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Wu A, Salom D, Hong JD, Tworak A, Watanabe K, Pardon E, Steyaert J, Kandori H, Katayama K, Kiser PD, Palczewski K. Structural basis for the allosteric modulation of rhodopsin by nanobody binding to its extracellular domain. Nat Commun 2023; 14:5209. [PMID: 37626045 PMCID: PMC10457330 DOI: 10.1038/s41467-023-40911-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 08/16/2023] [Indexed: 08/27/2023] Open
Abstract
Rhodopsin is a prototypical G protein-coupled receptor (GPCR) critical for vertebrate vision. Research on GPCR signaling states has been facilitated using llama-derived nanobodies (Nbs), some of which bind to the intracellular surface to allosterically modulate the receptor. Extracellularly binding allosteric nanobodies have also been investigated, but the structural basis for their activity has not been resolved to date. Here, we report a library of Nbs that bind to the extracellular surface of rhodopsin and allosterically modulate the thermodynamics of its activation process. Crystal structures of Nb2 in complex with native rhodopsin reveal a mechanism of allosteric modulation involving extracellular loop 2 and native glycans. Nb2 binding suppresses Schiff base deprotonation and hydrolysis and prevents intracellular outward movement of helices five and six - a universal activation event for GPCRs. Nb2 also mitigates protein misfolding in a disease-associated mutant rhodopsin. Our data show the power of nanobodies to modulate the photoactivation of rhodopsin and potentially serve as therapeutic agents for disease-associated rhodopsin misfolding.
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Affiliation(s)
- Arum Wu
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, CA, 92697, USA
| | - David Salom
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, CA, 92697, USA
| | - John D Hong
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, CA, 92697, USA
- Department of Chemistry, University of California, Irvine, CA, 92697, USA
| | - Aleksander Tworak
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, CA, 92697, USA
| | - Kohei Watanabe
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, 466- 8555, Japan
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, 466- 8555, Japan
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan
| | - Kota Katayama
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, 466- 8555, Japan.
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan.
| | - Philip D Kiser
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, CA, 92697, USA.
- Department of Physiology & Biophysics, University of California, Irvine, CA, USA.
- Department of Clinical Pharmacy Practice, University of California, Irvine, CA, USA.
- Research Service, VA Long Beach Healthcare System, Long Beach, CA, USA.
| | - Krzysztof Palczewski
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, CA, 92697, USA.
- Department of Chemistry, University of California, Irvine, CA, 92697, USA.
- Department of Physiology & Biophysics, University of California, Irvine, CA, USA.
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, 92697, USA.
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2
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Zhang J, Choi EH, Tworak A, Salom D, Leinonen H, Sander CL, Hoang TV, Handa JT, Blackshaw S, Palczewska G, Kiser PD, Palczewski K. Photic generation of 11- cis-retinal in bovine retinal pigment epithelium. J Biol Chem 2019; 294:19137-19154. [PMID: 31694912 DOI: 10.1074/jbc.ra119.011169] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 10/25/2019] [Indexed: 12/19/2022] Open
Abstract
Photoisomerization of the 11-cis-retinal chromophore of rod and cone visual pigments to an all-trans-configuration is the initiating event for vision in vertebrates. The regeneration of 11-cis-retinal, necessary for sustained visual function, is an endergonic process normally conducted by specialized enzyme systems. However, 11-cis-retinal also can be formed through reverse photoisomerization from all-trans-retinal. A nonvisual opsin known as retinal pigment epithelium (RPE)-retinal G-protein-coupled receptor (RGR) was previously shown to mediate visual chromophore regeneration in photic conditions, but conflicting results have cast doubt on its role as a photoisomerase. Here, we describe high-level production of 11-cis-retinal from RPE membranes stimulated by illumination at a narrow band of wavelengths. This activity was associated with RGR and enhanced by cellular retinaldehyde-binding protein (CRALBP), which binds the 11-cis-retinal produced by RGR and prevents its re-isomerization to all-trans-retinal. The activity was recapitulated with cells heterologously expressing RGR and with purified recombinant RGR. Using an RGR variant, K255A, we confirmed that a Schiff base linkage at Lys-255 is critical for substrate binding and isomerization. Single-cell RNA-Seq analysis of the retina and RPE tissue confirmed that RGR is expressed in human and bovine RPE and Müller glia, whereas mouse RGR is expressed in RPE but not in Müller glia. These results provide key insights into the mechanisms of physiological retinoid photoisomerization and suggest a novel mechanism by which RGR, in concert with CRALBP, regenerates the visual chromophore in the RPE under sustained light conditions.
