1
|
Suzuki R, Nagashima T, Kojima K, Hironishi R, Hirohata M, Ueta T, Murata T, Yamazaki T, Sudo Y, Takahashi H. Nuclear Magnetic Resonance Detection of Hydrogen Bond Network in a Proton Pump Rhodopsin RxR and Its Alteration during the Cyclic Photoreaction. J Am Chem Soc 2023. [PMID: 37410967 DOI: 10.1021/jacs.3c02833] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
Hydrogen bond formation and deformation are crucial for the structural construction and functional expression of biomolecules. However, direct observation of exchangeable hydrogens, especially for oxygen-bound hydrogens, relevant to hydrogen bonds is challenging for current structural analysis approaches. Using solution-state NMR spectroscopy, this study detected the functionally important exchangeable hydrogens (i.e., Y49-ηOH and Y178-ηOH) involved in the pentagonal hydrogen bond network in the active site of R. xylanophilus rhodopsin (RxR), which functions as a light-driven proton pump. Moreover, utilization of the original light-irradiation NMR approach allowed us to detect and characterize the late photointermediate state (i.e., O-state) of RxR and revealed that hydrogen bonds relevant to Y49 and Y178 are still maintained during the photointermediate state. In contrast, the hydrogen bond between W75-εNH and D205-γCOO- is strengthened and stabilizes the O-state.
Collapse
Affiliation(s)
- Rika Suzuki
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa 230-0045, Japan
| | - Toshio Nagashima
- RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan
| | - Keiichi Kojima
- Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan
| | - Reika Hironishi
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa 230-0045, Japan
| | - Masafumi Hirohata
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa 230-0045, Japan
| | - Tetsuya Ueta
- Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan
| | - Takeshi Murata
- Graduate School of Science, Chiba University, Inage, Chiba 263-8522, Japan
| | - Toshio Yamazaki
- RIKEN Center for Biosystems Dynamics Research, Yokohama, Kanagawa 230-0045, Japan
| | - Yuki Sudo
- Faculty of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan
| | - Hideo Takahashi
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Kanagawa 230-0045, Japan
| |
Collapse
|
2
|
Siemers M, Lazaratos M, Karathanou K, Guerra F, Brown LS, Bondar AN. Bridge: A Graph-Based Algorithm to Analyze Dynamic H-Bond Networks in Membrane Proteins. J Chem Theory Comput 2019; 15:6781-6798. [DOI: 10.1021/acs.jctc.9b00697] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Malte Siemers
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, Arnimallee 14, D14195 Berlin, Germany
| | - Michalis Lazaratos
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, Arnimallee 14, D14195 Berlin, Germany
| | - Konstantina Karathanou
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, Arnimallee 14, D14195 Berlin, Germany
| | - Federico Guerra
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, Arnimallee 14, D14195 Berlin, Germany
| | - Leonid S. Brown
- Department of Physics and Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada
| | - Ana-Nicoleta Bondar
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics, Arnimallee 14, D14195 Berlin, Germany
| |
Collapse
|
3
|
Tamogami J, Kikukawa T, Ohkawa K, Ohsawa N, Nara T, Demura M, Miyauchi S, Kimura-Someya T, Shirouzu M, Yokoyama S, Shimono K, Kamo N. Interhelical interactions between D92 and C218 in the cytoplasmic domain regulate proton uptake upon N-decay in the proton transport of Acetabularia rhodopsin II. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2018; 183:35-45. [PMID: 29684719 DOI: 10.1016/j.jphotobiol.2018.04.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/07/2018] [Accepted: 04/07/2018] [Indexed: 01/01/2023]
Abstract
Acetabularia rhodopsin II (ARII or Ace2), an outward light-driven algal proton pump found in the giant unicellular marine alga Acetabularia acetabulum, has a unique property in the cytoplasmic (CP) side of its channel. The X-ray crystal structure of ARII in a dark state suggested the formation of an interhelical hydrogen bond between C218ARII and D92ARII, an internal proton donor to the Schiff base (Wada et al., 2011). In this report, we investigated the photocycles of two mutants at position C218ARII: C218AARII which disrupts the interaction with D92ARII, and C218SARII which potentially forms a stronger hydrogen bond. Both mutants exhibited slower photocycles compared to the wild-type pump. Together with several kinetic changes of the photoproducts in the first half of the photocycle, these replacements led to specific retardation of the N-to-O transition in the second half of the photocycle. In addition, measurements of the flash-induced proton uptake and release using a pH-sensitive indium-tin oxide electrode revealed a concomitant delay in the proton uptake. These observations strongly suggest the importance of a native weak hydrogen bond between C218ARII and D92ARII for proper proton translocation in the CP channel during N-decay. A putative role for the D92ARII-C218ARII interhelical hydrogen bond in the function of ARII is discussed.
