1
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Muehler D, Morini S, Geißert J, Engesser C, Hiller KA, Widbiller M, Maisch T, Buchalla W, Cieplik F. Stress response in Escherichia coli following sublethal phenalene-1-one mediated antimicrobial photodynamic therapy: an RNA-Seq study. Photochem Photobiol Sci 2024; 23:1573-1586. [PMID: 39103724 DOI: 10.1007/s43630-024-00617-3] [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: 01/22/2024] [Accepted: 07/20/2024] [Indexed: 08/07/2024]
Abstract
Since the molecular mechanisms behind adaptation and the bacterial stress response toward antimicrobial photodynamic therapy (aPDT) are not entirely clear yet, the aim of the present study was to investigate the transcriptomic stress response in Escherichia coli after sublethal treatment with aPDT using RNA sequencing (RNA-Seq). Planktonic cultures of stationary phase E. coli were treated with aPDT using a sublethal dose of the photosensitizer SAPYR. After treatment, RNA was extracted, and RNA-Seq was performed on the Illumina NextSeq 500. Differentially expressed genes were analyzed and validated by qRT-PCR. Furthermore, expression of specific stress response proteins was investigated using Western blot analysis.The analysis of the differential gene expression following pathway enrichment analysis revealed a considerable number of genes and pathways significantly up- or down-regulated in E. coli after sublethal treatment with aPDT. Expression of 1018 genes was up-regulated and of 648 genes was down-regulated after sublethal treatment with aPDT as compared to irradiated controls. Analysis of differentially expressed genes and significantly de-regulated pathways showed regulation of genes involved in oxidative stress response and bacterial membrane damage. In conclusion, the results show a transcriptomic stress response in E. coli upon exposure to aPDT using SAPYR and give an insight into potential molecular mechanisms that may result in development of adaptation.
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Affiliation(s)
- Denise Muehler
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Regensburg, Germany
| | - Silvia Morini
- Quantitative Biology Center (QBiC), University of Tübingen, Tübingen, Germany
| | - Janina Geißert
- NGS-Competence Center Tübingen, Institute for Medical Microbiology and Hygiene, University Hospital Tübingen, Tübingen, Germany
| | - Christina Engesser
- NGS-Competence Center Tübingen, Institute for Medical Microbiology and Hygiene, University Hospital Tübingen, Tübingen, Germany
| | - Karl-Anton Hiller
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Regensburg, Germany
| | - Matthias Widbiller
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Regensburg, Germany
| | - Tim Maisch
- Department of Dermatology, University Hospital Regensburg, Regensburg, Germany
| | - Wolfgang Buchalla
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Regensburg, Germany
| | - Fabian Cieplik
- Department of Conservative Dentistry and Periodontology, University Hospital Regensburg, Regensburg, Germany.
- Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Medical Center - University of Freiburg, Medical Faculty, University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany.
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2
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Wallace ML, Sabatini BL. Synaptic and circuit functions of multitransmitter neurons in the mammalian brain. Neuron 2023; 111:2969-2983. [PMID: 37463580 PMCID: PMC10592565 DOI: 10.1016/j.neuron.2023.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/31/2023] [Accepted: 06/08/2023] [Indexed: 07/20/2023]
Abstract
Neurons in the mammalian brain are not limited to releasing a single neurotransmitter but often release multiple neurotransmitters onto postsynaptic cells. Here, we review recent findings of multitransmitter neurons found throughout the mammalian central nervous system. We highlight recent technological innovations that have made the identification of new multitransmitter neurons and the study of their synaptic properties possible. We also focus on mechanisms and molecular constituents required for neurotransmitter corelease at the axon terminal and synaptic vesicle, as well as some possible functions of multitransmitter neurons in diverse brain circuits. We expect that these approaches will lead to new insights into the mechanism and function of multitransmitter neurons, their role in circuits, and their contribution to normal and pathological brain function.
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Affiliation(s)
- Michael L Wallace
- Department of Anatomy and Neurobiology, Boston University Chobanian & Avedisian School of Medicine, Boston, MA, USA.
| | - Bernardo L Sabatini
- Howard Hughes Medical Institute, Department of Neurobiology, Harvard Medical School, Boston, MA, USA
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3
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Yamazaki Y, Eura Y, Kokame K. V-ATPase V0a1 promotes Weibel-Palade body biogenesis through the regulation of membrane fission. eLife 2021; 10:71526. [PMID: 34904569 PMCID: PMC8718113 DOI: 10.7554/elife.71526] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 12/13/2021] [Indexed: 01/09/2023] Open
Abstract
Membrane fission, the division of a membrane-bound structure into two discrete compartments, is essential for diverse cellular events, such as endocytosis and vesicle/granule biogenesis; however, the process remains unclear. The hemostatic protein von Willebrand factor is produced in vascular endothelial cells and packaged into specialized secretory granules, Weibel–Palade bodies (WPBs) at the trans-Golgi network (TGN). Here, we reported that V0a1, a V-ATPase component, is required for the membrane fission of WPBs. We identified two V0a isoforms in distinct populations of WPBs in cultured endothelial cells, V0a1 and V0a2, on mature and nascent WPBs, respectively. Although WPB buds were formed, WPBs could not separate from the TGN in the absence of V0a1. Screening using dominant–negative forms of known membrane fission regulators revealed protein kinase D (PKD) as an essential factor in biogenesis of WPBs. Further, we showed that the induction of wild-type PKDs in V0a1-depleted cells does not support the segregation of WPBs from the TGN; suggesting a primary role of V0a1 in the membrane fission of WPBs. The identification of V0a1 as a new membrane fission regulator should facilitate the understanding of molecular events that enable membrane fission.
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Affiliation(s)
- Yasuo Yamazaki
- Department of Molecular Pathogenesis, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Yuka Eura
- Department of Molecular Pathogenesis, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Koichi Kokame
- Department of Molecular Pathogenesis, National Cerebral and Cardiovascular Center, Osaka, Japan
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4
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Petrovszki P, Sebők-Nagy K, Páli T. The Activity of Native Vacuolar Proton-ATPase in an Oscillating Electric Field - Demystifying an Apparent Effect of Music on a Biomolecule. Front Mol Biosci 2021; 8:772167. [PMID: 34805280 PMCID: PMC8595334 DOI: 10.3389/fmolb.2021.772167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 10/21/2021] [Indexed: 11/13/2022] Open
Abstract
The effect of an oscillating electric field generated from music on yeast vacuolar proton-ATPase (V-ATPase) activity in its native environment is reported. An oscillating electric field is generated by electrodes that are immersed into a dispersion of yeast vacuolar membrane vesicles natively hosting a high concentration of active V-ATPase. The substantial difference in the ATP hydrolysing activity of V-ATPase under the most stimulating and inhibiting music is unprecedented. Since the topic, i.e., an effect of music on biomolecules, is very attractive for non-scientific, esoteric mystification, we provide a rational explanation for the observed new phenomenon. Good correlation is found between changes in the specific activity of the enzyme and the combined intensity of certain frequency bands of the Fourier spectra of the music clips. Most prominent identified frequencies are harmonically related to each other and to the estimated rotation rate of the enzyme. These results lead to the conclusion that the oscillating electric field interferes with periodic trans-membrane charge motions in the working enzyme.
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Affiliation(s)
- Pál Petrovszki
- Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
| | - Krisztina Sebők-Nagy
- Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
| | - Tibor Páli
- Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
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5
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Li Y, Valdez NA, Mnatsakanyan N, Weber J. The nucleotide binding affinities of two critical conformations of Escherichia coli ATP synthase. Arch Biochem Biophys 2021; 707:108899. [PMID: 33991499 PMCID: PMC8278868 DOI: 10.1016/j.abb.2021.108899] [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: 01/14/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 10/21/2022]
Abstract
ATP synthase is essential in aerobic energy metabolism, and the rotary catalytic mechanism is one of the core concepts to understand the energetic functions of ATP synthase. Disulfide bonds formed by oxidizing a pair of cysteine mutations halted the rotation of the γ subunit in two critical conformations, the ATP-waiting dwell (αE284C/γQ274C) and the catalytic dwell (αE284C/γL276C). Tryptophan fluorescence was used to measure the nucleotide binding affinities for MgATP, MgADP and MgADP-AlF4 (a transition state analog) to wild-type and mutant F1 under reducing and oxidizing conditions. In the reduced state, αE284C/γL276C F1 showed a wild-type-like nucleotide binding pattern; after oxidation to lock the enzyme in the catalytic dwell state, the nucleotide binding parameters remained unchanged. In contrast, αE284C/γQ274C F1 showed significant differences in the affinities of the oxidized versus the reduced state. Locking the enzyme in the ATP-waiting dwell reduced nucleotide binding affinities of all three catalytic sites. Most importantly, the affinity of the low affinity site was reduced to such an extent that it could no longer be detected in the binding assay (Kd > 5 mM). The results of the present study allow to present a model for the catalytic mechanism of ATP synthase under consideration of the nucleotide affinity changes during a 360° cycle of the rotor.
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Affiliation(s)
- Yunxiang Li
- Department of Chemistry and Biochemistry, Texas Woman's University, Denton, TX, 76204, USA; Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79409, USA.
| | - Neydy A Valdez
- Department of Biology, Texas Woman's University, Denton, TX, 76204, USA
| | - Nelli Mnatsakanyan
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79409, USA; School of Medicine, Yale University, New Haven, CT, 06520, USA
| | - Joachim Weber
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79409, USA; Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, 79430, USA.
