1
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Sugimoto T, Katayama K, Kandori H. FTIR study of light-induced proton transfer and Ca 2+ binding in T82D mutant of TAT rhodopsin. Biophys J 2024:S0006-3495(24)00527-7. [PMID: 39118325 DOI: 10.1016/j.bpj.2024.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 07/18/2024] [Accepted: 08/05/2024] [Indexed: 08/10/2024] Open
Abstract
Proton transfer reactions play important functional roles in many proteins, such as enzymes and transporters, which is also the case in rhodopsins. In fact, functional expression of rhodopsins accompanies intramolecular proton transfer reactions in many cases. One of the exceptional cases can be seen in the protonated form of marine bacterial TAT rhodopsin, which isomerizes the retinal by light but returns to the original state within 10-5 s. Thus, light energy is converted into heat without any function. In contrast, the T82D mutant of TAT rhodopsin conducts the light-induced deprotonation of the Schiff base at high pH. In this article, we report the structural analysis of T82D by means of difference Fourier transform infrared (FTIR) spectroscopy. In the light-induced difference FTIR spectra at 77 K, we observed little hydrogen out-of-plane vibrations for T82D as well as the wild-type (WT), suggesting that the planar chromophore structure itself is not the origin of the reversion from the K intermediate in WT TAT rhodopsin. Upon relaxation of the K intermediate, T82D forms the following intermediate, such as M, whereas K of WT returns to the original state. Present FTIR analysis revealed the proton transfer from the Schiff base to D82 in T82D upon formation of the M intermediate. It is accompanied by the second proton transfer from E54 to the Schiff base, forming the N intermediate, particularly in membranes. The equilibrium between the M and N intermediates corresponds to the protonation equilibrium between E54 and the Schiff base. We also found that Ca2+ binding takes place in T82D as well as WT but with 6 times lower affinity. An altered hydrogen-bonding network would be the origin of low affinity in T82D, where deprotonation of E54 is involved in the Ca2+ binding.
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Affiliation(s)
- Teppei Sugimoto
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
| | - Kota Katayama
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan; OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan; OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Japan.
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2
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Bertalan É, Konno M, Del Carmen Marín M, Bagherzadeh R, Nagata T, Brown L, Inoue K, Bondar AN. Hydrogen-Bonding and Hydrophobic Interaction Networks as Structural Determinants of Microbial Rhodopsin Function. J Phys Chem B 2024; 128:7407-7426. [PMID: 39024507 DOI: 10.1021/acs.jpcb.4c02946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Microbial pump rhodopsins are highly versatile light-driven membrane proteins that couple protein conformational dynamics with ion translocation across the cell membranes. Understanding how microbial pump rhodopsins use specific amino acid residues at key functional sites to control ion selectivity and ion pumping direction is of general interest for membrane transporters, and could guide site-directed mutagenesis for optogenetics applications. To enable direct comparisons between proteins with different sequences we implement, for the first time, a unique numbering scheme for the microbial pump rhodopsin residues, NS-mrho. We use NS-mrho to show that distinct microbial pump rhodopsins typically have hydrogen-bond networks that are less conserved than anticipated from the amino acid residue conservation, whereas their hydrophobic interaction networks are largely conserved. To illustrate the role of the hydrogen-bond networks as structural elements that determine the functionality of microbial pump rhodopsins, we performed experiments, atomic-level simulations, and hydrogen bond network analyses on GR, the outward proton pump from Gloeobacter violaceus, and KR2, the outward sodium pump from Krokinobacter eikastus. The experiments indicate that multiple mutations that recover KR2 amino acid residues in GR not only fail to convert it into a sodium pump, but completely inactivate GR by abolishing photoisomerization of the retinal chromophore. This observation could be attributed to the drastically altered hydrogen-bond interaction network identified with simulations and network analyses. Taken together, our findings suggest that functional specificity could be encoded in the collective hydrogen-bond network of microbial pump rhodopsins.
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Affiliation(s)
- Éva Bertalan
- Department of Mathematics and Natural Sciences, RWTH Aachen University, Templergraben 59, 52062 Aachen, Germany
| | - Masae Konno
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwano-ha, Kashiwa 277-8581, Chiba, Japan
| | - María Del Carmen Marín
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwano-ha, Kashiwa 277-8581, Chiba, Japan
| | - Reza Bagherzadeh
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwano-ha, Kashiwa 277-8581, Chiba, Japan
| | - Takashi Nagata
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwano-ha, Kashiwa 277-8581, Chiba, Japan
| | - Leonid Brown
- Department of Physics, University of Guelph, 488 Gordon Street, Guelph, Ontario N1G 2W1, Canada
| | - Keiichi Inoue
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwano-ha, Kashiwa 277-8581, Chiba, Japan
| | - Ana-Nicoleta Bondar
- Institute of Computational Biomedicine, Forschungszentrum Jülich, IAS-5/INM-9, Wilhelm-Johnen Straße, 5428 Jülich, Germany
- Faculty of Physics, University of Bucharest, Atomiştilor 405, 077125 Măgurele, Romania
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3
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Noji T, Chiba Y, Saito K, Ishikita H. Energetics of the H-Bond Network in Exiguobacterium sibiricum Rhodopsin. Biochemistry 2024; 63:1505-1512. [PMID: 38745402 PMCID: PMC11155677 DOI: 10.1021/acs.biochem.4c00182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 05/08/2024] [Accepted: 05/08/2024] [Indexed: 05/16/2024]
Abstract
Exiguobacterium sibiricum rhodopsin (ESR) functions as a light-driven proton pump utilizing Lys96 for proton uptake and maintaining its activity over a wide pH range. Using a combination of methodologies including the linear Poisson-Boltzmann equation and a quantum mechanical/molecular mechanical approach with a polarizable continuum model, we explore the microscopic mechanisms underlying its pumping activity. Lys96, the primary proton uptake site, remains deprotonated owing to the loss of solvation in the ESR protein environment. Asp85, serving as a proton acceptor group for Lys96, does not form a low-barrier H-bond with His57. Instead, deprotonated Asp85 forms a salt-bridge with protonated His57, and the proton is predominantly located at the His57 moiety. Glu214, the only acidic residue at the end of the H-bond network exhibits a pKa value of ∼6, slightly elevated due to solvation loss. It seems likely that the H-bond network [Asp85···His57···H2O···Glu214] serves as a proton-conducting pathway toward the protein bulk surface.
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Affiliation(s)
- Tomoyasu Noji
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Yoshihiro Chiba
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Keisuke Saito
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Hiroshi Ishikita
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
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4
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Tomida S, Wada A, Furutani Y. Protonation of Asp116 and distortion of the all-trans retinal chromophore in Krokinobacter eikastus rhodopsin 2 causes a redshift in absorption maximum upon dehydration. Photochem Photobiol Sci 2023; 22:2499-2517. [PMID: 37498510 DOI: 10.1007/s43630-023-00464-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 07/19/2023] [Indexed: 07/28/2023]
Abstract
Water is usually indispensable for protein function. For ion-pumping rhodopsins, water molecules inside the proteins play an important role in ion transportation. In addition to amino acid residues, water molecules regulate the colors of retinal proteins. It was reported that a sodium-pumping rhodopsin, Krokinobacter eikastus rhodopsin 2 (KR2), showed a color change from red to purple upon dehydration under crystalline conditions. Here, we applied comprehensive visible and IR absorption spectroscopy and resonance Raman spectroscopy to KR2 in liposomes under hydration-controlled conditions. A large increase in the hydrogen-out-of-plane (HOOP) vibration at 947 (H-C11=C12-H Au mode) and moderate increases at 893 (C7-H and C10-H) and 808 (C14-H) cm-1 were observed under dehydrated conditions, which were assigned by using systematically deuterated retinal. Moreover, the Asn variant at Asp116, which functions as a counter ion for the protonated retinal Schiff base (PRSB), caused a large redshift in the absorption maximum and constitutive increase in the HOOP modes under hydrated and dehydrated conditions. The protonation of a counter ion at Asp116 clearly causes a redshift in the absorption maximum as the all-trans retinal chromophore twists upon dehydration. Namely, the results strongly suggested that water molecules are important for maintaining the hydrogen-bonding network at the PRSB and deprotonation state of Asp116 in KR2.
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Affiliation(s)
- Sahoko Tomida
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan
| | - Akimori Wada
- Laboratory of Organic Chemistry for Life Science, Kobe Pharmaceutical University, Higashinada-ku, Kobe, 658-8558, Japan
| | - Yuji Furutani
- 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.
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5
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Govorunova EG, Sineshchekov OA. Channelrhodopsins: From Phototaxis to Optogenetics. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1555-1570. [PMID: 38105024 DOI: 10.1134/s0006297923100115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 07/09/2023] [Accepted: 07/09/2023] [Indexed: 12/19/2023]
Abstract
Channelrhodopsins stand out among other retinal proteins because of their capacity to generate passive ionic currents following photoactivation. Owing to that, channelrhodopsins are widely used in neuroscience and cardiology as instruments for optogenetic manipulation of the activity of excitable cells. Photocurrents generated by channelrhodopsins were first discovered in the cells of green algae in the 1970s. In this review we describe this discovery and discuss the current state of research in the field.
