1
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Lee Y, Jeong HS, Jung S, Hwang J, Le CTH, Jun SH, Du EJ, Kang K, Kim BG, Lim HH, Lee S. Cryo-EM structures of the plant anion channel SLAC1 from Arabidopsis thaliana suggest a combined activation model. Nat Commun 2023; 14:7345. [PMID: 37963863 PMCID: PMC10645844 DOI: 10.1038/s41467-023-43193-3] [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: 11/07/2022] [Accepted: 11/02/2023] [Indexed: 11/16/2023] Open
Abstract
The anion channel SLAC1 functions as a crucial effector in the ABA signaling, leading to stomata closure. SLAC1 is activated by phosphorylation in its intracellular domains. Both a binding-activation model and an inhibition-release model for activation have been proposed based on only the closed structures of SLAC1, rendering the structure-based activation mechanism controversial. Here we report cryo-EM structures of Arabidopsis SLAC1 WT and its phosphomimetic mutants in open and closed states. Comparison of the open structure with the closed ones reveals the structural basis for opening of the conductance pore. Multiple phosphorylation of an intracellular domain (ICD) causes dissociation of ICD from the transmembrane domain. A conserved, positively-charged sequence motif in the intracellular loop 2 (ICL2) seems to be capable of sensing of the negatively charged phosphorylated ICD. Interactions between ICL2 and ICD drive drastic conformational changes, thereby widening the pore. From our results we propose that SLAC1 operates by a mechanism combining the binding-activation and inhibition-release models.
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Affiliation(s)
- Yeongmok Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Hyeon Seong Jeong
- Neurovascular Unit Research Group, Korea Brain Research Institute, Daegu, 41068, Republic of Korea
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu, 42988, Republic of Korea
| | - Seoyeon Jung
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Junmo Hwang
- Neurovascular Unit Research Group, Korea Brain Research Institute, Daegu, 41068, Republic of Korea
| | - Chi Truc Han Le
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Sung-Hoon Jun
- Electron Microscopy Research Center, Korea Basic Science Institute, Cheongju, 28119, Republic of Korea
| | - Eun Jo Du
- Neurovascular Unit Research Group, Korea Brain Research Institute, Daegu, 41068, Republic of Korea
| | - KyeongJin Kang
- Neurovascular Unit Research Group, Korea Brain Research Institute, Daegu, 41068, Republic of Korea
| | - Beom-Gi Kim
- Metabolic Engineering Division, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju, 54874, Republic of Korea
| | - Hyun-Ho Lim
- Neurovascular Unit Research Group, Korea Brain Research Institute, Daegu, 41068, Republic of Korea
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu, 42988, Republic of Korea
| | - Sangho Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
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2
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Sučec I, Mammeri NE, Dregni AJ, Hong M. Rapid Determination of the Topology of Oligomeric α-Helical Membrane Proteins by Water- and Lipid-Edited Methyl NMR. J Phys Chem B 2023; 127:7518-7530. [PMID: 37606918 PMCID: PMC10893779 DOI: 10.1021/acs.jpcb.3c05295] [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] [Indexed: 08/23/2023]
Abstract
Single-span oligomeric α-helical transmembrane proteins are common in virus ion channels, which are targets of antiviral drugs. Knowledge about the high-resolution structures of these oligomeric α-helical bundles is so far scarce. Structure determination of these membrane proteins by solid-state NMR traditionally requires resolving and assigning protein chemical shifts and measuring many interhelical distances, which are time-consuming. To accelerate experimental structure determination, here we introduce a simple solid-state NMR approach that uses magnetization transfer from water and lipid protons to the protein. By detecting the water- and lipid-transferred intensities of the high-sensitivity methyl 13C signals of Leu, Val, and Ile residues, which are highly enriched in these membrane proteins, we can derive models of the topology of these homo-oligomeric helical bundles. The topology is specified by the positions of amino acid residues in heptad repeats and the orientations of residues relative to the channel pore, lipids, and the helical interface. We demonstrate this water- and lipid-edited methyl NMR approach on the envelope (E) protein of SARS-CoV-2, the causative agent of the COVID-19 pandemic. We show that water-edited and lipid-edited 2D 13C-13C correlation spectra can be measured with sufficient sensitivity. Even without resolving multiple residues of the same type in the NMR spectra, we can obtain the helical bundle topology. We apply these experiments to the structurally unknown E proteins of the MERS coronavirus and the human coronavirus NL63. The resulting structural topologies show interesting differences in the positions of the aromatic residues in these three E proteins, suggesting that these viroporins may have different mechanisms of activation and ion conduction.
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Affiliation(s)
- Iva Sučec
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139
| | - Nadia El Mammeri
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139
| | - Aurelio J. Dregni
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139
| | - Mei Hong
- Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, MA 02139
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3
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Understanding Life at High Temperatures: Relationships of Molecular Channels in Enzymes of Methanogenic Archaea and Their Growth Temperatures. Int J Mol Sci 2022; 23:ijms232315149. [PMID: 36499474 PMCID: PMC9741079 DOI: 10.3390/ijms232315149] [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: 10/25/2022] [Revised: 11/18/2022] [Accepted: 11/28/2022] [Indexed: 12/04/2022] Open
Abstract
Analyses of protein structures have shown the existence of molecular channels in enzymes from Prokaryotes. Those molecular channels suggest a critical role of spatial voids in proteins, above all, in those enzymes functioning under high temperature. It is expected that these spaces within the protein structure are required to access the active site and to maximize availability and thermal stability of their substrates and cofactors. Interestingly, numerous substrates and cofactors have been reported to be highly temperature-sensitive biomolecules. Methanogens represent a singular phylogenetic group of Archaea that performs anaerobic respiration producing methane during growth. Methanogens inhabit a variety of environments including the full range of temperatures for the known living forms. Herein, we carry out a dimensional analysis of molecular tunnels in key enzymes of the methanogenic pathway from methanogenic Archaea growing optimally over a broad temperature range. We aim to determine whether the dimensions of the molecular tunnels are critical for those enzymes from thermophiles. Results showed that at increasing growth temperature the dimensions of molecular tunnels in the enzymes methyl-coenzyme M reductase and heterodisulfide reductase become increasingly restrictive and present strict limits at the highest growth temperatures, i.e., for hyperthermophilic methanogens. However, growth at lower temperature allows a wide dimensional range for the molecular spaces in these enzymes. This is in agreement with previous suggestions on a potential major role of molecular tunnels to maintain biomolecule stability and activity of some enzymes in microorganisms growing at high temperatures. These results contribute to better understand archaeal growth at high temperatures. Furthermore, an optimization of the dimensions of molecular tunnels would represent an important adaptation required to maintain the activity of key enzymes of the methanogenic pathway for those methanogens growing optimally at high temperatures.
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4
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Saha S, Mohanta S, Das R, Dalai R, Divyanshi, Tiwari N, Tiwari A, Kumar A, Goswami C. Ratio of Hydrophobic-Hydrophilic and Positive-Negative Residues at Lipid-Water-Interface Influences Surface Expression and Channel Gating of TRPV1. J Membr Biol 2022; 255:319-339. [PMID: 35608627 DOI: 10.1007/s00232-022-00243-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 05/03/2022] [Indexed: 12/19/2022]
Abstract
During evolution, TRPV1 has lost, retained or selected certain residues at Lipid-Water-Interface (LWI) and formed specific patterns there. The ratio of "hydrophobic-hydrophilic" and "positive-negative-charged" residues at the inner LWI remains conserved throughout vertebrate evolution and plays important role in regulating TRPV1 trafficking and localization. Arg575 is an important residue as Arg575Asp mutant has reduced surface expression, co-localization with lipid raft markers, cell area and increased cell lethality. This lethality is most likely due to the disruption of the ratio between positive-negative charges caused by the mutation. Such lethality can be rescued by either using TRPV1-specfic inhibitor 5'-IRTX or by restoring the positive-negative charge ratio at that position, i.e. by introducing Asp576Arg mutation in Arg575Asp backbone. We propose that Arg575Asp mutation confers TRPV1 in a "constitutive-open-like" condition. These findings have broader implication in understanding the molecular evolution of thermo-sensitive ion channels and the micro-environments involved in processes that goes erratic in different diseases. The segment of TRPV1 that is present at the inner lipid-water-interface (LWI) has a specific pattern of amino acid combinations. The overall ratio of +ve charge /-ve charge and the ratio of hydrophobicity/hydrophilicity remain constant throughout the vertebrate evolution (ca 450 million years). This specific pattern is not observed in the outer LWI region of TRPV1.
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Affiliation(s)
- Somdatta Saha
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Sushama Mohanta
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Rashmita Das
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Ritesh Dalai
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Divyanshi
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Nikhil Tiwari
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India
| | - Ankit Tiwari
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India
| | - Abhishek Kumar
- Institute of Bioinformatics, International Technology Park, Bangalore, 560066, India.,Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, 576104, India
| | - Chandan Goswami
- School of Biological Sciences, National Institute of Science Education and Research, Jatni Campus, Bhubaneswar, Orissa, 752050, India. .,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, 400094, India.
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5
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Gisriel CJ, Wang J, Liu J, Flesher DA, Reiss KM, Huang HL, Yang KR, Armstrong WH, Gunner MR, Batista VS, Debus RJ, Brudvig GW. High-resolution cryo-electron microscopy structure of photosystem II from the mesophilic cyanobacterium, Synechocystis sp. PCC 6803. Proc Natl Acad Sci U S A 2022; 119:e2116765118. [PMID: 34937700 PMCID: PMC8740770 DOI: 10.1073/pnas.2116765118] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2021] [Indexed: 12/15/2022] Open
Abstract
Photosystem II (PSII) enables global-scale, light-driven water oxidation. Genetic manipulation of PSII from the mesophilic cyanobacterium Synechocystis sp. PCC 6803 has provided insights into the mechanism of water oxidation; however, the lack of a high-resolution structure of oxygen-evolving PSII from this organism has limited the interpretation of biophysical data to models based on structures of thermophilic cyanobacterial PSII. Here, we report the cryo-electron microscopy structure of PSII from Synechocystis sp. PCC 6803 at 1.93-Å resolution. A number of differences are observed relative to thermophilic PSII structures, including the following: the extrinsic subunit PsbQ is maintained, the C terminus of the D1 subunit is flexible, some waters near the active site are partially occupied, and differences in the PsbV subunit block the Large (O1) water channel. These features strongly influence the structural picture of PSII, especially as it pertains to the mechanism of water oxidation.
