1
|
Clifton LA, Wacklin-Knecht HP, Ådén J, Mushtaq AU, Sparrman T, Gröbner G. Creation of distinctive Bax-lipid complexes at mitochondrial membrane surfaces drives pore formation to initiate apoptosis. SCIENCE ADVANCES 2023; 9:eadg7940. [PMID: 37267355 PMCID: PMC10413641 DOI: 10.1126/sciadv.adg7940] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 04/28/2023] [Indexed: 06/04/2023]
Abstract
Apotosis is an essential process tightly regulated by the Bcl-2 protein family where proapoptotic Bax triggers cell death by perforating the mitochondrial outer membrane. Although intensively studied, the molecular mechanism by which these proteins create apoptotic pores remains elusive. Here, we show that Bax creates pores by extracting lipids from outer mitochondrial membrane mimics by formation of Bax/lipid clusters that are deposited on the membrane surface. Time-resolved neutron reflectometry and Fourier transform infrared spectroscopy revealed two kinetically distinct phases in the pore formation process, both of which were critically dependent on cardiolipin levels. The initially fast adsorption of Bax on the mitochondrial membrane surface is followed by a slower formation of pores and Bax-lipid clusters on the membrane surface. Our findings provide a robust molecular understanding of mitochondrial membrane perforation by cell-killing Bax protein and illuminate the initial phases of programmed cellular death.
Collapse
Affiliation(s)
- Luke A. Clifton
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 OQX, UK
| | - Hanna P. Wacklin-Knecht
- European Spallation Source ERIC, ESS, P.O. Box 176, SE-22100 Lund, Sweden
- Department of Chemistry, Division of Physical Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| | - Jörgen Ådén
- Department of Chemistry, University of Umeå, SE-90187 Umeå, Sweden
| | - Ameeq Ul Mushtaq
- Department of Chemistry, University of Umeå, SE-90187 Umeå, Sweden
| | - Tobias Sparrman
- Department of Chemistry, University of Umeå, SE-90187 Umeå, Sweden
| | - Gerhard Gröbner
- Department of Chemistry, University of Umeå, SE-90187 Umeå, Sweden
| |
Collapse
|
2
|
Martin A, Jemmett PN, Howitt T, Wood MH, Burley AW, Cox LR, Dafforn TR, Welbourn RJL, Campana M, Skoda MW, Thompson JJ, Hussain H, Rawle JL, Carlà F, Nicklin CL, Arnold T, Horswell SL. Effect of Anionic Lipids on Mammalian Plasma Cell Membrane Properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:2676-2691. [PMID: 36757323 PMCID: PMC9948536 DOI: 10.1021/acs.langmuir.2c03161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 01/19/2023] [Indexed: 06/18/2023]
Abstract
The effect of lipid composition on models of the inner leaflet of mammalian cell membranes has been investigated. Grazing incidence X-ray diffraction and X-ray and neutron reflectivity have been used to characterize lipid packing and solvation, while electrochemical and infrared spectroscopic methods have been employed to probe phase behavior in an applied electric field. Introducing a small quantity of the anionic lipid dimyristoylphosphatidylserine (DMPS) into bilayers of zwitterionic dimyristoylphosphatidylethanolamine (DMPE) results in a significant change in the bilayer response to an applied field: the tilt of the hydrocarbon chains increases before returning to the original tilt angle on detachment of the bilayer. Equimolar mixtures, with slightly closer chain packing, exhibit a similar but weaker response. The latter also tend to incorporate more solvent during this electrochemical phase transition, at levels similar to those of pure DMPS. Reflectivity measurements reveal greater solvation of lipid layers for DMPS > 30 mol %, matching the greater propensity for DMPS-rich bilayers to incorporate water. Taken together, the data indicate that the range of 10-35 mol % DMPS provides optimum bilayer properties (in flexibility and function as a barrier), which may explain why the DMPS content of cell membranes tends to be found within this range.
Collapse
Affiliation(s)
- Alexandra
L. Martin
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Philip N. Jemmett
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Thomas Howitt
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Mary H. Wood
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Andrew W. Burley
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Liam R. Cox
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Timothy R. Dafforn
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| | - Rebecca J. L. Welbourn
- ISIS
Pulsed Neutron and Muon Source, Science
and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, OxfordshireOX11 0QX, U.K.
| | - Mario Campana
- ISIS
Pulsed Neutron and Muon Source, Science
and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, OxfordshireOX11 0QX, U.K.
| | - Maximilian W.
A. Skoda
- ISIS
Pulsed Neutron and Muon Source, Science
and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, OxfordshireOX11 0QX, U.K.
| | - Joseph J. Thompson
- Diamond
Light Source, Harwell Science and Innovation
Campus, Chilton, Didcot, OxfordshireOX11 0DE, U.K.
| | - Hadeel Hussain
- Diamond
Light Source, Harwell Science and Innovation
Campus, Chilton, Didcot, OxfordshireOX11 0DE, U.K.
| | - Jonathan L. Rawle
- Diamond
Light Source, Harwell Science and Innovation
Campus, Chilton, Didcot, OxfordshireOX11 0DE, U.K.
| | - Francesco Carlà
- Diamond
Light Source, Harwell Science and Innovation
Campus, Chilton, Didcot, OxfordshireOX11 0DE, U.K.
| | - Christopher L. Nicklin
- Diamond
Light Source, Harwell Science and Innovation
Campus, Chilton, Didcot, OxfordshireOX11 0DE, U.K.
| | - Thomas Arnold
- ISIS
Pulsed Neutron and Muon Source, Science
and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell, OxfordshireOX11 0QX, U.K.
- Diamond
Light Source, Harwell Science and Innovation
Campus, Chilton, Didcot, OxfordshireOX11 0DE, U.K.
- European
Spallation Source ERIC PO Box 176, SE-221 00Lund, Sweden
- Department
of Chemistry, University of Bath, Claverton Down, BathBA2 7AY, U.K.
| | - Sarah L. Horswell
- School of
Chemistry and School of Biosciences, University of Birmingham, Edgbaston, BirminghamB15 2TT, U.K.
| |
Collapse
|
3
|
Sea Anemones, Actinoporins, and Cholesterol. Int J Mol Sci 2022; 23:ijms23158771. [PMID: 35955905 PMCID: PMC9369217 DOI: 10.3390/ijms23158771] [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: 07/11/2022] [Revised: 08/01/2022] [Accepted: 08/05/2022] [Indexed: 11/17/2022] Open
Abstract
Spanish or Spanish-speaking scientists represent a remarkably populated group within the scientific community studying pore-forming proteins. Some of these scientists, ourselves included, focus on the study of actinoporins, a fascinating group of metamorphic pore-forming proteins produced within the venom of several sea anemones. These toxic proteins can spontaneously transit from a water-soluble fold to an integral membrane ensemble because they specifically recognize sphingomyelin in the membrane. Once they bind to the bilayer, they subsequently oligomerize into a pore that triggers cell-death by osmotic shock. In addition to sphingomyelin, some actinoporins are especially sensible to some other membrane components such as cholesterol. Our group from Universidad Complutense of Madrid has focused greatly on the role played by sterols in this water–membrane transition, a question which still remains only partially solved and constitutes the main core of the article below.