Collapse
Affiliation(s)
- Jun Tamogami
- College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime 790-8578, Japan.
| | - Takashi Kikukawa
- Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan; Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo 001-0021, Japan
| | - Keisuke Ohkawa
- College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime 790-8578, Japan
| | - Noboru Ohsawa
- RIKEN Systems and Structural Biology Center, Yokohama 230-0045, Japan; RIKEN Center for Life Science Technologies, Yokohama 230-0045, Japan
| | - Toshifumi Nara
- College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime 790-8578, Japan
| | - Makoto Demura
- Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan; Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo 001-0021, Japan
| | - Seiji Miyauchi
- College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime 790-8578, Japan; Graduate School of Pharmaceutical Sciences, Toho University, Funabashi, Chiba 274-8510, Japan
| | - Tomomi Kimura-Someya
- RIKEN Systems and Structural Biology Center, Yokohama 230-0045, Japan; RIKEN Center for Life Science Technologies, Yokohama 230-0045, Japan
| | - Mikako Shirouzu
- RIKEN Systems and Structural Biology Center, Yokohama 230-0045, Japan; RIKEN Center for Life Science Technologies, Yokohama 230-0045, Japan
| | - Shigeyuki Yokoyama
- RIKEN Systems and Structural Biology Center, Yokohama 230-0045, Japan; RIKEN Structural Biology Laboratory, Yokohama 230-0045, Japan
| | - Kazumi Shimono
- College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime 790-8578, Japan; Graduate School of Pharmaceutical Sciences, Toho University, Funabashi, Chiba 274-8510, Japan
| | - Naoki Kamo
- College of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime 790-8578, Japan; Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan
| |
Collapse
|
4
|
Dai G, Geng X, Chaoluomeng, Tamogami J, Kikukawa T, Demura M, Kamo N, Iwasa T. Photocycle of Sensory Rhodopsin II from Halobacterium salinarum (HsSRII): Mutation of D103 Accelerates M Decay and Changes the Decay Pathway of a 13-cis O-like Species. Photochem Photobiol 2018. [PMID: 29512821 DOI: 10.1111/php.12917] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aspartic acid 103 (D103) of sensory rhodopsin II from Halobacterium salinarum (HsSRII, or also called phoborhodopsin) corresponds to D115 of bacteriorhodopsin (BR). This amino acid residue is functionally important in BR. This work reveals that a substitution of D103 with asparagine (D103N) or glutamic acid (D103E) can cause large changes in HsSRII photocycle. These changes include (1) shortened lifetime of the M intermediate in the following order: the wild-type > D103N > D103E; (2) altered decay pathway of a 13-cis O-like species. The 13-cis O-like species, tentatively named Px, was detected in HsSRII photocycle. Px appeared to undergo branched reactions at 0°C, leading to a recovery of the unphotolyzed state and formation of a metastable intermediate, named P370, that slowly decayed to the unphotolyzed state at room temperature. In wild-type HsSRII at 0°C, Px mainly decayed to the unphotolyzed state, and the decay reaction toward P370 was negligible. In mutant D103E at 0°C, Px decayed to P370, while the recovery of the unphotolyzed state became unobservable. In mutant D103N, the two reactions proceeded at comparable rates. Thus, D103 of HsSRII may play an important role in regulation of the photocycle of HsSRII.