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6
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Kapur B, Baldessari F, Lazaratos M, Nar H, Schnapp G, Giorgetti A, Bondar AN. Protons taken hostage: Dynamic H-bond networks of the pH-sensing GPR68. Comput Struct Biotechnol J 2023; 21:4370-4384. [PMID: 37711190 PMCID: PMC10498176 DOI: 10.1016/j.csbj.2023.08.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/30/2023] [Accepted: 08/30/2023] [Indexed: 09/16/2023] Open
Abstract
Proton-sensing G Protein Coupled Receptors (GPCRs) sense changes in the extracellular pH to effect cell signaling for cellular homeostasis. They tend to be overexpressed in solid tumors associated with acidic extracellular pH, and are of direct interest as drug targets. How proton-sensing GPCRs sense extracellular acidification and activate upon protonation change is important to understand, because it may guide the design of therapeutics. Lack of publicly available experimental structures make it challenging to discriminate between conflicting mechanisms proposed for proton-binding, as main roles have been assigned to either an extracellular histidine cluster or to an internal carboxylic triad. Here we present a protocol to derive and evaluate structural models of the proton-sensing GPR68. This approach integrates state-of-the-art homology modeling with microsecond-timescale atomistic simulations, and with a detailed assessment of the compatibility of the structural models with known structural features of class A GPCRs. To decipher structural elements of potential interest for protonation-coupled conformational changes of GPR68, we used the best-compatible model as a starting point for independent atomistic simulations of GPR68 with different protonation states, and graph computations to characterize the response of GPR68 to changes in protonation. We found that GPR68 hosts an extended hydrogen-bond network that inter-connects the extracellular histidine cluster to the internal carboxylic triad, and which can even reach groups at the cytoplasmic G-protein binding site. Taken together, results suggest that GPR68 relies on dynamic, hydrogen-bond networks to inter-connect extracellular and internal proton-binding sites, and to elicit conformational changes at the cytoplasmic G-protein binding site.
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Affiliation(s)
- Bhav Kapur
- Boehringer-Ingelheim Pharma GmbH & Co. KG, Birkendorfer Straße 65, 88397 Biberach an der Riß, Germany
- Christian-Albrechts-University of Kiel, 24118 Kiel, Germany
| | | | - Michalis Lazaratos
- Department of Physics, Theoretical Molecular Biophysics Group, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Herbert Nar
- Boehringer-Ingelheim Pharma GmbH & Co. KG, Birkendorfer Straße 65, 88397 Biberach an der Riß, Germany
| | - Gisela Schnapp
- Boehringer-Ingelheim Pharma GmbH & Co. KG, Birkendorfer Straße 65, 88397 Biberach an der Riß, Germany
| | - Alejandro Giorgetti
- University of Verona, Department of Biotechnology, 37134 Verona, Italy
- Forschungszentrum Jülich, Institute for Neuroscience and Medicine and Institute for Advanced Simulations (IAS-5/INM-9), Computational Biomedicine, Wilhelm-Johnen Straße, 52525 Jülich, Germany
| | - Ana-Nicoleta Bondar
- Forschungszentrum Jülich, Institute for Neuroscience and Medicine and Institute for Advanced Simulations (IAS-5/INM-9), Computational Biomedicine, Wilhelm-Johnen Straße, 52525 Jülich, Germany
- University of Bucharest, Faculty of Physics, Str. Atomiştilor 405, 077125 Bucharest-Măgurele, Romania
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7
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Kuroi K, Tsukamoto T, Honda N, Sudo Y, Furutani Y. Concerted primary proton transfer reactions in a thermophilic rhodopsin studied by time-resolved infrared spectroscopy at high temperature. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148980. [PMID: 37080329 DOI: 10.1016/j.bbabio.2023.148980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 04/06/2023] [Accepted: 04/12/2023] [Indexed: 04/22/2023]
Abstract
The primary proton transfer reactions of thermophilic rhodopsin, which was first discovered in an extreme thermophile, Thermus thermophilus JL-18, were investigated using time-resolved Fourier transform infrared spectroscopy at various temperatures ranging from 298 to 343 K (25 to 70 °C) and proton transport activity analysis. The analyses were performed using counterion (D95E, D95N, D229E, and D229N) and proton donor mutants (E106D and E106Q) as well. First, the initial proton transfer from the protonated retinal Schiff base (PRSB) to D95 was identified. The temperature dependency showed that the proton transfer reaction in the intermediate states dramatically changed above 318 K (45 °C). In addition, the proton transfer reaction correlated well with the structural change from turn to β-strand in the protein moiety, suggesting that this step may be regulated by the rigidity of the loop region. We also elucidated that the proton transfer reaction from proton donor E106 to the retinal Schiff base occurred synchronously with the primary proton transfer from the PRSB to D95. Surprisingly, we discovered that the direction of proton transfer was regulated by the secondary counterion, D229. Comparative analysis of Gloeobacter rhodopsin from the mesophile, Gloeobacter violaceus, highlighted that the primary proton transfer reactions in thermophilic rhodopsin were optimized at high temperatures partly due to the specific turn to β-strand structural change. This was not observed in Gloeobacter rhodopsin and other related proteins such as bacteriorhodopsin.
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Affiliation(s)
- Kunisato Kuroi
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
| | - Takashi Tsukamoto
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan; Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan
| | - Naoya Honda
- Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan
| | - Yuki Sudo
- Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan; Faculty of Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-Naka, Okayama 700-8530, Japan.
| | - Yuji Furutani
- Department of Life and Coordination-Complex Molecular Science, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan; Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
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8
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Hanai S, Nagata T, Katayama K, Inukai S, Koyanagi M, Inoue K, Terakita A, Kandori H. Difference FTIR Spectroscopy of Jumping Spider Rhodopsin-1 at 77 K. Biochemistry 2023; 62:1347-1359. [PMID: 37001008 DOI: 10.1021/acs.biochem.3c00022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
Animal visual rhodopsins can be classified into monostable and bistable rhodopsins, which are typically found in vertebrates and invertebrates, respectively. The former example is bovine rhodopsin (BovRh), whose structures and functions have been extensively studied. On the other hand, those of bistable rhodopsins are less known, despite their importance in optogenetics. Here, low-temperature Fourier-transform infrared (FTIR) spectroscopy was applied to jumping spider rhodopsin-1 (SpiRh1) at 77 K, and the obtained light-induced spectral changes were compared with those of squid rhodopsin (SquRh) and BovRh. Although chromophore distortion of the resting state monitored by HOOP vibrations is not distinctive between invertebrate and vertebrate rhodopsins, distortion of the all-trans chromophore after photoisomerization is unique for BovRh, and the distortion was localized at the center of the chromophore in SpiRh1 and SquRh. Highly conserved aspartate (D83 in BovRh) does not change the hydrogen-bonding environment in invertebrate rhodopsins. Thus, present FTIR analysis provides specific structural changes, leading to activation of invertebrate and vertebrate rhodopsins. On the other hand, the analysis of O-D stretching vibrations in D2O revealed unique features of protein-bound water molecules. Numbers of water bands in SpiRh1 and SquRh were less and more than those in BovRh. The X-ray crystal structure of SpiRh1 observed a bridged water molecule between the protonated Schiff base and its counterion (E194), but strongly hydrogen-bonded water molecules were never detected in SpiRh1, as well as SquRh and BovRh. Thus, absence of strongly hydrogen-bonded water molecules is substantial for animal rhodopsins, which is distinctive from microbial rhodopsins.
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9
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Furutani Y, Yang CS. Ion-transporting mechanism in microbial rhodopsins: Mini-review relating to the session 5 at the 19th International Conference on Retinal Proteins. Biophys Physicobiol 2023; 20:e201005. [PMID: 38362333 PMCID: PMC10865854 DOI: 10.2142/biophysico.bppb-v20.s005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 01/06/2023] [Indexed: 01/11/2023] Open
Affiliation(s)
- Yuji Furutani
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Chii-Shen Yang
- Department of Biochemical Science and Technology, National Taiwan University, Taipei 10617, Taiwan
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10
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Bertalan É, Bondar AN. Graphs of protein-water hydrogen bond networks to dissect structural movies of ion-transfer microbial rhodopsins. Front Chem 2023; 10:1075648. [PMID: 36712989 PMCID: PMC9880326 DOI: 10.3389/fchem.2022.1075648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 12/31/2022] [Indexed: 01/15/2023] Open
Abstract
Microbial rhodopsins are membrane proteins that use the energy absorbed by the covalently bound retinal chromophore to initiate reaction cycles resulting in ion transport or signal transduction. Thousands of distinct microbial rhodopsins are known and, for many rhodopsins, three-dimensional structures have been solved with structural biology, including as entire sets of structures solved with serial femtosecond crystallography. This sets the stage for comprehensive studies of large datasets of static protein structures to dissect structural elements that provide functional specificity to the various microbial rhodopsins. A challenge, however, is how to analyze efficiently intra-molecular interactions based on large datasets of static protein structures. Our perspective discusses the usefulness of graph-based approaches to dissect structural movies of microbial rhodopsins solved with time-resolved crystallography.