Collapse
|
4
|
Ramos J, Laux V, Haertlein M, Forsyth VT, Mossou E, Larsen S, Langkilde AE. The impact of folding modes and deuteration on the atomic resolution structure of hen egg-white lysozyme. Acta Crystallogr D Struct Biol 2021; 77:1579-1590. [PMID: 34866613 PMCID: PMC8647175 DOI: 10.1107/s2059798321010950] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 10/20/2021] [Indexed: 11/10/2022] Open
Abstract
The biological function of a protein is intimately related to its structure and dynamics, which in turn are determined by the way in which it has been folded. In vitro refolding is commonly used for the recovery of recombinant proteins that are expressed in the form of inclusion bodies and is of central interest in terms of the folding pathways that occur in vivo. Here, biophysical data are reported for in vitro-refolded hydrogenated hen egg-white lysozyme, in combination with atomic resolution X-ray diffraction analyses, which allowed detailed comparisons with native hydrogenated and refolded perdeuterated lysozyme. Distinct folding modes are observed for the hydrogenated and perdeuterated refolded variants, which are determined by conformational changes to the backbone structure of the Lys97-Gly104 flexible loop. Surprisingly, the structure of the refolded perdeuterated protein is closer to that of native lysozyme than that of the refolded hydrogenated protein. These structural differences suggest that the observed decreases in thermal stability and enzymatic activity in the refolded perdeuterated and hydrogenated proteins are consequences of the macromolecular deuteration effect and of distinct folding dynamics, respectively. These results are discussed in the context of both in vitro and in vivo folding, as well as of lysozyme amyloidogenesis.
Collapse
Affiliation(s)
- Joao Ramos
- Life Sciences Group, Institute Laue–Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France
- Partnership for Structural Biology (PSB), 71 Avenue des Martyrs, 38000 Grenoble, France
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Valerie Laux
- Life Sciences Group, Institute Laue–Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France
- Partnership for Structural Biology (PSB), 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Michael Haertlein
- Life Sciences Group, Institute Laue–Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France
- Partnership for Structural Biology (PSB), 71 Avenue des Martyrs, 38000 Grenoble, France
| | - V. Trevor Forsyth
- Life Sciences Group, Institute Laue–Langevin, 71 Avenue des Martyrs, 38000 Grenoble, France
- Partnership for Structural Biology (PSB), 71 Avenue des Martyrs, 38000 Grenoble, France
- Faculty of Natural Sciences, Keele University, Newcastle ST5 5BG, United Kingdom
- Faculty of Medicine, Lund University, 221 00 Lund, Sweden
- LINXS Institute for Advanced Neutron and X-ray Science, Scheelvagen 19, 223 70 Lund, Sweden
| | - Estelle Mossou
- Partnership for Structural Biology (PSB), 71 Avenue des Martyrs, 38000 Grenoble, France
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Sine Larsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Annette E. Langkilde
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| |
Collapse
|
5
|
Ilangumaran Ponmalar I, Sarangi NK, Basu JK, Ayappa KG. Pore Forming Protein Induced Biomembrane Reorganization and Dynamics: A Focused Review. Front Mol Biosci 2021; 8:737561. [PMID: 34568431 PMCID: PMC8459938 DOI: 10.3389/fmolb.2021.737561] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 07/30/2021] [Indexed: 11/13/2022] Open
Abstract
Pore forming proteins are a broad class of pathogenic proteins secreted by organisms as virulence factors due to their ability to form pores on the target cell membrane. Bacterial pore forming toxins (PFTs) belong to a subclass of pore forming proteins widely implicated in bacterial infections. Although the action of PFTs on target cells have been widely investigated, the underlying membrane response of lipids during membrane binding and pore formation has received less attention. With the advent of superresolution microscopy as well as the ability to carry out molecular dynamics (MD) simulations of the large protein membrane assemblies, novel microscopic insights on the pore forming mechanism have emerged over the last decade. In this review, we focus primarily on results collated in our laboratory which probe dynamic lipid reorganization induced in the plasma membrane during various stages of pore formation by two archetypal bacterial PFTs, cytolysin A (ClyA), an α-toxin and listeriolysin O (LLO), a β-toxin. The extent of lipid perturbation is dependent on both the secondary structure of the membrane inserted motifs of pore complex as well as the topological variations of the pore complex. Using confocal and superresolution stimulated emission depletion (STED) fluorescence correlation spectroscopy (FCS) and MD simulations, lipid diffusion, cholesterol reorganization and deviations from Brownian diffusion are correlated with the oligomeric state of the membrane bound protein as well as the underlying membrane composition. Deviations from free diffusion are typically observed at length scales below ∼130 nm to reveal the presence of local dynamical heterogeneities that emerge at the nanoscale-driven in part by preferential protein binding to cholesterol and domains present in the lipid membrane. Interrogating the lipid dynamics at the nanoscale allows us further differentiate between binding and pore formation of β- and α-PFTs to specific domains in the membrane. The molecular insights gained from the intricate coupling that occurs between proteins and membrane lipids and receptors during pore formation are expected to improve our understanding of the virulent action of PFTs.
Collapse
Affiliation(s)
| | - Nirod K. Sarangi
- School of Chemical Science, Dublin City University, Dublin, Ireland
| | - Jaydeep K. Basu
- Department of Physics, Indian Institute of Science, Bangalore, India
| | - K. Ganapathy Ayappa
- Center for BioSystems Science and Engineering, Indian Institute of Science, Bangalore, India
- Department of Chemical Engineering, Indian Institute of Science, Bengaluru, India
| |
Collapse
|
6
|
Kulma M, Anderluh G. Beyond pore formation: reorganization of the plasma membrane induced by pore-forming proteins. Cell Mol Life Sci 2021; 78:6229-6249. [PMID: 34387717 PMCID: PMC11073440 DOI: 10.1007/s00018-021-03914-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 07/09/2021] [Accepted: 08/03/2021] [Indexed: 12/23/2022]
Abstract
Pore-forming proteins (PFPs) are a heterogeneous group of proteins that are expressed and secreted by a wide range of organisms. PFPs are produced as soluble monomers that bind to a receptor molecule in the host cell membrane. They then assemble into oligomers that are incorporated into the lipid membrane to form transmembrane pores. Such pore formation alters the permeability of the plasma membrane and is one of the most common mechanisms used by PFPs to destroy target cells. Interestingly, PFPs can also indirectly manipulate diverse cellular functions. In recent years, increasing evidence indicates that the interaction of PFPs with lipid membranes is not only limited to pore-induced membrane permeabilization but is also strongly associated with extensive plasma membrane reorganization. This includes lateral rearrangement and deformation of the lipid membrane, which can lead to the disruption of target cell function and finally death. Conversely, these modifications also constitute an essential component of the membrane repair system that protects cells from the lethal consequences of pore formation. Here, we provide an overview of the current knowledge on the changes in lipid membrane organization caused by PFPs from different organisms.
Collapse
Affiliation(s)
- Magdalena Kulma
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1001, Ljubljana, Slovenia.
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1001, Ljubljana, Slovenia
| |
Collapse
|
7
|
Palacios-Ortega J, García-Linares S, Rivera-de-Torre E, Heras-Márquez D, Gavilanes JG, Slotte JP, Martínez-Del-Pozo Á. Structural foundations of sticholysin functionality. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2021; 1869:140696. [PMID: 34246789 DOI: 10.1016/j.bbapap.2021.140696] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/05/2021] [Accepted: 07/06/2021] [Indexed: 01/22/2023]
Abstract
Actinoporins constitute a family of α pore-forming toxins produced by sea anemones. The soluble fold of these proteins consists of a β-sandwich flanked by two α-helices. Actinoporins exert their activity by specifically recognizing sphingomyelin at their target membranes. Once there, they penetrate the membrane with their N-terminal α-helices, a process that leads to the formation of cation-selective pores. These pores kill the target cells by provoking an osmotic shock on them. In this review, we examine the role and relevance of the structural features of actinoporins, down to the residue level. We look at the specific amino acids that play significant roles in the function of actinoporins and their fold. Particular emphasis is given to those residues that display a high degree of conservation across the actinoporin sequences known to date. In light of the latest findings in the field, the membrane requirements for pore formation, the effect of lipid composition, and the process of pore formation are also discussed.