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6
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The milk-derived lactoferrin inhibits V-ATPase activity by targeting its V1 domain. Int J Biol Macromol 2021; 186:54-70. [PMID: 34237360 DOI: 10.1016/j.ijbiomac.2021.06.200] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 06/20/2021] [Accepted: 06/29/2021] [Indexed: 11/20/2022]
Abstract
Lactoferrin (Lf), a bioactive milk protein, exhibits strong anticancer and antifungal activities. The search for Lf targets and mechanisms of action is of utmost importance to enhance its effective applications. A common feature among Lf-treated cancer and fungal cells is the inhibition of a proton pump called V-ATPase. Lf-driven V-ATPase inhibition leads to cytosolic acidification, ultimately causing cell death of cancer and fungal cells. Given that a detailed elucidation of how Lf and V-ATPase interact is still missing, herein we aimed to fill this gap by employing a five-stage computational approach. Molecular dynamics simulations of both proteins were performed to obtain a robust sampling of their conformational landscape, followed by clustering, which allowed retrieving representative structures, to then perform protein-protein docking. Subsequently, molecular dynamics simulations of the docked complexes and free binding energy calculations were carried out to evaluate the dynamic binding process and build a final ranking based on the binding affinities. Detailed atomist analysis of the top ranked complexes clearly indicates that Lf binds to the V1 cytosolic domain of V-ATPase. Particularly, our data suggest that Lf binds to the interfaces between A/B subunits, where the ATP hydrolysis occurs, thus inhibiting this process. The free energy decomposition analysis further identified key binding residues that will certainly aid in the rational design of follow-up experimental studies, hence bridging computational and experimental biochemistry.
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7
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Biofuels from Micro-Organisms: Thermodynamic Considerations on the Role of Electrochemical Potential on Micro-Organisms Growth. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11062591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Biofuels from micro-organisms represents a possible response to the carbon dioxide mitigation. One open problem is to improve their productivity, in terms of biofuels production. To do so, an improvement of the present model of growth and production is required. However, this implies an understanding of the growth spontaneous conditions of the bacteria. In this paper, a thermodynamic approach is developed in order to highlight the fundamental role of the electrochemical potential in bacteria proliferation. Temperature effect on the biosystem behaviour has been pointed out. The results link together the electrochemical potential, the membrane electric potential, the pH gradient through the membrane, and the temperature, with the result of improving the thermodynamic approaches, usually introduced in this topic of research.
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8
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Yuan H, Liu X, Wang L, Ma X. Fundamentals and applications of enzyme powered micro/nano-motors. Bioact Mater 2020; 6:1727-1749. [PMID: 33313451 PMCID: PMC7711193 DOI: 10.1016/j.bioactmat.2020.11.022] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 12/22/2022] Open
Abstract
Micro/nanomotors (MNMs) are miniaturized machines that can convert many kinds of energy into mechanical motion. Over the past decades, a variety of driving mechanisms have been developed, which have greatly extended the application scenarios of MNMs. Enzymes exist in natural organisms which can convert chemical energy into mechanical force. It is an innovative attempt to utilize enzymes as biocatalyst providing driving force for MNMs. The fuels for enzymatic reactions are biofriendly as compared to traditional counterparts, which makes enzyme-powered micro/nanomotors (EMNMs) of great value in biomedical field for their nature of biocompatibility. Until now, EMNMs with various shapes can be propelled by catalase, urease and many others. Also, they can be endowed with multiple functionalities to accomplish on-demand tasks. Herein, combined with the development process of EMNMs, we are committed to present a comprehensive understanding of EMNMs, including their types, propelling principles, and potential applications. In this review, we will introduce single enzyme that can be used as motor, enzyme powered molecule motors and other micro/nano-architectures. The fundamental mechanism of energy conversion process of EMNMs and crucial factors that affect their movement behavior will be discussed. The current progress of proof-of-concept applications of EMNMs will also be elaborated in detail. At last, we will summarize and prospect the opportunities and challenges that EMNMs will face in their future development. Clear classification and description of different enzyme-powered micro/nanomotors (EMNMs). Discussion of the fundamental mechanism of energy conversion process of EMNMs and their movement influence factors. Introduction of the current progress of proof-of-concept applications of EMNMs.
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Affiliation(s)
- Hao Yuan
- Flexible Printed Electronic Technology Center and School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Xiaoxia Liu
- Flexible Printed Electronic Technology Center and School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Liying Wang
- Flexible Printed Electronic Technology Center and School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Xing Ma
- Flexible Printed Electronic Technology Center and School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.,Shenzhen Bay Laboratory, No. 9 Duxue Road, Shenzhen, 518055, China.,Key Laboratory of Microsystems and Microstructures Manufacturing, Harbin Institute of Technology, Harbin, Heilongjiang, 150001, China
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9
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Wallnöfer EA, Thurner GC, Kremser C, Talasz H, Stollenwerk MM, Helbok A, Klammsteiner N, Albrecht-Schgoer K, Dietrich H, Jaschke W, Debbage P. Albumin-based nanoparticles as contrast medium for MRI: vascular imaging, tissue and cell interactions, and pharmacokinetics of second-generation nanoparticles. Histochem Cell Biol 2020; 155:19-73. [PMID: 33040183 DOI: 10.1007/s00418-020-01919-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2020] [Indexed: 12/14/2022]
Abstract
This multidisciplinary study examined the pharmacokinetics of nanoparticles based on albumin-DTPA-gadolinium chelates, testing the hypothesis that these nanoparticles create a stronger vessel signal than conventional gadolinium-based contrast agents and exploring if they are safe for clinical use. Nanoparticles based on human serum albumin, bearing gadolinium and designed for use in magnetic resonance imaging, were used to generate magnet resonance images (MRI) of the vascular system in rats ("blood pool imaging"). At the low nanoparticle doses used for radionuclide imaging, nanoparticle-associated metals were cleared from the blood into the liver during the first 4 h after nanoparticle application. At the higher doses required for MRI, the liver became saturated and kidney and spleen acted as additional sinks for the metals, and accounted for most processing of the nanoparticles. The multiple components of the nanoparticles were cleared independently of one another. Albumin was detected in liver, spleen, and kidneys for up to 2 days after intravenous injection. Gadolinium was retained in the liver, kidneys, and spleen in significant concentrations for much longer. Gadolinium was present as significant fractions of initial dose for longer than 2 weeks after application, and gadolinium clearance was only complete after 6 weeks. Our analysis could not account quantitatively for the full dose of gadolinium that was applied, but numerous organs were found to contain gadolinium in the collagen of their connective tissues. Multiple lines of evidence indicated intracellular processing opening the DTPA chelates and leading to gadolinium long-term storage, in particular inside lysosomes. Turnover of the stored gadolinium was found to occur in soluble form in the kidneys, the liver, and the colon for up to 3 weeks after application. Gadolinium overload poses a significant hazard due to the high toxicity of free gadolinium ions. We discuss the relevance of our findings to gadolinium-deposition diseases.
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Affiliation(s)
- E A Wallnöfer
- Department of Radiology, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria
| | - G C Thurner
- Department of Radiology, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria
- Division of Histology and Embryology, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Müllerstrasse 59, 6020, Innsbruck, Austria
| | - C Kremser
- Department of Radiology, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria
| | - H Talasz
- Division of Clinical Biochemistry, Biocenter, Medical University of Innsbruck, Innrain 80-82, 6020, Innsbruck, Austria
| | - M M Stollenwerk
- Faculty of Health and Society, Biomedical Laboratory Science, University Hospital MAS, Malmö University, 205 06, Malmö, Sweden
- Division of Histology and Embryology, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Müllerstrasse 59, 6020, Innsbruck, Austria
| | - A Helbok
- Department of Nuclear Medicine, Innsbruck Medical University, Anichstrasse 35, 6020, Innsbruck, Austria
| | - N Klammsteiner
- Division of Histology and Embryology, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Müllerstrasse 59, 6020, Innsbruck, Austria
| | - K Albrecht-Schgoer
- Department of Pharmaceutical Technology, Institute of Pharmacy, Leopold-Franzens-University Innsbruck, Innrain 80-82/IV, 6020, Innsbruck, Austria
- Institute of Cell Genetics, Department for Pharmacology and Genetics, Medical University of Innsbruck, Peter-Mayr-Strasse 1a, 6020, Innsbruck, Austria
| | - H Dietrich
- Central Laboratory Animal Facilities, Innsbruck Medical University, Peter-Mayr-Strasse 4a, 6020, Innsbruck, Austria
| | - W Jaschke
- Department of Radiology, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria
| | - P Debbage
- Division of Histology and Embryology, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Müllerstrasse 59, 6020, Innsbruck, Austria.
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10
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Sims KR, Maceren JP, Liu Y, Rocha GR, Koo H, Benoit DSW. Dual antibacterial drug-loaded nanoparticles synergistically improve treatment of Streptococcus mutans biofilms. Acta Biomater 2020; 115:418-431. [PMID: 32853808 PMCID: PMC7530141 DOI: 10.1016/j.actbio.2020.08.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 08/12/2020] [Accepted: 08/13/2020] [Indexed: 12/12/2022]
Abstract
Dental caries (i.e., tooth decay), which is caused by biofilm formation on tooth surfaces, is the most prevalent oral disease worldwide. Unfortunately, many anti-biofilm drugs lack efficacy within the oral cavity due to poor solubility, retention, and penetration into biofilms. While drug delivery systems (DDS) have been developed to overcome these hurdles and improve traditional antimicrobial treatments, including farnesol, efficacy is still modest due to myriad resistance mechanisms employed by biofilms, suggesting that synergistic drug treatments may be more efficacious. Streptococcus mutans (S. mutans), a cariogenic pathogen and biofilm forming model organism, has several key virulence factors including acidogenicity and exopolysaccharide (EPS) matrix synthesis. Flavonoids, such as myricetin, can reduce both biofilm acidogenicity and EPS synthesis. Therefore, a nanoparticle carrier (NPC) DDS with flexibility to co-load farnesol in the hydrophobic core and myricetin within the cationic corona, was tested in vitro using established and developing S. mutans biofilms. Co-loaded NPC treatments effectively disrupted biofilm biomass (i.e., dry weight) and reduced biofilm viability by ~3 log CFU/mL versus single drug-only controls in developing biofilms, suggesting dual-drug delivery exhibits synergistic anti-biofilm effects. Mechanistic studies revealed that co-loaded NPCs synergistically inhibited planktonic bacterial growth compared to controls and reduced S. mutans acidogenicity due to decreased atpD expression, a gene associated with acid tolerance. Moreover, the myricetin-loaded NPC corona enhanced NPC binding to tooth-mimetic surfaces, which can increase drug efficacy through improved retention at the biofilm-apatite interface. Altogether, these findings suggest promise for co-delivery of myricetin and farnesol DDS as an alternative anti-biofilm treatment to prevent dental caries.