Collapse
Affiliation(s)
- Gang Dai
- College of Chemistry and Environmental Science, Inner Mongolia Normal University, Hohhot, 010018, China
| | - Xiong Geng
- Division of Engineering, Muroran Institute of Technology, Muroran, 050-8585, Japan
| | - Chaoluomeng
- Division of Engineering, Muroran Institute of Technology, Muroran, 050-8585, Japan
| | - Jun Tamogami
- College of Pharmaceutical Science, Matsuyama University, Matsuyama, 790-8578, Japan
| | - Takashi Kikukawa
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, 060-0810, Japan.,Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, 001-0021, Japan
| | - Makoto Demura
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, 060-0810, Japan.,Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, 001-0021, Japan
| | - Naoki Kamo
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Tatsuo Iwasa
- Division of Engineering, Muroran Institute of Technology, Muroran, 050-8585, Japan
| |
Collapse
|
5
|
Ward ME, Wang S, Munro R, Ritz E, Hung I, Gor'kov PL, Jiang Y, Liang H, Brown LS, Ladizhansky V. In situ structural studies of Anabaena sensory rhodopsin in the E. coli membrane. Biophys J 2016; 108:1683-1696. [PMID: 25863060 DOI: 10.1016/j.bpj.2015.02.018] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 12/18/2014] [Accepted: 02/12/2015] [Indexed: 01/06/2023] Open
Abstract
Magic-angle spinning nuclear magnetic resonance is well suited for the study of membrane proteins in the nativelike lipid environment. However, the natural cellular membrane is invariably more complex than the proteoliposomes most often used for solid-state NMR (SSNMR) studies, and differences may affect the structure and dynamics of the proteins under examination. In this work we use SSNMR and other biochemical and biophysical methods to probe the structure of a seven-transmembrane helical photoreceptor, Anabaena sensory rhodopsin (ASR), prepared in the Escherichia coli inner membrane, and compare it to that in a bilayer formed by DMPC/DMPA lipids. We find that ASR is organized into trimers in both environments but forms two-dimensional crystal lattices of different symmetries. It favors hexagonal packing in liposomes, but may form a square lattice in the E. coli membrane. To examine possible changes in structure site-specifically, we perform two- and three-dimensional SSNMR experiments and analyze the differences in chemical shifts and peak intensities. Overall, this analysis reveals that the structure of ASR is largely conserved in the inner membrane of E. coli, with many of the important structural features of rhodopsins previously observed in ASR in proteoliposomes being preserved. Small, site-specific perturbations in protein structure that occur as a result of the membrane changes indicate that the protein can subtly adapt to its environment without large structural rearrangement.
Collapse
Affiliation(s)
- Meaghan E Ward
- Department of Physics, University of Guelph, Guelph, Ontario, Canada; Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | - Shenlin Wang
- Department of Physics, University of Guelph, Guelph, Ontario, Canada; Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | - Rachel Munro
- Department of Physics, University of Guelph, Guelph, Ontario, Canada; Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada
| | - Emily Ritz
- Department of Physics, University of Guelph, Guelph, Ontario, Canada
| | - Ivan Hung
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida
| | - Peter L Gor'kov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida
| | - Yunjiang Jiang
- Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado
| | - Hongjun Liang
- Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado
| | - Leonid S Brown
- Department of Physics, University of Guelph, Guelph, Ontario, Canada; Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada.
| | - Vladimir Ladizhansky
- Department of Physics, University of Guelph, Guelph, Ontario, Canada; Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario, Canada.
| |
Collapse
|
6
|
Machan CW, Chabolla SA, Yin J, Gilson MK, Tezcan FA, Kubiak CP. Supramolecular Assembly Promotes the Electrocatalytic Reduction of Carbon Dioxide by Re(I) Bipyridine Catalysts at a Lower Overpotential. J Am Chem Soc 2014; 136:14598-607. [DOI: 10.1021/ja5085282] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Charles W. Machan
- Department
of Chemistry and Biochemistry, University of California-San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
| | - Steven A. Chabolla
- Department
of Chemistry and Biochemistry, University of California-San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
| | - Jian Yin
- Skaggs
School of Pharmacy and Pharmaceutical Sciences, University of California-San Diego, 9500 Gilman Drive, La Jolla, California 92093-0736, United States
| | - Michael K. Gilson
- Skaggs