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Affiliation(s)
- Jianye Zhang
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697
| | - Elliot H Choi
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697.,Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Aleksander Tworak
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697
| | - David Salom
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697
| | - Henri Leinonen
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697
| | - Christopher L Sander
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697.,Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Thanh V Hoang
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - James T Handa
- Department of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.,Department of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | | | - Philip D Kiser
- Department of Physiology and Biophysics, University of California, Irvine, California 92697.,Research Service, Veterans Affairs Long Beach Healthcare System, Long Beach, California 90822
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697
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3
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Getter T, Suh S, Hoang T, Handa JT, Dong Z, Ma X, Chen Y, Blackshaw S, Palczewski K. The selective estrogen receptor modulator raloxifene mitigates the effect of all- trans-retinal toxicity in photoreceptor degeneration. J Biol Chem 2019; 294:9461-9475. [PMID: 31073029 DOI: 10.1074/jbc.ra119.008697] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/08/2019] [Indexed: 12/19/2022] Open
Abstract
The retinoid cycle is a metabolic process in the vertebrate retina that continuously regenerates 11-cis-retinal (11-cisRAL) from the all-trans-retinal (atRAL) isomer. atRAL accumulation can cause photoreceptor degeneration and irreversible visual dysfunction associated with incurable blinding retinal diseases, such as Stargardt disease, retinitis pigmentosa (RP), and atrophic age-related macular degeneration (AMD). The underlying cellular mechanisms leading to retinal degeneration remain uncertain, although previous studies have shown that atRAL promotes calcium influx associated with cell apoptosis. To identify compounds that mitigate the effects of atRAL toxicity, here we developed an unbiased and robust image-based assay that can detect changes in intracellular calcium levels in U2OS cells. Using our assay in a high-throughput screen of 2,400 compounds, we noted that selective estrogen receptor modulators (SERMs) potently stabilize intracellular calcium and thereby counteract atRAL-induced toxicity. In a light-induced retinal degeneration mouse model (Abca4 -/- Rdh8 -/-), raloxifene (a benzothiophene-type scaffold SERM) prevented the onset of photoreceptor apoptosis and thus protected the retina from degeneration. The minor structural differences between raloxifene and one of its derivatives (Y 134) had a major impact on calcium homeostasis after atRAL exposure in vitro, and we verified this differential impact in vivo In summary, the SERM raloxifene has structural and functional neuroprotective effects in the retina. We propose that the highly sensitive image-based assay developed here could be applied for the discovery of additional drug candidates preventing photoreceptor degeneration.
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Affiliation(s)
- Tamar Getter
- From the Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697, .,the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Susie Suh
- From the Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697.,the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Thanh Hoang
- the Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - James T Handa
- the Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | | | - Xiuli Ma
- Polgenix Inc., Irvine, California 92617
| | - Yuanyuan Chen
- the Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, and.,the McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Seth Blackshaw
- the Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Krzysztof Palczewski
- From the Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697, .,the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
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4
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Park JW, Jung KH, Lee JH, Moon SH, Cho YS, Lee KH. Inhibition of aldehyde dehydrogenase 1 enhances the cytotoxic effect of retinaldehyde on A549 cancer cells. Oncotarget 2017; 8:99382-99393. [PMID: 29245909 PMCID: PMC5725100 DOI: 10.18632/oncotarget.19544] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 06/26/2017] [Indexed: 01/05/2023] Open
Abstract
We hypothesized that aldehyde dehydrogenase1 (ALDH1) protects cancer cells from retinaldehyde-induced cytotoxicity, and that targeting this enzyme would enhance the therapeutic effect of retinaldehyde. ALDEFLUOR™ assays showed high ALDH activity in A549 and H522 cancer cells and low activity in H1666 and T47D cancer cells. Immunoblots showed that expression of ALDH1A1 and ALDH1A3 was high in A549 and H522 cells, but low in H1666 cells. HPLC confirmed that N, N-diethylaminobenzaldehyde (DEAB) inhibits ALDH-mediated disposal of retinaldehyde in A549 cells and lysates. Treatment of A549 cells with retinaldehyde in the presence of DEAB augmented reactive oxygen species production and decreased glucose uptake and oxygen consumption. Importantly, DEAB substantially potentiated the ability of retinaldehyde to dose-dependently suppress the survival of A549 and H522 cells, whereas the added effect of DEAB was minor in H1666 and T47D cells. Gene silencing with specific siRNA revealed that ALDH1A1 contributed to protection of A549 cells against retinaldehyde toxicity. These results demonstrate that ALDH1 confers protection against retinaldehyde toxicity in cancer cells.