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Affiliation(s)
- Éva Bertalan
- Physikzentrum, RWTH Aachen University, Aachen, Germany
| | - Ana-Nicoleta Bondar
- Forschungszentrum Jülich, Institute of Computational Biomedicine, Jülich, Germany,Faculty of Physics, University of Bucharest, Măgurele, Romania,*Correspondence: Ana-Nicoleta Bondar, ,
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11
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Ido S, Kobayashi K, Oyabu N, Hirata Y, Matsushige K, Yamada H. Structured Water Molecules on Membrane Proteins Resolved by Atomic Force Microscopy. NANO LETTERS 2022; 22:2391-2397. [PMID: 35274954 DOI: 10.1021/acs.nanolett.2c00029] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Water structuring on the outer surface of protein molecules called the hydration shell is essential as well as the internal water structures for higher-order structuring of protein molecules and their biological activities in vivo. We now show the molecular-scale hydration structure measurements of native purple membrane patches composed of proton pump proteins by a noninvasive three-dimensional force mapping technique based on frequency modulation atomic force microscopy. We successfully resolved the ordered water molecules localized near the proton uptake channels on the cytoplasmic side of the individual bacteriorhodopsin proteins in the purple membrane. We demonstrate that the three-dimensional force mapping can be widely applicable for molecular-scale investigations of the solid-liquid interfaces of various soft nanomaterials.
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Affiliation(s)
- Shinichiro Ido
- Department of Electronic Science and Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo, Kyoto, 615-8510, Japan
| | - Kei Kobayashi
- Department of Electronic Science and Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo, Kyoto, 615-8510, Japan
| | - Noriaki Oyabu
- Department of Electronic Science and Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo, Kyoto, 615-8510, Japan
| | - Yoshiki Hirata
- National Institute of Advanced Industrial Science and Technology, 1-1 Umezono, Tsukuba, Ibaraki 305-8566, Japan
| | - Kazumi Matsushige
- Department of Electronic Science and Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo, Kyoto, 615-8510, Japan
| | - Hirofumi Yamada
- Department of Electronic Science and Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Nishikyo, Kyoto, 615-8510, Japan
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12
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Bondar AN. Mechanisms of long-distance allosteric couplings in proton-binding membrane transporters. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2022; 128:199-239. [PMID: 35034719 DOI: 10.1016/bs.apcsb.2021.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Membrane transporters that use proton binding and proton transfer for function couple local protonation change with changes in protein conformation and water dynamics. Changes of protein conformation might be required to allow transient formation of hydrogen-bond networks that bridge proton donor and acceptor pairs separated by long distances. Inter-helical hydrogen-bond networks adjust rapidly to protonation change, and ensure rapid response of the protein structure and dynamics. Membrane transporters with known three-dimensional structures and proton-binding groups inform on general principles of protonation-coupled protein conformational dynamics. Inter-helical hydrogen bond motifs between proton-binding carboxylate groups and a polar sidechain are observed in unrelated membrane transporters, suggesting common principles of coupling protonation change with protein conformational dynamics.
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Affiliation(s)
- Ana-Nicoleta Bondar
- University of Bucharest, Faculty of Physics, Măgurele, Romania; Forschungszentrum Jülich, Institute of Computational Biomedicine, Jülich, Germany.
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13
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Abstract
Vibrational spectroscopy such as FTIR and Raman spectroscopy is a powerful, sensitive, and informative method for studying protein structural changes in rhodopsins during their functions. The usefulness has been historically proven for the study of bacteriorhodopsin and bovine rhodopsin before their structural determination of rhodopsins. We now have atomic structures of many animal and microbial rhodopsins, and it is now important to know the structural dynamics of rhodopsins for function. FTIR and Raman spectroscopy provides useful information for this aim. In this chapter, we introduce the methods of FTIR and resonance Raman spectroscopy applied to rhodopsins. These vibrational methods offer deeper understanding on the mechanism how rhodopsins change their structures for function.
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Affiliation(s)
- Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, Japan.
| | - Yasuhisa Mizutani
- Department of Chemistry, Graduate School of Science, Osaka University, Osaka, Japan
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14
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Nakai H, Takemura T, Ono J, Nishimura Y. Quantum-Mechanical Molecular Dynamics Simulations on Secondary Proton Transfer in Bacteriorhodopsin Using Realistic Models. J Phys Chem B 2021; 125:10947-10963. [PMID: 34582194 DOI: 10.1021/acs.jpcb.1c06231] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Bacteriorhodopsin (BR) transports a proton from intracellular to extracellular (EC) sites through five proton transfers. The second proton transfer is the release of an excess proton stored in BR into the EC medium, and an atomistic understanding of this whole process has remained unexplored due to its ubiquitous environment. Here, fully quantum mechanical (QM) molecular dynamics (MD) and metadynamics (MTD) simulations for this process were performed at the divide-and-conquer density-functional tight-binding level using realistic models (∼50000 and ∼20000 atoms) based on the time-resolved photointermediate structures from an X-ray free electron laser. Regarding the proton storage process, the QM-MD/MTD simulations confirmed the Glu-shared mechanism, in which an excess proton is stored between Glu194 and Glu204, and clarified that the activation occurs by localizing the proton at Glu204 in the photocycle. Furthermore, the QM-MD/MTD simulations elucidated a release pathway from Glu204 through Ser193 to the EC water molecules and clarified that the proton release starts at ∼250 μs. In the ubiquitous proton diffusion in the EC medium, the transient proton receptors predicted experimentally were assigned to carboxylates in Glu9 and Glu74. Large-scale QM-MD/MTD simulations beyond the conventional sizes, which provided the above findings and confirmations, were possible by adopting our Dcdftbmd program.
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Affiliation(s)
- Hiromi Nakai
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan.,Waseda Research Institute for Science and Engineering (WISE), Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan.,Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto 615-8245, Japan
| | - Toshiaki Takemura
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
| | - Junichi Ono
- Waseda Research Institute for Science and Engineering (WISE), Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan.,Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto 615-8245, Japan
| | - Yoshifumi Nishimura
- Waseda Research Institute for Science and Engineering (WISE), Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
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15
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Yagi K, Sugita Y. Anharmonic Vibrational Calculations Based on Group-Localized Coordinates: Applications to Internal Water Molecules in Bacteriorhodopsin. J Chem Theory Comput 2021; 17:5007-5020. [PMID: 34296615 PMCID: PMC10986902 DOI: 10.1021/acs.jctc.1c00060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
An efficient anharmonic vibrational method is developed exploiting the locality of molecular vibration. Vibrational coordinates localized to a group of atoms are employed to divide the potential energy surface (PES) of a system into intra- and inter-group contributions. Then, the vibrational Schrödinger equation is solved based on a PES, in which the inter-group coupling is truncated at the harmonic level while accounting for the intra-group anharmonicity. The method is applied to a pentagonal hydrogen bond network (HBN) composed of internal water molecules and charged residues in a membrane protein, bacteriorhodopsin. The PES is calculated by the quantum mechanics/molecular mechanics (QM/MM) calculation at the level of B3LYP-D3/aug-cc-pVDZ. The infrared (IR) spectrum is computed using a set of coordinates localized to each water molecule and amino acid residue by second-order vibrational quasi-degenerate perturbation theory (VQDPT2). Benchmark calculations show that the proposed method yields the N-D/O-D stretching frequencies with an error of 7 cm-1 at the cost reduced by more than five times. In contrast, the harmonic approximation results in a severe error of 150 cm-1. Furthermore, the size of QM regions is carefully assessed to find that the QM regions should include not only the pentagonal HBN itself but also its HB partners. VQDPT2 calculations starting from transient structures obtained by molecular dynamics simulations have shown that the structural sampling has a significant impact on the calculated IR spectrum. The incorporation of anharmonicity, sufficiently large QM regions, and structural samplings are of essential importance to reproduce the experimental IR spectrum. The computational spectrum paves the way for decoding the IR signal of strong HBNs and helps elucidate their functional roles in biomolecules.
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Affiliation(s)
- Kiyoshi Yagi
- Theoretical
Molecular Science Laboratory, RIKEN Cluster
for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yuji Sugita
- Theoretical
Molecular Science Laboratory, RIKEN Cluster
for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Computational
Biophysics Research Team, RIKEN Center for
Computational Science, 7-1-26 Minatojima-Minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
- Laboratory
for Biomolecular Function Simulation, RIKEN
Center for Biosystems Dynamics Research, 1-6-5 Minatojima-Minamimachi,
Chuo-ku, Kobe, Hyogo 650-0047, Japan
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16
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Bondar AN. Proton-Binding Motifs of Membrane-Bound Proteins: From Bacteriorhodopsin to Spike Protein S. Front Chem 2021; 9:685761. [PMID: 34136464 PMCID: PMC8203321 DOI: 10.3389/fchem.2021.685761] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/18/2021] [Indexed: 11/13/2022] Open
Abstract
Membrane-bound proteins that change protonation during function use specific protein groups to bind and transfer protons. Knowledge of the identity of the proton-binding groups is of paramount importance to decipher the reaction mechanism of the protein, and protonation states of prominent are studied extensively using experimental and computational approaches. Analyses of model transporters and receptors from different organisms, and with widely different biological functions, indicate common structure-sequence motifs at internal proton-binding sites. Proton-binding dynamic hydrogen-bond networks that are exposed to the bulk might provide alternative proton-binding sites and proton-binding pathways. In this perspective article I discuss protonation coupling and proton binding at internal and external carboxylate sites of proteins that use proton transfer for function. An inter-helical carboxylate-hydroxyl hydrogen-bond motif is present at functionally important sites of membrane proteins from archaea to the brain. External carboxylate-containing H-bond clusters are observed at putative proton-binding sites of protonation-coupled model proteins, raising the question of similar functionality in spike protein S.