School of Pharmacy and Pharmaceutical Sciences, University of California-San Diego, 9500 Gilman Drive, La Jolla, California 92093-0736, United States
| | - F. Akif Tezcan
- Department
of Chemistry and Biochemistry, University of California-San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
| | - Clifford P. Kubiak
- Department
of Chemistry and Biochemistry, University of California-San Diego, 9500 Gilman Drive, La Jolla, California 92093-0358, United States
| |
Collapse
|
7
|
Coupling between inter-helical hydrogen bonding and water dynamics in a proton transporter. J Struct Biol 2014; 186:95-111. [DOI: 10.1016/j.jsb.2014.02.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 02/13/2014] [Accepted: 02/15/2014] [Indexed: 12/20/2022]
|
8
|
Lórenz-Fonfría VA, Heberle J. Channelrhodopsin unchained: structure and mechanism of a light-gated cation channel. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:626-42. [PMID: 24212055 DOI: 10.1016/j.bbabio.2013.10.014] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 10/21/2013] [Accepted: 10/30/2013] [Indexed: 12/25/2022]
Abstract
The new and vibrant field of optogenetics was founded by the seminal discovery of channelrhodopsin, the first light-gated cation channel. Despite the numerous applications that have revolutionised neurophysiology, the functional mechanism is far from understood on the molecular level. An arsenal of biophysical techniques has been established in the last decades of research on microbial rhodopsins. However, application of these techniques is hampered by the duration and the complexity of the photoreaction of channelrhodopsin compared with other microbial rhodopsins. A particular interest in resolving the molecular mechanism lies in the structural changes that lead to channel opening and closure. Here, we review the current structural and mechanistic knowledge that has been accomplished by integrating the static structure provided by X-ray crystallography and electron microscopy with time-resolved spectroscopic and electrophysiological techniques. The dynamical reactions of the chromophore are effectively coupled to structural changes of the protein, as shown by ultrafast spectroscopy. The hierarchical sequence of structural changes in the protein backbone that spans the time range from 10(-12)s to 10(-3)s prepares the channel to open and, consequently, cations can pass. Proton transfer reactions that are associated with channel gating have been resolved. In particular, glutamate 253 and aspartic acid 156 were identified as proton acceptor and donor to the retinal Schiff base. The reprotonation of the latter is the critical determinant for channel closure. The proton pathway that eventually leads to proton pumping is also discussed. This article is part of a Special Issue entitled: Retinal Proteins - You can teach an old dog new tricks.
Collapse
Affiliation(s)
- Víctor A Lórenz-Fonfría
- Freie Universität Berlin, Experimental Molecular Biophysics, Arnimallee 14, 14195 Berlin, Germany
| | - Joachim Heberle
- Freie Universität Berlin, Experimental Molecular Biophysics, Arnimallee 14, 14195 Berlin, Germany.
| |
Collapse
|
9
|
Transient protonation changes in channelrhodopsin-2 and their relevance to channel gating. Proc Natl Acad Sci U S A 2013; 110:E1273-81. [PMID: 23509282 DOI: 10.1073/pnas.1219502110] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The discovery of the light-gated ion channel channelrhodopsin (ChR) set the stage for the novel field of optogenetics, where cellular processes are controlled by light. However, the underlying molecular mechanism of light-induced cation permeation in ChR2 remains unknown. Here, we have traced the structural changes of ChR2 by time-resolved FTIR spectroscopy, complemented by functional electrophysiological measurements. We have resolved the vibrational changes associated with the open states of the channel (P(2)(390) and P(3)(520)) and characterized several proton transfer events. Analysis of the amide I vibrations suggests a transient increase in hydration of transmembrane α-helices with a t(1/2) = 60 μs, which tallies with the onset of cation permeation. Aspartate 253 accepts the proton released by the Schiff base (t(1/2) = 10 μs), with the latter being reprotonated by aspartic acid 156 (t(1/2) = 2 ms). The internal proton acceptor and donor groups, corresponding to D212 and D115 in bacteriorhodopsin, are clearly different from other microbial rhodopsins, indicating that their spatial position in the protein was relocated during evolution. Previous conclusions on the involvement of glutamic acid 90 in channel opening are ruled out by demonstrating that E90 deprotonates exclusively in the nonconductive P(4)(480) state. Our results merge into a mechanistic proposal that relates the observed proton transfer reactions and the protein conformational changes to the gating of the cation channel.