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Affiliation(s)
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520
| | - Jinchan Liu
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520
| | - David A Flesher
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520
| | - Krystle M Reiss
- Department of Chemistry, Yale University, New Haven, CT 06520
| | - Hao-Li Huang
- Department of Chemistry, Yale University, New Haven, CT 06520
| | - Ke R Yang
- Department of Chemistry, Yale University, New Haven, CT 06520
| | | | - M R Gunner
- Department of Physics, City College of New York, New York, NY 100031
| | | | - Richard J Debus
- Department of Biochemistry, University of California, Riverside, CA 92521
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, CT 06520;
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520
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6
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Zhu C, Zhang AM, Li Y, Li HX, Qian Y, Fu Y, Wu X, Li Y. A biomimetic metal–organic framework with cuboid inner cavities for enantioselective separation. Inorg Chem Front 2022. [DOI: 10.1039/d2qi00152g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A biomimetic metal–organic framework with cuboid inner cavities and multiple recognition sites was constructed from a phenylalanine-derived ligand. It can enantioselectively separate various racemic alcohols, diols and epoxides with ee up to 99.5%.
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Affiliation(s)
- Chengfeng Zhu
- Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, P. R. China
| | - A-Mei Zhang
- Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, P. R. China
| | - Ying Li
- Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, P. R. China
| | - Han-Xue Li
- Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, P. R. China
| | - Yijian Qian
- Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, P. R. China
| | - Yanming Fu
- Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, P. R. China
| | - Xiang Wu
- Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, P. R. China
| | - Yougui Li
- Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, P. R. China
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7
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8
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Sadiq SK, Muñiz Chicharro A, Friedrich P, Wade RC. Multiscale Approach for Computing Gated Ligand Binding from Molecular Dynamics and Brownian Dynamics Simulations. J Chem Theory Comput 2021; 17:7912-7929. [PMID: 34739248 DOI: 10.1021/acs.jctc.1c00673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We develop an approach to characterize the effects of gating by a multiconformation protein consisting of macrostate conformations that are either accessible or inaccessible to ligand binding. We first construct a Markov state model of the apo-protein from atomistic molecular dynamics simulations from which we identify macrostates and their conformations, compute their relative macrostate populations and interchange kinetics, and structurally characterize them in terms of ligand accessibility. We insert the calculated first-order rate constants for conformational transitions into a multistate gating theory from which we derive a gating factor γ that quantifies the degree of conformational gating. Applied to HIV-1 protease, our approach yields a kinetic network of three accessible (semi-open, open, and wide-open) and two inaccessible (closed and a newly identified, "parted") macrostate conformations. The parted conformation sterically partitions the active site, suggesting a possible role in product release. We find that the binding kinetics of drugs and drug-like inhibitors to HIV-1 protease falls in the slow gating regime. However, because γ = 0.75, conformational gating only modestly slows ligand binding. Brownian dynamics simulations of the diffusional association of eight inhibitors to the protease─having a wide range of experimental association constants (∼104-1010 M-1 s-1)─yields gated rate constants in the range of ∼0.5-5.7 × 108 M-1 s-1. This indicates that, whereas the association rate of some inhibitors could be described by the model, for many inhibitors either subsequent conformational transitions or alternate binding mechanisms may be rate-limiting. For systems known to be modulated by conformational gating, the approach could be scaled computationally efficiently to screen association kinetics for a large number of ligands.
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Affiliation(s)
- S Kashif Sadiq
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany.,Genome Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany.,Infection Biology Unit, Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), C/Doctor Aiguader 88, 08003 Barcelona, Spain
| | - Abraham Muñiz Chicharro
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, Im Neuenheimer Feld 234, 69120 Heidelberg, Germany
| | - Patrick Friedrich
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany
| | - Rebecca C Wade
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany.,Center for Molecular Biology (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.,Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
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9
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Islam MS, Gaston JP, Baker MAB. Fluorescence Approaches for Characterizing Ion Channels in Synthetic Bilayers. MEMBRANES 2021; 11:857. [PMID: 34832086 PMCID: PMC8619978 DOI: 10.3390/membranes11110857] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 10/25/2021] [Accepted: 10/28/2021] [Indexed: 12/12/2022]
Abstract
Ion channels are membrane proteins that play important roles in a wide range of fundamental cellular processes. Studying membrane proteins at a molecular level becomes challenging in complex cellular environments. Instead, many studies focus on the isolation and reconstitution of the membrane proteins into model lipid membranes. Such simpler, in vitro, systems offer the advantage of control over the membrane and protein composition and the lipid environment. Rhodopsin and rhodopsin-like ion channels are widely studied due to their light-interacting properties and are a natural candidate for investigation with fluorescence methods. Here we review techniques for synthesizing liposomes and for reconstituting membrane proteins into lipid bilayers. We then summarize fluorescence assays which can be used to verify the functionality of reconstituted membrane proteins in synthetic liposomes.
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Affiliation(s)
- Md. Sirajul Islam
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2052, Australia; (M.S.I.); (J.P.G.)
| | - James P. Gaston
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2052, Australia; (M.S.I.); (J.P.G.)
| | - Matthew A. B. Baker
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2052, Australia; (M.S.I.); (J.P.G.)
- CSIRO Synthetic Biology Future Science Platform, GPO Box 2583, Brisbane, QLD 4001, Australia
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10
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Meng S, An R, Li Z, Schwaneberg U, Ji Y, Davari MD, Wang F, Wang M, Qin M, Nie K, Liu L. Tunnel engineering for modulating the substrate preference in cytochrome P450 BsβHI. BIORESOUR BIOPROCESS 2021; 8:26. [PMID: 38650198 PMCID: PMC10992877 DOI: 10.1186/s40643-021-00379-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/25/2021] [Indexed: 01/07/2023] Open
Abstract
An active site is normally located inside enzymes, hence substrates should go through a tunnel to access the active site. Tunnel engineering is a powerful strategy for refining the catalytic properties of enzymes. Here, P450BsβHI (Q85H/V170I) derived from hydroxylase P450Bsβ from Bacillus subtilis was chosen as the study model, which is reported as a potential decarboxylase. However, this enzyme showed low decarboxylase activity towards long-chain fatty acids. Here, a tunnel engineering campaign was performed for modulating the substrate preference and improving the decarboxylation activity of P450BsβHI. The finally obtained BsβHI-F79A variant had a 15.2-fold improved conversion for palmitic acid; BsβHI-F173V variant had a 3.9-fold improved conversion for pentadecanoic acid. The study demonstrates how the substrate preference can be modulated by tunnel engineering strategy.
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Affiliation(s)
- Shuaiqi Meng
- Beijing Bioprocess Key Laboratory, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany
| | - Ruipeng An
- Beijing Bioprocess Key Laboratory, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Zhongyu Li
- Beijing Bioprocess Key Laboratory, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Ulrich Schwaneberg
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany
- DWI-Leibniz Institute for Interactive Materials, Forckenbeckstraße 50, 52074, Aachen, Germany
| | - Yu Ji
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany
| | - Mehdi D Davari
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074, Aachen, Germany
| | - Fang Wang
- Beijing Bioprocess Key Laboratory, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Meng Wang
- Beijing Bioprocess Key Laboratory, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Meng Qin
- Beijing Bioprocess Key Laboratory, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Kaili Nie
- Beijing Bioprocess Key Laboratory, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China
| | - Luo Liu
- Beijing Bioprocess Key Laboratory, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China.
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11
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Langan PS, Vandavasi VG, Kopec W, Sullivan B, Afonne PV, Weiss KL, de Groot BL, Coates L. The structure of a potassium-selective ion channel reveals a hydrophobic gate regulating ion permeation. IUCRJ 2020; 7:835-843. [PMID: 32939275 PMCID: PMC7467165 DOI: 10.1107/s2052252520008271] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
Protein dynamics are essential to function. One example of this is the various gating mechanisms within ion channels, which are transmembrane proteins that act as gateways into the cell. Typical ion channels switch between an open and closed state via a conformational transition which is often triggered by an external stimulus, such as ligand binding or pH and voltage differences. The atomic resolution structure of a potassium-selective ion channel named NaK2K has allowed us to observe that a hydro-phobic residue at the bottom of the selectivity filter, Phe92, appears in dual conformations. One of the two conformations of Phe92 restricts the diameter of the exit pore around the selectivity filter, limiting ion flow through the channel, while the other conformation of Phe92 provides a larger-diameter exit pore from the selectivity filter. Thus, it can be concluded that Phe92 acts as a hydro-phobic gate, regulating the flow of ions through the selectivity filter.
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Affiliation(s)
- Patricia S. Langan
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
- Lentigen Technologies, 910 Clopper Road, Gaithersburg, MD 20878, USA
| | - Venu Gopal Vandavasi
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
- Department of Chemistry, Princeton University, Princeton, NJ 08540, USA
| | - Wojciech Kopec
- Biomolecular Dynamics Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Brendan Sullivan
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Pavel V. Afonne
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kevin L. Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Bert L. de Groot
- Biomolecular Dynamics Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Leighton Coates
- Neutron Scattering Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
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12
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Zhang Y, Zhao J, Kan Y, Ji R, Pan J, Huang W, Xu Z, Si W, Sha J. Concentration effects on capture rate and translocation configuration of nanopore-based DNA detection. Electrophoresis 2020; 41:1523-1528. [PMID: 32529653 DOI: 10.1002/elps.202000016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 01/21/2023]
Abstract
Nanopore is a kind of powerful tool to detect single molecules and investigate fundamental biological processes. In biological cells or real detection systems, concentration of DNA molecules is various. Here, we report an experimental study of the effects of DNA concentration on capture rate and translocation configuration with different sized nanopores and applied voltages. Three classes of DNA translocation configurations have been observed including linear translocation, folded translocation, and cotranslocation. In the case of relatively large sized nanopore or high applied voltage, considerable cotranslocation events have been detected. The percentage of cotranslocation events also increases with DNA concentration, which leads to the relationship between capture rate and DNA concentration deviates from linearity. Therefore, in order to reflect the number of translocation molecules accurately, the capture rate should be corrected by double-counting cotranslocation events. These results will provide a valuable reference for the design of nanopore sensors.