Collapse
Affiliation(s)
- Juan Palacios-Ortega
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain; Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland.
| | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
| | - Esperanza Rivera-de-Torre
- Department of Biochemistry and Biotechnology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Diego Heras-Márquez
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
| | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
| | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Álvaro Martínez-Del-Pozo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
| |
Collapse
|
8
|
Mushtaq AU, Ådén J, Clifton LA, Wacklin-Knecht H, Campana M, Dingeldein APG, Persson C, Sparrman T, Gröbner G. Neutron reflectometry and NMR spectroscopy of full-length Bcl-2 protein reveal its membrane localization and conformation. Commun Biol 2021; 4:507. [PMID: 33907308 PMCID: PMC8079415 DOI: 10.1038/s42003-021-02032-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 03/25/2021] [Indexed: 12/20/2022] Open
Abstract
B-cell lymphoma 2 (Bcl-2) proteins are the main regulators of mitochondrial apoptosis. Anti-apoptotic Bcl-2 proteins possess a hydrophobic tail-anchor enabling them to translocate to their target membrane and to shift into an active conformation where they inhibit pro-apoptotic Bcl-2 proteins to ensure cell survival. To address the unknown molecular basis of their cell-protecting functionality, we used intact human Bcl-2 protein natively residing at the mitochondrial outer membrane and applied neutron reflectometry and NMR spectroscopy. Here we show that the active full-length protein is entirely buried into its target membrane except for the regulatory flexible loop domain (FLD), which stretches into the aqueous exterior. The membrane location of Bcl-2 and its conformational state seems to be important for its cell-protecting activity, often infamously upregulated in cancers. Most likely, this situation enables the Bcl-2 protein to sequester pro-apoptotic Bcl-2 proteins at the membrane level while sensing cytosolic regulative signals via its FLD region.
Collapse
Affiliation(s)
| | - Jörgen Ådén
- Department of Chemistry, University of Umeå, Umeå, Sweden
| | - Luke A Clifton
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science&Innovation Campus, Didcot, Oxfordshire, UK
| | - Hanna Wacklin-Knecht
- European Spallation Source ERIC, ESS, Lund, Sweden
- Department of Chemistry, Division of Physical Chemistry, Lund University, Lund, Sweden
| | - Mario Campana
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science&Innovation Campus, Didcot, Oxfordshire, UK
| | | | - Cecilia Persson
- The Swedish NMR Center, University of Gothenburg, Gothenburg, Sweden
| | | | | |
Collapse
|
9
|
Kinnun JJ, Scott HL, Ashkar R, Katsaras J. Biomembrane Structure and Material Properties Studied With Neutron Scattering. Front Chem 2021; 9:642851. [PMID: 33987167 PMCID: PMC8110834 DOI: 10.3389/fchem.2021.642851] [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: 12/16/2020] [Accepted: 03/16/2021] [Indexed: 12/12/2022] Open
Abstract
Cell membranes and their associated structures are dynamical supramolecular structures where different physiological processes take place. Detailed knowledge of their static and dynamic structures is therefore needed, to better understand membrane biology. The structure–function relationship is a basic tenet in biology and has been pursued using a range of different experimental approaches. In this review, we will discuss one approach, namely the use of neutron scattering techniques as applied, primarily, to model membrane systems composed of lipid bilayers. An advantage of neutron scattering, compared to other scattering techniques, is the differential sensitivity of neutrons to isotopes of hydrogen and, as a result, the relative ease of altering sample contrast by substituting protium for deuterium. This property makes neutrons an ideal probe for the study of hydrogen-rich materials, such as biomembranes. In this review article, we describe isotopic labeling studies of model and viable membranes, and discuss novel applications of neutron contrast variation in order to gain unique insights into the structure, dynamics, and molecular interactions of biological membranes. We specifically focus on how small-angle neutron scattering data is modeled using different contrast data and molecular dynamics simulations. We also briefly discuss neutron reflectometry and present a few recent advances that have taken place in neutron spin echo spectroscopy studies and the unique membrane mechanical data that can be derived from them, primarily due to new models used to fit the data.
Collapse
Affiliation(s)
- Jacob J Kinnun
- Large Scale Structures Group, Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Oak Ridge National Laboratory, Shull-Wollan Center, Oak Ridge, TN, United States
| | - Haden L Scott
- Large Scale Structures Group, Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Oak Ridge National Laboratory, Shull-Wollan Center, Oak Ridge, TN, United States
| | - Rana Ashkar
- Department of Physics, Virginia Tech, Blacksburg, VA, United States.,Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA, United States
| | - John Katsaras
- Oak Ridge National Laboratory, Shull-Wollan Center, Oak Ridge, TN, United States.,Sample Environment Group, Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, United States
| |
Collapse
|
10
|
The Antifungal Mechanism of Amphotericin B Elucidated in Ergosterol and Cholesterol-Containing Membranes Using Neutron Reflectometry. NANOMATERIALS 2020; 10:nano10122439. [PMID: 33291326 PMCID: PMC7762259 DOI: 10.3390/nano10122439] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 12/25/2022]
Abstract
We have characterized and compared the structures of ergosterol- and cholesterol-containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membranes before and after interaction with the amphiphilic antifungal drug amphotericin B (AmB) using neutron reflection. AmB inserts into both pure POPC and sterol-containing membranes in the lipid chain region and does not significantly perturb the structure of pure POPC membranes. By selective per-deuteration of the lipids/sterols, we show that AmB extracts ergosterol but not cholesterol from the bilayers and inserts to a much higher degree in the cholesterol-containing membranes. Ergosterol extraction by AmB is accompanied by membrane thinning. Our results provide new insights into the mechanism and antifungal effect of AmB in these simple models of fungal and mammalian membranes and help understand the molecular origin of its selectivity and toxic side effects.
Collapse
|
11
|
Evaluation of different approaches used to study membrane permeabilization by actinoporins on model lipid vesicles. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183311. [DOI: 10.1016/j.bbamem.2020.183311] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 03/12/2020] [Accepted: 04/13/2020] [Indexed: 02/01/2023]
|
12
|
Heinrich F, Kienzle PA, Hoogerheide DP, Lösche M. Information gain from isotopic contrast variation in neutron reflectometry on protein-membrane complex structures. J Appl Crystallogr 2020; 53:800-810. [PMID: 32684895 PMCID: PMC7312142 DOI: 10.1107/s1600576720005634] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 04/21/2020] [Indexed: 12/25/2022] Open
Abstract
A framework is applied to quantify information gain from neutron or X-ray reflectometry experiments [Treece, Kienzle, Hoogerheide, Majkrzak, Lösche & Heinrich (2019). J. Appl. Cryst. 52, 47-59], in an in-depth investigation into the design of scattering contrast in biological and soft-matter surface architectures. To focus the experimental design on regions of interest, the marginalization of the information gain with respect to a subset of model parameters describing the structure is implemented. Surface architectures of increasing complexity from a simple model system to a protein-lipid membrane complex are simulated. The information gain from virtual surface scattering experiments is quantified as a function of the scattering length density of molecular components of the architecture and the surrounding aqueous bulk solvent. It is concluded that the information gain is mostly determined by the local scattering contrast of a feature of interest with its immediate molecular environment, and experimental design should primarily focus on this region. The overall signal-to-noise ratio of the measured reflectivity modulates the information gain globally and is a second factor to be taken into consideration.