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Affiliation(s)
- Kenneth R Sims
- University of Rochester School of Medicine and Dentistry, Translational Biomedical Science, Rochester, NY, United States; University of Rochester, Department of Biomedical Engineering, Rochester, NY, United States
| | - Julian P Maceren
- University of Rochester, Department of Chemistry, Rochester, NY, United States
| | - Yuan Liu
- University of Pennsylvania, Center for Innovation and Precision Dentistry, School of Dental Medicine, Department of Orthodontics, Philadelphia, PA, United States
| | - Guilherme R Rocha
- University of Rochester, Department of Biomedical Engineering, Rochester, NY, United States; São Paulo State University, Department of Dental Materials and Prosthodontics, Araraquara, São Paulo, Brazil
| | - Hyun Koo
- University of Pennsylvania, Center for Innovation and Precision Dentistry, School of Dental Medicine, Department of Orthodontics, Philadelphia, PA, United States
| | - Danielle S W Benoit
- University of Rochester, Department of Biomedical Engineering, Rochester, NY, United States; University of Rochester, Materials Science Program, NY, United States; University of Rochester, Department of Orthopaedics and Center for Musculoskeletal Research, NY, United States; University of Rochester, Center for Oral Biology, NY, United States; University of Rochester, Department of Chemical Engineering, NY, United States.
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11
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Non-Equilibrium Thermodynamic Approach to Ca2+-Fluxes in Cancer. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10196737] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Living systems waste heat in their environment. This is the measurable effect of the irreversibility of the biophysical and biochemical processes fundamental to their life. Non-equilibrium thermodynamics allows us to analyse the ion fluxes through the cell membrane, and to relate them to the membrane electric potential, in order to link this to the biochemical and biophysical behaviour of the living cells. This is particularly interesting in relation to cancer, because it could represent a new viewpoint, in order to develop new possible anticancer therapies, based on the thermoelectric behaviour of cancer itself. Here, we use a new approach, recently introduced in thermodynamics, in order to develop the analysis of the ion fluxes, and to point out consequences related to the membrane electric potential, from a thermodynamic viewpoint. We show how any increase in the cell temperature could generate a decrease in the membrane electric potential, with a direct relation between cancer and inflammation. Moreover, a thermal threshold, for the cell membrane electric potential gradient, has been obtained, and related to the mitotic activity. Finally, we obtained the external surface growth of the cancer results related (i) to the Ca2+-fluxes, (ii) to the temperature difference between the the system and its environment, and (iii) to the chemical potential of the ion species.
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12
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Mikoyan G, Karapetyan L, Vassilian A, Trchounian A, Trchounian K. External succinate and potassium ions influence Dcu dependent FOF1-ATPase activity and H+ flux of Escherichia coli at different pHs. J Bioenerg Biomembr 2020; 52:377-382. [DOI: 10.1007/s10863-020-09847-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/19/2020] [Indexed: 01/12/2023]
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13
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Kang C, Sun F, Yan L, Li R, Bai J, Caetano-Anollés G. Genome-Wide Identification and Characterization of the Vacuolar H +-ATPase Subunit H Gene Family in Crop Plants. Int J Mol Sci 2019; 20:ijms20205125. [PMID: 31623139 PMCID: PMC6829547 DOI: 10.3390/ijms20205125] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 10/13/2019] [Accepted: 10/14/2019] [Indexed: 02/07/2023] Open
Abstract
The vacuolar H+-ATPase (V-ATPase) plays many important roles in cell growth and in response to stresses in plants. The V-ATPase subunit H (VHA-H) is required to form a stable and active V-ATPase. Genome-wide analyses of VHA-H genes in crops contribute significantly to a systematic understanding of their functions. A total of 22 VHA-H genes were identified from 11 plants representing major crops including cotton, rice, millet, sorghum, rapeseed, maize, wheat, soybean, barley, potato, and beet. All of these VHA-H genes shared exon-intron structures similar to those of Arabidopsis thaliana. The C-terminal domain of VHA-H was shorter and more conserved than the N-terminal domain. The VHA-H gene was effectively used as a genetic marker to infer the phylogenetic relationships among plants, which were congruent with currently accepted taxonomic groupings. The VHA-H genes from six species of crops (Gossypium raimondii, Brassica napus, Glycine max, Solanum tuberosum, Triticum aestivum, and Zea mays) showed high gene structural diversity. This resulted from the gains and losses of introns. Seven VHA-H genes in six species of crops (Gossypium raimondii, Hordeum vulgare, Solanum tuberosum, Setaria italica, Triticum aestivum, and Zea mays) contained multiple transcript isoforms arising from alternative splicing. The study of cis-acting elements of gene promoters and RNA-seq gene expression patterns confirms the role of VHA-H genes as eco-enzymes. The gene structural diversity and proteomic diversity of VHA-H genes in our crop sampling facilitate understanding of their functional diversity, including stress responses and traits important for crop improvement.
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Affiliation(s)
- Chen Kang
- College of Biology Engineering, Shanxi University, Taiyuan 030006, Shanxi, China.
- Institute of Crop Sciences, Shanxi Academy of Agricultural Sciences, Taiyuan 030031, Shanxi, China.
| | - Fengjie Sun
- School of Science and Technology, Georgia Gwinnett College, Lawrenceville, GA 30043, USA.
| | - Lei Yan
- Institute of Crop Sciences, Shanxi Academy of Agricultural Sciences, Taiyuan 030031, Shanxi, China.
| | - Rui Li
- Institute of Crop Sciences, Shanxi Academy of Agricultural Sciences, Taiyuan 030031, Shanxi, China.
| | - Jianrong Bai
- Institute of Crop Sciences, Shanxi Academy of Agricultural Sciences, Taiyuan 030031, Shanxi, China.
| | - Gustavo Caetano-Anollés
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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14
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Hohlweg W, Wagner GE, Hofbauer HF, Sarkleti F, Setz M, Gubensäk N, Lichtenegger S, Falsone SF, Wolinski H, Kosol S, Oostenbrink C, Kohlwein SD, Zangger K. A cation-π interaction in a transmembrane helix of vacuolar ATPase retains the proton-transporting arginine in a hydrophobic environment. J Biol Chem 2018; 293:18977-18988. [PMID: 30209131 DOI: 10.1074/jbc.ra118.005276] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 08/24/2018] [Indexed: 11/06/2022] Open
Abstract
Vacuolar ATPases are multisubunit protein complexes that are indispensable for acidification and pH homeostasis in a variety of physiological processes in all eukaryotic cells. An arginine residue (Arg735) in transmembrane helix 7 (TM7) of subunit a of the yeast ATPase is known to be essential for proton translocation. However, the specific mechanism of its involvement in proton transport remains to be determined. Arginine residues are usually assumed to "snorkel" toward the protein surface when exposed to a hydrophobic environment. Here, using solution NMR spectroscopy, molecular dynamics simulations, and in vivo yeast assays, we obtained evidence for the formation of a transient, membrane-embedded cation-π interaction in TM7 between Arg735 and two highly conserved nearby aromatic residues, Tyr733 and Trp737 We propose a mechanism by which the transient, membrane-embedded cation-π complex provides the necessary energy to keep the charged side chain of Arg735 within the hydrophobic membrane. Such cation-π interactions may define a general mechanism to retain charged amino acids in a hydrophobic membrane environment.
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Affiliation(s)
| | - Gabriel E Wagner
- the Institute of Hygiene, Microbiology, and Environmental Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Harald F Hofbauer
- the Institute of Molecular Biosciences, BioTechMed-Graz, University of Graz, 8010 Graz, Austria
| | - Florian Sarkleti
- the Institute of Molecular Biosciences, BioTechMed-Graz, University of Graz, 8010 Graz, Austria
| | - Martina Setz
- the Institute of Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | | | - Sabine Lichtenegger
- the Institute of Hygiene, Microbiology, and Environmental Medicine, Medical University of Graz, 8010 Graz, Austria
| | | | - Heimo Wolinski
- the Institute of Molecular Biosciences, BioTechMed-Graz, University of Graz, 8010 Graz, Austria
| | - Simone Kosol
- the Department of Chemistry, University of Warwick, Gibbet Hill, Coventry CV4 7AL, United Kingdom
| | - Chris Oostenbrink
- the Institute of Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Sepp D Kohlwein
- the Institute of Molecular Biosciences, BioTechMed-Graz, University of Graz, 8010 Graz, Austria
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15
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Abstract
Mitochondria generate most of the heat in endotherms. Given some impedance of heat transfer across protein-rich bioenergetic membranes, mitochondria must operate at a higher temperature than body temperature in mammals and birds. But exactly how much hotter has been controversial, with physical calculations suggesting that maximal heat gradients across cells could not be greater than 10−5 K. Using the thermosensitive mitochondrial-targeted fluorescent dye Mito Thermo Yellow (MTY), Chrétien and colleagues suggest that mitochondria are optimised to nearly 50 °C, 10 °C hotter than body temperature. This extreme value questions what temperature really means in confined far-from-equilibrium systems but encourages a reconsideration of thermal biology.
