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Du J, Meki I, Li Q, Liu Y, Zhu Z, Pan C, Xia Y, Fu L, Yang L, Zhang S, Yin C, Luo Y, Wang T, Liu B, Chen X. A non-toxic recombinant Clostridium septicum α toxin induces protective immunity in mice and rabbits. Toxicon 2023; 233:107234. [PMID: 37543293 DOI: 10.1016/j.toxicon.2023.107234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/07/2023]
Abstract
Clostridium septicum alpha toxin (CSA) plays significant roles in ruminant's braxy. Genetically engineered CSA has been shown to function as a potential vaccine candidate in the prevention of the disease caused by Clostridium septicum. In the present study, we synthesized a non-toxic recombinant, rCSAm4/TMD by introducing four amino acid substitutions (C86L/N296A/H301A/W342A) and 11-amino-acid deletion (residues 212 to 222). Compared to recombinant CSA, rCSAm4/TMD showed no cytotoxicity to MDCK cells and was not fatal to mice. Moreover, rCSAm4/TMD could protect immunized mice against 5 × mouse LD100 (100% lethal dose) of crude CSA without obvious pathological change. Most importantly, rabbits immunized with rCSAm4/TMD produced high titers of neutralizing antibodies which protected the rabbits against crude CSA challenge. These data suggest that genetically detoxified rCSAm4/TMD is a potential subunit vaccine candidate against braxy.
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Affiliation(s)
- Jige Du
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Irene Meki
- International Atomic Energy Agency, Vienna, Austria
| | - Qianlin Li
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Ying Liu
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Zhen Zhu
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Chenfan Pan
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Yingju Xia
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Lizhi Fu
- Chongqing Academy of Animal Sciences, Chongqing, 402460, China
| | - Liu Yang
- Chongqing Academy of Animal Sciences, Chongqing, 402460, China
| | - Suhui Zhang
- Chongqing Academy of Animal Sciences, Chongqing, 402460, China
| | - Chunsheng Yin
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Yufeng Luo
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China
| | - Tuanjie Wang
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China.
| | - Bo Liu
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China; International Atomic Energy Agency, Vienna, Austria.
| | - Xiaoyun Chen
- China Institute of Veterinary Drug Control, Beijing, People's Republic of China.
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2
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Joudeh N, Linke D. Nanoparticle classification, physicochemical properties, characterization, and applications: a comprehensive review for biologists. J Nanobiotechnology 2022; 20:262. [PMID: 35672712 PMCID: PMC9171489 DOI: 10.1186/s12951-022-01477-8] [Citation(s) in RCA: 136] [Impact Index Per Article: 68.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/23/2022] [Indexed: 12/31/2022] Open
Abstract
Interest in nanomaterials and especially nanoparticles has exploded in the past decades primarily due to their novel or enhanced physical and chemical properties compared to bulk material. These extraordinary properties have created a multitude of innovative applications in the fields of medicine and pharma, electronics, agriculture, chemical catalysis, food industry, and many others. More recently, nanoparticles are also being synthesized ‘biologically’ through the use of plant- or microorganism-mediated processes, as an environmentally friendly alternative to the expensive, energy-intensive, and potentially toxic physical and chemical synthesis methods. This transdisciplinary approach to nanoparticle synthesis requires that biologists and biotechnologists understand and learn to use the complex methodology needed to properly characterize these processes. This review targets a bio-oriented audience and summarizes the physico–chemical properties of nanoparticles, and methods used for their characterization. It highlights why nanomaterials are different compared to micro- or bulk materials. We try to provide a comprehensive overview of the different classes of nanoparticles and their novel or enhanced physicochemical properties including mechanical, thermal, magnetic, electronic, optical, and catalytic properties. A comprehensive list of the common methods and techniques used for the characterization and analysis of these properties is presented together with a large list of examples for biogenic nanoparticles that have been previously synthesized and characterized, including their application in the fields of medicine, electronics, agriculture, and food production. We hope that this makes the many different methods more accessible to the readers, and to help with identifying the proper methodology for any given nanoscience problem.
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Rubio-Ramos A, Labat-de-Hoz L, Correas I, Alonso MA. The MAL Protein, an Integral Component of Specialized Membranes, in Normal Cells and Cancer. Cells 2021; 10:1065. [PMID: 33946345 PMCID: PMC8145151 DOI: 10.3390/cells10051065] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 12/12/2022] Open
Abstract
The MAL gene encodes a 17-kDa protein containing four putative transmembrane segments whose expression is restricted to human T cells, polarized epithelial cells and myelin-forming cells. The MAL protein has two unusual biochemical features. First, it has lipid-like properties that qualify it as a member of the group of proteolipid proteins. Second, it partitions selectively into detergent-insoluble membranes, which are known to be enriched in condensed cell membranes, consistent with MAL being distributed in highly ordered membranes in the cell. Since its original description more than thirty years ago, a large body of evidence has accumulated supporting a role of MAL in specialized membranes in all the cell types in which it is expressed. Here, we review the structure, expression and biochemical characteristics of MAL, and discuss the association of MAL with raft membranes and the function of MAL in polarized epithelial cells, T lymphocytes, and myelin-forming cells. The evidence that MAL is a putative receptor of the epsilon toxin of Clostridium perfringens, the expression of MAL in lymphomas, the hypermethylation of the MAL gene and subsequent loss of MAL expression in carcinomas are also presented. We propose a model of MAL as the organizer of specialized condensed membranes to make them functional, discuss the role of MAL as a tumor suppressor in carcinomas, consider its potential use as a cancer biomarker, and summarize the directions for future research.