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Affiliation(s)
- Yin Zhang
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Jiabin Zhao
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Yajing Kan
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Rui Ji
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Jianqiang Pan
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Weichi Huang
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Zheng Xu
- Key Laboratory for Micro/Nano Technology and System of Liaoning Province, Dalian University of Technology, Dalian, P. R. China
| | - Wei Si
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
| | - Jingjie Sha
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing, P. R. China
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13
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14
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Uzdensky AB. Multifunctional Proteins. Biophysics (Nagoya-shi) 2020. [DOI: 10.1134/s0006350920030227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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15
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Sacquin-Mora S. Coarse-grain simulations on NMR conformational ensembles highlight functional residues in proteins. J R Soc Interface 2019; 16:20190075. [PMID: 31288649 DOI: 10.1098/rsif.2019.0075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Dynamics are a key feature of protein function, and this is especially true of gating residues, which occupy cavity or tunnel lining positions in the protein structure, and will reversibly switch between open and closed conformations in order to control the diffusion of small molecules within a protein's internal matrix. Earlier work on globins and hydrogenases have shown that these gating residues can be detected using a multiscale scheme combining all-atom classic molecular dynamics simulations and coarse-grain calculations of the resulting conformational ensemble mechanical properties. Here, we show that the structural variations observed in the conformational ensembles produced by NMR spectroscopy experiments are sufficient to induce noticeable mechanical changes in a protein, which in turn can be used to identify residues important for function and forming a mechanical nucleus in the protein core. This new approach, which combines experimental data and rapid coarse-grain calculations and no longer needs to resort to time-consuming all-atom simulations, was successfully applied to five different protein families.
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Affiliation(s)
- Sophie Sacquin-Mora
- Laboratoire de Biochimie Théorique, CNRS UPR9080, Institut de Biologie Physico-Chimique , 13 rue Pierre et Marie Curie, 75005 Paris , France
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16
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Adhikary R, Zimmermann J, Stanfield RL, Wilson IA, Yu W, Oda M, Romesberg FE. Structure and Dynamics of Stacking Interactions in an Antibody Binding Site. Biochemistry 2019; 58:2987-2995. [PMID: 31243995 DOI: 10.1021/acs.biochem.9b00119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
For years, antibodies (Abs) have been used as a paradigm for understanding how protein structure contributes to molecular recognition. However, with the ability to evolve Abs that recognize specific chromophores, they also have great potential as models for how protein dynamics contribute to molecular recognition. We previously raised murine Abs to different chromophores and, with the use of three-pulse photon echo peak shift spectroscopy, demonstrated that the immune system is capable of producing Abs with widely varying flexibility. We now report the characterization of the complexes formed between two Abs, 5D11 and 10A6, and the chromophoric ligand that they were evolved to recognize, 8-methoxypyrene-1,3,6-trisulfonic acid (MPTS). The sequences of the Ab genes indicate that they evolved from a common precursor. We also used a variety of spectroscopic methods to probe the photophysics and dynamics of the Ab-MPTS complexes and found that they are similar to each other but distinct from previously characterized anti-MPTS Abs. Structural studies revealed that this difference likely results from a unique mode of binding in which MPTS is sandwiched between the side chain of PheH98, which interacts with the chromophore via T-stacking, and the side chain of TrpL91, which interacts with the chromophore via parallel stacking. The T-stacking interaction appears to mediate relaxation on the picosecond time scale, while the parallel stacking appears to mediate relaxation on an ultrafast, femtosecond time scale, which dominates the response. The anti-MPTS Abs thus not only demonstrate the simultaneous use of the two limiting modes of stacking for molecular recognition, but also provide a unique opportunity to characterize how dynamics might contribute to molecular recognition. Both types of stacking are common in proteins and protein complexes where they may similarly contribute to dynamics and molecular recognition.
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Affiliation(s)
| | | | | | | | | | - Masayuki Oda
- Graduate School of Life and Environmental Sciences , Kyoto Prefectural University , 1-5, Hangi-cho , Shimogamo, Sakyo-ku, Kyoto 606-8522 , Japan
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17
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Xing J, Mei H, Huang S, Zhang D, Pan X. An Energetically Favorable Ligand Entrance Gate of a Multidrug Transporter Revealed by Partial Nudged Elastic Band Simulations. Comput Struct Biotechnol J 2019; 17:319-323. [PMID: 30899446 PMCID: PMC6406077 DOI: 10.1016/j.csbj.2019.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 02/14/2019] [Accepted: 02/15/2019] [Indexed: 11/08/2022] Open
Abstract
P-glycoprotein (P-gp) is a multidrug transporter, which harnesses the chemical energy of ATP to power the efflux of diverse chemotherapeutics out of cells and thus contributes to the development of multidrug resistance (MDR) in cancer. It has been proved that the ligand-binding pocket of P-gp is located at the transmembrane domains (TMDs). However, the access of ligands into the binding pocket remains to be elucidated, which definitely hinder the development of P-gp inhibitors. Herein, the access pathways of a well-known substrate rhodamine-123 and a cyclopeptide inhibitor QZ-Leu were characterized by time-independent partial nudged elastic band (PNEB) simulations. The decreasing free energies along the PNEB-optimized access pathway indicated that TM4/6 cleft may be an energetically favorable entrance gate for ligand entry into the binding pocket of P-gp. The results can be reconciled with a range of experimental studies, further corroborating the reliability of the gate revealed by computational simulations. Our atomic level description of the ligand access pathway provides valuable insights into the gating mechanism for drug uptake and transport by P-gp and other multidrug transporters. P-gp contributes to the development of multidrug resistance in cancer. The entrance of drugs into P-gp binding pocket has yet to be elucidated. An energetically favorable entrance gate was revealed by PNEB simulations. The computational results were reconciled with the experimental data. The atomic simulations provide insights into the gating mechanism of P-gp.
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Affiliation(s)
- Juan Xing
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China.,Department of Pathophysiology, College of Basic Medical Science, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Hu Mei
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - ShuHeng Huang
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - Duo Zhang
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China
| | - XianChao Pan
- Key Laboratory of Biorheological Science and Technology (Ministry of Education), College of Bioengineering, Chongqing University, Chongqing 400045, China.,Department of Medicinal Chemistry, College of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China
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18
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Perini DA, Alcaraz A, Queralt-Martín M. Lipid Headgroup Charge and Acyl Chain Composition Modulate Closure of Bacterial β-Barrel Channels. Int J Mol Sci 2019; 20:ijms20030674. [PMID: 30764475 PMCID: PMC6386941 DOI: 10.3390/ijms20030674] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 01/30/2019] [Accepted: 01/31/2019] [Indexed: 12/14/2022] Open
Abstract
The outer membrane of Gram-negative bacteria contains β-barrel proteins that form high-conducting ion channels providing a path for hydrophilic molecules, including antibiotics. Traditionally, these proteins have been considered to exist only in an open state so that regulation of outer membrane permeability was accomplished via protein expression. However, electrophysiological recordings show that β-barrel channels respond to transmembrane voltages by characteristically switching from a high-conducting, open state, to a so-called 'closed' state, with reduced permeability and possibly exclusion of large metabolites. Here, we use the bacterial porin OmpF from E. coli as a model system to gain insight on the control of outer membrane permeability by bacterial porins through the modulation of their open state. Using planar bilayer electrophysiology, we perform an extensive study of the role of membrane lipids in the OmpF channel closure by voltage. We pay attention not only to the effects of charges in the hydrophilic lipid heads but also to the contribution of the hydrophobic tails in the lipid-protein interactions. Our results show that gating kinetics is governed by lipid characteristics so that each stage of a sequential closure is different from the previous one, probably because of intra- or intermonomeric rearrangements.
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Affiliation(s)
- D Aurora Perini
- Laboratory of Molecular Biophysics, Department of Physics, Universitat Jaume I, 12071 Castellón, Spain.
| | - Antonio Alcaraz
- Laboratory of Molecular Biophysics, Department of Physics, Universitat Jaume I, 12071 Castellón, Spain.
| | - María Queralt-Martín
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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19
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Feng Y, Wang Y, Chu H, Fan Y, Cao X, Liu Y, Li G, Xue S. Stereoselective catalysis controlled by a native leucine or variant isoleucine wing‐gatekeeper in 2‐haloacid dehalogenase. FEBS Lett 2018; 593:308-318. [DOI: 10.1002/1873-3468.13309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 11/21/2018] [Accepted: 11/24/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Yanbin Feng
- Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China
| | - Yayue Wang
- Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China
- School of Biology and Food Science Shangqiu Normal University China
| | - Huiying Chu
- Laboratory of Molecular Modeling and Design State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Science Dalian China
| | - Yan Fan
- Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China
- University of Chinese Academy of Sciences Beijing China
| | - Xupeng Cao
- Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China
| | - Yinghui Liu
- Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China
| | - Guohui Li
- Laboratory of Molecular Modeling and Design State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Science Dalian China
| | - Song Xue
- Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian China
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20
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Bykhovskaia M. Molecular Dynamics Simulations of the SNARE Complex. Methods Mol Biol 2018; 1860:3-13. [PMID: 30317495 DOI: 10.1007/978-1-4939-8760-3_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
Molecular dynamics (MD) simulations enable in silico investigations of the dynamic behavior of proteins and protein complexes. Here, we describe MD simulations of the SNARE complex and its interactions with the neuronal protein complexin. Complexin is an effector of neuronal secretion that inhibits spontaneous fusion and is thought to clamp the fusion process via the interactions with the SNARE complex. We describe MD simulations of the SNARE complex alone and bound to complexin. The MD simulations under external forces imitating the repulsion between lipid bilayers enabled us to investigate unraveling and assembly of the SNARE complex.
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Affiliation(s)
- Maria Bykhovskaia
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA. .,Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA.