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Affiliation(s)
- Nick Lane
- Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
- * E-mail:
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16
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Chen Y, Ju L, Rushdi M, Ge C, Zhu C. Receptor-mediated cell mechanosensing. Mol Biol Cell 2017; 28:3134-3155. [PMID: 28954860 PMCID: PMC5687017 DOI: 10.1091/mbc.e17-04-0228] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 09/06/2017] [Accepted: 09/19/2017] [Indexed: 12/22/2022] Open
Abstract
Mechanosensing depicts the ability of a cell to sense mechanical cues, which under some circumstances is mediated by the surface receptors. In this review, a four-step model is described for receptor-mediated mechanosensing. Platelet GPIb, T-cell receptor, and integrins are used as examples to illustrate the key concepts and players in this process. Mechanosensing describes the ability of a cell to sense mechanical cues of its microenvironment, including not only all components of force, stress, and strain but also substrate rigidity, topology, and adhesiveness. This ability is crucial for the cell to respond to the surrounding mechanical cues and adapt to the changing environment. Examples of responses and adaptation include (de)activation, proliferation/apoptosis, and (de)differentiation. Receptor-mediated cell mechanosensing is a multistep process that is initiated by binding of cell surface receptors to their ligands on the extracellular matrix or the surface of adjacent cells. Mechanical cues are presented by the ligand and received by the receptor at the binding interface; but their transmission over space and time and their conversion into biochemical signals may involve other domains and additional molecules. In this review, a four-step model is described for the receptor-mediated cell mechanosensing process. Platelet glycoprotein Ib, T-cell receptor, and integrins are used as examples to illustrate the key concepts and players in this process.
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Affiliation(s)
- Yunfeng Chen
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332.,Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332
| | - Lining Ju
- Charles Perkins Centre and Heart Research Institute, University of Sydney, Camperdown, NSW 2006, Australia
| | - Muaz Rushdi
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Chenghao Ge
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Cheng Zhu
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 .,Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
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17
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Sekiya M, Sakamoto Y, Futai M, Nakanishi-Matsui M. Role of α/β interface in F 1 ATPase rotational catalysis probed by inhibitors and mutations. Int J Biol Macromol 2017; 99:615-621. [DOI: 10.1016/j.ijbiomac.2017.02.089] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/24/2017] [Indexed: 01/26/2023]
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18
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Singh NS, Habicht KL, Moaddel R, Shimmo R. Development and characterization of mitochondrial membrane affinity chromatography columns derived from skeletal muscle and platelets for the study of mitochondrial transmembrane proteins. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1055-1056:144-148. [PMID: 28475928 DOI: 10.1016/j.jchromb.2017.04.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/05/2017] [Accepted: 04/12/2017] [Indexed: 12/25/2022]
Abstract
Mitochondrial membrane fragments from human platelets and monkey skeletal muscles were successfully immobilized onto immobilized artificial membrane chromatographic support for the first time, resulting in mitochondrial membrane affinity chromatography (MMAC) columns. These columns were validated by characterization of translocator protein (TSPO), where multiple concentrations of dipyridamole were run and the binding affinities (Kd) determined. Further, the relative ranking data of TSPO ligands was consistent with previously reported rankings for both, the platelet (MMAC-Platelet) and the skeletal muscle (MMAC-Muscle) column (dipyridamole>PK11195>protoporphyrin IX>rotenone). The functional immobilization of the F-ATPase/ATP synthase was demonstrated on MMAC-Muscle column. Online hydrolysis of ATP to ADP and synthesis of ATP from ADP were both demonstrated on the MMAC-Muscle column. Hydrolysis of ATP to ADP was inhibited by oligomycin A with an IC50 of 40.2±13.5nM (∼60% reduction in ATP hydrolysis, p<0.001), similar to previously reported values. Additionally, the Michaelis-Menten constant (Km) for ADP was found to be 1525±461μM based on the on column dose-dependent increase in ATP production.
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Affiliation(s)
- Nagendra Surendra Singh
- Biomedical Research Center, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Suite 100, 21224 Baltimore, MD, USA
| | - Kaia-Liisa Habicht
- Biomedical Research Center, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Suite 100, 21224 Baltimore, MD, USA; School of Natural Sciences and Health, Tallinn University, Narva mnt 29, 10120 Tallinn, Estonia
| | - Ruin Moaddel
- Biomedical Research Center, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Suite 100, 21224 Baltimore, MD, USA
| | - Ruth Shimmo
- School of Natural Sciences and Health, Tallinn University, Narva mnt 29, 10120 Tallinn, Estonia.
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19
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Farsi Z, Jahn R, Woehler A. Proton electrochemical gradient: Driving and regulating neurotransmitter uptake. Bioessays 2017; 39. [PMID: 28383767 DOI: 10.1002/bies.201600240] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Accumulation of neurotransmitters in the lumen of synaptic vesicles (SVs) relies on the activity of the vacuolar-type H+ -ATPase. This pump drives protons into the lumen, generating a proton electrochemical gradient (ΔμH+ ) across the membrane. Recent work has demonstrated that the balance between the chemical (ΔpH) and electrical (ΔΨ) components of ΔμH+ is regulated differently by some distinct vesicle types. As different neurotransmitter transporters use ΔpH and ΔΨ with different relative efficiencies, regulation of this gradient balance has the potential to influence neurotransmitter uptake. Nevertheless, the underlying mechanisms responsible for this regulation remain poorly understood. In this review, we provide an overview of current neurotransmitter uptake models, with a particular emphasis on the distinct roles of the electrical and chemical gradients and current hypotheses for regulatory mechanisms.
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Affiliation(s)
- Zohreh Farsi
- Max-Delbrück Center for Molecular Medicine, Berlin Institute for Medical Systems Biology, Berlin, Germany
| | - Reinhard Jahn
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Andrew Woehler
- Max-Delbrück Center for Molecular Medicine, Berlin Institute for Medical Systems Biology, Berlin, Germany
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20
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Ferencz CM, Petrovszki P, Dér A, Sebők-Nagy K, Kóta Z, Páli T. Oscillating Electric Field Measures the Rotation Rate in a Native Rotary Enzyme. Sci Rep 2017; 7:45309. [PMID: 28345665 PMCID: PMC5366918 DOI: 10.1038/srep45309] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 02/21/2017] [Indexed: 11/09/2022] Open
Abstract
Rotary enzymes are complex, highly challenging biomolecular machines whose biochemical working mechanism involves intersubunit rotation. The true intrinsic rate of rotation of any rotary enzyme is not known in a native, unmodified state. Here we use the effect of an oscillating electric (AC) field on the biochemical activity of a rotary enzyme, the vacuolar proton-ATPase (V-ATPase), to directly measure its mean rate of rotation in its native membrane environment, without any genetic, chemical or mechanical modification of the enzyme, for the first time. The results suggest that a transmembrane AC field is able to synchronise the steps of ion-pumping in individual enzymes via a hold-and-release mechanism, which opens up the possibility of biotechnological exploitation. Our approach is likely to work for other transmembrane ion-transporting assemblies, not only rotary enzymes, to determine intrinsic in situ rates of ion pumping.
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Affiliation(s)
- Csilla-Maria Ferencz
- Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, 6726, Szeged, Hungary
| | - Pál Petrovszki
- Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, 6726, Szeged, Hungary
| | - András Dér
- Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, 6726, Szeged, Hungary
| | - Krisztina Sebők-Nagy
- Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, 6726, Szeged, Hungary
| | - Zoltán Kóta
- Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, 6726, Szeged, Hungary
| | - Tibor Páli
- Institute of Biophysics, Biological Research Centre, Hungarian Academy of Sciences, Temesvári krt. 62, 6726, Szeged, Hungary
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21
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Anandakrishnan R, Zuckerman DM. Biophysical comparison of ATP-driven proton pumping mechanisms suggests a kinetic advantage for the rotary process depending on coupling ratio. PLoS One 2017; 12:e0173500. [PMID: 28319179 PMCID: PMC5358804 DOI: 10.1371/journal.pone.0173500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/21/2017] [Indexed: 12/15/2022] Open
Abstract
ATP-driven proton pumps, which are critical to the operation of a cell, maintain cytosolic and organellar pH levels within a narrow functional range. These pumps employ two very different mechanisms: an elaborate rotary mechanism used by V-ATPase H+ pumps, and a simpler alternating access mechanism used by P-ATPase H+ pumps. Why are two different mechanisms used to perform the same function? Systematic analysis, without parameter fitting, of kinetic models of the rotary, alternating access and other possible mechanisms suggest that, when the ratio of protons transported per ATP hydrolyzed exceeds one, the one-at-a-time proton transport by the rotary mechanism is faster than other possible mechanisms across a wide range of driving conditions. When the ratio is one, there is no intrinsic difference in the free energy landscape between mechanisms, and therefore all mechanisms can exhibit the same kinetic performance. To our knowledge all known rotary pumps have an H+:ATP ratio greater than one, and all known alternating access ATP-driven proton pumps have a ratio of one. Our analysis suggests a possible explanation for this apparent relationship between coupling ratio and mechanism. When the conditions under which the pump must operate permit a coupling ratio greater than one, the rotary mechanism may have been selected for its kinetic advantage. On the other hand, when conditions require a coupling ratio of one or less, the alternating access mechanism may have been selected for other possible advantages resulting from its structural and functional simplicity.