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Affiliation(s)
- Armando Rubio-Ramos
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049 Madrid, Spain; (A.R.-R.); (L.L.-d.-H.); (I.C.)
| | - Leticia Labat-de-Hoz
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049 Madrid, Spain; (A.R.-R.); (L.L.-d.-H.); (I.C.)
| | - Isabel Correas
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049 Madrid, Spain; (A.R.-R.); (L.L.-d.-H.); (I.C.)
- Department of Molecular Biology, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Miguel A. Alonso
- Centro de Biología Molecular “Severo Ochoa”, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049 Madrid, Spain; (A.R.-R.); (L.L.-d.-H.); (I.C.)
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4
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Parperis C, Wallace MI. Single-molecule imaging of pore-forming toxin dynamics in droplet interface bilayers. Methods Enzymol 2021; 649:431-459. [PMID: 33712195 DOI: 10.1016/bs.mie.2021.01.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Single-channel recording from pore-forming toxins (PFTs) provides a clear and direct molecular readout of toxin action. However to complete any mechanistic understanding of PFT behavior, this functional kinetic readout must be linked to the underlying changes in toxin structure, binding, conformation, or stoichiometry. Here we review how single-molecule imaging methods might be used to further our understanding of PFTs, and provide detailed practical guidance on the use of droplet interface bilayers as a method capable of examining both single-molecule fluorescence and single-channel electrical signals from PFTs.
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Affiliation(s)
- Christopher Parperis
- Department of Chemistry, Britannia House, King's College London, London, United Kingdom
| | - Mark I Wallace
- Department of Chemistry, Britannia House, King's College London, London, United Kingdom.
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5
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Bogdan MJ, Savin T. Errors in Energy Landscapes Measured with Particle Tracking. Biophys J 2019; 115:139-149. [PMID: 29972805 DOI: 10.1016/j.bpj.2018.05.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 04/28/2018] [Accepted: 05/01/2018] [Indexed: 01/29/2023] Open
Abstract
Tracking Brownian particles is often employed to map the energy landscape they explore. Such measurements have been exploited to study many biological processes and interactions in soft materials. Yet video tracking is irremediably contaminated by localization errors originating from two imaging artifacts: the "static" errors come from signal noise, and the "dynamic" errors arise from the motion blur due to finite frame-acquisition time. We show that these errors result in systematic and nontrivial biases in the measured energy landscapes. We derive a relationship between the true and the measured potential that elucidates, among other aberrations, the presence of false double-well minima in the apparent potentials reported in recent studies. We further assess several canonical trapping and pair-interaction potentials by using our analytically derived results and Brownian dynamics simulations. In particular, we show that the apparent spring stiffness of harmonic potentials (such as optical traps) is increased by dynamic errors but decreased by static errors. Our formula allows for the development of efficient corrections schemes, and we also present in this work a provisional method for reconstructing true potentials from the measured ones.
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Affiliation(s)
- Michał J Bogdan
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Thierry Savin
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom.
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6
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Abdesselem M, Ramodiharilafy R, Devys L, Gacoin T, Alexandrou A, Bouzigues CI. Fast quantitative ROS detection based on dual-color single rare-earth nanoparticle imaging reveals signaling pathway kinetics in living cells. NANOSCALE 2017; 9:656-665. [PMID: 27942670 DOI: 10.1039/c6nr07413h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Reactive oxygen species (ROS), and notably hydrogen peroxide H2O2, are cellular second messengers that are known to control a variety of signaling processes. They can finely regulate the dynamics of signal transduction, cell response and ultimately tissue function. However, there are very few local, quantitative and time-resolved descriptions of their cellular organization at the scale of molecular reactions, due to the lack of efficient sensors. We thus developed a novel nanoprobe-based ROS detection system using the simultaneous imaging of single lanthanide nanoparticles (YAG:Ce and chemically reduced Gd0.6Eu0.4VO4). We reveal that both particle luminescence signals are controlled by their H2O2 local environment. By simultaneously tracking their luminescence, we devised a new approach providing a quantitative (0.5 μM accuracy in the 1-10 μM range) H2O2 measurement with a 500 ms time resolution, surpassing all existing methods by two orders of magnitude, and revealing previously inaccessible molecular events controlling ROS concentration. We used this nanoprobe in living cells to track fast signaling pathways, by measuring the dynamics of H2O2 intracellular concentrations, induced by endothelin-1 (ET-1) stimulation. We thus revealed the mechanisms controlling ROS production, notably the activity modulation of the ROS-producing enzyme NADPH oxidase by fast (<10 s) EGFR transactivation, and measured quantitatively their kinetic parameters through a minimal analytical model. Altogether, these results illustrate how lanthanide nanoparticle-based sensors are a powerful tool to dynamically probe molecular mechanisms shaping the oxidative cell response.