Collapse
Affiliation(s)
- Frank Heinrich
- Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, USA
- Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-6102, USA
| | - Paul A. Kienzle
- Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-6102, USA
| | - David P. Hoogerheide
- Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-6102, USA
| | - Mathias Lösche
- Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, USA
- Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-6102, USA
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, USA
| |
Collapse
|
13
|
Protocol for Investigating the Interactions Between Intrinsically Disordered Proteins and Membranes by Neutron Reflectometry. Methods Mol Biol 2020; 2141:569-584. [PMID: 32696378 DOI: 10.1007/978-1-0716-0524-0_29] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Several intrinsically disordered proteins (IDPs) exhibit high affinity for lipid membranes. Among the different biophysical methods to probe protein-lipid interaction, neutron reflectometry (NR) can provide direct and structural detailed information on the location of the IDP with respect to the membrane. Supported lipid bilayers are commonly used as cell membrane models in such experiments. NR measurements can be collected on the supported lipid bilayer before and after the interaction with the IDP to characterize whether the protein molecules are mainly located on the membrane surface (interaction with the lipid headgroups), are penetrating into the hydrophobic region of the membrane (interaction with the lipid acyl chains), or are not interacting at all with the membrane. The lipid composition of the supported lipid bilayer can easily be tuned; hence the NR experiments can be designed to investigate selective IDP-lipid interactions.This chapter will describe the fundamental steps for performing an NR experiment and the subsequent data analysis aimed at characterizing IDP-lipid bilayer interactions. The specific case of an intrinsically disordered region (IDR) from the membrane protein Na+/H+ exchanger isoform 1 (NHE1) will be used as an example, but the same protocol can be easily adapted to other IDPs.
Collapse
|
14
|
Yap WY, Tan KJSX, Hwang JS. Expansion of Hydra actinoporin-like toxin (HALT) gene family: Expression divergence and functional convergence evolved through gene duplication. Toxicon 2019; 170:10-20. [PMID: 31513812 DOI: 10.1016/j.toxicon.2019.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 08/27/2019] [Accepted: 09/03/2019] [Indexed: 11/15/2022]
Abstract
Hydra actinoporin-like toxin 1 (HALT-1) was previously shown to cause cytolysis and haemolysis in a number of human cells and has similar functional properties to the actinoporins equinatoxin and sticholysin. In addition to HALT-1, five other HALTs (HALTs 2, 3, 4, 6 and 7) were also isolated from Hydra magnipapillata and expressed as recombinant proteins in this study. We demonstrated that recombinant HALTs have cytolytic activity on HeLa cells but each exhibited a different range of toxicity. All six recombinant HALTs bound to sulfatide, while rHALT-1 and rHALT-3 bound to two additional sphingolipids, lysophosphatidic acid and sphingosine-1-phosphate as indicated by the protein-lipid overlay assay. When either tryptophan133 or tyrosine129 of HALT-1 was mutated, the mutant protein lost binding to sulfatide, lysophosphatidic acid and sphingosine-1-phosphate. As further verification of HALTs' binding to sulfatide, we performed ELISA for each HALT. To determine the cell-type specific gene expression of seven HALTs in Hydra, we searched for individual HALT expression in the single-cell RNA-seq data set of Single Cell Portal. The results showed that HALT-1, 4 and 7 were expressed in differentiating stenoteles. HALT-1 and HALT-6 were expressed in the female germline during oogenesis. HALT-2 was strongly expressed in the gland and mucous cells in the endoderm. Information on HALT-3 and HALT-5 could not be found in the single-cell data set. Our findings show that subfunctionalisation of gene expression following duplication enabled HALTs to become specialized in various cell types of the interstitial cell lineage.
Collapse
Affiliation(s)
- Wei Yuen Yap
- Faculty of Applied Sciences, UCSI University, No. 1, Jalan Menara Gading, UCSI Heights Cheras, 56000, Kuala Lumpur, Malaysia
| | - Katrina Joan Shu Xian Tan
- Faculty of Applied Sciences, UCSI University, No. 1, Jalan Menara Gading, UCSI Heights Cheras, 56000, Kuala Lumpur, Malaysia
| | - Jung Shan Hwang
- Department of Medical Sciences, School of Healthcare and Medical Sciences, Sunway University, No. 5 Jalan Universiti, Bandar Sunway, 47500, Selangor Darul Ehsan, Malaysia.
| |
Collapse
|
15
|
Lakey JH. Recent advances in neutron reflectivity studies of biological membranes. Curr Opin Colloid Interface Sci 2019. [DOI: 10.1016/j.cocis.2019.02.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
16
|
Pore-Forming Proteins from Cnidarians and Arachnids as Potential Biotechnological Tools. Toxins (Basel) 2019; 11:toxins11060370. [PMID: 31242582 PMCID: PMC6628452 DOI: 10.3390/toxins11060370] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 06/18/2019] [Accepted: 06/21/2019] [Indexed: 12/31/2022] Open
Abstract
Animal venoms are complex mixtures of highly specialized toxic molecules. Cnidarians and arachnids produce pore-forming proteins (PFPs) directed against the plasma membrane of their target cells. Among PFPs from cnidarians, actinoporins stand out for their small size and molecular simplicity. While native actinoporins require only sphingomyelin for membrane binding, engineered chimeras containing a recognition antibody-derived domain fused to an actinoporin isoform can nonetheless serve as highly specific immunotoxins. Examples of such constructs targeted against malignant cells have been already reported. However, PFPs from arachnid venoms are less well-studied from a structural and functional point of view. Spiders from the Latrodectus genus are professional insect hunters that, as part of their toxic arsenal, produce large PFPs known as latrotoxins. Interestingly, some latrotoxins have been identified as potent and highly-specific insecticides. Given the proteinaceous nature of these toxins, their promising future use as efficient bioinsecticides is discussed throughout this Perspective. Protein engineering and large-scale recombinant production are critical steps for the use of these PFPs as tools to control agriculturally important insect pests. In summary, both families of PFPs, from Cnidaria and Arachnida, appear to be molecules with promising biotechnological applications.
Collapse
|
17
|
Neuropathy-related mutations alter the membrane binding properties of the human myelin protein P0 cytoplasmic tail. PLoS One 2019; 14:e0216833. [PMID: 31173589 PMCID: PMC6555526 DOI: 10.1371/journal.pone.0216833] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 04/29/2019] [Indexed: 01/19/2023] Open
Abstract
Schwann cells myelinate selected axons in the peripheral nervous system (PNS) and contribute to fast saltatory conduction via the formation of compact myelin, in which water is excluded from between tightly adhered lipid bilayers. Peripheral neuropathies, such as Charcot-Marie-Tooth disease (CMT) and Dejerine-Sottas syndrome (DSS), are incurable demyelinating conditions that result in pain, decrease in muscle mass, and functional impairment. Many Schwann cell proteins, which are directly involved in the stability of compact myelin or its development, are subject to mutations linked to these neuropathies. The most abundant PNS myelin protein is protein zero (P0); point mutations in this transmembrane protein cause CMT subtype 1B and DSS. P0 tethers apposing lipid bilayers together through its extracellular immunoglobulin-like domain. Additionally, P0 contains a cytoplasmic tail (P0ct), which is membrane-associated and contributes to the physical properties of the lipid membrane. Six CMT- and DSS-associated missense mutations have been reported in P0ct. We generated recombinant disease mutant variants of P0ct and characterized them using biophysical methods. Compared to wild-type P0ct, some mutants have negligible differences in function and folding, while others highlight functionally important amino acids within P0ct. For example, the D224Y variant of P0ct induced tight membrane multilayer stacking. Our results show a putative molecular basis for the hypermyelinating phenotype observed in patients with this particular mutation and provide overall information on the effects of disease-linked mutations in a flexible, membrane-binding protein segment. Using neutron reflectometry, we additionally show that P0ct embeds deep into a lipid bilayer, explaining the observed effects of P0ct on the physical properties of the membrane.