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Affiliation(s)
- Ana-Nicoleta Bondar
- Freie Universität Berlin, Department of Physics, Theoretical Molecular Biophysics Group, Berlin, Germany
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17
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Inoue K. Diversity, Mechanism, and Optogenetic Application of Light-Driven Ion Pump Rhodopsins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1293:89-126. [PMID: 33398809 DOI: 10.1007/978-981-15-8763-4_6] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ion-transporting microbial rhodopsins are widely used as major molecular tools in optogenetics. They are categorized into light-gated ion channels and light-driven ion pumps. While the former passively transport various types of cations and anions in a light-dependent manner, light-driven ion pumps actively transport specific ions, such as H+, Na+, Cl-, against electrophysiological potential by using light energy. Since the ion transport by these pumps induces hyperpolarization of membrane potential and inhibit neural firing, light-driven ion-pumping rhodopsins are mostly applied as inhibitory optogenetics tools. Recent progress in genome and metagenome sequencing identified more than several thousands of ion-pumping rhodopsins from a wide variety of microbes, and functional characterization studies has been revealing many new types of light-driven ion pumps one after another. Since light-gated channels were reviewed in other chapters in this book, here the rapid progress in functional characterization, molecular mechanism study, and optogenetic application of ion-pumping rhodopsins were reviewed.
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Affiliation(s)
- Keiichi Inoue
- The Institute for Solid State Physics, The University of Tokyo, Chiba, Japan.
- PRESTO, Japan Science and Technology Agency, Saitama, Japan.
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18
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Nagasaka Y, Hososhima S, Kubo N, Nagata T, Kandori H, Inoue K, Yawo H. Gate-keeper of ion transport-a highly conserved helix-3 tryptophan in a channelrhodopsin chimera, C1C2/ChRWR. Biophys Physicobiol 2020; 17:59-70. [PMID: 33173715 PMCID: PMC7593130 DOI: 10.2142/biophysico.bsj-2020007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 05/27/2020] [Indexed: 12/01/2022] Open
Abstract
Microbial rhodopsin is a large family of membrane proteins having seven transmembrane helices (TM1-7) with an all-trans retinal (ATR) chromophore that is covalently bound to Lys in the TM7. The Trp residue in the middle of TM3, which is homologous to W86 of bacteriorhodopsin (BR), is highly conserved among microbial rhodopsins with various light-driven functions. However, the significance of this Trp for the ion transport function of microbial rhodopsins has long remained unknown. Here, we replaced the W163 (BR W86 counterpart) of a channelrhodopsin (ChR), C1C2/ChRWR, which is a chimera between ChR1 and 2, with a smaller aromatic residue, Phe to verify its role in the ion transport. Under whole-cell patch clamp recordings from the ND7/23 cells that were transfected with the DNA plasmid coding human codon optimized C1C2/ChRWR (hWR) or its W163F mutant (hWR-W163F), the photocurrents were evoked by a pulsatile light at 475 nm. The ion-transporting activity of hWR was strongly altered by the W163F mutation in 3 points: (1) the H+ leak at positive membrane potential (Vm) and its light-adaptation, (2) the attenuation of cation channel activity and (3) the manifestation of outward H+ pump activity. All of these results strongly suggest that W163 has a role in stabilizing the structure involved in the gating-on and -off of the cation channel, the role of “gate keeper”. We can attribute the attenuation of cation channel activity to the incomplete gating-on and the H+ leak to the incomplete gating-off.
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Affiliation(s)
- Yujiro Nagasaka
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.,Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Shoko Hososhima
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya 466-8555, Japan
| | - Naoko Kubo
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.,Department of Physiology, Tohoku University Graduate School of Medicine, Sendai, Miyagi 980-8575, Japan
| | - Takashi Nagata
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.,Precursory Research for Embryonic Science and Technology (PRESTO) , Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Keiichi Inoue
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Hiromu Yawo
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
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19
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Ono J, Imai M, Nishimura Y, Nakai H. Hydroxide Ion Carrier for Proton Pumps in Bacteriorhodopsin: Primary Proton Transfer. J Phys Chem B 2020; 124:8524-8539. [DOI: 10.1021/acs.jpcb.0c05507] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Junichi Ono
- Waseda Research Institute for Science and Engineering (WISE), Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
- Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto 615-8245, Japan
| | - Minori Imai
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
| | - Yoshifumi Nishimura
- Waseda Research Institute for Science and Engineering (WISE), Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
| | - Hiromi Nakai
- Waseda Research Institute for Science and Engineering (WISE), Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
- Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30 Goryo-Ohara, Nishikyo-ku, Kyoto 615-8245, Japan
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
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20
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Nikolaev DM, Shtyrov AA, Mereshchenko AS, Panov MS, Tveryanovich YS, Ryazantsev MN. An assessment of water placement algorithms in quantum mechanics/molecular mechanics modeling: the case of rhodopsins' first spectral absorption band maxima. Phys Chem Chem Phys 2020; 22:18114-18123. [PMID: 32761024 DOI: 10.1039/d0cp02638g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Quantum mechanics/molecular mechanics (QM/MM) models are a widely used tool to obtain detailed insight into the properties and functioning of proteins. The outcome of QM/MM studies heavily depends on the quality of the applied QM/MM model. Prediction and right placement of internal water molecules in protein cavities is one of the critical parts of any QM/MM model construction. Herein, we performed a systematic study of four protein hydration algorithms. We tested these algorithms for their ability to predict X-ray-resolved water molecules for a set of membrane photosensitive rhodopsin proteins, as well as the influence of the applied water placement algorithms on the QM/MM calculated absorption maxima (λmax) of these proteins. We used 49 rhodopsins and their intermediates with available X-ray structures as the test set. We found that a proper choice of hydration algorithms and setups is needed to predict functionally important water molecules in the chromophore-binding cavity of rhodopsins, such as the water cluster in the N-H region of bacteriorhodopsin or two water molecules in the binding pocket of bovine visual rhodopsin. The QM/MM calculated λmax of rhodopsins is also quite sensitive to the applied protein hydration protocols. The best methodology allows obtaining an 18.0 nm average value for the absolute deviation of the calculated λmax from the experimental λmax. Although the major effect of water molecules on λmax originates from the water molecules located in the binding pocket, the water molecules outside the binding pocket also affect the calculated λmax mainly by causing a reorganization of the protein structure. The results reported in this study can be used for the evaluation and further development of hydration methodologies, in general, and rhodopsin QM/MM models, in particular.
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Affiliation(s)
- Dmitrii M Nikolaev
- Nanotechnology Research and Education Centre RAS, Saint Petersburg Academic University, 8/3 Khlopina Street, St. Petersburg 194021, Russia.
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21
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Kandori H. Structure/Function Study of Photoreceptive Proteins by FTIR Spectroscopy. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2020. [DOI: 10.1246/bcsj.20200109] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Hideki Kandori
- Department of Life Science and Applied Chemistry & OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi 466-8555, Japan
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22
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Chakravorty A, Pandey S, Pahari S, Zhao S, Alexov E. Capturing the Effects of Explicit Waters in Implicit Electrostatics Modeling: Qualitative Justification of Gaussian-Based Dielectric Models in DelPhi. J Chem Inf Model 2020; 60:2229-2246. [PMID: 32155062 PMCID: PMC9883665 DOI: 10.1021/acs.jcim.0c00151] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Our group has implemented a smooth Gaussian-based dielectric function in DelPhi (J. Chem. Theory Comput. 2013, 9 (4), 2126-2136) which models the solute as an object with inhomogeneous dielectric permittivity and provides a smooth transition of dielectric permittivity from surface-bound water to bulk solvent. Although it is well-understood that the protein hydrophobic core is less polarizable than the hydrophilic protein surface, less attention is paid to the polarizability of water molecules inside the solute and on its surface. Here, we apply explicit water simulations to study the behavior of water molecules buried inside a protein and on the surface of that protein and contrast it with the behavior of the bulk water. We selected a protein that is experimentally shown to have five cavities, most of which are occupied by water molecules. We demonstrate through molecular dynamics (MD) simulations that the behavior of water in the cavity is drastically different from that in the bulk. These observations were made by comparing the mean residence times, dipole orientation relaxation times, and average dipole moment fluctuations. We also show that the bulk region has a nonuniform distribution of these tempo-spatial properties. From the perspective of continuum electrostatics, we argue that the dielectric "constant" in water-filled cavities of proteins and the space close to the molecular surface should differ from that assigned to the bulk water. This provides support for the Gaussian-based smooth dielectric model for solving electrostatics in the Poisson-Boltzmann equation framework. Furthermore, we demonstrate that using a well-parametrized Gaussian-based model with a single energy-minimized configuration of a protein can also reproduce its ensemble-averaged polar solvation energy. Thus, we argue that the Gaussian-based smooth dielectric model not only captures accurate physics but also provides an efficient way of computing ensemble-averaged quantities.