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Affiliation(s)
- M Abdesselem
- Laboratory for Optics and Biosciences, Ecole Polytechnique, INSERM U1182 - CNRS UMR7645. and Universite Paris-Saclay, 91120 Palaiseau, France.
| | - R Ramodiharilafy
- Laboratory for Optics and Biosciences, Ecole Polytechnique, INSERM U1182 - CNRS UMR7645. and Universite Paris-Saclay, 91120 Palaiseau, France.
| | - L Devys
- Laboratory of Condensed Matter Physics, Ecole Polytechnique, CNRS UMR7643 and Universite Paris-Saclay, 91120 Palaiseau, France
| | - T Gacoin
- Laboratory of Condensed Matter Physics, Ecole Polytechnique, CNRS UMR7643 and Universite Paris-Saclay, 91120 Palaiseau, France
| | - A Alexandrou
- Laboratory for Optics and Biosciences, Ecole Polytechnique, INSERM U1182 - CNRS UMR7645. and Universite Paris-Saclay, 91120 Palaiseau, France.
| | - C I Bouzigues
- Laboratory for Optics and Biosciences, Ecole Polytechnique, INSERM U1182 - CNRS UMR7645. and Universite Paris-Saclay, 91120 Palaiseau, France.
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7
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El Beheiry M, Türkcan S, Richly MU, Triller A, Alexandrou A, Dahan M, Masson JB. A Primer on the Bayesian Approach to High-Density Single-Molecule Trajectories Analysis. Biophys J 2016; 110:1209-15. [PMID: 27028631 DOI: 10.1016/j.bpj.2016.01.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 01/13/2016] [Accepted: 01/15/2016] [Indexed: 10/22/2022] Open
Abstract
Tracking single molecules in living cells provides invaluable information on their environment and on the interactions that underlie their motion. New experimental techniques now permit the recording of large amounts of individual trajectories, enabling the implementation of advanced statistical tools for data analysis. In this primer, we present a Bayesian approach toward treating these data, and we discuss how it can be fruitfully employed to infer physical and biochemical parameters from single-molecule trajectories.
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Affiliation(s)
- Mohamed El Beheiry
- Laboratoire Physico-Chimie, Institut Curie, PSL Research University, Paris, France; Department of Radiation Oncology, Sorbonne Universités, Paris, France; Physics of Biological Systems, Institut Pasteur, Paris, France
| | - Silvan Türkcan
- Division of Medical Physics, Stanford University School of Medicine, Palo Alto, California
| | - Maximilian U Richly
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Université Paris-Saclay, Palaiseau, France
| | - Antoine Triller
- Biologie Cellulaire de la Synapse, École Normale Supérieure, PSL Research University, Paris, France
| | - Antigone Alexandrou
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Université Paris-Saclay, Palaiseau, France
| | - Maxime Dahan
- Laboratoire Physico-Chimie, Institut Curie, PSL Research University, Paris, France; Department of Radiation Oncology, Sorbonne Universités, Paris, France; Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia
| | - Jean-Baptiste Masson
- Physics of Biological Systems, Institut Pasteur, Paris, France; Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia.
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8
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Rumah KR, Ma Y, Linden JR, Oo ML, Anrather J, Schaeren-Wiemers N, Alonso MA, Fischetti VA, McClain MS, Vartanian T. The Myelin and Lymphocyte Protein MAL Is Required for Binding and Activity of Clostridium perfringens ε-Toxin. PLoS Pathog 2015; 11:e1004896. [PMID: 25993478 PMCID: PMC4439126 DOI: 10.1371/journal.ppat.1004896] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 04/19/2015] [Indexed: 12/18/2022] Open
Abstract
Clostridium perfringens ε-toxin (ETX) is a potent pore-forming toxin responsible for a central nervous system (CNS) disease in ruminant animals with characteristics of blood-brain barrier (BBB) dysfunction and white matter injury. ETX has been proposed as a potential causative agent for Multiple Sclerosis (MS), a human disease that begins with BBB breakdown and injury to myelin forming cells of the CNS. The receptor for ETX is unknown. Here we show that both binding of ETX to mammalian cells and cytotoxicity requires the tetraspan proteolipid Myelin and Lymphocyte protein (MAL). While native Chinese Hamster Ovary (CHO) cells are resistant to ETX, exogenous expression of MAL in CHO cells confers both ETX binding and susceptibility to ETX-mediated cell death. Cells expressing rat MAL are ~100 times more sensitive to ETX than cells expressing similar levels of human MAL. Insertion of the FLAG sequence into the second extracellular loop of MAL abolishes ETX binding and cytotoxicity. ETX is known to bind specifically and with high affinity to intestinal epithelium, renal tubules, brain endothelial cells and myelin. We identify specific binding of ETX to these structures and additionally show binding to retinal microvasculature and the squamous epithelial cells of the sclera in wild-type mice. In contrast, there is a complete absence of ETX binding to tissues from MAL knockout (MAL-/-) mice. Furthermore, MAL-/- mice exhibit complete resistance to ETX at doses in excess of 1000 times the symptomatic dose for wild-type mice. We conclude that MAL is required for both ETX binding and cytotoxicity.