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Affiliation(s)
- Ramu Anandakrishnan
- Dept. of Computational and Systems Biology, School of Medicine, University of Pittsburgh, PA, United States of America
- * E-mail: (RA); (DMZ)
| | - Daniel M. Zuckerman
- Dept. of Computational and Systems Biology, School of Medicine, University of Pittsburgh, PA, United States of America
- * E-mail: (RA); (DMZ)
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22
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Ma X, Hortelão AC, Patiño T, Sánchez S. Enzyme Catalysis To Power Micro/Nanomachines. ACS NANO 2016; 10:9111-9122. [PMID: 27666121 PMCID: PMC5228067 DOI: 10.1021/acsnano.6b04108] [Citation(s) in RCA: 142] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 09/25/2016] [Indexed: 05/18/2023]
Abstract
Enzymes play a crucial role in many biological processes which require harnessing and converting free chemical energy into kinetic forces in order to accomplish tasks. Enzymes are considered to be molecular machines, not only because of their capability of energy conversion in biological systems but also because enzymatic catalysis can result in enhanced diffusion of enzymes at a molecular level. Enlightened by nature's design of biological machinery, researchers have investigated various types of synthetic micro/nanomachines by using enzymatic reactions to achieve self-propulsion of micro/nanoarchitectures. Yet, the mechanism of motion is still under debate in current literature. Versatile proof-of-concept applications of these enzyme-powered micro/nanodevices have been recently demonstrated. In this review, we focus on discussing enzymes not only as stochastic swimmers but also as nanoengines to power self-propelled synthetic motors. We present an overview on different enzyme-powered micro/nanomachines, the current debate on their motion mechanism, methods to provide motion and speed control, and an outlook of the future potentials of this multidisciplinary field.
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Affiliation(s)
- Xing Ma
- Max
Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569 Stuttgart, Germany
- School
of Materials Science and Engineering, Shenzhen Graduate School, Harbin Institute of Technology, 518055 Shenzhen, China
| | - Ana C. Hortelão
- Max
Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569 Stuttgart, Germany
- Institut
de Bioenginyeria de Catalunya (IBEC), Baldiri i Reixac 10-12, 08028 Barcelona, Spain
| | - Tania Patiño
- Institut
de Bioenginyeria de Catalunya (IBEC), Baldiri i Reixac 10-12, 08028 Barcelona, Spain
| | - Samuel Sánchez
- Max
Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569 Stuttgart, Germany
- Institució
Catalana de Recerca i Estudis Avancats (ICREA), Pg. Lluís Companys 23, 08010 Barcelona, Spain
- Institut
de Bioenginyeria de Catalunya (IBEC), Baldiri i Reixac 10-12, 08028 Barcelona, Spain
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23
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Abstract
Janus particles, named after the two-faced Roman god Janus, have different surface makeups, structures or compartments on two sides. This review highlights recent advances in employing Janus particles as novel analytical tools for live cell imaging and biosensing. Unlike conventional particles used in analytical science, two-faced Janus particles provide asymmetry and directionality, and can combine different or even incompatible properties within a single particle. The broken symmetry enables imaging and quantification of rotational dynamics, revealing information beyond what traditional measurements offer. The spatial segregation of molecules on the surface of a single particle also allows analytical functions that would otherwise interfere with each other to be decoupled, opening up opportunities for novel multimodal analytical methods. We summarize here the development of Janus particles, a few general methods for their fabrication and, more importantly, the emerging and novel applications of Janus particles as multi-functional imaging probes and sensors.
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Affiliation(s)
- Yi Yi
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
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24
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Comparative protein profiles of Butea superba tubers under seasonal changes. Mol Biol Rep 2016; 43:719-36. [PMID: 27198528 DOI: 10.1007/s11033-016-4010-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 05/12/2016] [Indexed: 10/21/2022]
Abstract
Seasonal changes are major factors affecting environmental conditions which induce multiple stresses in plants, leading to changes in protein relative abundance in the complex cellular plant metabolic pathways. Proteomics was applied to study variations in proteome composition of Butea. superba tubers during winter, summer and rainy season throughout the year using two-dimensional polyacrylamide gel electrophoresis coupled with a nanoflow liquid chromatography coupled to electrospray ionization quadrupole-time-of-flight tandem mass spectrometry. A total of 191 protein spots were identified and also classified into 12 functional groups. The majority of these were mainly involved in carbohydrate and energy metabolism (30.37 %) and defense and stress (18.32 %). The results exhibited the highest numbers of identified proteins in winter-harvested samples. Forty-five differential proteins were found in different seasons, involving important metabolic pathways. Further analysis indicated that changes in the protein levels were due mainly to temperature stress during summer and to water stress during winter, which affected cellular structure, photosynthesis, signal transduction and homeostasis, amino-acid biosynthesis, protein destination and storage, protein biosynthesis and stimulated defense and stress mechanisms involving glycolytic enzymes and relative oxygen species catabolizing enzymes. The proteins with differential relative abundances might induce an altered physiological status within plant tubers for survival. The work provided new insights into the better understanding of the molecular basis of plant proteomes and stress tolerance mechanisms, especially during seasonal changes. The finding suggested proteins that might potentially be used as protein markers in differing seasons in other plants and aid in selecting B. superba tubers with the most suitable medicinal properties in the future.
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25
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Farsi Z, Preobraschenski J, van den Bogaart G, Riedel D, Jahn R, Woehler A. Single-vesicle imaging reveals different transport mechanisms between glutamatergic and GABAergic vesicles. Science 2016; 351:981-4. [DOI: 10.1126/science.aad8142] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/14/2016] [Indexed: 12/13/2022]
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26
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Nakanishi-Matsui M, Sekiya M, Futai M. ATP synthase from Escherichia coli : Mechanism of rotational catalysis, and inhibition with the ε subunit and phytopolyphenols. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:129-140. [DOI: 10.1016/j.bbabio.2015.11.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 10/19/2015] [Accepted: 11/13/2015] [Indexed: 10/22/2022]
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27
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Gráczer É, Szimler T, Garamszegi A, Konarev PV, Lábas A, Oláh J, Palló A, Svergun DI, Merli A, Závodszky P, Weiss MS, Vas M. Dual Role of the Active Site Residues of Thermus thermophilus 3-Isopropylmalate Dehydrogenase: Chemical Catalysis and Domain Closure. Biochemistry 2016; 55:560-74. [PMID: 26731489 DOI: 10.1021/acs.biochem.5b00839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The key active site residues K185, Y139, D217, D241, D245, and N102 of Thermus thermophilus 3-isopropylmalate dehydrogenase (Tt-IPMDH) have been replaced, one by one, with Ala. A drastic decrease in the kcat value (0.06% compared to that of the wild-type enzyme) has been observed for the K185A and D241A mutants. Similarly, the catalytic interactions (Km values) of these two mutants with the substrate IPM are weakened by more than 1 order of magnitude. The other mutants retained some (1-13%) of the catalytic activity of the wild-type enzyme and do not exhibit appreciable changes in the substrate Km values. The pH dependence of the wild-type enzyme activity (pK = 7.4) is shifted toward higher values for mutants K185A and D241A (pK values of 8.4 and 8.5, respectively). For the other mutants, smaller changes have been observed. Consequently, K185 and D241 may constitute a proton relay system that can assist in the abstraction of a proton from the OH group of IPM during catalysis. Molecular dynamics simulations provide strong support for the neutral character of K185 in the resting state of the enzyme, which implies that K185 abstracts the proton from the substrate and D241 assists the process via electrostatic interactions with K185. Quantum mechanics/molecular mechanics calculations revealed a significant increase in the activation energy of the hydride transfer of the redox step for both D217A and D241A mutants. Crystal structure analysis of the molecular contacts of the investigated residues in the enzyme-substrate complex revealed their additional importance (in particular that of K185, D217, and D241) in stabilizing the domain-closed active conformation. In accordance with this, small-angle X-ray scattering measurements indicated the complete absence of domain closure in the cases of D217A and D241A mutants, while only partial domain closure could be detected for the other mutants. This suggests that the same residues that are important for catalysis are also essential for inducing domain closure.
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Affiliation(s)
- Éva Gráczer
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Magyar tudósok krt. 2., H-1117 Budapest, Hungary
| | - Tamás Szimler
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Magyar tudósok krt. 2., H-1117 Budapest, Hungary
| | - Anita Garamszegi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Magyar tudósok krt. 2., H-1117 Budapest, Hungary
| | - Petr V Konarev
- European Molecular Biology Laboratory , Hamburg Outstation, Notkestrasse 85, 22603 Hamburg, Germany
| | - Anikó Lábas
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics , Gellért tér 4., H-1111 Budapest, Hungary
| | - Julianna Oláh
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics , Gellért tér 4., H-1111 Budapest, Hungary
| | - Anna Palló
- Institute of Organic Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Magyar tudósok krt. 2., H-1117 Budapest, Hungary
| | - Dmitri I Svergun
- European Molecular Biology Laboratory , Hamburg Outstation, Notkestrasse 85, 22603 Hamburg, Germany
| | - Angelo Merli
- Dipartimento di Bioscienze, Universitá degli Studi di Parma , Viale G.P. Usberti 23/A, I-43100 Parma, Italy
| | - Péter Závodszky
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Magyar tudósok krt. 2., H-1117 Budapest, Hungary
| | - Manfred S Weiss
- Macromolecular Crystallography (HZB-MX), Helmholtz-Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
| | - Mária Vas
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences , Magyar tudósok krt. 2., H-1117 Budapest, Hungary
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28
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Affiliation(s)
- Sundus Erbas-Cakmak
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - David A. Leigh
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Charlie T. McTernan
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Alina
L. Nussbaumer
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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29
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Tikhonov AN. Induction events and short-term regulation of electron transport in chloroplasts: an overview. PHOTOSYNTHESIS RESEARCH 2015; 125:65-94. [PMID: 25680580 DOI: 10.1007/s11120-015-0094-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 01/26/2015] [Indexed: 05/03/2023]
Abstract
Regulation of photosynthetic electron transport at different levels of structural and functional organization of photosynthetic apparatus provides efficient performance of oxygenic photosynthesis in plants. This review begins with a brief overview of the chloroplast electron transport chain. Then two noninvasive biophysical methods (measurements of slow induction of chlorophyll a fluorescence and EPR signals of oxidized P700 centers) are exemplified to illustrate the possibility of monitoring induction events in chloroplasts in vivo and in situ. Induction events in chloroplasts are considered and briefly discussed in the context of short-term mechanisms of the following regulatory processes: (i) pH-dependent control of the intersystem electron transport; (ii) the light-induced activation of the Calvin-Benson cycle; (iii) optimization of electron transport due to fitting alternative pathways of electron flow and partitioning light energy between photosystems I and II; and (iv) the light-induced remodeling of photosynthetic apparatus and thylakoid membranes.