Collapse
|
18
|
Palacios-Ortega J, García-Linares S, Rivera-de-Torre E, Gavilanes JG, Martínez-Del-Pozo Á, Slotte JP. Sticholysin, Sphingomyelin, and Cholesterol: A Closer Look at a Tripartite Interaction. Biophys J 2019; 116:2253-2265. [PMID: 31146924 DOI: 10.1016/j.bpj.2019.05.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/05/2019] [Accepted: 05/10/2019] [Indexed: 02/06/2023] Open
Abstract
Actinoporins are a group of soluble toxic proteins that bind to membranes containing sphingomyelin (SM) and oligomerize to form pores. Sticholysin II (StnII) is a member of the actinoporin family produced by Stichodactyla helianthus. Cholesterol (Chol) is known to enhance the activity of StnII. However, the molecular mechanisms behind this activation have remained obscure, although the activation is not Chol specific but rather sterol specific. To further explore how bilayer lipids affect or are affected by StnII, we have used a multiprobe approach (fluorescent analogs of both Chol and SM) in combination with a series of StnII tryptophan (Trp) mutants to study StnII/bilayer interactions. First, we compared StnII bilayer permeabilization in the presence of Chol or oleoyl-ceramide (OCer). The comparison was done because both Chol and OCer have a 1-hydroxyl, which helps to orient the molecule in the bilayer (although OCer has additional polar functional groups). Both Chol and OCer also have increased affinity for SM, which StnII may recognize. However, our results show that only Chol was able to activate StnII-induced bilayer permeabilization; OCer failed to activate it. To further examine possible Chol/StnII interactions, we measured Förster resonance energy transfer between Trp in StnII and cholestatrienol, a fluorescent analog of Chol. We could show higher Förster resonance energy transfer efficiency between cholestatrienol and Trps in position 100 and 114 of StnII when compared to three other Trp positions further away from the bilayer binding region of StnII. Taken together, our results suggest that StnII was able to attract Chol to its vicinity, maybe by showing affinity for Chol. SM interactions are known to be important for StnII binding to bilayers, and Chol is known to facilitate subsequent permeabilization of the bilayers by StnII. Our results help to better understand the role of these important membrane lipids for the bilayer properties of StnII.
Collapse
Affiliation(s)
- Juan Palacios-Ortega
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain; Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | | | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | | | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland.
| |
Collapse
|
19
|
Ramírez-Carreto S, Pérez-García EI, Salazar-García SI, Bernáldez-Sarabia J, Licea-Navarro A, Rudiño-Piñera E, Pérez-Martínez L, Pedraza-Alva G, Rodríguez-Almazán C. Identification of a pore-forming protein from sea anemone Anthopleura dowii Verrill (1869) venom by mass spectrometry. J Venom Anim Toxins Incl Trop Dis 2019; 25:e147418. [PMID: 31131002 PMCID: PMC6483413 DOI: 10.1590/1678-9199-jvatitd-1474-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 11/13/2018] [Indexed: 12/14/2022] Open
Abstract
Background: Pore-forming proteins (PFP) are a class of toxins abundant in the venom of
sea anemones. Owing to their ability to recognize and permeabilize cell
membranes, pore-forming proteins have medical potential in cancer therapy or
as biosensors. In the present study, we showed the partial purification and
sequencing of a pore-forming protein from Anthopleura dowii
Verrill (1869). 17. Methods: Cytolytic activity of A. dowii Verrill (1869) venom was
determined via hemolysis assay in the erythrocytes of four mammals (sheep,
goat, human and rabbit). The cytotoxic activity was analyzed in the human
adherent lung carcinoma epithelial cells (A549) by the cytosolic lactate
dehydrogenase (LDH) assay, and trypan blue staining. The venom was
fractionated via ammonium sulfate precipitation gradient, dialysis, and ion
exchange chromatography. The presence of a pore-forming protein in purified
fractions was evaluated through hemolytic and cytotoxic assays, and the
activity fraction was analyzed using the percent of osmotic protections
after polyethylene glycol (PEG) treatment and mass spectrometry. 18. Results: The amount of protein at which the venom produced 50% hemolysis
(HU50) was determined in hemolysis assays using erythrocytes
from sheep (HU50 = 10.7 ± 0.2 μg), goat (HU50 = 13.2 ±
0.3 μg), rabbit (HU50 = 34.7 ± 0.5 μg), and human
(HU50 = 25.6 ± 0.6 μg). The venom presented a cytotoxic
effect in A549 cells and the protein amount present in the venom responsible
for producing 50% death (IC50) was determined using a trypan blue
cytotoxicity assay (1.84 ± 0.40 μg/mL). The loss of membrane integrity in
the A549 cells caused by the venom was detected by the release of LDH in
proportion to the amount of protein. The venom was fractionated; and the
fraction with hemolytic and cytotoxic activities was analyzed by mass
spectrometry. A pore-forming protein was identified. The cytotoxicity in the
A549 cells produced by the fraction containing the pore-forming protein was
osmotically protected by PEG-3350 Da molecular mass, which corroborated that
the loss of integrity in the plasma membrane was produced via pore
formation. 19. Conclusion: A. dowii Verrill (1869) venom
contains a pore-forming protein suitable for designing new drugs for cancer
therapy.
Collapse
Affiliation(s)
- Santos Ramírez-Carreto
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Erick I Pérez-García
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Sandra I Salazar-García
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Johanna Bernáldez-Sarabia
- Centro de Investigación Científica y de Educación Superior de Ensenada, Departamento de Innovación Biomédica, Baja California, México
| | - Alexei Licea-Navarro
- Centro de Investigación Científica y de Educación Superior de Ensenada, Departamento de Innovación Biomédica, Baja California, México
| | - Enrique Rudiño-Piñera
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Leonor Pérez-Martínez
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Gustavo Pedraza-Alva
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Claudia Rodríguez-Almazán
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| |
Collapse
|
20
|
Penkauskas T, Preta G. Biological applications of tethered bilayer lipid membranes. Biochimie 2019; 157:131-141. [DOI: 10.1016/j.biochi.2018.11.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/19/2018] [Indexed: 12/16/2022]
|
21
|
Böhm P, Koutsioubas A, Moulin JF, Rädler JO, Sackmann E, Nickel B. Probing the Interface Structure of Adhering Cells by Contrast Variation Neutron Reflectometry. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:513-521. [PMID: 30518215 DOI: 10.1021/acs.langmuir.8b02228] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Cellular adhesion is a central element in tissue mechanics, biological cell-cell signaling, and cell motility. In this context, the cell-substrate distance has been investigated in the past by studying natural cells and biomimetic cell models adhering on solid substrates. The amount of water in the membrane substrate gap, however, is difficult to determine. Here, we present a neutron reflectivity (NR) structural study of confluent epithelial cell monolayers on silicon substrates. In order to ensure valid in vitro conditions, we developed a cell culture sample chamber allowing us to grow and cultivate cells under proper cell culture conditions while performing in vitro neutron reflectivity measurements. The cell chamber also enabled perfusion with cell medium and hence allowed for contrast variation in situ by sterile exchange of buffer with different H2O-to-D2O ratio. Contrast variation reduces the ambiguity of data modeling for determining the thickness and degree of hydration of the interfacial cleft between the adherent cells and the substrate. Our data suggest a three-layer interfacial organization. The first layer bound to the silicon surface interface is in agreement with a very dense protein film with a thickness of 9 ± 2 nm, followed by a highly hydrated 24 ± 4 nm thick layer, and a several tens of nanometers thick layer attributed to the composite membrane. Hence, the results provide clear evidence of a highly hydrated intermediate region between the composite cell membrane and the substrate, reminiscent of the basal lamina.