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21
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Liu H, Liu L, Cheng P, Huang X, Gong M. An odorant receptor from Anopheles sinensis in China is sensitive to oviposition attractants. Malar J 2018; 17:348. [PMID: 30290802 PMCID: PMC6173891 DOI: 10.1186/s12936-018-2501-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/01/2018] [Indexed: 01/01/2023] Open
Abstract
Background Anopheles sinensis is an important vector for the spread of malaria in China. Olfactory-related behaviours, particularly oviposition site seeking, offer opportunities for disrupting the disease-transmission process. Results This is the first report of the identification and characterization of AsinOrco and AsinOR10 in An. sinensis. AsinOrco and AsinOR10 share 97.49% and 90.37% amino acid sequence identity, respectively, with related sequences in Anopheles gambiae. A functional analysis demonstrated that AsinOrco- and AsinOR10-coexpressing HEK293 cells were highly sensitive to 3-methylindole, but showed no significant differences in response to other test odorants when compared to DMSO. Conclusions AsinOrco was characterized as a new member of the Orco ortholog subfamily. AsinOR10, which appears to be a member of the OR2-10 subfamily, is directly involved in identification of oviposition sites. This finding will help to elucidate the molecular mechanisms underlying olfactory signaling in An. sinensis and provide many more molecular targets for eco-friendly pest control. Electronic supplementary material The online version of this article (10.1186/s12936-018-2501-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hongmei Liu
- Department of Medical Entomology, Shandong Institute of Parasitic Diseases, Shandong Academy of Medical Sciences, Jining, 272033, Shandong, People's Republic of China.
| | - Luhong Liu
- Jining Center for Disease Control and Prevention, Jining, 272033, Shandong, People's Republic of China
| | - Peng Cheng
- Department of Medical Entomology, Shandong Institute of Parasitic Diseases, Shandong Academy of Medical Sciences, Jining, 272033, Shandong, People's Republic of China
| | - Xiaodan Huang
- Department of Medical Entomology, Shandong Institute of Parasitic Diseases, Shandong Academy of Medical Sciences, Jining, 272033, Shandong, People's Republic of China
| | - Maoqing Gong
- Department of Medical Entomology, Shandong Institute of Parasitic Diseases, Shandong Academy of Medical Sciences, Jining, 272033, Shandong, People's Republic of China.
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22
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Mahinthichaichan P, Morris DM, Wang Y, Jensen GJ, Tajkhorshid E. Selective Permeability of Carboxysome Shell Pores to Anionic Molecules. J Phys Chem B 2018; 122:9110-9118. [PMID: 30193460 PMCID: PMC6311388 DOI: 10.1021/acs.jpcb.8b06822] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Carboxysomes are closed polyhedral cellular microcompartments that increase the efficiency of carbon fixation in autotrophic bacteria. Carboxysome shells consist of small proteins that form hexameric units with semipermeable central pores containing binding sites for anions. This feature is thought to selectively allow access to RuBisCO enzymes inside the carboxysome by HCO3- (the dominant form of CO2 in the aqueous solution at pH 7.4) but not O2, which leads to a nonproductive reaction. To test this hypothesis, here we use molecular dynamics simulations to characterize the energetics and permeability of CO2, O2, and HCO3- through the central pores of two different shell proteins, namely, CsoS1A of α-carboxysome and CcmK4 of β-carboxysome shells. We find that the central pores are in fact selectively permeable to anions such as HCO3-, as predicted by the model.
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Affiliation(s)
- Paween Mahinthichaichan
- Department of Biochemistry, NIH Center for Macromolecular Modeling and Bioinformatics, Center for Biophysics and Quantitative Biology, Beckman Institute for Advanced Science and Technology , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801-3028 , United States
| | - Dylan M Morris
- Division of Biology and Biological Engineering , California Institute of Technology , Pasadena , California 91125 , United States
| | - Yi Wang
- Department of Physics , The Chinese University of Hong Kong , Shatin , New Territories, Hong Kong SAR , The People's Republic of China
| | - Grant J Jensen
- Division of Biology and Biological Engineering , California Institute of Technology , Pasadena , California 91125 , United States
- Howard Hughes Medical Institute , California Insitute of Technology , Pasadena , California 91125 , United States
| | - Emad Tajkhorshid
- Department of Biochemistry, NIH Center for Macromolecular Modeling and Bioinformatics, Center for Biophysics and Quantitative Biology, Beckman Institute for Advanced Science and Technology , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801-3028 , United States
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23
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Płuciennik A, Stolarczyk M, Bzówka M, Raczyńska A, Magdziarz T, Góra A. BALCONY: an R package for MSA and functional compartments of protein variability analysis. BMC Bioinformatics 2018; 19:300. [PMID: 30107777 PMCID: PMC6092823 DOI: 10.1186/s12859-018-2294-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 07/23/2018] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Here, we present an R package for entropy/variability analysis that facilitates prompt and convenient data extraction, manipulation and visualization of protein features from multiple sequence alignments. BALCONY can work with residues dispersed across a protein sequence and map them on the corresponding alignment of homologous protein sequences. Additionally, it provides several entropy and variability scores that indicate the conservation of each residue. RESULTS Our package allows the user to visualize evolutionary variability by locating the positions most likely to vary and to assess mutation candidates in protein engineering. CONCLUSION In comparison to other R packages BALCONY allows conservation/variability analysis in context of protein structure with linkage of the appropriate metrics with physicochemical features of user choice. AVAILABILITY CRAN project page: https://cran.r-project.org/package=BALCONY and our website: http://www.tunnelinggroup.pl/software/ for major platforms: Linux/Unix, Windows and Mac OS X.
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Affiliation(s)
- Alicja Płuciennik
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, ul. Krzywoustego 8, 44-100, Gliwice, Poland.,Institute of Automatic Control, Silesian University of Technology, Akademicka 16, 44-100, Gliwice, Poland
| | - Michał Stolarczyk
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, ul. Krzywoustego 8, 44-100, Gliwice, Poland.,Institute of Automatic Control, Silesian University of Technology, Akademicka 16, 44-100, Gliwice, Poland
| | - Maria Bzówka
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, ul. Krzywoustego 8, 44-100, Gliwice, Poland.,Faculty of Chemistry, Silesian University of Technology, ks. Marcina Strzody 9, 44-100, Gliwice, Poland
| | - Agata Raczyńska
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, ul. Krzywoustego 8, 44-100, Gliwice, Poland.,Institute of Automatic Control, Silesian University of Technology, Akademicka 16, 44-100, Gliwice, Poland
| | - Tomasz Magdziarz
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, ul. Krzywoustego 8, 44-100, Gliwice, Poland
| | - Artur Góra
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, ul. Krzywoustego 8, 44-100, Gliwice, Poland.
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24
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Guo L, Zhao H, Jiang Y. Expressional and functional interactions of two Apis cerana cerana olfactory receptors. PeerJ 2018; 6:e5005. [PMID: 29910990 PMCID: PMC6001824 DOI: 10.7717/peerj.5005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/29/2018] [Indexed: 11/20/2022] Open
Abstract
Apis cerana cerana relies on its sensitive olfactory system to perform foraging activities in the surrounding environment. Olfactory receptors (ORs) are a primary requirement for odorant recognition and coding. However, the molecular recognition of volatile compounds with ORs in A. cerana cerana is still not clear. Hence, in the present study, we achieved transient transfection and cell surface expression of A. cerana cerana ORs (AcerOr1 and AcerOr2; AcerOr2 is orthologous to the co-receptor) in Spodoptera frugiperda (Sf9) cells. AcerOr2 narrowly responded to N-(4-ethylphenyl)-2-((4-ethyl-5-(3-pyridinyl)-4H-1,2,4-triazol-3-yl) thio) acetamide (VUAA1), whereas AcerOr1 was sensitive to eugenol, lauric acid, ocimene, 1-nonanol, linolenic acid, hexyl acetate, undecanoic acid, 1-octyl alcohol, and nerol. Of the compounds tested, AcerOr1 showed the highest sensitivity to these odorants with EC50 values of 10−7 and 10−8 M, and AcerOr2 recognized VUAA1 with higher sensitivity [EC50 = (6.621 ± 0.26) × 10−8]. These results indicate that AcerOr2 is an essential gene for olfactory signaling, and AcerOr1 is a broadly tuned receptor. We discovered ligands that were useful for probing receptor activity during odor stimulation and validated three of them by electroantennography. The response increased with concentration of the odorant. The present study provides insight into the mechanism of olfactory discrimination in A. cerana cerana.
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Affiliation(s)
- Lina Guo
- College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, China
| | - Huiting Zhao
- College of Life Science, Shanxi Agricultural University, Taigu, China
| | - Yusuo Jiang
- College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, China
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25
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Zheng W, Yang X, Hu R, Cai R, Hofmann L, Wang Z, Hu Q, Liu X, Bulkley D, Yu Y, Tang J, Flockerzi V, Cao Y, Cao E, Chen XZ. Hydrophobic pore gates regulate ion permeation in polycystic kidney disease 2 and 2L1 channels. Nat Commun 2018; 9:2302. [PMID: 29899465 PMCID: PMC5998024 DOI: 10.1038/s41467-018-04586-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 05/01/2018] [Indexed: 01/20/2023] Open
Abstract
PKD2 and PKD1 genes are mutated in human autosomal dominant polycystic kidney disease. PKD2 can form either a homomeric cation channel or a heteromeric complex with the PKD1 receptor, presumed to respond to ligand(s) and/or mechanical stimuli. Here, we identify a two-residue hydrophobic gate in PKD2L1, and a single-residue hydrophobic gate in PKD2. We find that a PKD2 gain-of-function gate mutant effectively rescues PKD2 knockdown-induced phenotypes in embryonic zebrafish. The structure of a PKD2 activating mutant F604P by cryo-electron microscopy reveals a π- to α-helix transition within the pore-lining helix S6 that leads to repositioning of the gate residue and channel activation. Overall the results identify hydrophobic gates and a gating mechanism of PKD2 and PKD2L1. Mutations in the cation channel PKD2 cause human autosomal dominant polycystic kidney disease but its channel function and gating mechanism are poorly understood. Here authors study PKD2 using electrophysiology and cryo-EM, which identifies hydrophobic gates and proposes a gating mechanism for PKD2.