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Affiliation(s)
- Jin Won Park
- Department of Nuclear Medicine, Samsung Medical Center, Seoul, Korea
- Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kyung-Ho Jung
- Department of Nuclear Medicine, Samsung Medical Center, Seoul, Korea
- Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jin Hee Lee
- Department of Nuclear Medicine, Samsung Medical Center, Seoul, Korea
- Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Seung Hwan Moon
- Department of Nuclear Medicine, Samsung Medical Center, Seoul, Korea
| | - Young Seok Cho
- Department of Nuclear Medicine, Samsung Medical Center, Seoul, Korea
| | - Kyung-Han Lee
- Department of Nuclear Medicine, Samsung Medical Center, Seoul, Korea
- Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University School of Medicine, Seoul, Korea
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5
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Friesen JB, McAlpine JB, Chen SN, Pauli GF. Countercurrent Separation of Natural Products: An Update. JOURNAL OF NATURAL PRODUCTS 2015; 78:1765-96. [PMID: 26177360 PMCID: PMC4517501 DOI: 10.1021/np501065h] [Citation(s) in RCA: 196] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Indexed: 05/02/2023]
Abstract
This work assesses the current instrumentation, method development, and applications in countercurrent chromatography (CCC) and centrifugal partition chromatography (CPC), collectively referred to as countercurrent separation (CCS). The article provides a critical review of the CCS literature from 2007 since our last review (J. Nat. Prod. 2008, 71, 1489-1508), with a special emphasis on the applications of CCS in natural products research. The current state of CCS is reviewed in regard to three continuing topics (instrumentation, solvent system development, theory) and three new topics (optimization of parameters, workflow, bioactivity applications). The goals of this review are to deliver the necessary background with references for an up-to-date perspective of CCS, to point out its potential for the natural product scientist, and thereby to induce new applications in natural product chemistry, metabolome, and drug discovery research involving organisms from terrestrial and marine sources.
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Affiliation(s)
- J. Brent Friesen
- Department
of Medicinal Chemistry and Pharmacognosy and Institute for Tuberculosis Research,
College of Pharmacy, University of Illinois
at Chicago, Chicago, Illinois 60612, United
States
- Physical
Sciences Department, Rosary College of Arts and Sciences, Dominican University, River Forest, Illinois 60305, United States
| | - James B. McAlpine
- Department
of Medicinal Chemistry and Pharmacognosy and Institute for Tuberculosis Research,
College of Pharmacy, University of Illinois
at Chicago, Chicago, Illinois 60612, United
States
| | - Shao-Nong Chen
- Department
of Medicinal Chemistry and Pharmacognosy and Institute for Tuberculosis Research,
College of Pharmacy, University of Illinois
at Chicago, Chicago, Illinois 60612, United
States
| | - Guido F. Pauli
- Department
of Medicinal Chemistry and Pharmacognosy and Institute for Tuberculosis Research,
College of Pharmacy, University of Illinois
at Chicago, Chicago, Illinois 60612, United
States
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6
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Human infrared vision is triggered by two-photon chromophore isomerization. Proc Natl Acad Sci U S A 2014; 111:E5445-54. [PMID: 25453064 DOI: 10.1073/pnas.1410162111] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Vision relies on photoactivation of visual pigments in rod and cone photoreceptor cells of the retina. The human eye structure and the absorption spectra of pigments limit our visual perception of light. Our visual perception is most responsive to stimulating light in the 400- to 720-nm (visible) range. First, we demonstrate by psychophysical experiments that humans can perceive infrared laser emission as visible light. Moreover, we show that mammalian photoreceptors can be directly activated by near infrared light with a sensitivity that paradoxically increases at wavelengths above 900 nm, and display quadratic dependence on laser power, indicating a nonlinear optical process. Biochemical experiments with rhodopsin, cone visual pigments, and a chromophore model compound 11-cis-retinyl-propylamine Schiff base demonstrate the direct isomerization of visual chromophore by a two-photon chromophore isomerization. Indeed, quantum mechanics modeling indicates the feasibility of this mechanism. Together, these findings clearly show that human visual perception of near infrared light occurs by two-photon isomerization of visual pigments.
