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  1. AU="Strandberg, Erik"
  2. AU="Dar Dowlatshahi"
  3. AU="Capote, Ailem Rabasa"
  4. AU="Richier, Q"
  5. AU="Jamla, Monica"
  6. AU="Shimomura, Taizou"
  7. AU="Tampakakis, Emmanouil"
  8. AU="Tabares, Jeffrey V"

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  1. Artikel ; Online: Antibiotic Potential and Biophysical Characterization of Amphipathic β-Stranded [XZ]

    Strandberg, Erik / Wadhwani, Parvesh / Ulrich, Anne S

    Frontiers in medical technology

    2021  Band 3, Seite(n) 622096

    Abstract: Cationic membrane-active peptides are considered to be promising candidates for antibiotic treatment. Many natural and artificial sequences show an antimicrobial activity when they are able to take on an amphipathic fold upon membrane binding, which in ... ...

    Abstract Cationic membrane-active peptides are considered to be promising candidates for antibiotic treatment. Many natural and artificial sequences show an antimicrobial activity when they are able to take on an amphipathic fold upon membrane binding, which in turn perturbs the integrity of the lipid bilayer. Most known structures are α-helices and β-hairpins, but also cyclic knots and other irregular conformations are known. Linear β-stranded antimicrobial peptides are not so common in nature, but numerous model sequences have been designed. Interestingly, many of them tend to be highly membranolytic, but also have a significant tendency to self-assemble into β-sheets by hydrogen-bonding. In this minireview we examine the literature on such amphipathic peptides consisting of simple repetitive sequences of alternating cationic and hydrophobic residues, and discuss their advantages and disadvantages. Their interactions with lipids have been characterized with a number of biophysical techniques-especially circular dichroism, fluorescence, and infrared-in order to determine their secondary structure, membrane binding, aggregation tendency, and ability to permeabilize vesicles. Their activities against bacteria, biofilms, erythrocytes, and human cells have also been studied using biological assays. In line with the main scope of this Special Issue, we attempt to correlate the biophysical results with the biological data, and in particular we discuss which properties (length, charge, aggregation tendency, etc.) of these simple model peptides are most relevant for their biological function. The overview presented here offers ideas for future experiments, and also suggests a few design rules for promising β-stranded peptides to develop efficient antimicrobial agents.
    Sprache Englisch
    Erscheinungsdatum 2021-02-04
    Erscheinungsland Switzerland
    Dokumenttyp Journal Article ; Review
    ISSN 2673-3129
    ISSN (online) 2673-3129
    DOI 10.3389/fmedt.2021.622096
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  2. Artikel ; Online: High-angle deflection of metagrating-integrated laser emission for high-contrast microscopy.

    Juodėnas, Mindaugas / Strandberg, Erik / Grabowski, Alexander / Gustavsson, Johan / Šípová-Jungová, Hana / Larsson, Anders / Käll, Mikael

    Light, science & applications

    2023  Band 12, Heft 1, Seite(n) 251

    Abstract: Flat metaoptics components are looking to replace classical optics elements and could lead to extremely compact biophotonics devices if integrated with on-chip light sources and detectors. However, using metasurfaces to shape light into wide angular ... ...

    Abstract Flat metaoptics components are looking to replace classical optics elements and could lead to extremely compact biophotonics devices if integrated with on-chip light sources and detectors. However, using metasurfaces to shape light into wide angular range wavefronts with high efficiency, as is typically required in high-contrast microscopy applications, remains a challenge. Here we demonstrate curved GaAs metagratings integrated on vertical-cavity surface-emitting lasers (VCSELs) that enable on-chip illumination in total internal reflection and dark field microscopy. Based on an unconventional design that circumvents the aspect ratio dependent etching problems in monolithic integration, we demonstrate off-axis emission centred at 60° in air and 63° in glass with > 90% and > 70% relative deflection efficiency, respectively. The resulting laser beam is collimated out-of-plane but maintains Gaussian divergence in-plane, resulting in a long and narrow illumination area. We show that metagrating-integrated VCSELs of different kinds can be combined to enable rapid switching between dark-field and total internal reflection illumination. Our approach provides a versatile illumination solution for high-contrast imaging that is compatible with conventional microscopy setups and can be integrated with biophotonics devices, such as portable microscopy, NIR-II range bioimaging, and lab-on-a-chip devices.
    Sprache Englisch
    Erscheinungsdatum 2023-10-13
    Erscheinungsland England
    Dokumenttyp Journal Article
    ZDB-ID 2662628-7
    ISSN 2047-7538 ; 2047-7538
    ISSN (online) 2047-7538
    ISSN 2047-7538
    DOI 10.1038/s41377-023-01286-0
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  3. Artikel ; Online: Chiral supramolecular architecture of stable transmembrane pores formed by an α-helical antibiotic peptide in the presence of lyso-lipids.

    Strandberg, Erik / Bentz, David / Wadhwani, Parvesh / Ulrich, Anne S

    Scientific reports

    2020  Band 10, Heft 1, Seite(n) 4710

    Abstract: The amphipathic α-helical antimicrobial peptide MSI-103 (aka KIA21) can form stable transmembrane pores when the bilayer takes on a positive spontaneous curvature, e.g. by the addition of lyso-lipids. Solid- ... ...

