H Farag
- Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Max Planck Institute for the Structure and Dynamics of Matter , Atomically Resolved Dynamics Division, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Alexei Halpin
- Departments of Chemistry & Physics, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Takefumi Morizumi
- Department of Biochemistry, University of Toronto , 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Valentyn I Prokhorenko
- Max Planck Institute for the Structure and Dynamics of Matter , Atomically Resolved Dynamics Division, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Jasper Knoester
- Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Thomas L C Jansen
- Zernike Institute for Advanced Materials, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Oliver P Ernst
- Department of Biochemistry, University of Toronto , 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada.,Department of Molecular Genetics, University of Toronto , 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - R J Dwayne Miller
- Departments of Chemistry & Physics, University of Toronto , 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.,Max Planck Institute for the Structure and Dynamics of Matter , Atomically Resolved Dynamics Division, Luruper Chaussee 149, Hamburg 22761, Germany
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Coupled HOOP signature correlates with quantum yield of isorhodopsin and analog pigments. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1858:118-125. [PMID: 27836700 DOI: 10.1016/j.bbabio.2016.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 09/29/2016] [Accepted: 11/04/2016] [Indexed: 11/21/2022]
Abstract
With a quantum yield of 0.66±0.03 the photoisomerization efficiency of the visual pigment rhodopsin (11-cis⇒all-trans chromophore) is exceptionally high. This is currently explained by coherent coupling of the excited state electronic wavepacket with local vibrational nuclear modes, facilitating efficient cross-over at a conical intersection onto the photoproduct energy surface. The 9-cis counterpart of rhodopsin, dubbed isorhodopsin, has a much lower quantum yield (0.26±0.03), which, however, can be markedly enhanced by modification of the retinal chromophore (7,8-dihydro and 9-cyclopropyl derivatives). The coherent coupling in the excited state is promoted by torsional skeletal and coupled HOOP vibrational modes, in combination with a twisted conformation around the isomerization region. Since such torsion will strongly enhance the infrared intensity of coupled HOOP modes, we investigated FTIR difference spectra of rhodopsin, isorhodopsin and several analog pigments in the spectral range of isolated and coupled HCCH wags. As a result we propose that the coupled HOOP signature in these retinal pigments correlates with the distribution of torsion over counteracting segments in the retinylidene polyene chain. As such the HOOP signature can act as an indicator for the photoisomerization efficiency, and can explain the higher quantum yield of the 7,8-dihydro and 9-cyclopropyl-isorhodopsin analogs.
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Ockenfels A, Schapiro I, Gärtner W. Rhodopsins carrying modified chromophores--the 'making of', structural modelling and their light-induced reactivity. Photochem Photobiol Sci 2016; 15:297-308. [PMID: 26860474 DOI: 10.1039/c5pp00322a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A series of vitamin-A aldehydes (retinals) with modified alkyl group substituents (9-demethyl-, 9-ethyl-, 9-isopropyl-, 10-methyl, 10-methyl-13-demethyl-, and 13-demethyl retinal) was synthesized and their 11-cis isomers were used as chromophores to reconstitute the visual pigment rhodopsin. Structural changes were selectively introduced around the photoisomerizing C11=C12 bond. The effect of these structural changes on rhodopsin formation and bleaching was determined. Global fit of assembly kinetics yielded lifetimes and spectral features of the assembly intermediates. Rhodopsin formation proceeds stepwise with prolonged lifetimes especially for 9-demethyl retinal (longest lifetime τ3 = 7500 s, cf., 3500 s for retinal), and for 10-methyl retinal (τ3 = 7850 s). These slowed-down processes are interpreted as either a loss of fixation (9dm) or an increased steric hindrance (10me) during the conformational adjustment within the protein. Combined quantum mechanics and molecular mechanics (QM/MM) simulations provided structural insight into the retinal analogues-assembled, full-length rhodopsins. Extinction coefficients, quantum yields and kinetics of the bleaching process (μs-to-ms time range) were determined. Global fit analysis yielded lifetimes and spectral features of bleaching intermediates, revealing remarkably altered kinetics: whereas the slowest process of wild-type rhodopsin and of bleached and 11-cis retinal assembled rhodopsin takes place with lifetimes of 7 and 3.8 s, respectively, this process for 10-methyl-13-demethyl retinal was nearly 10 h (34670 s), coming to completion only after ca. 50 h. The structural changes in retinal derivatives clearly identify the precise interactions between chromophore and protein during the light-induced changes that yield the outstanding efficiency of rhodopsin.