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Mai YZ, Li YW, Li RJ, Li W, Huang XZ, Mo ZQ, Li AX. Proteomic analysis of differentially expressed proteins in the marine fish parasitic ciliate Cryptocaryon irritans. Vet Parasitol 2015; 211:1-11. [PMID: 25997646 DOI: 10.1016/j.vetpar.2015.05.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 03/26/2015] [Accepted: 05/07/2015] [Indexed: 12/24/2022]
Abstract
Cryptocaryoniasis is a severe disease of farmed marine fish caused by the parasitic ciliate Cryptocaryon irritans. This disease can lead to considerable economic loss, but studies on proteins linked to disease development and antigenic proteins for vaccine development have been relatively scarce to date. In this study, 53 protein spots with differential abundance, representing 12 proteins, were identified based on a pair-wise comparison among theronts, trophonts, and tomonts. Meanwhile, 33 protein spots that elicited serological responses in rabbits were identified, representing 9 proteins. In addition, 27 common antigenic protein spots reacted with grouper anti-sera, representing 10 proteins. Most of the identified proteins were involved in cytoskeletal and metabolic pathways. Among these proteins, actin and α-tubulin appeared in all three developmental stages with differences in molecular weights and isoelectric points; 4 proteins (vacuolar ATP synthase catalytic subunit α, mcm2-3-5 family protein, 26S proteasome subunit P45 family protein and dnaK protein) were highly expressed only in theronts; while protein kinase domain containing protein and heat shock protein 70 showed high levels of expression only in trophonts and tomonts, respectively. Moreover, actin was co-detected with 3 rabbit anti-sera while β-tubulin, V-type ATPase α subunit family protein, heat shock protein 70, mitochondrial-type hsp70, and dnaK proteins showed immunoreactivity with corresponding rabbit anti-sera in theronts, trophonts, and tomonts. Furthermore, β-tubulin, the metabolic-related protein enolase, NADH-ubiquinone oxidoreductase 75 kDa subunit, malate dehydrogenase, as well as polypyrimidine tract-binding protein, glutamine synthetase, protein kinase domain containing protein, TNFR/NGFR cysteine-rich region family protein, and vacuolar ATP synthase catalytic subunit α, were commonly detected by grouper anti-sera. Therefore, these findings could contribute to an understanding of the differences in gene expression and phenotypes among the different stages of parasitic infection, and might be considered as a source of candidate proteins for disease diagnosis and vaccine development.
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Affiliation(s)
- Yong-Zhan Mai
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Yan-Wei Li
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Rui-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Wei Li
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Xia-Zi Huang
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Ze-Quan Mo
- College of Animal Science, South China Agricultural University, Guangzhou, China
| | - An-Xing Li
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.
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31
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Lucena MN, Pinto MR, Garçon DP, McNamara JC, Leone FA. A kinetic characterization of the gill V(H+)-ATPase in juvenile and adult Macrobrachium amazonicum, a diadromous palaemonid shrimp. Comp Biochem Physiol B Biochem Mol Biol 2015; 181:15-25. [DOI: 10.1016/j.cbpb.2014.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/05/2014] [Accepted: 11/07/2014] [Indexed: 10/24/2022]
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Balashov SP, Imasheva ES, Dioumaev A, Wang JM, Jung KH, Lanyi JK. Light-driven Na(+) pump from Gillisia limnaea: a high-affinity Na(+) binding site is formed transiently in the photocycle. Biochemistry 2014; 53:7549-61. [PMID: 25375769 PMCID: PMC4263435 DOI: 10.1021/bi501064n] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 10/17/2014] [Indexed: 02/06/2023]
Abstract
A group of microbial retinal proteins most closely related to the proton pump xanthorhodopsin has a novel sequence motif and a novel function. Instead of, or in addition to, proton transport, they perform light-driven sodium ion transport, as reported for one representative of this group (KR2) from Krokinobacter. In this paper, we examine a similar protein, GLR from Gillisia limnaea, expressed in Escherichia coli, which shares some properties with KR2 but transports only Na(+). The absorption spectrum of GLR is insensitive to Na(+) at concentrations of ≤3 M. However, very low concentrations of Na(+) cause profound differences in the decay and rise time of photocycle intermediates, consistent with a switch from a "Na(+)-independent" to a "Na(+)-dependent" photocycle (or photocycle branch) at ∼60 μM Na(+). The rates of photocycle steps in the latter, but not the former, are linearly dependent on Na(+) concentration. This suggests that a high-affinity Na(+) binding site is created transiently after photoexcitation, and entry of Na(+) from the bulk to this site redirects the course of events in the remainder of the cycle. A greater concentration of Na(+) is needed for switching the reaction path at lower pH. The data suggest therefore competition between H(+) and Na(+) to determine the two alternative pathways. The idea that a Na(+) binding site can be created at the Schiff base counterion is supported by the finding that upon perturbation of this region in the D251E mutant, Na(+) binds without photoexcitation. Binding of Na(+) to the mutant shifts the chromophore maximum to the red like that of H(+), which occurs in the photocycle of the wild type.
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Affiliation(s)
- Sergei P. Balashov
- Department
of Physiology and Biophysics, University
of California, Irvine, California 92697, United States
| | - Eleonora S. Imasheva
- Department
of Physiology and Biophysics, University
of California, Irvine, California 92697, United States
| | - Andrei
K. Dioumaev
- Department
of Physiology and Biophysics, University
of California, Irvine, California 92697, United States
| | - Jennifer M. Wang
- Department
of Physiology and Biophysics, University
of California, Irvine, California 92697, United States
| | - Kwang-Hwan Jung
- Department
of Life Science and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Shinsu-Dong 1, Mapo-Gu, Seoul 121-742, Korea
| | - Janos K. Lanyi
- Department
of Physiology and Biophysics, University
of California, Irvine, California 92697, United States
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Schumacher K. pH in the plant endomembrane system-an import and export business. CURRENT OPINION IN PLANT BIOLOGY 2014; 22:71-76. [PMID: 25282587 DOI: 10.1016/j.pbi.2014.09.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/11/2014] [Accepted: 09/12/2014] [Indexed: 05/06/2023]
Abstract
pH homeostasis is an essential process in all plant cells and the maintenance of correct luminal pH in the compartments of the endomembrane system is important not only for secondary active transport but also for a variety of cellular functions including protein modification, sorting, and trafficking. Due to their electrogenicity primary H(+)-pumps cannot establish and control the often large proton-gradients single-handedly but require the co-action of other ion transporters that serve as either shunt conductances or proton-leaks. Here, I will thus focus on recent results that highlight the interplay of proton-pumps and proton-coupled transporters in controlling pH in the compartments of the plant endomembrane system.
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Affiliation(s)
- Karin Schumacher
- Dep. of Cell Biology, Centre for Organismal Studies (COS), Universität Heidelberg, 69120 Heidelberg, Germany.
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34
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Lucia U, Ponzetto A, Deisboeck TS. A thermo-physical analysis of the proton pump vacuolar-ATPase: the constructal approach. Sci Rep 2014; 4:6763. [PMID: 25342534 PMCID: PMC4208057 DOI: 10.1038/srep06763] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 10/07/2014] [Indexed: 01/23/2023] Open
Abstract
Pumping protons across a membrane was a critical step at the origin of life on earth, and it is still performed in all living organisms, including in human cells. Proton pumping is paramount to keep normal cells alive, e.g. for lysosomal digestion and for preparing peptides for immune recognition, but it goes awry in cancer cells. They acidify their microenvironment hence membrane voltage is lowered, which in turn induces cell proliferation, a hallmark of cancer. Proton pumping is achieved by means of rotary motors, namely vacuolar ATPases (V-ATPase), which are present at many of the multiple cellular interfaces. Therefore, we undertook an examination of the thermodynamic properties of V-ATPases. The principal result is that the V-ATPase-mediated control of the cell membrane potential and the related and consequent environmental pH can potentially represent a valuable support strategy for anticancer therapies. A constructal theory approach is used as a new viewpoint to study how V-ATPase can be modulated for therapeutic purposes. In particular, V-ATPase can be regulated by using external fields, such as electromagnetic fields, and a theoretical approach has been introduced to quantify the appropriate field strength and frequency for this new adjuvant therapeutic strategy.
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Affiliation(s)
- Umberto Lucia
- Dipartimento Energia, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Antonio Ponzetto
- Department of Medical Sciences, University of Torino, Corso A.M. Dogliotti 14, 10126 Torino, Italy
| | - Thomas S. Deisboeck
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
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35
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A unique mechanism of curcumin inhibition on F1 ATPase. Biochem Biophys Res Commun 2014; 452:940-4. [DOI: 10.1016/j.bbrc.2014.09.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 09/05/2014] [Indexed: 11/21/2022]
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36
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Nakanishi-Matsui M, Sekiya M, Yano S, Futai M. Inhibition of F1-ATPase rotational catalysis by the carboxyl-terminal domain of the ϵ subunit. J Biol Chem 2014; 289:30822-30831. [PMID: 25228697 DOI: 10.1074/jbc.m114.578872] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Escherichia coli ATP synthase (F0F1) couples catalysis and proton transport through subunit rotation. The ϵ subunit, an endogenous inhibitor, lowers F1-ATPase activity by decreasing the rotation speed and extending the duration of the inhibited state (Sekiya, M., Hosokawa, H., Nakanishi-Matsui, M., Al-Shawi, M. K., Nakamoto, R. K., and Futai, M. (2010) Single molecule behavior of inhibited and active states of Escherichia coli ATP synthase F1 rotation. J. Biol. Chem. 285, 42058-42067). In this study, we constructed a series of ϵ subunits truncated successively from the carboxyl-terminal domain (helix 1/loop 2/helix 2) and examined their effects on rotational catalysis (ATPase activity, average rotation rate, and duration of inhibited state). As expected, the ϵ subunit lacking helix 2 caused about ½-fold reduced inhibition, and that without loop 2/helix 2 or helix 1/loop 2/helix 2 showed a further reduced effect. Substitution of ϵSer(108) in loop 2 and ϵTyr(114) in helix 2, which possibly interact with the β and γ subunits, respectively, decreased the inhibitory effect. These results suggest that the carboxyl-terminal domain of the ϵ subunit plays a pivotal role in the inhibition of F1 rotation through interaction with other subunits.