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Affiliation(s)
- Wang Zheng
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, Hubei, 430068, China.,Department of Physiology, Membrane Protein Disease Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Xiaoyong Yang
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA
| | - Ruikun Hu
- School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Ruiqi Cai
- Department of Physiology, Membrane Protein Disease Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Laura Hofmann
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, Homburg, 66421, Germany
| | - Zhifei Wang
- Department of Biological Sciences, St. John's University, Queens, NY, 11439, USA
| | - Qiaolin Hu
- Department of Physiology, Membrane Protein Disease Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Xiong Liu
- Department of Physiology, Membrane Protein Disease Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - David Bulkley
- Keck Advanced Microscopy Laboratory and Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Yong Yu
- Department of Biological Sciences, St. John's University, Queens, NY, 11439, USA
| | - Jingfeng Tang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Veit Flockerzi
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, Homburg, 66421, Germany
| | - Ying Cao
- School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China
| | - Erhu Cao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA.
| | - Xing-Zhen Chen
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, Hubei, 430068, China. .,Department of Physiology, Membrane Protein Disease Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada.
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26
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Kaushik S, Marques SM, Khirsariya P, Paruch K, Libichova L, Brezovsky J, Prokop Z, Chaloupkova R, Damborsky J. Impact of the access tunnel engineering on catalysis is strictly ligand‐specific. FEBS J 2018; 285:1456-1476. [DOI: 10.1111/febs.14418] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 02/02/2018] [Accepted: 02/20/2018] [Indexed: 01/01/2023]
Affiliation(s)
- Shubhangi Kaushik
- Loschmidt Laboratories Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment (RECETOX) Faculty of Science Masaryk University Brno Czech Republic
| | - Sérgio M. Marques
- Loschmidt Laboratories Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment (RECETOX) Faculty of Science Masaryk University Brno Czech Republic
- International Clinical Research Center St. Anne's University Hospital Brno Czech Republic
| | - Prashant Khirsariya
- International Clinical Research Center St. Anne's University Hospital Brno Czech Republic
- Department of Chemistry CZ‐OPENSCREEN Faculty of Science Masaryk University Brno Czech Republic
| | - Kamil Paruch
- International Clinical Research Center St. Anne's University Hospital Brno Czech Republic
- Department of Chemistry CZ‐OPENSCREEN Faculty of Science Masaryk University Brno Czech Republic
| | - Lenka Libichova
- Loschmidt Laboratories Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment (RECETOX) Faculty of Science Masaryk University Brno Czech Republic
| | - Jan Brezovsky
- Loschmidt Laboratories Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment (RECETOX) Faculty of Science Masaryk University Brno Czech Republic
- International Clinical Research Center St. Anne's University Hospital Brno Czech Republic
| | - Zbynek Prokop
- Loschmidt Laboratories Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment (RECETOX) Faculty of Science Masaryk University Brno Czech Republic
- International Clinical Research Center St. Anne's University Hospital Brno Czech Republic
| | - Radka Chaloupkova
- Loschmidt Laboratories Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment (RECETOX) Faculty of Science Masaryk University Brno Czech Republic
- International Clinical Research Center St. Anne's University Hospital Brno Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment (RECETOX) Faculty of Science Masaryk University Brno Czech Republic
- International Clinical Research Center St. Anne's University Hospital Brno Czech Republic
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Sharma B, Jamdar SN, Ghosh B, Yadav P, Kumar A, Kundu S, Goyal VD, Makde RD. Active site gate of M32 carboxypeptidases illuminated by crystal structure and molecular dynamics simulations. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1406-1415. [PMID: 28844748 DOI: 10.1016/j.bbapap.2017.07.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 07/21/2017] [Accepted: 07/24/2017] [Indexed: 01/09/2023]
Abstract
Enzyme gates are important dynamic features that regulate function. Study of these features is critical for understanding of enzyme mechanism. In this study, the active-site gate of M32 carboxypeptidases (M32CP) is illuminated. Only a handful of members of this family have been structurally and functionally characterized and various aspects of their activity and mechanism are yet not clarified. Here, crystal structure of putative M32CP from Deinococcus radiodurans (M32dr) was solved to 2.4Å resolution. Enzymatic assays confirmed its identity as a carboxypeptidase. Open and relatively closed conformations observed in the structure provided supporting evidence for previously hypothesized hinge motion in this family of enzymes. Molecular dynamics simulations of 1.5μs displayed distinct open and closed conformations revealing amplitude of the motion to be beyond what was observed in the crystal structure. Hinge region and anchoring region of this shell-type gate were identified. A small displacement of 3Å and a helical tilt of 9° propagated by the hinge region translates into a 10Å motion at the top of the gate. The dynamics of the gate was supported by our mutagenesis experiment involving formation of disulphide bond across helices of the gate. The nearly inactive mutant enzyme showed 65-fold increase in the enzymatic activity in presence of reducing agent. Further, while a previously proposed structural basis would have led to its classification in subfamily II, experimentally observed substrate length restriction places M32dr in subfamily I of M32CPs.
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Affiliation(s)
- Bhaskar Sharma
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, India; Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | - Sahayog N Jamdar
- Food Technology Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Biplab Ghosh
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Pooja Yadav
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Ashwani Kumar
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Suman Kundu
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | - Venuka Durani Goyal
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, India.
| | - Ravindra D Makde
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, India.
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28
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Rauh O, Urban M, Henkes LM, Winterstein T, Greiner T, Van Etten JL, Moroni A, Kast SM, Thiel G, Schroeder I. Identification of Intrahelical Bifurcated H-Bonds as a New Type of Gate in K + Channels. J Am Chem Soc 2017; 139:7494-7503. [PMID: 28499087 PMCID: PMC6638992 DOI: 10.1021/jacs.7b01158] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Gating
of ion channels is based on structural transitions between
open and closed states. To uncover the chemical basis of individual
gates, we performed a comparative experimental and computational analysis
between two K+ channels, KcvS and KcvNTS. These small viral encoded K+ channel proteins, with
a monomer size of only 82 amino acids, resemble the pore module of
all complex K+ channels in terms of structure and function.
Even though both proteins share about 90% amino acid sequence identity,
they exhibit different open probabilities with ca. 90% in KcvNTS and 40% in KcvS. Single channel analysis, mutational
studies and molecular dynamics simulations show that the difference
in open probability is caused by one long closed state in KcvS. This state is structurally created in the tetrameric channel
by a transient, Ser mediated, intrahelical hydrogen bond. The resulting
kink in the inner transmembrane domain swings the aromatic rings from
downstream Phes in the cavity of the channel, which blocks ion flux.
The frequent occurrence of Ser or Thr based helical kinks in membrane
proteins suggests that a similar mechanism could also occur in the
gating of other ion channels.
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Affiliation(s)
- Oliver Rauh
- Plant Membrane Biophysics, Technical University Darmstadt , 64289 Darmstadt, Germany
| | - Martin Urban
- Physikalische Chemie III, Technische Universität Dortmund , 44227 Dortmund, Germany
| | - Leonhard M Henkes
- Physikalische Chemie III, Technische Universität Dortmund , 44227 Dortmund, Germany
| | - Tobias Winterstein
- Plant Membrane Biophysics, Technical University Darmstadt , 64289 Darmstadt, Germany
| | - Timo Greiner
- Plant Membrane Biophysics, Technical University Darmstadt , 64289 Darmstadt, Germany
| | - James L Van Etten
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska Lincoln , Lincoln, Nebraska 68583-0900, United States
| | - Anna Moroni
- Department of Biosciences and CNR IBF-Mi, Università degli Studi di Milano , 20122 Milano, Italy
| | - Stefan M Kast
- Physikalische Chemie III, Technische Universität Dortmund , 44227 Dortmund, Germany
| | - Gerhard Thiel
- Plant Membrane Biophysics, Technical University Darmstadt , 64289 Darmstadt, Germany
| | - Indra Schroeder
- Plant Membrane Biophysics, Technical University Darmstadt , 64289 Darmstadt, Germany
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29
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A Gate Hinge Controls the Epithelial Calcium Channel TRPV5. Sci Rep 2017; 7:45489. [PMID: 28374795 PMCID: PMC5379628 DOI: 10.1038/srep45489] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 02/27/2017] [Indexed: 12/03/2022] Open
Abstract
TRPV5 is unique within the large TRP channel family for displaying a high Ca2+ selectivity together with Ca2+-dependent inactivation. Our study aims to uncover novel insights into channel gating through in-depth structure-function analysis. We identify an exceptional tryptophan (W583) at the terminus of the intracellular pore that is unique for TRPV5 (and TRPV6). A combination of site-directed mutagenesis, biochemical and electrophysiological analysis, together with homology modeling, demonstrates that W583 is part of the gate for Ca2+ permeation. The W583 mutants show increased cell death due to profoundly enhanced Ca2+ influx, resulting from altered channel function. A glycine residue above W583 might act as flexible linker to rearrange the tryptophan gate. Furthermore, we hypothesize functional crosstalk between the pore region and carboxy terminus, involved in Ca2+-calmodulin-mediated inactivation. This study proposes a unique channel gating mechanism and delivers detailed molecular insight into the Ca2+ permeation pathway that can be extrapolated to other Ca2+-selective channels.
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30
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Abstract
Ligand-induced activation of G protein-coupled receptors (GPCRs) is a key mechanism permitting communication between cells and organs. Enormous progress has recently elucidated the structural and dynamic features of GPCR transmembrane signaling. Nanobodies, the recombinant antigen-binding fragments of camelid heavy-chain-only antibodies, have emerged as important research tools to lock GPCRs in particular conformational states. Active-state stabilizing nanobodies have elucidated several agonist-bound structures of hormone-activated GPCRs and have provided insight into the dynamic character of receptors. Nanobodies have also been used to stabilize transient GPCR transmembrane signaling complexes, yielding the first structural insights into GPCR signal transduction across the cellular membrane. Beyond their in vitro uses, nanobodies have served as conformational biosensors in living systems and have provided novel ways to modulate GPCR function. Here, we highlight several examples of how nanobodies have enabled the study of GPCR function and give insights into potential future uses of these important tools.