Collapse
|
10
|
Simón-Vázquez R, Domínguez M, Lórenz-Fonfría VA, Alvarez S, Bourdelande JL, de Lera AR, Padrós E, Perálvarez-Marín A. Probing a polar cluster in the retinal binding pocket of bacteriorhodopsin by a chemical design approach. PLoS One 2012; 7:e42447. [PMID: 22879987 PMCID: PMC3411786 DOI: 10.1371/journal.pone.0042447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 07/06/2012] [Indexed: 11/24/2022] Open
Abstract
Bacteriorhodopsin has a polar cluster of amino acids surrounding the retinal molecule, which is responsible for light harvesting to fuel proton pumping. From our previous studies, we have shown that threonine 90 is the pivotal amino acid in this polar cluster, both functionally and structurally. In an attempt to perform a phenotype rescue, we have chemically designed a retinal analogue molecule to compensate the drastic effects of the T90A mutation in bacteriorhodopsin. This analogue substitutes the methyl group at position C13 of the retinal hydrocarbon chain by and ethyl group (20-methyl retinal). We have analyzed the effect of reconstituting the wild-type and the T90A mutant apoproteins with all-trans-retinal and its 20-methyl derivative (hereafter, 13-ethyl retinal). Biophysical characterization indicates that recovering the steric interaction between the residue 90 and retinal, eases the accommodation of the chromophore, however it is not enough for a complete phenotype rescue. The characterization of these chemically engineered chromoproteins provides further insight into the role of the hydrogen bond network and the steric interactions involving the retinal binding pocket in bacteriorhodopsin and other microbial sensory rhodopsins.
Collapse
Affiliation(s)
- Rosana Simón-Vázquez
- Departament de Bioquímica i de Biologia Molecular and Centre d'Estudis en Biofísica, Universitat Autònoma de Barcelona, Barcelona, Spain
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Lórenz-Fonfría VA, Kandori H, Padrós E. Probing specific molecular processes and intermediates by time-resolved Fourier transform infrared spectroscopy: application to the bacteriorhodopsin photocycle. J Phys Chem B 2011; 115:7972-85. [PMID: 21615095 DOI: 10.1021/jp201739w] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present a general approach for probing the kinetics of specific molecular processes in proteins by time-resolved Fourier transform infrared (IR) spectroscopy. Using bacteriorhodopsin (bR) as a model we demonstrate that by appropriately monitoring some selected IR bands it is possible obtaining the kinetics of the most important events occurring in the photocycle, namely changes in the chromophore and the protein backbone conformation, and changes in the protonation state of the key residues implicated in the proton transfers. Besides confirming widely accepted views of the bR photocycle, our analysis also sheds light into some disputed issues: the degree of retinal torsion in the L intermediate to respect the ground state; the possibility of a proton transfer from Asp85 to Asp212; the relationship between the protonation/deprotonation of Asp85 and the proton release complex; and the timing of the protein backbone dynamics. By providing a direct way to estimate the kinetics of photocycle intermediates the present approach opens new prospects for a robust quantitative kinetic analysis of the bR photocycle, which could also benefit the study of other proteins involved in photosynthesis, in phototaxis, or in respiratory chains.
Collapse
Affiliation(s)
- Víctor A Lórenz-Fonfría
- Unitat de Biofísica, Departament de Bioquímica i de Biologia Molecular, and Centre d'Estudis en Biofísica, Universitat Autònoma de Barcelona, Barcelona 08193, Spain.
| | | | | |
Collapse
|
12
|
Polarizable atomic multipole x-ray refinement: hydration geometry and application to macromolecules. Biophys J 2010; 98:2984-92. [PMID: 20550911 DOI: 10.1016/j.bpj.2010.02.057] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 02/05/2010] [Accepted: 02/17/2010] [Indexed: 11/23/2022] Open
Abstract
We recently developed a polarizable atomic multipole refinement method assisted by the AMOEBA force field for macromolecular crystallography. Compared to standard refinement procedures, the method uses a more rigorous treatment of x-ray scattering and electrostatics that can significantly improve the resultant information contained in an atomic model. We applied this method to high-resolution lysozyme and trypsin data sets, and validated its utility for precisely describing biomolecular electron density, as indicated by a 0.4-0.6% decrease in the R- and R(free)-values, and a corresponding decrease in the relative energy of 0.4-0.8 Kcal/mol/residue. The re-refinements illustrate the ability of force-field electrostatics to orient water networks and catalytically relevant hydrogens, which can be used to make predictions regarding active site function, activity, and protein-ligand interaction energies. Re-refinement of a DNA crystal structure generates the zigzag spine pattern of hydrogen bonding in the minor groove without manual intervention. The polarizable atomic multipole electrostatics model implemented in the AMOEBA force field is applicable and informative for crystal structures solved at any resolution.