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Affiliation(s)
- Mayumi Nakanishi-Matsui
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Iwate Medical University, Nishitokuta 2-1-1, Yahaba, Iwate 028-3694, Japan.
| | - Mizuki Sekiya
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Iwate Medical University, Nishitokuta 2-1-1, Yahaba, Iwate 028-3694, Japan
| | - Shio Yano
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Iwate Medical University, Nishitokuta 2-1-1, Yahaba, Iwate 028-3694, Japan
| | - Masamitsu Futai
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Iwate Medical University, Nishitokuta 2-1-1, Yahaba, Iwate 028-3694, Japan
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37
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Sekiya M, Chiba E, Satoh M, Yamakoshi H, Iwabuchi Y, Futai M, Nakanishi-Matsui M. Strong inhibitory effects of curcumin and its demethoxy analog on Escherichia coli ATP synthase F1 sector. Int J Biol Macromol 2014; 70:241-5. [DOI: 10.1016/j.ijbiomac.2014.06.055] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 06/15/2014] [Accepted: 06/30/2014] [Indexed: 01/30/2023]
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38
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Mayer F, Müller V. Adaptations of anaerobic archaea to life under extreme energy limitation. FEMS Microbiol Rev 2014; 38:449-72. [DOI: 10.1111/1574-6976.12043] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 08/30/2013] [Accepted: 09/03/2013] [Indexed: 11/28/2022] Open
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Česen MH, Repnik U, Turk V, Turk B. Siramesine triggers cell death through destabilisation of mitochondria, but not lysosomes. Cell Death Dis 2013; 4:e818. [PMID: 24091661 PMCID: PMC3824671 DOI: 10.1038/cddis.2013.361] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 07/18/2013] [Accepted: 07/22/2013] [Indexed: 01/30/2023]
Abstract
A sigma-2 receptor agonist siramesine has been shown to trigger cell death of cancer cells and to exhibit a potent anticancer activity in vivo. However, its mechanism of action is still poorly understood. We show that siramesine can induce rapid cell death in a number of cell lines at concentrations above 20 μM. In HaCaT cells, cell death was accompanied by caspase activation, rapid loss of mitochondrial membrane potential (MMP), cytochrome c release, cardiolipin peroxidation and typical apoptotic morphology, whereas in U-87MG cells most apoptotic hallmarks were not notable, although MMP was rapidly lost. In contrast to the rapid loss of MMP above 20 μM siramesine, a rapid increase in lysosomal pH was observed at all concentrations tested (5–40 μM); however, it was not accompanied by lysosomal membrane permeabilisation (LMP) and the release of lysosomal enzymes into the cytosol. Increased lysosomal pH reduced the lysosomal degradation potential as indicated by the accumulation of immature forms of cysteine cathepsins. The lipophilic antioxidant α-tocopherol, but not the hydrophilic antioxidant N-acetyl-cysteine, considerably reduced cell death and destabilisation of mitochondrial membranes, but did not prevent the increase in lysosomal pH. At concentrations below 15 μM, siramesine triggered cell death after 2 days or later, which seems to be associated with a general metabolic and energy imbalance due to defects in the endocytic pathway, intracellular trafficking and energy production, and not by a specific molecular event. Overall, we show that cell death in siramesine-treated cells is induced by destabilisation of mitochondria and is independent of LMP and the release of cathepsins into the cytosol. Moreover, it is unlikely that siramesine acts exclusively through sigma-2 receptors, but rather through multiple molecular targets inside the cell. Our findings are therefore of significant importance in designing the next generation of siramesine analogues with high anticancer potential.
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Affiliation(s)
- M Hafner Česen
- 1] Department of Biochemistry and Molecular and Structural Biology, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia [2] Jožef Stefan's International Postgraduate School, Jamova 39, 1000 Ljubljana, Slovenia
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40
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Engineered Escherichia coli with periplasmic carbonic anhydrase as a biocatalyst for CO2 sequestration. Appl Environ Microbiol 2013; 79:6697-705. [PMID: 23974145 DOI: 10.1128/aem.02400-13] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Carbonic anhydrase is an enzyme that reversibly catalyzes the hydration of carbon dioxide (CO2). It has been suggested recently that this remarkably fast enzyme can be used for sequestration of CO2, a major greenhouse gas, making this a promising alternative for chemical CO2 mitigation. To promote the economical use of enzymes, we engineered the carbonic anhydrase from Neisseria gonorrhoeae (ngCA) in the periplasm of Escherichia coli, thereby creating a bacterial whole-cell catalyst. We then investigated the application of this system to CO2 sequestration by mineral carbonation, a process with the potential to store large quantities of CO2. ngCA was highly expressed in the periplasm of E. coli in a soluble form, and the recombinant bacterial cell displayed the distinct ability to hydrate CO2 compared with its cytoplasmic ngCA counterpart and previously reported whole-cell CA systems. The expression of ngCA in the periplasm of E. coli greatly accelerated the rate of calcium carbonate (CaCO3) formation and exerted a striking impact on the maximal amount of CaCO3 produced under conditions of relatively low pH. It was also shown that the thermal stability of the periplasmic enzyme was significantly improved. These results demonstrate that the engineered bacterial cell with periplasmic ngCA can successfully serve as an efficient biocatalyst for CO2 sequestration.
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41
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Nakanishi-Matsui M, Sekiya M, Futai M. Rotating proton pumping ATPases: subunit/subunit interactions and thermodynamics. IUBMB Life 2013; 65:247-54. [PMID: 23441040 DOI: 10.1002/iub.1134] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 12/21/2012] [Indexed: 11/05/2022]
Abstract
In this article, we discuss single molecule observation of rotational catalysis by E. coli ATP synthase (F-ATPase) using small gold beads. Studies involving a low viscous drag probe showed the stochastic properties of the enzyme in alternating catalytically active and inhibited states. The importance of subunit interaction between the rotor and the stator, and thermodynamics of the catalysis are also discussed. "Single Molecule Enzymology" is a new trend for understanding enzyme mechanisms in biochemistry and physiology.
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Affiliation(s)
- Mayumi Nakanishi-Matsui
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Iwate Medical University, and Futai Special Laboratory, Yahaba, Iwate, Japan.
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42
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Gajadeera CS, Weber J. Escherichia coli F1Fo-ATP synthase with a b/δ fusion protein allows analysis of the function of the individual b subunits. J Biol Chem 2013; 288:26441-7. [PMID: 23893411 DOI: 10.1074/jbc.m113.503722] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The "stator stalk" of F1Fo-ATP synthase is essential for rotational catalysis as it connects the nonrotating portions of the enzyme. In Escherichia coli, the stator stalk consists of two (identical) b subunits and the δ subunit. In mycobacteria, one of the b subunits and the δ subunit are replaced by a b/δ fusion protein; the remaining b subunit is of the shorter b' type. In the present study, it is shown that it is possible to generate a functional E. coli ATP synthase containing a b/δ fusion protein. This construct allowed the analysis of the roles of the individual b subunits. The full-length b subunit (which in this case is covalently linked to δ in the fusion protein) is responsible for connecting the stalk to the catalytic F1 subcomplex. It is not required for interaction with the membrane-embedded Fo subcomplex, as its transmembrane helix can be removed. Attachment to Fo is the function of the other b subunit which in turn has only a minor (if any at all) role in binding to δ. Also in E. coli the second b subunit can be shortened to a b' type.
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Affiliation(s)
- Chathurada S Gajadeera
- From the Department of Chemistry and Biochemistry and the Center for Chemical Biology, Texas Tech University, Lubbock, Texas 79409 and the Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, Texas 79430
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43
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Transporter Proteins. Mol Pharmacol 2012. [DOI: 10.1002/9781118451908.ch5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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44
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Ferencz C, Petrovszki P, Kóta Z, Fodor-Ayaydin E, Haracska L, Bóta A, Varga Z, Dér A, Marsh D, Páli T. Estimating the rotation rate in the vacuolar proton-ATPase in native yeast vacuolar membranes. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2012; 42:147-58. [PMID: 23160754 DOI: 10.1007/s00249-012-0871-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 10/10/2012] [Accepted: 10/25/2012] [Indexed: 11/25/2022]
Abstract
The rate of rotation of the rotor in the yeast vacuolar proton-ATPase (V-ATPase), relative to the stator or steady parts of the enzyme, is estimated in native vacuolar membrane vesicles from Saccharomyces cerevisiae under standardised conditions. Membrane vesicles are formed spontaneously after exposing purified yeast vacuoles to osmotic shock. The fraction of total ATPase activity originating from the V-ATPase is determined by using the potent and specific inhibitor of the enzyme, concanamycin A. Inorganic phosphate liberated from ATP in the vacuolar membrane vesicle system, during ten min of ATPase activity at 20 °C, is assayed spectrophotometrically for different concanamycin A concentrations. A fit of the quadratic binding equation, assuming a single concanamycin A binding site on a monomeric V-ATPase (our data are incompatible with models assuming multiple binding sites), to the inhibitor titration curve determines the concentration of the enzyme. Combining this with the known ATP/rotation stoichiometry of the V-ATPase and the assayed concentration of inorganic phosphate liberated by the V-ATPase, leads to an average rate of ~10 Hz for full 360° rotation (and a range of 6-32 Hz, considering the ± standard deviation of the enzyme concentration), which, from the time-dependence of the activity, extrapolates to ~14 Hz (8-48 Hz) at the beginning of the reaction. These are lower-limit estimates. To our knowledge, this is the first report of the rotation rate in a V-ATPase that is not subjected to genetic or chemical modification and is not fixed to a solid support; instead it is functioning in its native membrane environment.