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Affiliation(s)
- Kareem Rashid Rumah
- Brain and Mind Research Institute, Weill Cornell Medical College, New York City, New York, United States of America
- Laboratory of Bacterial Pathogenesis and Immunology, The Rockefeller University, New York City, New York, United States of America
| | - Yinghua Ma
- Brain and Mind Research Institute, Weill Cornell Medical College, New York City, New York, United States of America
| | - Jennifer R. Linden
- Brain and Mind Research Institute, Weill Cornell Medical College, New York City, New York, United States of America
| | - Myat Lin Oo
- Brain and Mind Research Institute, Weill Cornell Medical College, New York City, New York, United States of America
| | - Josef Anrather
- Brain and Mind Research Institute, Weill Cornell Medical College, New York City, New York, United States of America
| | - Nicole Schaeren-Wiemers
- Neurobiology, Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Miguel A. Alonso
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Cantoblanco, Madrid, Spain
| | - Vincent A. Fischetti
- Laboratory of Bacterial Pathogenesis and Immunology, The Rockefeller University, New York City, New York, United States of America
| | - Mark S. McClain
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Timothy Vartanian
- Brain and Mind Research Institute, Weill Cornell Medical College, New York City, New York, United States of America
- * E-mail:
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9
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Herrmann A, Sieben C. Single-virus force spectroscopy unravels molecular details of virus infection. Integr Biol (Camb) 2015; 7:620-32. [PMID: 25923471 DOI: 10.1039/c5ib00041f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Virus infection is a multistep process that has significant effects on the structure and function of both the virus and the host cell. The first steps of virus replication include cell binding, entry and release of the viral genome. Single-virus force spectroscopy (SVFS) has become a promising tool to understand the molecular details of those steps. SVFS data complemented by biochemical and biophysical, including theoretical modeling approaches provide valuable insights into molecular events that accompany virus infection. Properties of virus-cell interaction as well as structural alterations of the virus essential for infection can be investigated on a quantitative level. Here we review applications of SVFS to virus binding, structure and mechanics. We demonstrate that SVFS offers unexpected new insights not accessible by other methods.
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Affiliation(s)
- Andreas Herrmann
- Humboldt-Universität zu Berlin, Institut für Biologie, Molekulare Biophysik, Invalidenstr. 42, D-10115 Berlin, Germany.
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10
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Chakravorty A, Awad MM, Cheung JK, Hiscox TJ, Lyras D, Rood JI. The pore-forming α-toxin from clostridium septicum activates the MAPK pathway in a Ras-c-Raf-dependent and independent manner. Toxins (Basel) 2015; 7:516-34. [PMID: 25675415 PMCID: PMC4344638 DOI: 10.3390/toxins7020516] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 02/02/2015] [Indexed: 12/13/2022] Open
Abstract
Clostridium septicum is the causative agent of atraumatic gas gangrene, with α-toxin, an extracellular pore-forming toxin, essential for disease. How C. septicum modulates the host’s innate immune response is poorly defined, although α-toxin-intoxicated muscle cells undergo cellular oncosis, characterised by mitochondrial dysfunction and release of reactive oxygen species. Nonetheless, the signalling events that occur prior to the initiation of oncosis are poorly characterised. Our aims were to characterise the ability of α-toxin to activate the host mitogen activated protein kinase (MAPK) signalling pathway both in vitro and in vivo. Treatment of Vero cells with purified α-toxin activated the extracellular-signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 arms of the MAPK pathway and stimulated the release of TNF-α in a dose-dependent manner. Studies using inhibitors of all three MAPK components suggested that activation of ERK occurred in a Ras-c-Raf dependent manner, whereas activation of JNK and p38 occurred by a Ras-independent mechanism. Toxin-mediated activation was dependent on efficient receptor binding and pore formation and on an influx of extracellular calcium ions. In the mouse myonecrosis model we showed that the MAPK pathway was activated in tissues of infected mice, implying that it has an important role in the disease process.