Collapse
Affiliation(s)
- Philip Böhm
- Fakultät für Physik and Center for NanoScience , Ludwig-Maximilians-Universität , Geschwister-Scholl-Platz 1 , 80539 München , Germany
- Nanosystems Initiative Munich , Schellingstraße 4 , 80799 München , Germany
| | - Alexandros Koutsioubas
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ) , Forschungszentrum Jülich GmbH , Lichtenbergstr. 1 , 85748 Garching , Germany
| | - Jean-François Moulin
- Helmholtz-Zentrum Geesthacht, Zentrum für Material und Küstenforschung , Außenstelle am MLZ in Garching bei München , Lichtenbergstraße 1 , 85748 Garching , Germany
| | - Joachim O Rädler
- Fakultät für Physik and Center for NanoScience , Ludwig-Maximilians-Universität , Geschwister-Scholl-Platz 1 , 80539 München , Germany
- Nanosystems Initiative Munich , Schellingstraße 4 , 80799 München , Germany
| | - Erich Sackmann
- Physikdepartment E22 , Technische Universität München , James-Franck-Str.1 , 85748 Garching , Germany
| | - Bert Nickel
- Fakultät für Physik and Center for NanoScience , Ludwig-Maximilians-Universität , Geschwister-Scholl-Platz 1 , 80539 München , Germany
- Nanosystems Initiative Munich , Schellingstraße 4 , 80799 München , Germany
| |
Collapse
|
22
|
Combet S, Cousin F, Rezaei H, Noinville S. Membrane interaction of off-pathway prion oligomers and lipid-induced on-pathway intermediates during prion conversion: A clue for neurotoxicity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1861:514-523. [PMID: 30529078 DOI: 10.1016/j.bbamem.2018.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/21/2018] [Accepted: 12/04/2018] [Indexed: 12/31/2022]
Abstract
Soluble oligomers of prion proteins (PrP), produced during amyloid aggregation, have emerged as the primary neurotoxic species, instead of the fibrillar end-products, in transmissible spongiform encephalopathies. However, whether the membrane is among their direct targets, that mediate the downstream adverse effects, remains a question of debate. Recently, questions arise from the formation of membrane-active oligomeric species generated during the β-aggregation pathway, either in solution, or in lipid environment. In the present study, we characterized membrane interaction of off-pathway oligomers from recombinant prion protein generated along the amyloid aggregation and compared to lipid-induced intermediates produced during lipid-accelerated fibrillation. Using calcein-leakage assay, we show that the soluble prion oligomers are the most potent in producing leakage with negatively charged vesicles. Binding affinities, conformational states, mode of action of the different PrP assemblies were determined by thioflavin T binding-static light scattering experiments on DOPC/DOPS vesicles, as well as by FTIR-ATR spectroscopy and specular neutron reflectivity onto the corresponding supported lipid bilayers. Our results indicate that the off-pathway PrP oligomers interact with lipid membrane via a distinct mechanism, compared to the inserted lipid-induced intermediates. Thus, separate neurotoxic mechanisms could exist following the puzzling intermediates generated in the different cell compartments. These results not only reveal an important regulation of lipid membrane on PrP behavior but may also provide clues for designing stage-specific and prion-targeted therapy.
Collapse
Affiliation(s)
- Sophie Combet
- Laboratoire Léon-Brillouin, UMR 12 CEA-CNRS, Université Paris-Saclay, CEA-Saclay, F-91191 Gif-sur-Yvette CEDEX, France
| | - Fabrice Cousin
- Laboratoire Léon-Brillouin, UMR 12 CEA-CNRS, Université Paris-Saclay, CEA-Saclay, F-91191 Gif-sur-Yvette CEDEX, France
| | - Human Rezaei
- Laboratoire de Virologie et Immunologie Moléculaires, UR892, Institut National de la Recherche Agronomique (INRA), F-78352 Jouy-en-Josas, France
| | - Sylvie Noinville
- Laboratoire MONARIS, UMR 8233, Sorbonne Université, CNRS, F-75005 Paris, France.
| |
Collapse
|
23
|
Kerr D, Tietjen GT, Gong Z, Tajkhorshid E, Adams EJ, Lee KYC. Sensitivity of peripheral membrane proteins to the membrane context: A case study of phosphatidylserine and the TIM proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2126-2133. [PMID: 29920237 DOI: 10.1016/j.bbamem.2018.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/11/2018] [Accepted: 06/12/2018] [Indexed: 12/17/2022]
Abstract
There is a diverse class of peripheral membrane-binding proteins that specifically bind phosphatidylserine (PS), a lipid that signals apoptosis or cell fusion depending on the membrane context of its presentation. PS-receptors are specialized for particular PS-presenting pathways, indicating that they might be sensitive to the membrane context. In this review, we describe a combination of thermodynamic, structural, and computational techniques that can be used to investigate the mechanisms underlying this sensitivity. As an example, we focus on three PS-receptors of the T-cell Immunoglobulin and Mucin containing (TIM) protein family, which we have previously shown to differ in their sensitivity to PS surface density.
Collapse
Affiliation(s)
- Daniel Kerr
- Program in Biophysical Sciences, Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, United States of America
| | - Gregory T Tietjen
- Program in Biophysical Sciences, Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, United States of America
| | - Zhiliang Gong
- Department of Chemistry, The University of Chicago, Chicago, IL, United States of America
| | - Emad Tajkhorshid
- Department of Biochemistry, Center for Biophysics and Quantitative Biology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Erin J Adams
- Department of Biochemistry and Molecular Biology and Committee on Immunology, The University of Chicago, Chicago, IL, United States of America
| | - Ka Yee C Lee
- Program in Biophysical Sciences, Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, United States of America; Department of Chemistry, The University of Chicago, Chicago, IL, United States of America; James Franck Institute, The University of Chicago, Chicago, IL, United States of America.
| |
Collapse
|
24
|
Pore-forming toxins in Cnidaria. Semin Cell Dev Biol 2017; 72:133-141. [DOI: 10.1016/j.semcdb.2017.07.026] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 07/14/2017] [Accepted: 07/20/2017] [Indexed: 01/05/2023]
|
25
|
Rivera-de-Torre E, Palacios-Ortega J, García-Linares S, Gavilanes JG, Martínez-Del-Pozo Á. One single salt bridge explains the different cytolytic activities shown by actinoporins sticholysin I and II from the venom of Stichodactyla helianthus. Arch Biochem Biophys 2017; 636:79-89. [PMID: 29138096 DOI: 10.1016/j.abb.2017.11.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/06/2017] [Accepted: 11/10/2017] [Indexed: 10/18/2022]
Abstract
Sticholysins I and II (StnI and StnII), α-pore forming toxins from the sea anemone Stichodactyla helianthus, are water-soluble toxic proteins which upon interaction with lipid membranes of specific composition bind to the bilayer, extend and insert their N-terminal α-helix, and become oligomeric integral membrane structures. The result is a pore that leads to cell death by osmotic shock. StnI and StnII show 93% of sequence identity, but also different membrane pore-forming activities. The hydrophobicity profile along the first 18 residues revealed differences which were canceled by substituting StnI amino acids 2 and 9. Accordingly, the StnID9A mutant, and the corresponding StnIE2AD9A variant, showed enhanced hemolytic activity. They also revealed a key role for an exposed salt bridge between Asp9 and Lys68. This interaction is not possible in StnII but appears conserved in the other two well-characterized actinoporins, equinatoxin II and fragaceatoxin C. The StnII mutant A8D showed that this single replacement was enough to transform StnII into a version with impaired pore-forming activity. Overall, the results show the key importance of this salt bridge linking the N-terminal stretch to the β-sandwich core. A conclusion of general application for the understanding of salt bridges role in protein design, folding and stability.