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Affiliation(s)
- Csilla Ferencz
- Institute of Biophysics, Biological Research Centre, Temesvári krt. 62, 6726, Szeged, Hungary
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45
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Gol’dshtein BN, Aksirov AM, Zakrzhevskaya DT. Irregular activity oscillations of a rotary molecular motor: A simple kinetic model of F1-ATPase. Mol Biol 2012. [DOI: 10.1134/s0026893312040048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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46
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Lewis JH, Beausang JF, Sweeney HL, Goldman YE. The azimuthal path of myosin V and its dependence on lever-arm length. ACTA ACUST UNITED AC 2012; 139:101-20. [PMID: 22291144 PMCID: PMC3269788 DOI: 10.1085/jgp.201110715] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Myosin V (myoV) is a two-headed myosin capable of taking many successive steps along actin per diffusional encounter, enabling it to transport vesicular and ribonucleoprotein cargos in the dense and complex environment within cells. To better understand how myoV navigates along actin, we used polarized total internal reflection fluorescence microscopy to examine angular changes of bifunctional rhodamine probes on the lever arms of single myoV molecules in vitro. With a newly developed analysis technique, the rotational motions of the lever arm and the local orientation of each probe relative to the lever arm were estimated from the probe’s measured orientation. This type of analysis could be applied to similar studies on other motor proteins, as well as other proteins with domains that undergo significant rotational motions. The experiments were performed on recombinant constructs of myoV that had either the native-length (six IQ motifs and calmodulins [CaMs]) or truncated (four IQ motifs and CaMs) lever arms. Native-length myoV-6IQ mainly took straight steps along actin, with occasional small azimuthal tilts around the actin filament. Truncated myoV-4IQ showed an increased frequency of azimuthal steps, but the magnitudes of these steps were nearly identical to those of myoV-6IQ. The results show that the azimuthal deflections of myoV on actin are more common for the truncated lever arm, but the range of these deflections is relatively independent of its lever-arm length.
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Affiliation(s)
- John H Lewis
- The Pennsylvania Muscle Institute and Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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47
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Sekiya M, Nakamoto RK, Nakanishi-Matsui M, Futai M. Binding of phytopolyphenol piceatannol disrupts β/γ subunit interactions and rate-limiting step of steady-state rotational catalysis in Escherichia coli F1-ATPase. J Biol Chem 2012; 287:22771-80. [PMID: 22582396 DOI: 10.1074/jbc.m112.374868] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In observations of single molecule behavior under V(max) conditions with minimal load, the F(1) sector of the ATP synthase (F-ATPase) rotates through continuous cycles of catalytic dwells (∼0.2 ms) and 120° rotation steps (∼0.6 ms). We previously established that the rate-limiting transition step occurs during the catalytic dwell at the initiation of the 120° rotation. Here, we use the phytopolyphenol, piceatannol, which binds to a pocket formed by contributions from α and β stator subunits and the carboxyl-terminal region of the rotor γ subunit. Piceatannol did not interfere with the movement through the 120° rotation step, but caused increased duration of the catalytic dwell. The duration time of the intrinsic inhibited state of F(1) also became significantly longer with piceatannol. All of the beads rotated at a lower rate in the presence of saturating piceatannol, indicating that the inhibitor stays bound throughout the rotational catalytic cycle. The Arrhenius plot of the temperature dependence of the reciprocal of the duration of the catalytic dwell (catalytic rate) indicated significantly increased activation energy of the rate-limiting step to trigger the 120° rotation. The activation energy was further increased by combination of piceatannol and substitution of γ subunit Met(23) with Lys, indicating that the inhibitor and the β/γ interface mutation affect the same transition step, even though they perturb physically separated rotor-stator interactions.
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Affiliation(s)
- Mizuki Sekiya
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, and Futai Special Laboratory, Iwate Medical University, Yahaba, Iwate 028-3694, Japan
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48
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Rotational catalysis in proton pumping ATPases: from E. coli F-ATPase to mammalian V-ATPase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1711-21. [PMID: 22459334 DOI: 10.1016/j.bbabio.2012.03.015] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Revised: 03/10/2012] [Accepted: 03/13/2012] [Indexed: 01/28/2023]
Abstract
We focus on the rotational catalysis of Escherichia coli F-ATPase (ATP synthase, F(O)F(1)). Using a probe with low viscous drag, we found stochastic fluctuation of the rotation rates, a flat energy pathway, and contribution of an inhibited state to the overall behavior of the enzyme. Mutational analyses revealed the importance of the interactions among β and γ subunits and the β subunit catalytic domain. We also discuss the V-ATPase, which has different physiological roles from the F-ATPase, but is structurally and mechanistically similar. We review the rotation, diversity of subunits, and the regulatory mechanism of reversible subunit dissociation/assembly of Saccharomyces cerevisiae and mammalian complexes. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012).
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Chan CY, Prudom C, Raines SM, Charkhzarrin S, Melman SD, De Haro LP, Allen C, Lee SA, Sklar LA, Parra KJ. Inhibitors of V-ATPase proton transport reveal uncoupling functions of tether linking cytosolic and membrane domains of V0 subunit a (Vph1p). J Biol Chem 2012; 287:10236-10250. [PMID: 22215674 DOI: 10.1074/jbc.m111.321133] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Vacuolar ATPases (V-ATPases) are important for many cellular processes, as they regulate pH by pumping cytosolic protons into intracellular organelles. The cytoplasm is acidified when V-ATPase is inhibited; thus we conducted a high-throughput screen of a chemical library to search for compounds that acidify the yeast cytosol in vivo using pHluorin-based flow cytometry. Two inhibitors, alexidine dihydrochloride (EC(50) = 39 μM) and thonzonium bromide (EC(50) = 69 μM), prevented ATP-dependent proton transport in purified vacuolar membranes. They acidified the yeast cytosol and caused pH-sensitive growth defects typical of V-ATPase mutants (vma phenotype). At concentrations greater than 10 μM the inhibitors were cytotoxic, even at the permissive pH (pH 5.0). Membrane fractions treated with alexidine dihydrochloride and thonzonium bromide fully retained concanamycin A-sensitive ATPase activity despite the fact that proton translocation was inhibited by 80-90%, indicating that V-ATPases were uncoupled. Mutant V-ATPase membranes lacking residues 362-407 of the tether of Vph1p subunit a of V(0) were resistant to thonzonium bromide but not to alexidine dihydrochloride, suggesting that this conserved sequence confers uncoupling potential to V(1)V(0) complexes and that alexidine dihydrochloride uncouples the enzyme by a different mechanism. The inhibitors also uncoupled the Candida albicans enzyme and prevented cell growth, showing further specificity for V-ATPases. Thus, a new class of V-ATPase inhibitors (uncouplers), which are not simply ionophores, provided new insights into the enzyme mechanism and original evidence supporting the hypothesis that V-ATPases may not be optimally coupled in vivo. The consequences of uncoupling V-ATPases in vivo as potential drug targets are discussed.
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Affiliation(s)
- Chun-Yuan Chan
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
| | - Catherine Prudom
- Center for Molecular Discovery, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
| | - Summer M Raines
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
| | - Sahba Charkhzarrin
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
| | - Sandra D Melman
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
| | - Leyma P De Haro
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
| | - Chris Allen
- Center for Molecular Discovery, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
| | - Samuel A Lee
- Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
| | - Larry A Sklar
- Center for Molecular Discovery, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131; Department of Pathology and Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
| | - Karlett J Parra
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131.
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Usukura E, Suzuki T, Furuike S, Soga N, Saita EI, Hisabori T, Kinosita K, Yoshida M. Torque generation and utilization in motor enzyme F0F1-ATP synthase: half-torque F1 with short-sized pushrod helix and reduced ATP Synthesis by half-torque F0F1. J Biol Chem 2011; 287:1884-91. [PMID: 22128167 DOI: 10.1074/jbc.m111.305938] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
ATP synthase (F(0)F(1)) is made of two motors, a proton-driven motor (F(0)) and an ATP-driven motor (F(1)), connected by a common rotary shaft, and catalyzes proton flow-driven ATP synthesis and ATP-driven proton pumping. In F(1), the central γ subunit rotates inside the α(3)β(3) ring. Here we report structural features of F(1) responsible for torque generation and the catalytic ability of the low-torque F(0)F(1). (i) Deletion of one or two turns in the α-helix in the C-terminal domain of catalytic β subunit at the rotor/stator contact region generates mutant F(1)s, termed F(1)(1/2)s, that rotate with about half of the normal torque. This helix would support the helix-loop-helix structure acting as a solid "pushrod" to push the rotor γ subunit, but the short helix in F(1)(1/2)s would fail to accomplish this task. (ii) Three different half-torque F(0)F(1)(1/2)s were purified and reconstituted into proteoliposomes. They carry out ATP-driven proton pumping and build up the same small transmembrane ΔpH, indicating that the final ΔpH is directly related to the amount of torque. (iii) The half-torque F(0)F(1)(1/2)s can catalyze ATP synthesis, although slowly. The rate of synthesis varies widely among the three F(0)F(1)(1/2)s, which suggests that the rate reflects subtle conformational variations of individual mutants.
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Affiliation(s)
- Eiji Usukura
- Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta 4259, Yokohama 226-8503
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