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Affiliation(s)
- Aashish Manglik
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305; ,
| | - Brian K Kobilka
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305; ,
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel, 1050 Brussels, Belgium;
- VIB Structural Biology Research Center, Vrije Universiteit Brussel, 1050 Brussels, Belgium
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31
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Marques SM, Daniel L, Buryska T, Prokop Z, Brezovsky J, Damborsky J. Enzyme Tunnels and Gates As Relevant Targets in Drug Design. Med Res Rev 2016; 37:1095-1139. [PMID: 27957758 DOI: 10.1002/med.21430] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 10/11/2016] [Accepted: 11/07/2016] [Indexed: 12/28/2022]
Abstract
Many enzymes contain tunnels and gates that are essential to their function. Gates reversibly switch between open and closed conformations and thereby control the traffic of small molecules-substrates, products, ions, and solvent molecules-into and out of the enzyme's structure via molecular tunnels. Many transient tunnels and gates undoubtedly remain to be identified, and their functional roles and utility as potential drug targets have received comparatively little attention. Here, we describe a set of general concepts relating to the structural properties, function, and classification of these interesting structural features. In addition, we highlight the potential of enzyme tunnels and gates as targets for the binding of small molecules. The different types of binding that are possible and the potential pharmacological benefits of such targeting are discussed. Twelve examples of ligands bound to the tunnels and/or gates of clinically relevant enzymes are used to illustrate the different binding modes and to explain some new strategies for drug design. Such strategies could potentially help to overcome some of the problems facing medicinal chemists and lead to the discovery of more effective drugs.
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Affiliation(s)
- Sergio M Marques
- Loschmidt Laboratories, Faculty of Science, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Lukas Daniel
- Loschmidt Laboratories, Faculty of Science, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic
| | - Tomas Buryska
- Loschmidt Laboratories, Faculty of Science, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic
| | - Zbynek Prokop
- Loschmidt Laboratories, Faculty of Science, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic
| | - Jan Brezovsky
- Loschmidt Laboratories, Faculty of Science, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories, Faculty of Science, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, RECETOX, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital, Pekarska 53, 656 91, Brno, Czech Republic
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32
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Brezovsky J, Babkova P, Degtjarik O, Fortova A, Gora A, Iermak I, Rezacova P, Dvorak P, Smatanova IK, Prokop Z, Chaloupkova R, Damborsky J. Engineering a de Novo Transport Tunnel. ACS Catal 2016. [DOI: 10.1021/acscatal.6b02081] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Jan Brezovsky
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Petra Babkova
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Oksana Degtjarik
- Faculty
of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic
- Center for Nanobiology and Structural Biology ASCR, Zamek 136, 37333 Nove Hrady, Czech Republic
| | - Andrea Fortova
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Artur Gora
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Iuliia Iermak
- Faculty
of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic
- Center for Nanobiology and Structural Biology ASCR, Zamek 136, 37333 Nove Hrady, Czech Republic
| | - Pavlina Rezacova
- Institute of Organic Chemistry and Biochemistry ASCR, v.v.i. Flemingovo nam. 2, 166 10 Prague 6, Czech Republic
- Institute of Molecular Genetics of the ASCR, v.v.i. Videnska 1083, 142 20 Prague 4, Czech Republic
| | - Pavel Dvorak
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Ivana Kuta Smatanova
- Faculty
of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 37005 Ceske Budejovice, Czech Republic
- Center for Nanobiology and Structural Biology ASCR, Zamek 136, 37333 Nove Hrady, Czech Republic
| | - Zbynek Prokop
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Radka Chaloupkova
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt
Laboratories, Department of Experimental Biology and Research Centre
for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
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33
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Liu H, Liu T, Xie L, Wang X, Deng Y, Chen CH, James AA, Chen XG. Functional analysis of Orco and odorant receptors in odor recognition in Aedes albopictus. Parasit Vectors 2016; 9:363. [PMID: 27350348 PMCID: PMC4924234 DOI: 10.1186/s13071-016-1644-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 06/13/2016] [Indexed: 11/10/2022] Open
Abstract
Background Aedes albopictus is a globally invasive mosquito and a major vector of arboviruses, including dengue, Zika and Chikungunya. Olfactory-related behaviors, particularly host-seeking, offer opportunities to disrupt the disease-transmission process. A better understanding of odorant receptors (ORs) may assist in explaining host selection and location, and contribute to novel strategy of vector control. Methods Based on previous prediction of 158 putative odorant receptors by Ae. albopictus genome analysis, 29 AalORs were selected for tissue-specific expression profiles in the present study. AalOrco (AalOR7), AalOR10 and AalOR88, highly expressed in female olfactory tissues, were chosen for further structure predictions as well as functional validation including calcium imaging assay in human embryonic kidney (HEK293) cells and RNA interference assay in Ae. albopictus. We also conducted electrophysiological and behavioral assays in mosquitoes after RNA interference of the three genes to determine their roles in host-seeking. Results The results support previous conclusions that individual conventional (ORXs) and Orco can form heteromeric complexes to recognize odorants and respond to components of human volatiles in HEK293 cells. The reduction of AalOrco transcript levels led to a significant decrease in host-seeking and confusion in host preference. In contrast, AalOR10 and AalOR88 knockdown mosquitoes showed no significant behavioral differences compared with controls. The functions of conventional ORs at least AalOR10 and AalOR88 are abolished with inhibited expression of the Orco gene orthologs, along with the concomitant relevant olfactory behavior. Conclusions Combining structural and functional data, we conclude that the product of the Orco gene in this mosquito is crucial for transmitting olfactory signaling and conventional ORs contribute directly to odorant recognition. Our results provide insight into the linkage between odorant receptors and host-seeking in this important vector species. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1644-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hongmei Liu
- Department of Pathogen Biology, Key Laboratory of Prevention and Control of Emerging Infectious Diseases of Guangdong Higher Education Institutes, School of Public Health, Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Tong Liu
- Department of Pathogen Biology, Key Laboratory of Prevention and Control of Emerging Infectious Diseases of Guangdong Higher Education Institutes, School of Public Health, Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Lihua Xie
- Department of Pathogen Biology, Key Laboratory of Prevention and Control of Emerging Infectious Diseases of Guangdong Higher Education Institutes, School of Public Health, Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Xiaoming Wang
- Department of Pathogen Biology, Key Laboratory of Prevention and Control of Emerging Infectious Diseases of Guangdong Higher Education Institutes, School of Public Health, Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Yuhua Deng
- Department of Pathogen Biology, Key Laboratory of Prevention and Control of Emerging Infectious Diseases of Guangdong Higher Education Institutes, School of Public Health, Southern Medical University, Guangzhou, Guangdong, People's Republic of China
| | - Chun-Hong Chen
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Anthony A James
- Departments of Microbiology and Molecular Genetics, and Molecular Biology and Biochemistry, 3205 McGaugh Hall, University of California, Irvine, CA, 92697-3900, USA
| | - Xiao-Guang Chen
- Department of Pathogen Biology, Key Laboratory of Prevention and Control of Emerging Infectious Diseases of Guangdong Higher Education Institutes, School of Public Health, Southern Medical University, Guangzhou, Guangdong, People's Republic of China.
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Mahinthichaichan P, Gennis RB, Tajkhorshid E. All the O2 Consumed by Thermus thermophilus Cytochrome ba3 Is Delivered to the Active Site through a Long, Open Hydrophobic Tunnel with Entrances within the Lipid Bilayer. Biochemistry 2016; 55:1265-78. [PMID: 26845082 DOI: 10.1021/acs.biochem.5b01255] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Cytochrome ba3 is a proton-pumping heme-copper oxygen reductase from the extreme thermophile Thermus thermophilus. Despite the fact that the enzyme's active site is buried deep within the protein, the apparent second order rate constant for the initial binding of O2 to the active-site heme has been experimentally found to be 10(9) M(-1) s(-1) at 298 K, at or near the diffusion limit, and 2 orders of magnitude faster than for O2 binding to myoglobin. To provide quantitative and microscopic descriptions of the O2 delivery pathway and mechanism in cytochrome ba3, extensive molecular dynamics simulations of the enzyme in its membrane-embedded form have been performed, including different protocols of explicit ligand sampling (flooding) simulations with O2, implicit ligand sampling analysis, and in silico mutagenesis. The results show that O2 diffuses to the active site exclusively via a Y-shaped hydrophobic tunnel with two 25-Å long membrane-accessible branches that coincide with the pathway previously suggested by the crystallographically identified xenon binding sites. The two entrances of the bifurcated tunnel of cytochrome ba3 are located within the lipid bilayer, where O2 is preferentially partitioned from the aqueous phase. The largest barrier to O2 migration within the tunnel is estimated to be only 1.5 kcal/mol, allowing O2 to reach the enzyme active site virtually impeded by one-dimensional diffusion once it reaches a tunnel entrance at the protein surface. Unlike other O2-utilizing proteins, the tunnel is "open" with no transient barriers observed due to protein dynamics. This unique low-barrier passage through the protein ensures that O2 transit through the protein is never rate-limiting.
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Affiliation(s)
- Paween Mahinthichaichan
- Department of Biochemistry, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Robert B Gennis
- Department of Biochemistry, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Emad Tajkhorshid
- Department of Biochemistry, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
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35
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Structural Changes Fundamental to Gating of the Cystic Fibrosis Transmembrane Conductance Regulator Anion Channel Pore. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 925:13-32. [PMID: 27311317 DOI: 10.1007/5584_2016_33] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), an epithelial cell anion channel. Potentiator drugs used in the treatment of cystic fibrosis act on the channel to increase overall channel function, by increasing the stability of its open state and/or decreasing the stability of its closed state. The structure of the channel in either the open state or the closed state is not currently known. However, changes in the conformation of the protein as it transitions between these two states have been studied using functional investigation and molecular modeling techniques. This review summarizes our current understanding of the architecture of the transmembrane channel pore that controls the movement of chloride and other small anions, both in the open state and in the closed state. Evidence for different kinds of changes in the conformation of the pore as it transitions between open and closed states is described, as well as the mechanisms by which these conformational changes might be controlled to regulate normal channel gating. The ways that key conformational changes might be targeted by small compounds to influence overall CFTR activity are also discussed. Understanding the changes in pore structure that might be manipulated by such small compounds is key to the development of novel therapeutic strategies for the treatment of cystic fibrosis.