Collapse
Affiliation(s)
- Esperanza Rivera-de-Torre
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid, Spain
| | - Juan Palacios-Ortega
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid, Spain
| | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid, Spain
| | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid, Spain.
| | - Álvaro Martínez-Del-Pozo
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid, Spain.
| |
Collapse
|
26
|
Palacios-Ortega J, García-Linares S, Rivera-de-Torre E, Gavilanes JG, Martínez-Del-Pozo Á, Slotte JP. Differential Effect of Bilayer Thickness on Sticholysin Activity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:11018-11027. [PMID: 28933861 DOI: 10.1021/acs.langmuir.7b01765] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this study, we examined the influence of bilayer thickness on the activity of the actinoporin toxins sticholysin I and II (StnI and StnII) at 25 °C. Bilayer thickness was varied using dimonounsaturated phosphatidylcholine (PC) analogues (with 14:1, 16:1, 18:1, 20:1, and 22:1 acyl chains). In addition, N-14:0-sphingomyelin (SM) was always included because StnI and StnII are SM specific. Cholesterol was also incorporated as indicated. In cholesterol-free large unilamellar vesicles (LUVs) the PC:SM molar ratio was 4:1, and when cholesterol was included, the complete molar ratio was 4:1:0.5 (PC:SM:cholesterol, respectively). Stn toxins promote bilayer leakage through pores formed by oligomerized toxin monomers. Initial calcein leakage was moderately dependent on bilayer PC acyl chain length (and thus bilayer thickness), with higher rates observed with di-16:1 and di-18:1 PC bilayers. In the presence of cholesterol, the maximum rates of calcein leakage were observed in di-14:1 and di-16:1 PC bilayers. Using isothermal titration calorimetry to study the Stn-LUV interaction, we observed that the bilayer affinity constant (Ka) peaked with LUVs containing di-18:1 PC, and was lower in shorter and longer PC acyl chain bilayers. The presence of cholesterol increased the binding affinity approximately 30-fold at the optimal bilayer thickness (di-18:1-PC). We conclude that bilayer thickness affects both functional and conformational aspects of Stn membrane binding and pore formation. Moreover, the length of the actinoporins' N-terminal α-helix, which penetrates the membrane to form a functional pore, appears to be optimal for the membrane thickness represented by di-18:1 PC.
Collapse
Affiliation(s)
- Juan Palacios-Ortega
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense , Madrid 28040, Spain
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , 20500 Turku, Finland
| | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense , Madrid 28040, Spain
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , 20500 Turku, Finland
| | | | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense , Madrid 28040, Spain
| | - Álvaro Martínez-Del-Pozo
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense , Madrid 28040, Spain
| | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , 20500 Turku, Finland
| |
Collapse
|
27
|
Soto C, del Valle A, Valiente PA, Ros U, Lanio ME, Hernández AM, Alvarez C. Differential binding and activity of the pore-forming toxin sticholysin II in model membranes containing diverse ceramide-derived lipids. Biochimie 2017; 138:20-31. [DOI: 10.1016/j.biochi.2017.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 04/04/2017] [Indexed: 01/07/2023]
|
28
|
Frangež R, Šuput D, Molgó J, Benoit E. Ostreolysin A/Pleurotolysin B and Equinatoxins: Structure, Function and Pathophysiological Effects of These Pore-Forming Proteins. Toxins (Basel) 2017; 9:toxins9040128. [PMID: 28379176 PMCID: PMC5408202 DOI: 10.3390/toxins9040128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 03/30/2017] [Accepted: 03/31/2017] [Indexed: 12/17/2022] Open
Abstract
Acidic ostreolysin A/pleurotolysin B (OlyA/PlyB, formerly known as ostreolysin (Oly), and basic 20 kDa equinatoxins (EqTs) are cytolytic proteins isolated from the edible mushroom Pleurotus ostreatus and the sea anemone Actinia equina, respectively. Both toxins, although from different sources, share many similar biological activities: (i) colloid-osmotic shock by forming pores in cellular and artificial membranes enriched in cholesterol and sphingomyelin; (ii) increased vascular endothelial wall permeability in vivo and perivascular oedema; (iii) dose-dependent contraction of coronary vessels; (iv) haemolysis with pronounced hyperkalaemia in vivo; (v) bradycardia, myocardial ischemia and ventricular extrasystoles accompanied by progressive fall of arterial blood pressure and respiratory arrest in rodents. Both types of toxins are haemolytic within nanomolar range concentrations, and it seems that hyperkalaemia plays an important role in toxin cardiotoxicity. However, it was observed that the haemolytically more active EqT III is less toxic than EqT I, the most toxic and least haemolytic EqT. In mice, EqT II is more than 30 times more toxic than OlyA/PlyB when applied intravenously. These observations imply that haemolysis with hyperkalaemia is not the sole cause of the lethal activity of both toxins. Additional mechanisms responsible for lethal action of the two toxins are direct effects on heart, coronary vasoconstriction and related myocardial hypoxia. In this review, we appraise the pathophysiological mechanisms related to the chemical structure of OlyA/PlyB and EqTs, as well as their toxicity.
Collapse
Affiliation(s)
- Robert Frangež
- Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana; 1115-Ljubljana, Slovenia.
| | - Dušan Šuput
- Laboratory for Cell Physiology and Toxinology, Institute of Pathophysiology, School of Medicine, University of Ljubljana, P.O. Box 11, 1105-Ljubljana, Slovenia.
| | - Jordi Molgó
- DRF/Institut de Sciences de la Vie Frédéric Joliot/SIMOPRO, CEA de Saclay, and Institut des Neurosciences Paris-Saclay (Neuro-PSI), UMR 9197 CNRS/Université Paris-Sud, 91190 Gif-sur-Yvette, France.
| | - Evelyne Benoit
- DRF/Institut de Sciences de la Vie Frédéric Joliot/SIMOPRO, CEA de Saclay, and Institut des Neurosciences Paris-Saclay (Neuro-PSI), UMR 9197 CNRS/Université Paris-Sud, 91190 Gif-sur-Yvette, France.