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Affiliation(s)
- Arghya Chakravorty
- Computational Biophysics and Bioinformatics, Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634, United States,Corresponding Authors:,
| | - Shailesh Pandey
- Computational Biophysics and Bioinformatics, Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634, United States
| | - Swagata Pahari
- Computational Biophysics and Bioinformatics, Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634, United States
| | - Shan Zhao
- Department of Mathematics, University of Alabama, Tuscaloosa, Alabama 35487, Unites States
| | - Emil Alexov
- Computational Biophysics and Bioinformatics, Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634, United States,Corresponding Authors:,
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23
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Matsuda Y, Hirano Y, Mizutani S, Sakai D, Fujii A, Maeda S, Ohno K. Migrations and Catalytic Action of Water Molecules in the Ionized Formamide-(H 2O) 2 Cluster. J Phys Chem A 2020; 124:2802-2807. [PMID: 32187496 DOI: 10.1021/acs.jpca.0c00637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Isomerization dynamics involving the migrations, proton transfer reaction, and catalytic actions of water molecules upon vertical ionization of the formamide (FA)-(H2O)2 cluster is investigated by the infrared spectroscopy and theoretical reaction path search calculation. The infrared spectroscopic result indicates the [FA-(H2O)2]+ cation has the hydrogen-bonded structure of the enol isomer cation of formamide and the water dimer. This structure is formed by proton transfer from the CH bond to the carbonyl group through the catalytic action of the water molecules. The isomerization paths involving this enolization in ionized FA-(H2O)2 are explored by using the anharmonic downward distortion following method. We found multiple enolization paths which accompany proton exchanges among the formamide moiety and water molecules through the catalytic actions of the water molecules.
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Affiliation(s)
- Yoshiyuki Matsuda
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Yutaro Hirano
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Shinichi Mizutani
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Daichi Sakai
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Asuka Fujii
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Satoshi Maeda
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan.,Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo, 001-0021, Japan.,National Institute for Materials Science (NIMS) Research and Services Division of Materials Data and Integrated System (MaDIS) Tsukuba, 305-0044, Japan
| | - Koichi Ohno
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3, Aramaki Aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan.,Institute for Quantum Chemical Exploration, 13F Area Shinagawa, Konan 1-9-36, Minato-ku, Tokyo, 108-0075, Japan
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24
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Abstract
Infrared difference spectroscopy probes vibrational changes of proteins upon their perturbation. Compared with other spectroscopic methods, it stands out by its sensitivity to the protonation state, H-bonding, and the conformation of different groups in proteins, including the peptide backbone, amino acid side chains, internal water molecules, or cofactors. In particular, the detection of protonation and H-bonding changes in a time-resolved manner, not easily obtained by other techniques, is one of the most successful applications of IR difference spectroscopy. The present review deals with the use of perturbations designed to specifically change the protein between two (or more) functionally relevant states, a strategy often referred to as reaction-induced IR difference spectroscopy. In the first half of this contribution, I review the technique of reaction-induced IR difference spectroscopy of proteins, with special emphasis given to the preparation of suitable samples and their characterization, strategies for the perturbation of proteins, and methodologies for time-resolved measurements (from nanoseconds to minutes). The second half of this contribution focuses on the spectral interpretation. It starts by reviewing how changes in H-bonding, medium polarity, and vibrational coupling affect vibrational frequencies, intensities, and bandwidths. It is followed by band assignments, a crucial aspect mostly performed with the help of isotopic labeling and site-directed mutagenesis, and complemented by integration and interpretation of the results in the context of the studied protein, an aspect increasingly supported by spectral calculations. Selected examples from the literature, predominately but not exclusively from retinal proteins, are used to illustrate the topics covered in this review.
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25
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Kandori H. Biophysics of rhodopsins and optogenetics. Biophys Rev 2020; 12:355-361. [PMID: 32065378 DOI: 10.1007/s12551-020-00645-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 02/10/2020] [Indexed: 01/19/2023] Open
Abstract
Rhodopsins are photoreceptive proteins and key tools in optogenetics. Although rhodopsin was originally named as a red-colored pigment for vision, the modern meaning of rhodopsin encompasses photoactive proteins containing a retinal chromophore in animals and microbes. Animal and microbial rhodopsins respectively possess 11-cis and all-trans retinal, respectively. As cofactors bound with their animal and microbial rhodopsin (seven transmembrane α-helices) environments, 11-cis and all-trans retinal undergo photoisomerization into all-trans and 13-cis retinal forms as part of their functional cycle. While animal rhodopsins are G protein coupled receptors, the function of microbial rhodopsins is highly divergent. Many of the microbial rhodopsins are able to transport ions in a passive or an active manner. These light-gated channels or light-driven pumps represent the main tools for respectively effecting neural excitation and silencing in the emerging field of optogenetics. In this article, the biophysics of rhodopsins and their relationship to optogenetics are reviewed. As history has proven, understanding the molecular mechanism of microbial rhodopsins is a prerequisite for their rational exploitation as the optogenetics tools of the future.
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26
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Chatterjee K, Dopfer O. Protonation of Naphthalene–(Water)n Nanoclusters: Intracluster Proton Transfer to Hydration Shell Revealed by Infrared Photodissociation Spectroscopy. J Phys Chem A 2020; 124:1134-1151. [DOI: 10.1021/acs.jpca.9b11779] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kuntal Chatterjee
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany
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27
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Kandori H. Retinal Proteins: Photochemistry and Optogenetics. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2020. [DOI: 10.1246/bcsj.20190292] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi 466-8555, Japan
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi 466-8555, Japan
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28
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Friedrich D, Brünig FN, Nieuwkoop AJ, Netz RR, Hegemann P, Oschkinat H. Collective exchange processes reveal an active site proton cage in bacteriorhodopsin. Commun Biol 2020; 3:4. [PMID: 31925324 PMCID: PMC6941954 DOI: 10.1038/s42003-019-0733-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 12/02/2019] [Indexed: 01/01/2023] Open
Abstract
Proton translocation across membranes is vital to all kingdoms of life. Mechanistically, it relies on characteristic proton flows and modifications of hydrogen bonding patterns, termed protonation dynamics, which can be directly observed by fast magic angle spinning (MAS) NMR. Here, we demonstrate that reversible proton displacement in the active site of bacteriorhodopsin already takes place in its equilibrated dark-state, providing new information on the underlying hydrogen exchange processes. In particular, MAS NMR reveals proton exchange at D85 and the retinal Schiff base, suggesting a tautomeric equilibrium and thus partial ionization of D85. We provide evidence for a proton cage and detect a preformed proton path between D85 and the proton shuttle R82. The protons at D96 and D85 exchange with water, in line with ab initio molecular dynamics simulations. We propose that retinal isomerization makes the observed proton exchange processes irreversible and delivers a proton towards the extracellular release site. Daniel Friedrich et al. show that reversible proton translocation occurs in the dark–state of bacteriorhodopsin, involving the retinal Schiff base and D85 exchanging protons with H2O. They find evidence of an active site proton cage and possible proton transfer via R82.
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Affiliation(s)
- Daniel Friedrich
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany.,Freie Universität Berlin, Institut für Chemie und Biochemie, 14195, Berlin, Germany.,Department of Molecular and Cellular Biology, Harvard University, 52 Oxford Street, Cambridge, MA, 02138, USA.,Department of Cancer Biology, Dana-Farber Cancer Institute, 360 Longwood Avenue, Boston, MA, 02215, USA
| | - Florian N Brünig
- Freie Universität Berlin, Fachbereich Physik, 14195, Berlin, Germany
| | - Andrew J Nieuwkoop
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany.,Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 123 Bevier Road, Piscataway, NJ, 08854, USA
| | - Roland R Netz
- Freie Universität Berlin, Fachbereich Physik, 14195, Berlin, Germany
| | - Peter Hegemann
- Humboldt-Universität zu Berlin, Institut für Biologie, Invalidenstr. 42, 10115, Berlin, Germany
| | - Hartmut Oschkinat
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Robert-Rössle-Str. 10, 13125, Berlin, Germany. .,Freie Universität Berlin, Institut für Chemie und Biochemie, 14195, Berlin, Germany.
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29
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Senger M, Eichmann V, Laun K, Duan J, Wittkamp F, Knör G, Apfel UP, Happe T, Winkler M, Heberle J, Stripp ST. How [FeFe]-Hydrogenase Facilitates Bidirectional Proton Transfer. J Am Chem Soc 2019; 141:17394-17403. [PMID: 31580662 PMCID: PMC6823627 DOI: 10.1021/jacs.9b09225] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Hydrogenases are metalloenzymes that
catalyze the conversion of
protons and molecular hydrogen, H2. [FeFe]-hydrogenases
show particularly high rates of hydrogen turnover and have inspired
numerous compounds for biomimetic H2 production. Two decades
of research on the active site cofactor of [FeFe]-hydrogenases have
put forward multiple models of the catalytic proceedings. In comparison,
our understanding of proton transfer is poor. Previously, residues
were identified forming a hydrogen-bonding network between active
site cofactor and bulk solvent; however, the exact mechanism of catalytic
proton transfer remained inconclusive. Here, we employ in
situ infrared difference spectroscopy on the [FeFe]-hydrogenase
from Chlamydomonas reinhardtii evaluating dynamic
changes in the hydrogen-bonding network upon photoreduction. While
proton transfer appears to be impaired in the oxidized state (Hox), the presented data support continuous proton transfer
in the reduced state (Hred). Our analysis allows for
a direct, molecular unique assignment to individual amino acid residues.