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Affiliation(s)
- Andreas Ockenfels
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, D-45470 Mülheim, Germany.
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Chen D, Han X, Du Y, Wang HL, Xu P. In Situ Raman Monitoring of Silver(I)-Aided Laser-Driven Cleavage Reaction of Cyclobutane. Chemphyschem 2016; 17:46-50. [PMID: 26510491 DOI: 10.1002/cphc.201500874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Indexed: 11/07/2022]
Abstract
The cyclobutane cleavage reaction is an important process and has received continuous interest. Herein, we demonstrate the visible laser-driven cleavage reaction of cyclobutane in crystal form by using in situ Raman spectroscopy. Silver(I) coordination-induced strain and thermal effects from the laser irradiation are the two main driving forces for the cleavage of cyclobutane crystals. This work may open up a new avenue for studying cyclobutane cleavage reactions, as compared to the conventional routes using ex situ techniques.
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Affiliation(s)
- Dengtai Chen
- Department of Chemistry, Harbin Institute of Technology, Harbin, 150001, P. R. China
| | - Xijiang Han
- Department of Chemistry, Harbin Institute of Technology, Harbin, 150001, P. R. China.
| | - Yunchen Du
- Department of Chemistry, Harbin Institute of Technology, Harbin, 150001, P. R. China
| | - Hsing-Lin Wang
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Ping Xu
- Department of Chemistry, Harbin Institute of Technology, Harbin, 150001, P. R. China.
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Walczak E, Andruniów T. Impacts of retinal polyene (de)methylation on the photoisomerization mechanism and photon energy storage of rhodopsin. Phys Chem Chem Phys 2015; 17:17169-81. [DOI: 10.1039/c5cp01939g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Similar to native rhodopsin, a two-mode space-saving isomerization mechanism drives the photoreaction in (de)methylated rhodopsin analogues.
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Affiliation(s)
- Elżbieta Walczak
- Department of Chemistry
- Wroclaw University of Technology
- 50-370 Wroclaw
- Poland
| | - Tadeusz Andruniów
- Department of Chemistry
- Wroclaw University of Technology
- 50-370 Wroclaw
- Poland
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Álvarez R, Vaz B, Gronemeyer H, de Lera ÁR. Functions, therapeutic applications, and synthesis of retinoids and carotenoids. Chem Rev 2013; 114:1-125. [PMID: 24266866 DOI: 10.1021/cr400126u] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Rosana Álvarez
- Departamento de Química Orgánica, Centro de Investigación Biomédica (CINBIO), and Instituto de Investigación Biomédica de Vigo (IBIV), Universidade de Vigo , 36310 Vigo, Spain
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Klaffki N, Weingart O, Garavelli M, Spohr E. Sampling excited state dynamics: influence of HOOP mode excitations in a retinal model. Phys Chem Chem Phys 2012; 14:14299-305. [DOI: 10.1039/c2cp41994g] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Abstract
Methods of preparing fluorinated retinoids with labels located on odd-numbered carbons as well on even-numbered carbons and those containing trifluoromethyl groups are reviewed. The use of such retinoids in studies of protein-bound species is summarized, including the application of (19)F NMR spectroscopy for elucidating the mechanism of cis/trans isomerization, restricted rotation within the protein binding pocket, and identification of specific protein-substrate interactions. The fluorine label was also useful for wavelength attenuation of protein-bound species (including formation of NIR absorbing pigments) and for other unique applications. The more limited studies available on fluorinated carotenoids are also reviewed.