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36
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Carraher C, Dalziel J, Jordan MD, Christie DL, Newcomb RD, Kralicek AV. Towards an understanding of the structural basis for insect olfaction by odorant receptors. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 66:31-41. [PMID: 26416146 DOI: 10.1016/j.ibmb.2015.09.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 09/16/2015] [Accepted: 09/16/2015] [Indexed: 06/05/2023]
Abstract
Insects have co-opted a unique family of seven transmembrane proteins for odour sensing. Odorant receptors are believed to have evolved from gustatory receptors somewhere at the base of the Hexapoda and have expanded substantially to become the dominant class of odour recognition elements within the Insecta. These odorant receptors comprise an obligate co-receptor, Orco, and one of a family of highly divergent odorant "tuning" receptors. The two subunits are thought to come together at some as-yet unknown stoichiometry to form a functional complex that is capable of both ionotropic and metabotropic signalling. While there are still no 3D structures for these proteins, site-directed mutagenesis, resonance energy transfer, and structural modelling efforts, all mainly on Drosophila odorant receptors, are beginning to inform hypotheses of their structures and how such complexes function in odour detection. Some of the loops, especially the second extracellular loop that has been suggested to form a lid over the binding pocket, and the extracellular regions of some transmembrane helices, especially the third and to a less extent the sixth and seventh, have been implicated in ligand recognition in tuning receptors. The possible interaction between Orco and tuning receptor subunits through the final intracellular loop and the adjacent transmembrane helices is thought to be important for transducing ligand binding into receptor activation. Potential phosphorylation sites and a calmodulin binding site in the second intracellular loop of Orco are also thought to be involved in regulating channel gating. A number of new methods have recently been developed to express and purify insect odorant receptor subunits in recombinant expression systems. These approaches are enabling high throughput screening of receptors for agonists and antagonists in cell-based formats, as well as producing protein for the application of biophysical methods to resolve the 3D structure of the subunits and their complexes.
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Affiliation(s)
- Colm Carraher
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 92169, Auckland 1142, New Zealand
| | - Julie Dalziel
- Food Nutrition & Health Team, Food & Bio-based Products Group, AgResearch Private Bag 11008, Palmerston North 4442, New Zealand
| | - Melissa D Jordan
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 92169, Auckland 1142, New Zealand
| | - David L Christie
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Richard D Newcomb
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 92169, Auckland 1142, New Zealand; School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Andrew V Kralicek
- The New Zealand Institute for Plant & Food Research Limited, Private Bag 92169, Auckland 1142, New Zealand.
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37
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Temporal evolution of helix hydration in a light-gated ion channel correlates with ion conductance. Proc Natl Acad Sci U S A 2015; 112:E5796-804. [PMID: 26460012 DOI: 10.1073/pnas.1511462112] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The discovery of channelrhodopsins introduced a new class of light-gated ion channels, which when genetically encoded in host cells resulted in the development of optogenetics. Channelrhodopsin-2 from Chlamydomonas reinhardtii, CrChR2, is the most widely used optogenetic tool in neuroscience. To explore the connection between the gating mechanism and the influx and efflux of water molecules in CrChR2, we have integrated light-induced time-resolved infrared spectroscopy and electrophysiology. Cross-correlation analysis revealed that ion conductance tallies with peptide backbone amide I vibrational changes at 1,665(-) and 1,648(+) cm(-1). These two bands report on the hydration of transmembrane α-helices as concluded from vibrational coupling experiments. Lifetime distribution analysis shows that water influx proceeded in two temporally separated steps with time constants of 10 μs (30%) and 200 μs (70%), the latter phase concurrent with the start of ion conductance. Water efflux and the cessation of the ion conductance are synchronized as well, with a time constant of 10 ms. The temporal correlation between ion conductance and hydration of helices holds for fast (E123T) and slow (D156E) variants of CrChR2, strengthening its functional significance.
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38
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Abstract
In this review, we describe the construction of gated molecular baskets, discuss their mechanism of action in regulating the exchange of guests and illustrate the potential of these concave hosts to act as catalysts for controlling chemical reactions. Importantly, a number of computational and experimental studies have suggested that gated baskets ought to unfold their gates at the rim for permitting the passage of guests to/from their inner space. These dynamic hosts are therefore offered as useful models for investigating the process of gating in artificial systems. Furthermore, gated baskets should permit examining the benefit of controlling the rate by which reactants access a gated catalyst for promoting chemical reactions occurring in its confined space.
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Affiliation(s)
- Keith Hermann
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA.
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39
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Masood TB, Sandhya S, Chandra N, Natarajan V. CHEXVIS: a tool for molecular channel extraction and visualization. BMC Bioinformatics 2015; 16:119. [PMID: 25888118 PMCID: PMC4411761 DOI: 10.1186/s12859-015-0545-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/20/2015] [Indexed: 12/11/2022] Open
Abstract
Background Understanding channel structures that lead to active sites or traverse the molecule is important in the study of molecular functions such as ion, ligand, and small molecule transport. Efficient methods for extracting, storing, and analyzing protein channels are required to support such studies. Further, there is a need for an integrated framework that supports computation of the channels, interactive exploration of their structure, and detailed visual analysis of their properties. Results We describe a method for molecular channel extraction based on the alpha complex representation. The method computes geometrically feasible channels, stores both the volume occupied by the channel and its centerline in a unified representation, and reports significant channels. The representation also supports efficient computation of channel profiles that help understand channel properties. We describe methods for effective visualization of the channels and their profiles. These methods and the visual analysis framework are implemented in a software tool, ChExVis. We apply the method on a number of known channel containing proteins to extract pore features. Results from these experiments on several proteins show that ChExVis performance is comparable to, and in some cases, better than existing channel extraction techniques. Using several case studies, we demonstrate how ChExVis can be used to study channels, extract their properties and gain insights into molecular function. Conclusion ChExVis supports the visual exploration of multiple channels together with their geometric and physico-chemical properties thereby enabling the understanding of the basic biology of transport through protein channels. The ChExVis web-server is freely available at http://vgl.serc.iisc.ernet.in/chexvis/. The web-server is supported on all modern browsers with latest Java plug-in. Electronic supplementary material The online version of this article (doi:10.1186/s12859-015-0545-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Talha Bin Masood
- Department of Computer Science and Automation, Indian Institute of Science, Bangalore, 560012, India.
| | - Sankaran Sandhya
- Department of Biochemistry, Indian Institute of Science, Bangalore, 560012, India.
| | - Nagasuma Chandra
- Department of Biochemistry, Indian Institute of Science, Bangalore, 560012, India.
| | - Vijay Natarajan
- Department of Computer Science and Automation, Indian Institute of Science, Bangalore, 560012, India. .,Supercomputer Education and Research Centre, Indian Institute of Science, Bangalore, 560012, India.
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Bourne Y, Renault L, Marchot P. Crystal structure of snake venom acetylcholinesterase in complex with inhibitory antibody fragment Fab410 bound at the peripheral site: evidence for open and closed states of a back door channel. J Biol Chem 2014; 290:1522-35. [PMID: 25411244 DOI: 10.1074/jbc.m114.603902] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The acetylcholinesterase found in the venom of Bungarus fasciatus (BfAChE) is produced as a soluble, non-amphiphilic monomer with a canonical catalytic domain but a distinct C terminus compared with the other vertebrate enzymes. Moreover, the peripheral anionic site of BfAChE, a surface site located at the active site gorge entrance, bears two substitutions altering sensitivity to cationic inhibitors. Antibody Elec410, generated against Electrophorus electricus acetylcholinesterase (EeAChE), inhibits EeAChE and BfAChE by binding to their peripheral sites. However, both complexes retain significant residual catalytic activity, suggesting incomplete gorge occlusion by bound antibody and/or high frequency back door opening. To explore a novel acetylcholinesterase species, ascertain the molecular bases of inhibition by Elec410, and document the determinants and mechanisms for back door opening, we solved a 2.7-Å resolution crystal structure of natural BfAChE in complex with antibody fragment Fab410. Crystalline BfAChE forms the canonical dimer found in all acetylcholinesterase structures. Equally represented open and closed states of a back door channel, associated with alternate positions of a tyrosine phenol ring at the active site base, coexist in each subunit. At the BfAChE molecular surface, Fab410 is seated on the long Ω-loop between two N-glycan chains and partially occludes the gorge entrance, a position that fully reflects the available mutagenesis and biochemical data. Experimentally based flexible molecular docking supports a similar Fab410 binding mode onto the EeAChE antigen. These data document the molecular and dynamic peculiarities of BfAChE with high frequency back door opening, and the mode of action of Elec410 as one of the largest peptidic inhibitors targeting the acetylcholinesterase peripheral site.
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Affiliation(s)
- Yves Bourne
- From Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques, campus Luminy, 13228 Marseille cedex 09, France, CNRS, Architecture et Fonction des Macromolécules Biologiques, campus Luminy, 13228 Marseille cedex 09, France, and
| | - Ludovic Renault
- CNRS/Aix-Marseille Université, Ingénierie des Protéines, Faculté de Médecine-Secteur Nord, 13344 Marseille cedex 15, France
| | - Pascale Marchot
- From Aix-Marseille Université, Architecture et Fonction des Macromolécules Biologiques, campus Luminy, 13228 Marseille cedex 09, France, CNRS, Architecture et Fonction des Macromolécules Biologiques, campus Luminy, 13228 Marseille cedex 09, France, and CNRS/Aix-Marseille Université, Ingénierie des Protéines, Faculté de Médecine-Secteur Nord, 13344 Marseille cedex 15, France
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41
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Lu M, Lu HP. Probing protein multidimensional conformational fluctuations by single-molecule multiparameter photon stamping spectroscopy. J Phys Chem B 2014; 118:11943-55. [PMID: 25222115 PMCID: PMC4199541 DOI: 10.1021/jp5081498] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Conformational motions of proteins
are highly dynamic and intrinsically
complex. To capture the temporal and spatial complexity of conformational
motions and further to understand their roles in protein functions,
an attempt is made to probe multidimensional conformational dynamics
of proteins besides the typical one-dimensional FRET coordinate or
the projected conformational motions on the one-dimensional FRET coordinate.