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7
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Ying H, Jiang H, Liu H, Chen F, Du Q. Ethyl acetate-n-butanol gradient solvent system for high-speed countercurrent chromatography to screen bioactive substances in okra. J Chromatogr A 2014; 1359:117-23. [PMID: 25069743 DOI: 10.1016/j.chroma.2014.07.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 06/24/2014] [Accepted: 07/10/2014] [Indexed: 10/25/2022]
Abstract
High-speed countercurrent chromatographic separation (HSCCC) possesses the property of zero-loss of sample, which is very useful for the screening of bioactive components. In the present study, the ethyl acetate-n-butanol gradient HSCCC solvent system composed of n-hexane-ethyl acetate-n-butanol-water was investigated for the screening of bioactive substances. To screen the antiproliferative compounds in okra extract, we used the stationary phase ethyl acetate-n-butanol-water (1:1:10) as the stationary phase, and eluted the antiproliferative components by 6-steps of gradient using mobile phases n-hexane-ethyl acetate (1:2), n-hexane-ethyl acetate (1:4), n-hexane-ethyl acetate (0:4), n-butanol-ethyl acetate (1:4) n-butanol-ethyl acetate (1:2), n-butanol-ethyl acetate (2:2), and n-butanol-ethyl acetate (2:1). The fractions collected from HSCCC separation with the gradient solvent system were assayed for antiproliferative activity against cancer cells. Bioactive components were identified: a major anti-cancer compound, 4'-hydroxy phenethyl trans-ferulate, with middle activity, and a minor anti-cancer compound, carolignan, with strong activity. The result shows that the gradient solvent system is potential for the screening of bioactive compounds from natural products.
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Affiliation(s)
- Hao Ying
- Institute of Food Chemistry, Zhejiang Gongshang University, 149 Jiaogong Road, Hangzhou, Zhejiang 310012, China
| | - Heyuan Jiang
- Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China
| | - Huan Liu
- Institute of Food Chemistry, Zhejiang Gongshang University, 149 Jiaogong Road, Hangzhou, Zhejiang 310012, China
| | - Fangjuan Chen
- Institute of Food Chemistry, Zhejiang Gongshang University, 149 Jiaogong Road, Hangzhou, Zhejiang 310012, China
| | - Qizhen Du
- Institute of Food Chemistry, Zhejiang Gongshang University, 149 Jiaogong Road, Hangzhou, Zhejiang 310012, China.
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8
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Araujo NA, Sanz-Rodríguez CE, Bubis J. Binding of rhodopsin and rhodopsin analogues to transducin, rhodopsin kinase and arrestin-1. World J Biol Chem 2014; 5:254-268. [PMID: 24921014 PMCID: PMC4050118 DOI: 10.4331/wjbc.v5.i2.254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Revised: 02/10/2014] [Accepted: 04/17/2014] [Indexed: 02/05/2023] Open
Abstract
AIM: To investigate the interaction of reconstituted rhodopsin, 9-cis-retinal-rhodopsin and 13-cis-retinal-rhodopsin with transducin, rhodopsin kinase and arrestin-1.