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Affiliation(s)
- Anjana Chakravorty
- Department of Microbiology, Monash University, Clayton, VIC 3800, Australia.
| | - Milena M Awad
- Department of Microbiology, Monash University, Clayton, VIC 3800, Australia.
| | - Jackie K Cheung
- Department of Microbiology, Monash University, Clayton, VIC 3800, Australia.
| | - Thomas J Hiscox
- Department of Microbiology, Monash University, Clayton, VIC 3800, Australia.
| | - Dena Lyras
- Department of Microbiology, Monash University, Clayton, VIC 3800, Australia.
| | - Julian I Rood
- Department of Microbiology, Monash University, Clayton, VIC 3800, Australia.
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11
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Clostridial pore-forming toxins: Powerful virulence factors. Anaerobe 2014; 30:220-38. [DOI: 10.1016/j.anaerobe.2014.05.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/16/2014] [Accepted: 05/25/2014] [Indexed: 01/05/2023]
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12
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Abdesselem M, Schoeffel M, Maurin I, Ramodiharilafy R, Autret G, Clément O, Tharaux PL, Boilot JP, Gacoin T, Bouzigues C, Alexandrou A. Multifunctional rare-Earth vanadate nanoparticles: luminescent labels, oxidant sensors, and MRI contrast agents. ACS NANO 2014; 8:11126-11137. [PMID: 25290552 DOI: 10.1021/nn504170x] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Collecting information on multiple pathophysiological parameters is essential for understanding complex pathologies, especially given the large interindividual variability. We report here multifunctional nanoparticles which are luminescent probes, oxidant sensors, and contrast agents in magnetic resonance imaging (MRI). Eu(3+) ions in an yttrium vanadate matrix have been demonstrated to emit strong, nonblinking, and stable luminescence. Time- and space-resolved optical oxidant detection is feasible after reversible photoreduction of Eu(3+) to Eu(2+) and reoxidation by oxidants, such as H2O2, leading to a modulation of the luminescence emission. The incorporation of paramagnetic Gd(3+) confers in addition proton relaxation enhancing properties to the system. We synthesized and characterized nanoparticles of either 5 or 30 nm diameter with compositions of GdVO4 and Gd0.6Eu0.4VO4. These particles retain the luminescence and oxidant detection properties of YVO4:Eu. Moreover, the proton relaxivity of GdVO4 and Gd0.6Eu0.4VO4 nanoparticles of 5 nm diameter is higher than that of the commercial Gd(3+) chelate compound Dotarem at 20 MHz. Nuclear magnetic resonance dispersion spectroscopy showed a relaxivity increase above 10 MHz. Complexometric titration indicated that rare-earth leaching is negligible. The 5 nm nanoparticles injected in mice were observed with MRI to concentrate in the liver and the bladder after 30 min. Thus, these multifunctional rare-earth vanadate nanoparticles pave the way for simultaneous optical and magnetic resonance detection, in particular, for in vivo localization evolution and reactive oxygen species detection in a broad range of physiological and pathophysiological conditions.
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Affiliation(s)
- Mouna Abdesselem
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique , CNRS UMR 7645-INSERM U696, 91128 Palaiseau Cedex, France
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13
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Alves GG, Machado de Ávila RA, Chávez-Olórtegui CD, Lobato FCF. Clostridium perfringens epsilon toxin: the third most potent bacterial toxin known. Anaerobe 2014; 30:102-7. [PMID: 25234332 DOI: 10.1016/j.anaerobe.2014.08.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 08/18/2014] [Accepted: 08/19/2014] [Indexed: 01/24/2023]
Abstract
Epsilon toxin (ETX) is produced by Clostridium perfringens type B and D strains and causes enterotoxemia, a highly lethal disease with major impacts on the farming of domestic ruminants, particularly sheep. ETX belongs to the aerolysin-like pore-forming toxin family. Although ETX has striking similarities to other toxins in this family, ETX is often more potent, with an LD50 of 100 ng/kg in mice. Due to this high potency, ETX is considered as a potential bioterrorism agent and has been classified as a category B biological agent by the Centers for Disease Control and Prevention (CDC) of the United States. The protoxin is converted to an active toxin through proteolytic cleavage performed by specific proteases. ETX is absorbed and acts locally in the intestines then subsequently binds to and causes lesions in other organs, including the kidneys, lungs and brain. The importance of this toxin for veterinary medicine and its possible use as a biological weapon have drawn the attention of researchers and have led to a large number of studies investigating ETX. The aim of the present work is to review the existing knowledge on ETX from C. perfringens type B and D.