We found that transient protonation changes of glutamic acid residue
E141 and, most notably, arginine R148 facilitate bidirectional proton
transfer in [FeFe]-hydrogenases.
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Affiliation(s)
- Moritz Senger
- Experimental Molecular Biophysics, Department of Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Viktor Eichmann
- Experimental Molecular Biophysics, Department of Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Konstantin Laun
- Experimental Molecular Biophysics, Department of Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | | | | | - Günther Knör
- Institute of Inorganic Chemistry , Johannes Kepler Universität Linz , Altenberger Straße 69 , 4040 Linz , Austria
| | | | | | | | - Joachim Heberle
- Experimental Molecular Biophysics, Department of Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
| | - Sven Timo Stripp
- Experimental Molecular Biophysics, Department of Physics , Freie Universität Berlin , Arnimallee 14 , 14195 Berlin , Germany
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30
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Katayama K, Imai H, Kandori H. FTIR Study of S180A Mutant of Primate Red-sensitive Pigment. CHEM LETT 2019. [DOI: 10.1246/cl.190458] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Kota Katayama
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi 466-8555, Japan
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi 466-8555, Japan
| | - Hiroo Imai
- Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi 466-8555, Japan
- OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi 466-8555, Japan
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31
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Karathanou K, Bondar AN. Using Graphs of Dynamic Hydrogen-Bond Networks To Dissect Conformational Coupling in a Protein Motor. J Chem Inf Model 2019; 59:1882-1896. [PMID: 31038944 DOI: 10.1021/acs.jcim.8b00979] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
DExD/H-box proteins are soluble enzymes that couple binding and hydrolysis of adenosine triphosphate (ATP) with reactions involving RNA metabolism or bind and push newly synthesized proteins across bacterial cell membranes. Knowledge of the reaction mechanism of these enzymes could help the development of new therapeutics. In order to explore the mechanism of long-distance conformational coupling in SecA, the DEAD-box motor of the Sec protein secretion in bacteria, we implemented algorithms that provide simplified graph representations of the protein's dynamic hydrogen-bond networks. We find that mutations near the nucleotide-binding site or changes of the nucleotide-binding state of SecA associate with altered dynamics at the preprotein binding domain and identify extended networks of hydrogen bonds that connect the active site of SecA to the region where SecA binds newly synthesized secretory proteins. Water molecules participate in hydrogen-bonded water chains that bridge functional domains of SecA and could contribute to long-distance conformational coupling.
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Affiliation(s)
- Konstantina Karathanou
- Freie Universität Berlin , Department of Physics, Theoretical Molecular Biophysics Group , Arnimallee 14 , D-14195 Berlin , Germany
| | - Ana-Nicoleta Bondar
- Freie Universität Berlin , Department of Physics, Theoretical Molecular Biophysics Group , Arnimallee 14 , D-14195 Berlin , Germany
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32
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Gupta PK, Esser A, Forbert H, Marx D. Toward theoretical terahertz spectroscopy of glassy aqueous solutions: partially frozen solute-solvent couplings of glycine in water. Phys Chem Chem Phys 2019; 21:4975-4987. [PMID: 30758388 DOI: 10.1039/c8cp07489e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The molecular-level understanding of THz spectra of aqueous solutions under ambient conditions has been greatly advanced in recent years. Here, we go beyond previous analyses by performing ab initio molecular dynamics simulations of glycine in water with artificially frozen solute or solvent molecules, respectively, while computing the total THz response as well as its decomposition into mode-specific resonances based on the "supermolecular solvation complex" technique. Clamping the water molecules and keeping glycine moving breaks the coupling of glycine to the structural dynamics of the solvent, however, the polarization and dielectric solvation effects in the static solvation cage are still at work since the full electronic structure of the quenched solvent is taken into account. The complementary approach of fixing glycine reveals both the dynamical and electronic response of the solvation cage at the level of its THz response. Moreover, to quantitatively account for the electronic contribution solely due to solvent embedding, the solute species is "vertically desolvated", thus preserving the fully coupled solute-solvent motion in terms of the solute's structural dynamics in solution, while its electronic structure is no longer subject to solute-solvent polarization and charge transfer effects. When referenced to the free simulation of Gly(aq), this three-fold approach allows us to decompose the THz spectral contributions due to the correlated solute-solvent dynamics into entirely structural and purely electronic effects. Beyond providing hitherto unknown insights, the observed systematic changes of THz spectra in terms of peak shifts and lineshape modulations due to conformational freezing and frozen solvation cages might be useful to investigate the solvation of molecules in highly viscous H-bonding solvents such as ionic liquids and even in cryogenic ices as relevant to polar stratospheric and dark interstellar clouds.
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Affiliation(s)
- Prashant Kumar Gupta
- Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum, Germany
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33
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Miyahara T, Nakatsuji H. Light-Driven Proton, Sodium Ion, and Chloride Ion Transfer Mechanisms in Rhodopsins: SAC-CI Study. J Phys Chem A 2019; 123:1766-1784. [DOI: 10.1021/acs.jpca.8b10203] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Tomoo Miyahara
- Quantum Chemistry Research Institute, Kyoto Technoscience Center 16, 14 Yoshida Kawara-machi, Sakyou-ku, Kyoto 606-8305, Japan
| | - Hiroshi Nakatsuji
- Quantum Chemistry Research Institute, Kyoto Technoscience Center 16, 14 Yoshida Kawara-machi, Sakyou-ku, Kyoto 606-8305, Japan
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34
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Iwaki M, Takeshita K, Kondo HX, Kinoshita K, Okamura Y, Takano Y, Nakagawa A, Kandori H. Zn2+-Binding to the Voltage-Gated Proton Channel Hv1/VSOP. J Phys Chem B 2018; 122:9076-9080. [DOI: 10.1021/acs.jpcb.8b04890] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Hiroko X. Kondo
- Department of Biomedical Information Sciences, Graduate School of Information Sciences, Hiroshima City University, 3-4-1 Ozuka-Higashi, Asa-Minami-Ku, Hiroshima 731-3194, Japan
- Laboratory for Computational Molecular Design, RIKEN Center for Biosystems Dynamics Research, 6-2-3, Furuedai, Suita, 565-0874, Japan
| | - Kengo Kinoshita
- Department of Applied Information Sciences, Graduate School of Information Sciences, Tohoku University, 6-3-09 Aramaki-Aza-Aoba, Aoba-ku, Sendai, 980-8579, Japan
- Tohoku Medical Megabank Organization, Tohoku University, 2-1 Seityo-machi, Aoba-ku, Sendai, 980-8573, Japan
- Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryocho, Aoba-ku, Sendai, 980-8575, Japan
| | | | - Yu Takano
- Department of Biomedical Information Sciences, Graduate School of Information Sciences, Hiroshima City University, 3-4-1 Ozuka-Higashi, Asa-Minami-Ku, Hiroshima 731-3194, Japan
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35
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Theoretical study on excited-state multiple proton-transfer process of 7-azaindole with ammonia and mixed water-ammonia: Stepwise or concerted? J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2018.06.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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36
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Terpugov EL, Degtyareva OV, Fesenko EE. Microwave-Induced Structural Changes in Bacteriorhodopsin: Studies by Optical and Fourier Transform Infrared Difference Spectroscopy. Biophysics (Nagoya-shi) 2018. [DOI: 10.1134/s0006350918050226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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37
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Ito S, Kandori H, Lorenz-Fonfria VA. Potential Second-Harmonic Ghost Bands in Fourier Transform Infrared (FT-IR) Difference Spectroscopy of Proteins. APPLIED SPECTROSCOPY 2018; 72:956-963. [PMID: 29350538 DOI: 10.1177/0003702818757521] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Fourier transform infrared (FT-IR) difference absorption spectroscopy is a common method for studying the structural and dynamical aspects behind protein function. In particular, the 2800-1800 cm-1 spectral range has been used to obtain information about internal (deuterated) water molecules, as well as site-specific details about cysteine residues and chemically modified and artificial amino acids. Here, we report on the presence of ghost bands in cryogenic light-induced FT-IR difference spectra of the protein bacteriorhodopsin. The presence of these ghost bands can be particularly problematic in the 2800-1900 cm-1 region, showing intensities similar to O-D vibrations from water molecules. We demonstrate that they arise from second harmonics from genuine chromophore bands located in the 1400-850 cm-1 region, generated by double-modulation artifacts caused from reflections of the IR beam at the sample and at the cryostat windows back to the interferometer (inter-reflections). The second-harmonic ghost bands can be physically removed by placing an optical filter of suitable cutoff in the beam path, but at the cost of losing part of the multiplexing advantage of FT-IR spectroscopy. We explored alternatives to the use of optical filters. Tilting the cryostat windows was effective in reducing the intensity of the second harmonic artifacts but tilting the sample windows was not, presumably by their close proximity to the focal point of the IR beam. We also introduce a simple numerical post-processing approach that can partially, but not fully, correct for second-harmonic ghost bands in FT-IR difference spectra.