METHODS: Rod outer segments (ROS) were isolated from bovine retinas. Following bleaching of ROS membranes with hydroxylamine, rhodopsin and rhodopsin analogues were generated with the different retinal isomers and the concentration of the reconstituted pigments was calculated from their UV/visible absorption spectra. Transducin and arrestin-1 were purified to homogeneity by column chromatography, and an enriched-fraction of rhodopsin kinase was obtained by extracting freshly prepared ROS in the dark. The guanine nucleotide binding activity of transducin was determined by Millipore filtration using β,γ-imido-(3H)-guanosine 5’-triphosphate. Recognition of the reconstituted pigments by rhodopsin kinase was determined by autoradiography following incubation of ROS membranes containing the various regenerated pigments with partially purified rhodopsin kinase in the presence of (γ-32P) ATP. Binding of arrestin-1 to the various pigments in ROS membranes was determined by a sedimentation assay analyzed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis.
RESULTS: Reconstituted rhodopsin and rhodopsin analogues containing 9-cis-retinal and 13-cis-retinal rendered an absorption spectrum showing a maximum peak at 498 nm, 486 nm and about 467 nm, respectively, in the dark; which was shifted to 380 nm, 404 nm and about 425 nm, respectively, after illumination. The percentage of reconstitution of rhodopsin and the rhodopsin analogues containing 9-cis-retinal and 13-cis-retinal was estimated to be 88%, 81% and 24%, respectively. Although only residual activation of transducin was observed in the dark when reconstituted rhodopsin and 9-cis-retinal-rhodopsin was used, the rhodopsin analogue containing the 13-cis isomer of retinal was capable of activating transducin independently of light. Moreover, only a basal amount of the reconstituted rhodopsin and 9-cis-retinal-rhodopsin was phosphorylated by rhodopsin kinase in the dark, whereas the pigment containing the 13-cis-retinal was highly phosphorylated by rhodopsin kinase even in the dark. In addition, arrestin-1 was incubated with rhodopsin, 9-cis-retinal-rhodopsin or 13-cis-retinal-rhodopsin. Experiments were performed using both phosphorylated and non-phosphorylated regenerated pigments. Basal amounts of arrestin-1 interacted with rhodopsin, 9-cis-retinal-rhodopsin and 13-cis-retinal-rhodopsin under dark and light conditions. Residual arrestin-1 was also recognized by the phosphorylated rhodopsin and phosphorylated 9-cis-retinal-rhodopsin in the dark. However, arrestin-1 was recognized by phosphorylated 13-cis-retinal-rhodopsin in the dark. As expected, all reformed pigments were capable of activating transducin and being phosphorylated by rhodopsin kinase in a light-dependent manner. Additionally, all reconstituted photolyzed and phosphorylated pigments were capable of interacting with arrestin-1.
CONCLUSION: In the dark, the rhodopsin analogue containing the 13-cis isomer of retinal appears to fold in a pseudo-active conformation that mimics the active photointermediate of rhodopsin.
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9
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Meng M, Feng Y, Liu Y, Wang Y, Yan Y. Preparation of composite-imprinted alumina membrane for effective separation ofp-hydroxybenzonic acid from its isomer using Box-Behnken design-based statistical modeling. J Appl Polym Sci 2014. [DOI: 10.1002/app.40621] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Minjia Meng
- School of Chemistry and Chemical Engineering; Jiangsu University; Zhenjiang 212013 China
| | - Yonghai Feng
- School of Material Science and Engineering; Jiangsu University; Zhenjiang 212013 China
| | - Yan Liu
- School of Chemistry and Chemical Engineering; Jiangsu University; Zhenjiang 212013 China
| | - Yun Wang
- School of Chemistry and Chemical Engineering; Jiangsu University; Zhenjiang 212013 China
| | - Yongsheng Yan
- School of Chemistry and Chemical Engineering; Jiangsu University; Zhenjiang 212013 China
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10
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Wang KW, Wang SW, Du QZ. Complete NMR assignment of retinal and its related compounds. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2013; 51:435-438. [PMID: 23630063 DOI: 10.1002/mrc.3956] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 02/26/2013] [Accepted: 03/20/2013] [Indexed: 06/02/2023]
Abstract
Complete and unambiguous (1)H and (13)C NMR chemical shift assignments for all-trans-retinal, 13-cis-retinal, 11-cis-retinal and 9-cis-retinal (1-4) have been established by means of two-dimensional COSY, HSQC, HMBC and NOESY spectroscopic experiments.
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Affiliation(s)
- Kui-Wu Wang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310035, China.
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