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Affiliation(s)
- Guilherme Guerra Alves
- Veterinary School, Universidade Federal de Minas Gerais (UFMG), Antônio Carlos Avenue, 6627, Belo Horizonte, MG CEP 31.270-901, Brazil.
| | | | - Carlos Delfin Chávez-Olórtegui
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Antônio Carlos Avenue, 6627, Belo Horizonte, MG CEP 31.270-901, Brazil
| | - Francisco Carlos Faria Lobato
- Veterinary School, Universidade Federal de Minas Gerais (UFMG), Antônio Carlos Avenue, 6627, Belo Horizonte, MG CEP 31.270-901, Brazil.
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14
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Nguyên TL, Castaing M, Gacoin T, Boilot JP, Balembois F, Georges P, Alexandrou A. Single YVO4:Eu nanoparticle emission spectra using direct Eu3+ ion excitation with a sum-frequency 465-nm solid-state laser. OPTICS EXPRESS 2014; 22:20542-20550. [PMID: 25321259 DOI: 10.1364/oe.22.020542] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report emission spectrum measurements on single YxEu(1-x)VO4 nanoparticles. The inhomogeneous widths of the emission peaks are identical for single nanoparticles and for ensembles of nanoparticles, while being broader than those of the bulk material. This indicates that individual nanoparticles are identical in terms of the distribution of different local Eu3+ sites due to crystalline defects and confirms their usability as identical, single-particle oxidant biosensors. Moreover, we report a 465 nm solid-state laser based on sum-frequency mixing that provides a compact, efficient solution for direct Eu3+ excitation of these nanoparticles. Both these two aspects should broaden the scope of Eu-doped nanoparticle applications.
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Türkcan S, Richly MU, Bouzigues CI, Allain JM, Alexandrou A. Receptor displacement in the cell membrane by hydrodynamic force amplification through nanoparticles. Biophys J 2014; 105:116-26. [PMID: 23823230 DOI: 10.1016/j.bpj.2013.05.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 05/07/2013] [Accepted: 05/20/2013] [Indexed: 12/11/2022] Open
Abstract
We introduce an intrinsically multiplexed and easy to implement method to apply an external force to a biomolecule and thus probe its interaction with a second biomolecule or, more generally, its environment (for example, the cell membrane). We take advantage of the hydrodynamic interaction with a controlled fluid flow within a microfluidic channel to apply a force. By labeling the biomolecule with a nanoparticle that acts as a kite and increases the hydrodynamic interaction with the fluid, the drag induced by convection becomes important. We use this approach to track the motion of single membrane receptors, the Clostridium perfringens ε-toxin (CPεT) receptors that are confined in lipid raft platforms, and probe their interaction with the environment. Under external force, we observe displacements over distances up to 10 times the confining domain diameter due to elastic deformation of a barrier and return to the initial position after the flow is stopped. Receptors can also jump over such barriers. Analysis of the receptor motion characteristics before, during, and after a force is applied via the flow indicates that the receptors are displaced together with their confining raft platform. Experiments before and after incubation with latrunculin B reveal that the barriers are part of the actin cytoskeleton and have an average spring constant of 2.5 ± 0.6 pN/μm before vs. 0.6 ± 0.2 pN/μm after partial actin depolymerization. Our data, in combination with our previous work demonstrating that the ε-toxin receptor confinement is not influenced by the cytoskeleton, imply that it is the raft platform and its constituents rather than the receptor itself that encounters and deforms the barriers formed by the actin cytoskeleton.
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Affiliation(s)
- Silvan Türkcan
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale U696, Palaiseau Cedex, France
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Türkcan S, Masson JB. Bayesian decision tree for the classification of the mode of motion in single-molecule trajectories. PLoS One 2013; 8:e82799. [PMID: 24376584 PMCID: PMC3869729 DOI: 10.1371/journal.pone.0082799] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 10/29/2013] [Indexed: 11/18/2022] Open
Abstract
Membrane proteins move in heterogeneous environments with spatially (sometimes temporally) varying friction and with biochemical interactions with various partners. It is important to reliably distinguish different modes of motion to improve our knowledge of the membrane architecture and to understand the nature of interactions between membrane proteins and their environments. Here, we present an analysis technique for single molecule tracking (SMT) trajectories that can determine the preferred model of motion that best matches observed trajectories. The method is based on Bayesian inference to calculate the posteriori probability of an observed trajectory according to a certain model. Information theory criteria, such as the Bayesian information criterion (BIC), the Akaike information criterion (AIC), and modified AIC (AICc), are used to select the preferred model. The considered group of models includes free Brownian motion, and confined motion in 2nd or 4th order potentials. We determine the best information criteria for classifying trajectories. We tested its limits through simulations matching large sets of experimental conditions and we built a decision tree. This decision tree first uses the BIC to distinguish between free Brownian motion and confined motion. In a second step, it classifies the confining potential further using the AIC. We apply the method to experimental Clostridium Perfingens [Formula: see text]-toxin (CP[Formula: see text]T) receptor trajectories to show that these receptors are confined by a spring-like potential. An adaptation of this technique was applied on a sliding window in the temporal dimension along the trajectory. We applied this adaptation to experimental CP[Formula: see text]T trajectories that lose confinement due to disaggregation of confining domains. This new technique adds another dimension to the discussion of SMT data. The mode of motion of a receptor might hold more biologically relevant information than the diffusion coefficient or domain size and may be a better tool to classify and compare different SMT experiments.