T4 lysozyme hinge-bending motions between two domains along α-helix
have been probed by single-molecule FRET. Nevertheless, the domain
motions of T4 lysozyme are rather complex involving multiple coupled
nuclear coordinates and most likely contain motions besides hinge-bending.
It is highly likely that the multiple dimensional protein conformational
motions beyond the typical enzymatic hinged-bending motions have profound
impact on overall enzymatic functions. In this report, we have developed
a single-molecule multiparameter photon stamping spectroscopy integrating
fluorescence anisotropy, FRET, and fluorescence lifetime. This spectroscopic
approach enables simultaneous observations of both FRET-related site-to-site
conformational dynamics and molecular rotational (or orientational)
motions of individual Cy3-Cy5 labeled T4 lysozyme molecules. We have
further observed wide-distributed rotational flexibility along orientation
coordinates by recording fluorescence anisotropy and simultaneously
identified multiple intermediate conformational states along FRET
coordinate by monitoring time-dependent donor lifetime, presenting
a whole picture of multidimensional conformational dynamics in the
process of T4 lysozyme open-close hinge-bending enzymatic turnover
motions under enzymatic reaction conditions. By analyzing the autocorrelation
functions of both lifetime and anisotropy trajectories, we have also
observed the dynamic and static inhomogeneity of T4 lysozyme multidimensional
conformational fluctuation dynamics, providing a fundamental understanding
of the enzymatic reaction turnover dynamics associated with overall
enzyme as well as the specific active-site conformational fluctuations
that are not identifiable and resolvable in the conventional ensemble-averaged
experiment.
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Affiliation(s)
- Maolin Lu
- Center for Photochemical Sciences, Department of Chemistry, Bowling Green State University , Bowling Green, Ohio 43403, United States
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42
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General rules for the arrangements and gating motions of pore-lining helices in homomeric ion channels. Nat Commun 2014; 5:4641. [PMID: 25105557 PMCID: PMC4133698 DOI: 10.1038/ncomms5641] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/09/2014] [Indexed: 12/20/2022] Open
Abstract
The pore-lining helix (PLH) bundles are central to the function of all ion channels,
as their conformational rearrangements dictate channel gating. Here we explore all
plausible oligomeric arrangements of the PLH bundles within homomeric ion channels
by building models using generic restraints. In particular, the distance between two
neighbouring PLHs was bounded both below and above in order to avoid steric clash
and allow proper packing. The resulting models provide a theoretical representation
of the accessible space for oligomeric arrangements. While the represented space is
confined, it encompasses nearly all the ion channel PLH bundles for which the
structures are currently known. For a multitude of channels, gating models suggested
by paths within the confined accessible space are in qualitative agreement with
those established in previous structural and computational studies. Rearrangements of the pore-lining helix (PLH) bundles of ion channels
are central to their gating mechanisms. Here, Dai et al. use a modelling approach
to define the general rules that govern the arrangements and gating motions of the PLHs
in homomeric ion channels.
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Pagliara S, Dettmer SL, Keyser UF. Channel-facilitated diffusion boosted by particle binding at the channel entrance. PHYSICAL REVIEW LETTERS 2014; 113:048102. [PMID: 25105657 DOI: 10.1103/physrevlett.113.048102] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Indexed: 06/03/2023]
Abstract
We investigate single-file diffusion of Brownian particles in arrays of closely confining microchannels permeated by a variety of attractive optical potentials and connecting two baths with equal particle concentration. We simultaneously test free diffusion in the channel, diffusion in optical traps coupled in the center of the channel, and diffusion in traps extending into the baths. We found that both classes of attractive optical potentials enhance the translocation rate through the channel with respect to free diffusion. Surprisingly, for the latter class of potentials we measure a 40-fold enhancement in the translocation rate with respect to free diffusion and find a sublinear power law dependence of the translocation rate on the average number of particles in the channel. Our results reveal the function of particle binding at the channel entrances for diffusive transport and open the way to a better understanding of membrane transport and design of synthetic membranes with enhanced diffusion rate.
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Porras Gutiérrez AG, Zeitouny J, Gomila A, Douziech B, Cosquer N, Conan F, Reinaud O, Hapiot P, Le Mest Y, Lagrost C, Le Poul N. Insights into water coordination associated with the CuII/CuI electron transfer at a biomimetic Cu centre. Dalton Trans 2014; 43:6436-45. [DOI: 10.1039/c3dt53548g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The coordination chemistry of an aqua Cu complex was investigated in non-coordinating solvents and in ionic liquids.
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45
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Kleckner IR, McElroy CA, Kuzmic P, Gollnick P, Foster MP. Homotropic cooperativity from the activation pathway of the allosteric ligand-responsive regulatory trp RNA-binding attenuation protein. Biochemistry 2013; 52:8855-65. [PMID: 24224873 DOI: 10.1021/bi401364v] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The trp RNA-binding attenuation protein (TRAP) assembles into an 11-fold symmetric ring that regulates transcription and translation of trp-mRNA in bacilli via heterotropic allosteric activation by the amino acid tryptophan (Trp). Whereas nuclear magnetic resonance studies have revealed that Trp-induced activation coincides with both microsecond to millisecond rigidification and local structural changes in TRAP, the pathway of binding of the 11 Trp ligands to the TRAP ring remains unclear. Moreover, because each of 11 bound Trp molecules is completely surrounded by protein, its release requires flexibility of Trp-bound (holo) TRAP. Here, we used stopped-flow fluorescence to study the kinetics of Trp binding by Bacillus stearothermophilus TRAP over a range of temperatures and observed well-separated kinetic steps. These data were analyzed using nonlinear least-squares fitting of several two- and three-step models. We found that a model with two binding steps best describes the data, although the structural equivalence of the binding sites in TRAP implies a fundamental change in the time-dependent structure of the TRAP rings upon Trp binding. Application of the two-binding step model reveals that Trp binding is much slower than the diffusion limit, suggesting a gating mechanism that depends on the dynamics of apo TRAP. These data also reveal that dissociation of Trp from the second binding mode is much slower than after the first Trp binding mode, revealing insight into the mechanism for positive homotropic allostery, or cooperativity. Temperature-dependent analyses reveal that both binding modes imbue increases in bondedness and order toward a more compressed active state. These results provide insight into mechanisms of cooperative TRAP activation and underscore the importance of protein dynamics for ligand binding, ligand release, protein activation, and allostery.
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Affiliation(s)
- Ian R Kleckner
- Department of Chemistry and Biochemistry, and Biophysics Program, The Ohio State University , 484 West 12th Avenue, Columbus, Ohio 43210, United States
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Affiliation(s)
- Artur Gora
- Loschmidt Laboratories,
Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Jan Brezovsky
- Loschmidt Laboratories,
Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories,
Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
- International Centre for Clinical
Research, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
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Wang PH, Bruschi M, De Gioia L, Blumberger J. Uncovering a dynamically formed substrate access tunnel in carbon monoxide dehydrogenase/acetyl-CoA synthase. J Am Chem Soc 2013; 135:9493-502. [PMID: 23713976 DOI: 10.1021/ja403110s] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The transport of small ligands to active sites of proteins is the basis of vital processes in biology such as enzymatic catalysis and cell signaling, but also of more destructive ones including enzyme inhibition and oxidative damage. Here, we show how a diffusion-reaction model solved by means of molecular dynamics and density functional theory calculations provides novel insight into the transport of small ligands in proteins. In particular, we unravel the existence of an elusive, dynamically formed gas channel, which CO2 takes to diffuse from the solvent to the active site (C-cluster) of the bifunctional multisubunit enzyme complex carbon monoxide dehydrogenase/acetyl-CoA synthase (CODH/ACS). Two cavities forming this channel are temporarily created by protein fluctuations and are not apparent in the X-ray structures. The ligand transport is controlled by two residues at the end of this tunnel, His113 and His116, and occurs on the same time scale on which chemical binding to the active site takes place (0.1-1 ms), resulting in an overall binding rate on the second time scale. We find that upon reduction of CO2 to CO, the newly formed Fe-hydroxy ligand greatly strengthens the hydrogen-bond network, preventing CO from exiting the protein through the same way that CO2 takes to enter the protein. This is the basis for directional transport of CO from the production site (C-cluster of CODH subunit) to the utilization site (A-cluster of ACS subunit). In view of these results, a general picture emerges of how large proteins guide small ligands toward their active sites.
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Affiliation(s)
- Po-hung Wang
- Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
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Koudelakova T, Chaloupkova R, Brezovsky J, Prokop Z, Sebestova E, Hesseler M, Khabiri M, Plevaka M, Kulik D, Kuta Smatanova I, Rezacova P, Ettrich R, Bornscheuer UT, Damborsky J. Engineering Enzyme Stability and Resistance to an Organic Cosolvent by Modification of Residues in the Access Tunnel. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201206708] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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49
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Koudelakova T, Chaloupkova R, Brezovsky J, Prokop Z, Sebestova E, Hesseler M, Khabiri M, Plevaka M, Kulik D, Kuta Smatanova I, Rezacova P, Ettrich R, Bornscheuer UT, Damborsky J. Engineering enzyme stability and resistance to an organic cosolvent by modification of residues in the access tunnel. Angew Chem Int Ed Engl 2013; 52:1959-63. [PMID: 23303607 DOI: 10.1002/anie.201206708] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2012] [Revised: 12/05/2012] [Indexed: 11/08/2022]
Affiliation(s)
- Tana Koudelakova
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
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50
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Ruan Y, Wang BY, Erb JM, Chen S, Hadad CM, Badjić JD. On the role of guests in enforcing the mechanism of action of gated baskets. Org Biomol Chem 2013; 11:7667-75. [DOI: 10.1039/c3ob41511b] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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