Collapse
|
13
|
Simón-Vázquez R, Lazarova T, Perálvarez-Marín A, Bourdelande JL, Padrós E. Cross-Linking of Transmembrane Helices Reveals a Rigid-Body Mechanism in Bacteriorhodopsin Transport. Angew Chem Int Ed Engl 2009; 48:8523-5. [DOI: 10.1002/anie.200904031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
14
|
Simón-Vázquez R, Lazarova T, Perálvarez-Marín A, Bourdelande JL, Padrós E. Cross-Linking of Transmembrane Helices Reveals a Rigid-Body Mechanism in Bacteriorhodopsin Transport. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200904031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
15
|
Sigala PA, Caaveiro JMM, Ringe D, Petsko GA, Herschlag D. Hydrogen bond coupling in the ketosteroid isomerase active site. Biochemistry 2009; 48:6932-9. [PMID: 19469568 DOI: 10.1021/bi900713j] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hydrogen bond networks are key elements of biological structure and function. Nevertheless, their structural properties are challenging to assess within complex macromolecules. Hydrogen-bonded protons are not observed in the vast majority of protein X-ray structures, and static crystallographic models provide limited information regarding the dynamical coupling within hydrogen bond networks. We have brought together 1.1-1.3 A resolution X-ray crystallography, (1)H NMR, site-directed mutagenesis, and deuterium isotope effects on the geometry and chemical shifts of hydrogen-bonded protons to probe the conformational coupling of hydrogen bonds donated by Y16 and D103 in the oxyanion hole of bacterial ketosteroid isomerase. Our results suggest a robust physical coupling of the equilibrium structures of these two hydrogen bonds such that a lengthening of one hydrogen bond by as little as 0.01 A results in a shortening of the neighbor by a similar magnitude. Furthermore, the structural rearrangements detected by NMR in response to mutations within the active site hydrogen bond network can be explained on the basis of the observed coupling. The results herein elucidate fundamental structural properties of hydrogen bonds within the idiosyncratic environment of an enzyme active site and provide a foundation for future experimental and computational explorations of the role of coupled motions within hydrogen bond networks.
Collapse
Affiliation(s)
- Paul A Sigala
- Department of Biochemistry, Stanford University, Stanford, California 94305, USA
| | | | | | | | | |
Collapse
|
16
|
Hydrogen bond dynamics in the active site of photoactive yellow protein. Proc Natl Acad Sci U S A 2009; 106:9232-7. [PMID: 19470452 DOI: 10.1073/pnas.0900168106] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hydrogen bonds play major roles in biological structure and function. Nonetheless, hydrogen-bonded protons are not typically observed by X-ray crystallography, and most structural studies provide limited insight into the conformational plasticity of individual hydrogen bonds or the dynamical coupling present within hydrogen bond networks. We report the NMR detection of the hydrogen-bonded protons donated by Tyr-42 and Glu-46 to the chromophore oxygen in the active site of the bacterial photoreceptor, photoactive yellow protein (PYP). We have used the NMR resonances for these hydrogen bonds to probe their conformational properties and ability to rearrange in response to nearby electronic perturbation. The detection of geometric isotope effects transmitted between the Tyr-42 and Glu-46 hydrogen bonds provides strong evidence for robust coupling of their equilibrium conformations. Incorporation of a modified chromophore containing an electron-withdrawing cyano group to delocalize negative charge from the chromophore oxygen, analogous to the electronic rearrangement detected upon photon absorption, results in a lengthening of the Tyr-42 and Glu-46 hydrogen bonds and an attenuated hydrogen bond coupling. The results herein elucidate fundamental properties of hydrogen bonds within the complex environment of a protein interior. Furthermore, the robust conformational coupling and plasticity of hydrogen bonds observed in the PYP active site may facilitate the larger-scale dynamical coupling and signal transduction inherent to the biological function that PYP has evolved to carry out and may provide a model for other coupled dynamic systems.