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Affiliation(s)
- Shota Ito
- 1 Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
| | - Hideki Kandori
- 1 Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan
- 2 OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Japan
| | - Victor A Lorenz-Fonfria
- 3 Institute of Molecular Science (ICMol), Universitat de València, Paterna, Spain
- 4 Department of Biochemistry and Molecular Biology, Universitat de València, Burjassot, Spain
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38
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Kandori H, Inoue K, Tsunoda SP. Light-Driven Sodium-Pumping Rhodopsin: A New Concept of Active Transport. Chem Rev 2018. [DOI: 10.1021/acs.chemrev.7b00548] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
| | - Keiichi Inoue
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Satoshi P. Tsunoda
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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39
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Mukherjee S, Mondal S, Deshmukh AA, Gopal B, Bagchi B. What Gives an Insulin Hexamer Its Unique Shape and Stability? Role of Ten Confined Water Molecules. J Phys Chem B 2018; 122:1631-1637. [DOI: 10.1021/acs.jpcb.8b00453] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Saumyak Mukherjee
- Solid
State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, India
| | - Sayantan Mondal
- Solid
State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, India
| | | | | | - Biman Bagchi
- Solid
State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, India
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40
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Saraei N, Hietsoi O, Mullins CS, Gupta AJ, Frye BC, Mashuta MS, Buchanan RM, Grapperhaus CA. Streams, cascades, and pools: various water cluster motifs in structurally similar Ni( ii) complexes. CrystEngComm 2018. [DOI: 10.1039/c8ce01153b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Hydrogen bonding (HB) interactions are well known to impact the properties of water in the bulk and within hydrated materials.
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Affiliation(s)
- Nina Saraei
- Department of Chemistry
- University of Louisville
- Louisville
- USA
| | | | | | | | - Brian C. Frye
- Department of Chemistry
- University of Louisville
- Louisville
- USA
| | - Mark S. Mashuta
- Department of Chemistry
- University of Louisville
- Louisville
- USA
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41
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Chen HF, Inoue K, Ono H, Abe-Yoshizumi R, Wada A, Kandori H. Time-resolved FTIR study of light-driven sodium pump rhodopsins. Phys Chem Chem Phys 2018; 20:17694-17704. [DOI: 10.1039/c8cp02599a] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Light-driven sodium ion pump rhodopsin (NaR) is a new functional class of microbial rhodopsin. Present step-scan time-resolved FTIR spectroscopy revealed that the K, L and O intermediates of NaRs contain 13-cis retinal with similar distortion.
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Affiliation(s)
- Hui-Fen Chen
- Department of Medicinal and Applied Chemistry
- Kaohsiung Medical University
- Kaohsiung
- Taiwan
- Department of Life Science and Applied Chemistry
| | - Keiichi Inoue
- Department of Life Science and Applied Chemistry
- Nagoya Institute of Technology
- Nagoya 466-8555
- Japan
- OptoBioTechnology Research Center
| | - Hikaru Ono
- Department of Life Science and Applied Chemistry
- Nagoya Institute of Technology
- Nagoya 466-8555
- Japan
| | - Rei Abe-Yoshizumi
- Department of Life Science and Applied Chemistry
- Nagoya Institute of Technology
- Nagoya 466-8555
- Japan
| | - Akimori Wada
- Laboratory of Organic Chemistry for Life Science
- Kobe Pharmaceutical University
- Kobe 658-8558
- Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry
- Nagoya Institute of Technology
- Nagoya 466-8555
- Japan
- OptoBioTechnology Research Center
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42
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Banerjee G, Ghosh I, Kim CJ, Debus RJ, Brudvig GW. Substitution of the D1-Asn 87 site in photosystem II of cyanobacteria mimics the chloride-binding characteristics of spinach photosystem II. J Biol Chem 2017; 293:2487-2497. [PMID: 29263091 DOI: 10.1074/jbc.m117.813170] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 12/19/2017] [Indexed: 11/06/2022] Open
Abstract
Photoinduced water oxidation at the O2-evolving complex (OEC) of photosystem II (PSII) is a complex process involving a tetramanganese-calcium cluster that is surrounded by a hydrogen-bonded network of water molecules, chloride ions, and amino acid residues. Although the structure of the OEC has remained conserved over eons of evolution, significant differences in the chloride-binding characteristics exist between cyanobacteria and higher plants. An analysis of amino acid residues in and around the OEC has identified residue 87 in the D1 subunit as the only significant difference between PSII in cyanobacteria and higher plants. We substituted the D1-Asn87 residue in the cyanobacterium Synechocystis sp. PCC 6803 (wildtype) with alanine, present in higher plants, or with aspartic acid. We studied PSII core complexes purified from D1-N87A and D1-N87D variant strains to probe the function of the D1-Asn87 residue in the water-oxidation mechanism. EPR spectra of the S2 state and flash-induced FTIR spectra of both D1-N87A and D1-N87D PSII core complexes exhibited characteristics similar to those of wildtype Synechocystis PSII core complexes. However, flash-induced O2-evolution studies revealed a decreased cycling efficiency of the D1-N87D variant, whereas the cycling efficiency of the D1-N87A PSII variant was similar to that of wildtype PSII. Steady-state O2-evolution activity assays revealed that substitution of the D1 residue at position 87 with alanine perturbs the chloride-binding site in the proton-exit channel. These findings provide new insight into the role of the D1-Asn87 site in the water-oxidation mechanism and explain the difference in the chloride-binding properties of cyanobacterial and higher-plant PSII.
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Affiliation(s)
- Gourab Banerjee
- From the Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107 and
| | - Ipsita Ghosh
- From the Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107 and
| | - Christopher J Kim
- the Department of Biochemistry, University of California, Riverside, California 92521
| | - Richard J Debus
- the Department of Biochemistry, University of California, Riverside, California 92521
| | - Gary W Brudvig
- From the Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107 and
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43
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Giliberti V, Badioli M, Nucara A, Calvani P, Ritter E, Puskar L, Aziz EF, Hegemann P, Schade U, Ortolani M, Baldassarre L. Heterogeneity of the Transmembrane Protein Conformation in Purple Membranes Identified by Infrared Nanospectroscopy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1701181. [PMID: 28960799 DOI: 10.1002/smll.201701181] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 08/02/2017] [Indexed: 06/07/2023]
Abstract
Cell membranes are intrinsically heterogeneous, as the local protein and lipid distribution is critical to physiological processes. Even in template systems embedding a single protein type, like purple membranes, there can be a different local response to external stimuli or environmental factors, resulting in heterogeneous conformational changes. Despite the dramatic advances of microspectroscopy techniques, the identification of the conformation heterogeneity is still a challenging task. Tip-enhanced infrared nanospectroscopy is here used to identify conformational changes connected to the hydration state of the transmembrane proteins contained in a 50 nm diameter cell membrane area, without the need for fluorescent labels. In dried purple membrane monolayers, areas with fully hydrated proteins are found among large numbers of molecules with randomly distributed hydration states. Infrared nanospectroscopy results are compared to the spectra obtained with diffraction-limited infrared techniques based on the use of synchrotron radiation, in which the diffraction limit still prevents the observation of nanoscale heterogeneity.
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Affiliation(s)
- Valeria Giliberti
- Istituto Italiano di Tecnologia, Center for Life NanoScience, Viale Regina Elena 291, I-00161, Roma, Italy
| | - Michela Badioli
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, I-00185, Roma, Italy
| | - Alessandro Nucara
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, I-00185, Roma, Italy
| | - Paolo Calvani
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, I-00185, Roma, Italy
| | - Eglof Ritter
- Humboldt-Universität zu Berlin, Institut für Biologie, Invalidenstraße 42, D-10115, Berlin, Germany
| | - Ljiljana Puskar
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489, Berlin, Germany
| | - Emad Flear Aziz
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489, Berlin, Germany
| | - Peter Hegemann
- Humboldt-Universität zu Berlin, Institut für Biologie, Invalidenstraße 42, D-10115, Berlin, Germany
| | - Ulrich Schade
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Str. 15, 12489, Berlin, Germany
| | - Michele Ortolani
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, I-00185, Roma, Italy
| | - Leonetta Baldassarre
- Istituto Italiano di Tecnologia, Center for Life NanoScience, Viale Regina Elena 291, I-00161, Roma, Italy
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, I-00185, Roma, Italy
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44
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Bertoldo JB, Rodrigues T, Dunsmore L, Aprile FA, Marques MC, Rosado LA, Boutureira O, Steinbrecher TB, Sherman W, Corzana F, Terenzi H, Bernardes GJL. A Water-Bridged Cysteine-Cysteine Redox Regulation Mechanism in Bacterial Protein Tyrosine Phosphatases. Chem 2017; 3:665-677. [PMID: 29094109 PMCID: PMC5656095 DOI: 10.1016/j.chempr.2017.07.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 06/01/2017] [Accepted: 07/07/2017] [Indexed: 11/25/2022]
Abstract
The emergence of multidrug-resistant Mycobacterium tuberculosis (Mtb) strains highlights the need to develop more efficacious and potent drugs. However, this goal is dependent on a comprehensive understanding of Mtb virulence protein effectors at the molecular level. Here, we used a post-expression cysteine (Cys)-to-dehydrolanine (Dha) chemical editing strategy to identify a water-mediated motif that modulates accessibility of the protein tyrosine phosphatase A (PtpA) catalytic pocket. Importantly, this water-mediated Cys-Cys non-covalent motif is also present in the phosphatase SptpA from Staphylococcus aureus, which suggests a potentially preserved structural feature among bacterial tyrosine phosphatases. The identification of this structural water provides insight into the known resistance of Mtb PtpA to the oxidative conditions that prevail within an infected host macrophage. This strategy could be applied to extend the understanding of the dynamics and function(s) of proteins in their native state and ultimately aid in the design of small-molecule modulators.