| |
Collapse
|
29
|
Narayanan T, Wacklin H, Konovalov O, Lund R. Recent applications of synchrotron radiation and neutrons in the study of soft matter. CRYSTALLOGR REV 2017. [DOI: 10.1080/0889311x.2016.1277212] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
| | - Hanna Wacklin
- European Spallation Source ERIC, Lund, Sweden
- Physical Chemistry, Lund University, Lund, Sweden
| | | | - Reidar Lund
- Department of Chemistry, University of Oslo, Blindern, Oslo, Norway
| |
Collapse
|
30
|
García-Linares S, Rivera-de-Torre E, Palacios-Ortega J, Gavilanes JG, Martínez-del-Pozo Á. The Metamorphic Transformation of a Water-Soluble Monomeric Protein Into an Oligomeric Transmembrane Pore. ADVANCES IN BIOMEMBRANES AND LIPID SELF-ASSEMBLY 2017. [DOI: 10.1016/bs.abl.2017.06.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
31
|
Biological Structures. NEUTRON SCATTERING - APPLICATIONS IN BIOLOGY, CHEMISTRY, AND MATERIALS SCIENCE 2017. [DOI: 10.1016/b978-0-12-805324-9.00001-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
32
|
García-Linares S, Rivera-de-Torre E, Morante K, Tsumoto K, Caaveiro JMM, Gavilanes JG, Slotte JP, Martínez-Del-Pozo Á. Differential Effect of Membrane Composition on the Pore-Forming Ability of Four Different Sea Anemone Actinoporins. Biochemistry 2016; 55:6630-6641. [PMID: 27933793 DOI: 10.1021/acs.biochem.6b01007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Sea anemone actinoporins constitute a protein family of multigene pore-forming toxins (PFT). Equinatoxin II (EqtII), fragaceatoxin C (FraC), and sticholysins I and II (StnI and StnII, respectively), produced by three different sea anemone species, are the only actinoporins whose molecular structures have been studied in depth. These four proteins show high sequence identities and practically coincident three-dimensional structures. However, their pore-forming activity can be quite different depending on the model lipid system employed, a feature that has not been systematically studied before. Therefore, the aim of this work was to evaluate and compare the influence of several distinct membrane conditions on their particular pore-forming behavior. Using a complex model membrane system, such as sheep erythrocytes, StnII showed hemolytic activity much higher than those of the other three actinoporins studied. In lipid model systems, pore-forming ability when assayed against 4:1 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/sphingomyelin (SM) vesicles, with the membrane binding being the rate-limiting step, decreased in the following order: StnI > StnII > EqtII > FraC. When using 1:1:1 DOPC/SM/cholesterol LUVs, the presence of Chol not only enhanced membrane binding affinities by ∼2 orders of magnitude but also revealed how StnII was much faster than the other three actinoporins in producing calcein release. This ability agrees with the proposal that explains this behavior in terms of their high sequence variability along their first 30 N-terminal residues. The influence of interfacial hydrogen bonding in SM- or dihydro-SM-containing bilayers was also shown to be a generalized feature of the four actinoporins studied. It is finally hypothesized that this observed variable ability could be explained as a consequence of their distinct specificities and/or membrane binding affinities. Eventually, this behavior can be modulated by the nature of their natural target membranes or the interaction with not yet characterized isotoxin forms from the same sea anemone species.
Collapse
Affiliation(s)
- Sara García-Linares
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense , Madrid, Spain.,Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , Turku, Finland
| | | | - Koldo Morante
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kouhei Tsumoto
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Jose M M Caaveiro
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular I, Universidad Complutense , Madrid, Spain
| | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University , Turku, Finland
| | | |
Collapse
|
33
|
Morante K, Bellomio A, Gil-Cartón D, Redondo-Morata L, Sot J, Scheuring S, Valle M, González-Mañas JM, Tsumoto K, Caaveiro JMM. Identification of a Membrane-bound Prepore Species Clarifies the Lytic Mechanism of Actinoporins. J Biol Chem 2016; 291:19210-19219. [PMID: 27445331 PMCID: PMC5016661 DOI: 10.1074/jbc.m116.734053] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Indexed: 11/06/2022] Open
Abstract
Pore-forming toxins (PFTs) are cytolytic proteins belonging to the molecular warfare apparatus of living organisms. The assembly of the functional transmembrane pore requires several intermediate steps ranging from a water-soluble monomeric species to the multimeric ensemble inserted in the cell membrane. The non-lytic oligomeric intermediate known as prepore plays an essential role in the mechanism of insertion of the class of β-PFTs. However, in the class of α-PFTs, like the actinoporins produced by sea anemones, evidence of membrane-bound prepores is still lacking. We have employed single-particle cryo-electron microscopy (cryo-EM) and atomic force microscopy to identify, for the first time, a prepore species of the actinoporin fragaceatoxin C bound to lipid vesicles. The size of the prepore coincides with that of the functional pore, except for the transmembrane region, which is absent in the prepore. Biochemical assays indicated that, in the prepore species, the N terminus is not inserted in the bilayer but is exposed to the aqueous solution. Our study reveals the structure of the prepore in actinoporins and highlights the role of structural intermediates for the formation of cytolytic pores by an α-PFT.
Collapse
Affiliation(s)
- Koldo Morante
- From the Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.,the Department of Biochemistry and Molecular Biology and.,Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, P. O. Box 644, 48080 Bilbao, Spain
| | - Augusto Bellomio
- the Department of Biochemistry and Molecular Biology and.,Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, P. O. Box 644, 48080 Bilbao, Spain
| | - David Gil-Cartón
- the Structural Biology Unit, Center for Cooperative Research in Biosciences, CICbiogune, 48160 Derio, Spain
| | - Lorena Redondo-Morata
- the U1006 INSERM, Aix-Marseille Université, Parc Scientifique et Technologique de Luminy, 163 Avenue de Luminy, 13009 Marseille, France, and
| | - Jesús Sot
- the Department of Biochemistry and Molecular Biology and.,Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, P. O. Box 644, 48080 Bilbao, Spain
| | - Simon Scheuring
- the U1006 INSERM, Aix-Marseille Université, Parc Scientifique et Technologique de Luminy, 163 Avenue de Luminy, 13009 Marseille, France, and
| | - Mikel Valle
- the Structural Biology Unit, Center for Cooperative Research in Biosciences, CICbiogune, 48160 Derio, Spain
| | | | - Kouhei Tsumoto
- From the Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan, .,the Institute of Medical Science, University of Tokyo, Minato-ku, 108-8639 Tokyo, Japan
| | - Jose M M Caaveiro
- From the Department of Bioengineering, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan,
| |
Collapse
|
34
|
Rivera-de-Torre E, García-Linares S, Alegre-Cebollada J, Lacadena J, Gavilanes JG, Martínez-Del-Pozo Á. Synergistic Action of Actinoporin Isoforms from the Same Sea Anemone Species Assembled into Functionally Active Heteropores. J Biol Chem 2016; 291:14109-14119. [PMID: 27129251 DOI: 10.1074/jbc.m115.710491] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Indexed: 11/06/2022] Open
Abstract
Among the toxic polypeptides secreted in the venom of sea anemones, actinoporins are the pore-forming toxins whose toxic activity relies on the formation of oligomeric pores within biological membranes. Intriguingly, actinoporins appear as multigene families that give rise to many protein isoforms in the same individual displaying high sequence identities but large functional differences. However, the evolutionary advantage of producing such similar isotoxins is not fully understood. Here, using sticholysins I and II (StnI and StnII) from the sea anemone Stichodactyla helianthus, it is shown that actinoporin isoforms can potentiate each other's activity. Through hemolysis and calcein releasing assays, it is revealed that mixtures of StnI and StnII are more lytic than equivalent preparations of the corresponding isolated isoforms. It is then proposed that this synergy is due to the assembly of heteropores because (i) StnI and StnII can be chemically cross-linked at the membrane and (ii) the affinity of sticholysin mixtures for the membrane is increased with respect to any of them acting in isolation, as revealed by isothermal titration calorimetry experiments. These results help us understand the multigene nature of actinoporins and may be extended to other families of toxins that require oligomerization to exert toxicity.
Collapse
Affiliation(s)
- Esperanza Rivera-de-Torre
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid
| | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid
| | | | - Javier Lacadena
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid
| | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid.
| | - Álvaro Martínez-Del-Pozo
- Departamento de Bioquímica y Biología Molecular I, Facultades de Química y Biología, Universidad Complutense, 28040 Madrid.
| |
Collapse
|