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Affiliation(s)
- Robert S H Liu
- Department of Chemistry, University of Hawaii, 2545 The Mall, Honolulu, Hawaii 96822, USA.
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deGrip WJ, Bovee-Geurts PHM, Wang Y, Verhoeven MA, Lugtenburg J. Cyclopropyl and isopropyl derivatives of 11-cis and 9-cis retinals at C-9 and C-13: subtle steric differences with major effects on ligand efficacy in rhodopsin. JOURNAL OF NATURAL PRODUCTS 2011; 74:383-390. [PMID: 21309593 DOI: 10.1021/np100744v] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Retinal is the natural ligand (chromophore) of the vertebrate rod visual pigment. It occurs in either the 11-cis (rhodopsin) or the 9-cis (isorhodopsin) configuration. In its evolution to a G protein coupled photoreceptor, rhodopsin has acquired exceptional photochemical properties. Illumination isomerizes the chromophore to the all-trans isomer, which acts as a full agonist. This process is extremely efficient, and there is abundant evidence that the C-9 and C-13 methyl groups of retinal play a pivotal role in this process. To examine the steric limits of the C-9 and C-13 methyl binding pocket of the binding site, we have prepared C-9 and C-13 cyclopropyl and isopropyl derivatives of its native ligands and of α-retinal at C-9. Most isopropyl analogues show very poor binding, except for 9-cis-13-isopropylretinal. Most cyclopropyl derivatives exhibit intermediate binding activity, except for 9-cis-13-cyclopropylretinal, which presents good binding activity. In general, the binding site shows preference for the 9-cis analogues over the 11-cis analogues. In fact, 13-isopropyl-9-cis-retinal acts as a superagonist after illumination. Another surprising finding was that 9-cyclopropylisorhodopsin is more like native rhodopsin with respect to spectral and photochemical properties, whereas 9-cyclopropylrhodopsin behaves more like native isorhodopsin in these aspects.
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Affiliation(s)
- Willem J deGrip
- Department of Biochemistry, UMCN 286, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
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Szundi I, Epps J, Lewis JW, Kliger DS. Temperature dependence of the lumirhodopsin I-lumirhodopsin II equilibrium. Biochemistry 2010; 49:5852-8. [PMID: 20545328 DOI: 10.1021/bi100566r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Time-resolved absorbance measurements, over a spectral range from 300 to 700 nm, were made at delays from 1 micros to 2 ms after photoexcitation of bovine rhodopsin in hypotonically washed membrane suspensions over a range of temperature from 10 to 35 degrees C. The purpose was to better understand the reversibility of the Lumi I-Lumi II process that immediately precedes Schiff base deprotonation in the activation of rhodopsin under physiological conditions. To prevent artifacts due to rotation of rhodopsin and its photoproducts in the membrane, probe light in the time-resolved absorbance studies was polarized at the magic angle (54.7 degrees) relative to the excitation laser polarization axis. The difference spectrum associated with the Lumi I to Lumi II reaction was found to have larger amplitude at 10 degrees C compared to higher temperatures, suggesting that a significant back-reaction exists for this process and that an equilibrated mixture forms. The equilibrium favors Lumi I entropically, and van't Hoff plot curvature shows the reaction enthalpy depends on temperature. The results suggest that Lumi II changes its interaction with the membrane in a temperature-dependent way, possibly binding a membrane lipid more strongly at lower temperatures (compared to its precursor). To elucidate the origin of the time-resolved absorbance changes, linear dichroism measurements were also made at 20 degrees C. The time constant for protein rotation in the membrane was found to be identical to the time constant for the Lumi I-Lumi II process, which is consistent with a common microscopic origin. We conclude that Lumi II (the last protonated Schiff base photointermediate under physiological conditions) is the first photointermediate whose properties depend on the protein-lipid environment.
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Affiliation(s)
- Istvan Szundi
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, USA
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