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Affiliation(s)
- Jean B Bertoldo
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.,Centro de Biologia Molecular Estrutural, Departamento de Bioquímica, Universidade Federal de Santa Catarina, 88040-970 Florianópolis-SC, Brazil
| | - Tiago Rodrigues
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028 Lisbon, Portugal
| | - Lavinia Dunsmore
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Francesco A Aprile
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Marta C Marques
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028 Lisbon, Portugal
| | - Leonardo A Rosado
- Centro de Biologia Molecular Estrutural, Departamento de Bioquímica, Universidade Federal de Santa Catarina, 88040-970 Florianópolis-SC, Brazil
| | - Omar Boutureira
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | | | - Woody Sherman
- Schrödinger, 120 West 45th Street, New York, NY 10036, USA
| | - Francisco Corzana
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006 Logroño, Spain
| | - Hernán Terenzi
- Centro de Biologia Molecular Estrutural, Departamento de Bioquímica, Universidade Federal de Santa Catarina, 88040-970 Florianópolis-SC, Brazil
| | - Gonçalo J L Bernardes
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028 Lisbon, Portugal
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45
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Mondal S, Mukherjee S, Bagchi B. Protein Hydration Dynamics: Much Ado about Nothing? J Phys Chem Lett 2017; 8:4878-4882. [PMID: 28978201 DOI: 10.1021/acs.jpclett.7b02324] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Sayantan Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science , Bengaluru, Karnataka 560 012, India
| | - Saumyak Mukherjee
- Solid State and Structural Chemistry Unit, Indian Institute of Science , Bengaluru, Karnataka 560 012, India
| | - Biman Bagchi
- Solid State and Structural Chemistry Unit, Indian Institute of Science , Bengaluru, Karnataka 560 012, India
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46
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Katayama K, Nonaka Y, Tsutsui K, Imai H, Kandori H. Spectral Tuning Mechanism of Primate Blue-sensitive Visual Pigment Elucidated by FTIR Spectroscopy. Sci Rep 2017; 7:4904. [PMID: 28687791 PMCID: PMC5501831 DOI: 10.1038/s41598-017-05177-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 05/24/2017] [Indexed: 11/17/2022] Open
Abstract
Protein-bound water molecules are essential for the structure and function of many membrane proteins, including G-protein-coupled receptors (GPCRs). Our prior work focused on studying the primate green- (MG) and red- (MR) sensitive visual pigments using low-temperature Fourier transform infrared (FTIR) spectroscopy, which revealed protein-bound waters in both visual pigments. Although the internal waters are located in the vicinity of both the retinal Schiff base and retinal β-ionone ring, only the latter showed differences between MG and MR, which suggests their role in color tuning. Here, we report FTIR spectra of primate blue-sensitive pigment (MB) in the entire mid-IR region, which reveal the presence of internal waters that possess unique water vibrational signals that are reminiscent of a water cluster. These vibrational signals of the waters are influenced by mutations at position Glu113 and Trp265 in Rh, which suggest that these waters are situated between these two residues. Because Tyr265 is the key residue for achieving the spectral blue-shift in λmax of MB, we propose that these waters are responsible for the increase in polarity toward the retinal Schiff base, which leads to the localization of the positive charge in the Schiff base and consequently causes the blue-shift of λmax.
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Affiliation(s)
- Kota Katayama
- 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, 466-855, Japan
| | - Yuki Nonaka
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan
| | - Kei Tsutsui
- Primate Research Institute, Kyoto University, Inuyama, 484-8506, Japan
| | - Hiroo Imai
- Primate Research Institute, Kyoto University, Inuyama, 484-8506, Japan
| | - 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, 466-855, Japan.
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47
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Ito S, Sugita S, Inoue K, Kandori H. FTIR Analysis of a Light-driven Inward Proton-pumping Rhodopsin at 77 K. Photochem Photobiol 2017; 93:1381-1387. [DOI: 10.1111/php.12771] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 02/22/2017] [Indexed: 01/27/2023]
Affiliation(s)
- Shota Ito
- Department of Life Science and Applied Chemistry; Nagoya Institute of Technology; Showa-ku Nagoya Japan
| | - Shinya Sugita
- Department of Life Science and Applied Chemistry; Nagoya Institute of Technology; Showa-ku Nagoya Japan
| | - Keiichi Inoue
- Department of Life Science and Applied Chemistry; Nagoya Institute of Technology; Showa-ku Nagoya Japan
- OptoBioTechnology Research Center; Nagoya Institute of Technology; Showa-ku Nagoya Japan
- PRESTO; Japan Science and Technology Agency; Kawaguchi Saitama Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry; Nagoya Institute of Technology; Showa-ku Nagoya Japan
- OptoBioTechnology Research Center; Nagoya Institute of Technology; Showa-ku Nagoya Japan
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48
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Yamauchi Y, Konno M, Ito S, Tsunoda SP, Inoue K, Kandori H. Molecular properties of a DTD channelrhodopsin from Guillardia theta. Biophys Physicobiol 2017. [PMID: 28630812 PMCID: PMC5468465 DOI: 10.2142/biophysico.14.0_57] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Microbial rhodopsins are membrane proteins found widely in archaea, eubacteria and eukaryotes (fungal and algal species). They have various functions, such as light-driven ion pumps, light-gated ion channels, light sensors and light-activated enzymes. A light-driven proton pump bacteriorhodopsin (BR) contains a DTD motif at positions 85, 89, and 96, which is unique to archaeal proton pumps. Recently, channelrhodopsins (ChRs) containing the DTD motif, whose sequential identity is ~20% similar to BR and to cation ChRs in Chlamydomonas reinhardtii (CrCCRs), were found. While extensive studies on ChRs have been performed with CrCCR2, the molecular properties of DTD ChRs remain an intrigue. In this paper, we studied a DTD rhodopsin from G. theta (GtCCR4) using electrophysiological measurements, flash photolysis, and low-temperature difference FTIR spectroscopy. Electrophysiological measurements clearly showed that GtCCR4 functions as a light-gated cation channel, similar to other G. theta DTD ChRs (GtCCR1-3). Light-driven proton pump activity was also suggested for GtCCR4. Both electrophysiological and flash photolysis experiments showed that channel closing occurs upon reprotonation of the Schiff base, suggesting that the dynamics of retinal and channels are tightly coupled in GtCCR4. From Fourier transform infrared (FTIR) spectroscopy at 77 K, we found that the primary reaction is an all-trans to a 13-cis photoisomerization, like other microbial rhodopsins, although perturbations in the secondary structure were much smaller in GtCCR4 than in CrCCR2.
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Affiliation(s)
- Yumeka Yamauchi
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Masae Konno
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Shota Ito
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Satoshi P Tsunoda
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
| | - Keiichi Inoue
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan.,Frontier Research Institute for Material Science, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
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49
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Kim CJ, Debus RJ. Evidence from FTIR Difference Spectroscopy That a Substrate H2O Molecule for O2 Formation in Photosystem II Is Provided by the Ca Ion of the Catalytic Mn4CaO5 Cluster. Biochemistry 2017; 56:2558-2570. [DOI: 10.1021/acs.biochem.6b01278] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Christopher J. Kim
- Department of Biochemistry, University of California, Riverside, California 92521, United States
| | - Richard J. Debus
- Department of Biochemistry, University of California, Riverside, California 92521, United States
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50
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Inoue K, Ito S, Kato Y, Nomura Y, Shibata M, Uchihashi T, Tsunoda SP, Kandori H. A natural light-driven inward proton pump. Nat Commun 2016; 7:13415. [PMID: 27853152 PMCID: PMC5118547 DOI: 10.1038/ncomms13415] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 09/28/2016] [Indexed: 01/03/2023] Open
Abstract
Light-driven outward H+ pumps are widely distributed in nature, converting sunlight energy into proton motive force. Here we report the characterization of an oppositely directed H+ pump with a similar architecture to outward pumps. A deep-ocean marine bacterium, Parvularcula oceani, contains three rhodopsins, one of which functions as a light-driven inward H+ pump when expressed in Escherichia coli and mouse neural cells. Detailed mechanistic analyses of the purified proteins reveal that small differences in the interactions established at the active centre determine the direction of primary H+ transfer. Outward H+ pumps establish strong electrostatic interactions between the primary H+ donor and the extracellular acceptor. In the inward H+ pump these electrostatic interactions are weaker, inducing a more relaxed chromophore structure that leads to the long-distance transfer of H+ to the cytoplasmic side. These results demonstrate an elaborate molecular design to control the direction of H+ transfers in proteins.
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Affiliation(s)
- Keiichi Inoue
- 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
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Shota Ito
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Yoshitaka Kato
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Yurika Nomura
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - Mikihiro Shibata
- Department of Physics, Kanazawa University, Kanazawa 920-1192, Japan
- Bio-AFM Frontier Research Center, Kanazawa University, Kanazawa 920-1192, Japan
| | - Takayuki Uchihashi
- Department of Physics, Kanazawa University, Kanazawa 920-1192, Japan
- Bio-AFM Frontier Research Center, Kanazawa University, Kanazawa 920-1192, Japan
| | - Satoshi P. Tsunoda
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan
| | - 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
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