Collapse
|
17
|
Lórenz-Fonfría VA, Kandori H. Spectroscopic and Kinetic Evidence on How Bacteriorhodopsin Accomplishes Vectorial Proton Transport under Functional Conditions. J Am Chem Soc 2009; 131:5891-901. [DOI: 10.1021/ja900334c] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Víctor A. Lórenz-Fonfría
- Department of Frontier Materials, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Hideki Kandori
- Department of Frontier Materials, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| |
Collapse
|
18
|
Influence of proline on the thermostability of the active site and membrane arrangement of transmembrane proteins. Biophys J 2008; 95:4384-95. [PMID: 18658225 DOI: 10.1529/biophysj.108.136747] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Proline residues play a fundamental and subtle role in the dynamics, structure, and function in many membrane proteins. Temperature derivative spectroscopy and differential scanning calorimetry have been used to determine the effect of proline substitution in the structural stability of the active site and transmembrane arrangement of bacteriorhodopsin. We have analyzed the Pro-to-Ala mutation for the helix-embedded prolines Pro50, Pro91, and Pro186 in the native membrane environment. This information has been complemented with the analysis of the respective crystallographic structures by the FoldX force field. Differential scanning calorimetry allowed us to determine distorted membrane arrangement for P50A and P186A. The protein stability was severely affected for P186A and P91A. In the case of Pro91, a single point mutation is capable of strongly slowing down the conformational diffusion along the denaturation coordinate, becoming a barrier-free downhill process above 371 K. Temperature derivative spectroscopy, applied for first time to study thermal stability of proteins, has been used to monitor the stability of the active site of bacteriorhodopsin. The mutation of Pro91 and Pro186 showed the most striking effects on the retinal binding pocket. These residues are the Pro in closer contact to the active site (activation energies for retinal release of 60.1 and 76.8 kcal/mol, respectively, compared to 115.8 kcal/mol for WT). FoldX analysis of the protein crystal structures indicates that the Pro-to-Ala mutations have both local and long-range effects on the structural stability of residues involved in the architecture of the protein and the active site and in the proton pumping function. Thus, this study provides a complete overview of the substitution effect of helix-embedded prolines in the thermodynamic and dynamic stability of a membrane protein, also related to its structure and function.
Collapse
|
19
|
Lórenz-Fonfría VA, Furutani Y, Kandori H. Active Internal Waters in the Bacteriorhodopsin Photocycle. A Comparative Study of the L and M Intermediates at Room and Cryogenic Temperatures by Infrared Spectroscopy. Biochemistry 2008; 47:4071-81. [DOI: 10.1021/bi7024063] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Víctor A. Lórenz-Fonfría
- Department of Materials Science and Engineering, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Yuji Furutani
- Department of Materials Science and Engineering, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Hideki Kandori
- Department of Materials Science and Engineering, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| |
Collapse
|
20
|
An ion-responsive motif in the second transmembrane segment of rhodopsin-like receptors. Amino Acids 2008; 35:1-15. [PMID: 18266053 DOI: 10.1007/s00726-008-0637-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Accepted: 11/06/2007] [Indexed: 12/13/2022]
Abstract
A L(M)xxxD(N, E) motif (x=a non-ionic amino acid residue, most frequently A, S, L or F; small capitals indicating a minor representation) is found in the second transmembrane (tm2) segment of most G-protein coupling metazoan receptors of the rhodopsin family (Rh-GPCRs). Changes in signal transduction, agonist binding and receptor cycling are known for numerous receptors bearing evolved or experimentally introduced mutations in this tm2 motif, especially of its aspartate residue. The [Na(+)] sensitivity of the receptor-agonist interaction relates to this aspartate in a number of Rh-GPCRs. Native non-conservative mutations in the tm2 motif only rarely coincide with significant changes in two other ubiquitous features of the rhodopsin family, the seventh transmembrane N(D)PxxY(F) motif and the D(E)RY(W,F) or analogous sequence at the border of the third transmembrane helix and the second intracellular loop. Native tm2 mutations with Rh-GPCRs frequently result in constitutive signaling, and with visual opsins also in shifts to short-wavelength sensitivity. Substitution of a strongly basic residue for the tm2 aspartate in Taste-2 receptors could be connected to a lack of sodium sensing by these receptors. These properties could be consistent with ionic interactions, and even of ion transfer, that involve the tm2 motif. A decrease in cation sensing by this motif is usually connected to an enhanced constitutive interaction of the mutated receptors with cognate G- proteins, and also relates to both the constitutive and the overall activity of the short-wavelength opsins.
Collapse
|
21
|
Barth A. Infrared spectroscopy of proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:1073-101. [PMID: 17692815 DOI: 10.1016/j.bbabio.2007.06.004] [Citation(s) in RCA: 2867] [Impact Index Per Article: 168.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 06/18/2007] [Accepted: 06/19/2007] [Indexed: 12/12/2022]
Abstract
This review discusses the application of infrared spectroscopy to the study of proteins. The focus is on the mid-infrared spectral region and the study of protein reactions by reaction-induced infrared difference spectroscopy.
Collapse
Affiliation(s)
- Andreas Barth
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, S-106 91 Stockholm, Sweden.
| |
Collapse
|