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Affiliation(s)
- Silvan Türkcan
- Physics of Biological Systems, Institut Pasteur, Paris, France
- Centre National de la Recherche Scientifique (CNRS), UMR 3525, Paris, France
- Laboratoire d’Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale U696, Palaiseau, France
- * E-mail:
| | - Jean-Baptiste Masson
- Physics of Biological Systems, Institut Pasteur, Paris, France
- Centre National de la Recherche Scientifique (CNRS), UMR 3525, Paris, France
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Richly MU, Türkcan S, Le Gall A, Fiszman N, Masson JB, Westbrook N, Perronet K, Alexandrou A. Calibrating optical tweezers with Bayesian inference. OPTICS EXPRESS 2013; 21:31578-31590. [PMID: 24514731 DOI: 10.1364/oe.21.031578] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present a new method for calibrating an optical-tweezer setup that does not depend on input parameters and is less affected by systematic errors like drift of the setup. It is based on an inference approach that uses Bayesian probability to infer the diffusion coefficient and the potential felt by a bead trapped in an optical or magnetic trap. It exploits a much larger amount of the information stored in the recorded bead trajectory than standard calibration approaches. We demonstrate that this method outperforms the equipartition method and the power-spectrum method in input information required (bead radius and trajectory length) and in output accuracy.
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Wioland L, Dupont JL, Bossu JL, Popoff MR, Poulain B. Attack of the nervous system by Clostridium perfringens Epsilon toxin: from disease to mode of action on neural cells. Toxicon 2013; 75:122-35. [PMID: 23632158 DOI: 10.1016/j.toxicon.2013.04.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 03/29/2013] [Accepted: 04/10/2013] [Indexed: 12/24/2022]
Abstract
Epsilon toxin (ET), produced by Clostridium perfringens types B and D, ranks among the four most potent poisonous substances known so far. ET-intoxication is responsible for enterotoxaemia in animals, mainly sheep and goats. This disease comprises several manifestations indicating the attack of the nervous system. This review aims to summarize the effects of ET on central nervous system. ET binds to endothelial cells of brain capillary vessels before passing through the blood-brain barrier. Therefore, it induces perivascular oedema and accumulates into brain. ET binding to different brain structures and to different component in the brain indicates regional susceptibility to the toxin. Histological examination has revealed nerve tissue and cellular lesions, which may be directly or indirectly caused by ET. The naturally occurring disease caused by ET-intoxication can be reproduced experimentally in rodents. In mice and rats, ET recognizes receptor at the surface of different neural cell types, including certain neurons (e.g. the granule cells in cerebellum) as well as oligodendrocytes, which are the glial cells responsible for the axons myelination. Moreover, ET induces release of glutamate and other transmitters, leading to firing of neural network. The precise mode of action of ET on neural cells remains to be determined.
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Affiliation(s)
- Laetitia Wioland
- Centre National de la Recherche Scientifique (CNRS) and Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives (INCI), UPR 3212, Strasbourg, France
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19
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Türkcan S, Richly MU, Alexandrou A, Masson JB. Probing membrane protein interactions with their lipid raft environment using single-molecule tracking and Bayesian inference analysis. PLoS One 2013; 8:e53073. [PMID: 23301023 PMCID: PMC3536804 DOI: 10.1371/journal.pone.0053073] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 11/22/2012] [Indexed: 11/18/2022] Open
Abstract
The statistical properties of membrane protein random walks reveal information on the interactions between the proteins and their environments. These interactions can be included in an overdamped Langevin equation framework where they are injected in either or both the friction field and the potential field. Using a Bayesian inference scheme, both the friction and potential fields acting on the ε-toxin receptor in its lipid raft have been measured. Two types of events were used to probe these interactions. First, active events, the removal of cholesterol and sphingolipid molecules, were used to measure the time evolution of confining potentials and diffusion fields. Second, passive rare events, de-confinement of the receptors from one raft and transition to an adjacent one, were used to measure hopping energies. Lipid interactions with the ε-toxin receptor are found to be an essential source of confinement. ε-toxin receptor confinement is due to both the friction and potential field induced by cholesterol and sphingolipids. Finally, the statistics of hopping energies reveal sub-structures of potentials in the rafts, characterized by small hopping energies, and the difference of solubilization energy between the inner and outer raft area, characterized by higher hopping energies.
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Affiliation(s)
- Silvan Türkcan
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM U696, Palaiseau, France
- Institut Pasteur, Physics of Biological Systems, Paris, France
- CNRS, URA 2171, Paris, France
| | - Maximilian U. Richly
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM U696, Palaiseau, France
| | - Antigoni Alexandrou
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS, INSERM U696, Palaiseau, France
| | - Jean-Baptiste Masson
- Institut Pasteur, Physics of Biological Systems, Paris, France
- CNRS, URA 2171, Paris, France
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Cho MH, Lee EJ, Son M, Lee JH, Yoo D, Kim JW, Park SW, Shin JS, Cheon J. A magnetic switch for the control of cell death signalling in in vitro and in vivo systems. NATURE MATERIALS 2012; 11:1038-43. [PMID: 23042417 DOI: 10.1038/nmat3430] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 08/23/2012] [Indexed: 05/20/2023]
Abstract
The regulation of cellular activities in a controlled manner is one of the most challenging issues in fields ranging from cell biology to biomedicine. Nanoparticles have the potential of becoming useful tools for controlling cell signalling pathways in a space and time selective fashion. Here, we have developed magnetic nanoparticles that turn on apoptosis cell signalling by using a magnetic field in a remote and non-invasive manner. The magnetic switch consists of zinc-doped iron oxide magnetic nanoparticles (Zn(0.4)Fe(2.6)O(4)), conjugated with a targeting antibody for death receptor 4 (DR4) of DLD-1 colon cancer cells. The magnetic switch, in its On mode when a magnetic field is applied to aggregate magnetic nanoparticle-bound DR4s, promotes apoptosis signalling pathways. We have also demonstrated that the magnetic switch is operable at the micrometre scale and that it can be applied in an in vivo system where apoptotic morphological changes of zebrafish are successfully induced.
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Affiliation(s)
- Mi Hyeon Cho
- Department of Chemistry, Yonsei University, Seoul 120-749, Korea
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Oligomerization of Clostridium perfringens epsilon toxin is dependent upon caveolins 1 and 2. PLoS One 2012; 7:e46866. [PMID: 23056496 PMCID: PMC3462777 DOI: 10.1371/journal.pone.0046866] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 09/06/2012] [Indexed: 01/27/2023] Open
Abstract
Evidence from multiple studies suggests that Clostridium perfringens ε-toxin is a pore-forming toxin, assembling into oligomeric complexes in the plasma membrane of sensitive cells. In a previous study, we used gene-trap mutagenesis to identify mammalian factors contributing to toxin activity, including caveolin-2 (CAV2). In this study, we demonstrate the importance of caveolin-2 and its interaction partner, caveolin-1 (CAV1), in ε-toxin-induced cytotoxicity. Using CAV2-specific shRNA in a toxin-sensitive human kidney cell line, ACHN, we confirmed that cells deficient in CAV2 exhibit increased resistance to ε-toxin. Similarly, using CAV1-specific shRNA, we demonstrate that cells deficient in CAV1 also exhibit increased resistance to the toxin. Immunoprecipitation of CAV1 and CAV2 from ε-toxin-treated ACHN cells demonstrated interaction of both CAV1 and -2 with the toxin. Furthermore, blue-native PAGE indicated that the toxin and caveolins were components of a 670 kDa protein complex. Although ε-toxin binding was only slightly perturbed in caveolin-deficient cells, oligomerization of the toxin was dramatically reduced in both CAV1- and CAV2-deficient cells. These results indicate that CAV1 and -2 potentiate ε-toxin induced cytotoxicity by promoting toxin oligomerization – an event which is requisite for pore formation and, by extension, cell death.
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Türkcan S, Alexandrou A, Masson JB. A Bayesian inference scheme to extract diffusivity and potential fields from confined single-molecule trajectories. Biophys J 2012; 102:2288-98. [PMID: 22677382 DOI: 10.1016/j.bpj.2012.01.063] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 11/16/2011] [Accepted: 01/03/2012] [Indexed: 11/19/2022] Open
Abstract
Currently used techniques for the analysis of single-molecule trajectories only exploit a small part of the available information stored in the data. Here, we apply a Bayesian inference scheme to trajectories of confined receptors that are targeted by pore-forming toxins to extract the two-dimensional confining potential that restricts the motion of the receptor. The receptor motion is modeled by the overdamped Langevin equation of motion. The method uses most of the information stored in the trajectory and converges quickly onto inferred values, while providing the uncertainty on the determined values. The inference is performed on the polynomial development of the potential and on the diffusivities that have been discretized on a mesh. Numerical simulations are used to test the scheme and quantify the convergence toward the input values for forces, potential, and diffusivity. Furthermore, we show that the technique outperforms the classical mean-square-displacement technique when forces act on confined molecules because the typical mean-square-displacement analysis does not account for them. We also show that the inferred potential better represents input potentials than the potential extracted from the position distribution based on Boltzmann statistics that assumes statistical equilibrium.
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Affiliation(s)
- Silvan Türkcan
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale U696, Palaiseau, France
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