    Abstract The amphipathic α-helical antimicrobial peptide MSI-103 (aka KIA21) can form stable transmembrane pores when the bilayer takes on a positive spontaneous curvature, e.g. by the addition of lyso-lipids. Solid-state
    Mesh-Begriff(e) Amino Acid Sequence ; Antimicrobial Cationic Peptides/chemistry ; Antimicrobial Cationic Peptides/pharmacology ; Cell Membrane/chemistry ; Lipid Bilayers/chemistry ; Lipids/chemistry ; Nuclear Magnetic Resonance, Biomolecular ; Protein Conformation, alpha-Helical ; Structure-Activity Relationship
    Chemische Substanzen Antimicrobial Cationic Peptides ; Lipid Bilayers ; Lipids
    Sprache Englisch
    Erscheinungsdatum 2020-03-13
    Erscheinungsland England
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-020-61526-w
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  4. Artikel ; Online: Membrane Interactions of Latarcins: Antimicrobial Peptides from Spider Venom.

    Wadhwani, Parvesh / Sekaran, Saiguru / Strandberg, Erik / Bürck, Jochen / Chugh, Archana / Ulrich, Anne S

    International journal of molecular sciences

    2021  Band 22, Heft 18

    Abstract: A group of seven peptides from spider venom with diverse sequences constitute the latarcin family. They have been described as membrane-active antibiotics, but their lipid interactions have not yet been addressed. Using circular dichroism and solid- ... ...

    Abstract A group of seven peptides from spider venom with diverse sequences constitute the latarcin family. They have been described as membrane-active antibiotics, but their lipid interactions have not yet been addressed. Using circular dichroism and solid-state
    Mesh-Begriff(e) Amino Acid Sequence ; Animals ; Antimicrobial Cationic Peptides/chemistry ; Cell Membrane/metabolism ; Circular Dichroism ; Hydrophobic and Hydrophilic Interactions ; Lipid Bilayers/chemistry ; Magnetic Resonance Spectroscopy ; Pore Forming Cytotoxic Proteins/chemistry ; Pore Forming Cytotoxic Proteins/metabolism ; Spider Venoms/chemistry
    Chemische Substanzen Antimicrobial Cationic Peptides ; Lipid Bilayers ; Pore Forming Cytotoxic Proteins ; Spider Venoms
    Sprache Englisch
    Erscheinungsdatum 2021-09-21
    Erscheinungsland Switzerland
    Dokumenttyp Journal Article
    ZDB-ID 2019364-6
    ISSN 1422-0067 ; 1422-0067 ; 1661-6596
    ISSN (online) 1422-0067
    ISSN 1422-0067 ; 1661-6596
    DOI 10.3390/ijms221810156
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  5. Artikel: Membranolytic Mechanism of Amphiphilic Antimicrobial β-Stranded [KL]

    Schweigardt, Fabian / Strandberg, Erik / Wadhwani, Parvesh / Reichert, Johannes / Bürck, Jochen / Cravo, Haroldo L P / Burger, Luisa / Ulrich, Anne S

    Biomedicines

    2022  Band 10, Heft 9

    Abstract: Amphipathic peptides can act as antibiotics due to membrane permeabilization. KL peptides with the repetitive sequence [Lys-Leu] ...

    Abstract Amphipathic peptides can act as antibiotics due to membrane permeabilization. KL peptides with the repetitive sequence [Lys-Leu]
    Sprache Englisch
    Erscheinungsdatum 2022-08-24
    Erscheinungsland Switzerland
    Dokumenttyp Journal Article
    ZDB-ID 2720867-9
    ISSN 2227-9059
    ISSN 2227-9059
    DOI 10.3390/biomedicines10092071
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  6. Artikel: AMPs and OMPs: Is the folding and bilayer insertion of β-stranded outer membrane proteins governed by the same biophysical principles as for α-helical antimicrobial peptides?

    Strandberg, Erik / Ulrich, Anne S

    Biochimica et biophysica acta

    2015  Band 1848, Heft 9, Seite(n) 1944–1954

    Abstract: The folding and function of membrane proteins is controlled not only by specific but also by unspecific interactions with the constituent lipids. In this review, we focus on the influence of the spontaneous lipid curvature on the folding and insertion of ...

    Abstract The folding and function of membrane proteins is controlled not only by specific but also by unspecific interactions with the constituent lipids. In this review, we focus on the influence of the spontaneous lipid curvature on the folding and insertion of peptides and proteins in membranes. Amphiphilic α-helical peptides, as represented by various antimicrobial sequences, are compared with β-barrel proteins, which are found in the outer membrane of Gram-negative bacteria. It has been shown that cationic amphiphilic peptides are always surface-bound in lipids with a negative spontaneous curvature like POPC, i.e. they are oriented parallel to the membrane plane. On the other hand, in lipids like DMPC with a positive curvature, these peptides can get tilted or completely inserted in a transmembrane state. Remarkably, the folding and spontaneous membrane insertion of β-barrel outer membrane proteins also proceeds more easily in lipids with a positive intrinsic curvature, while it is hampered by negative curvature. We therefore propose that a positive spontaneous curvature of the lipids promotes the ability of a surface-bound molecule to insert more deeply into the bilayer core, irrespective of the conformation, size, or shape of the peptide, protein, or folding intermediate. This article is part of a Special Issue entitled: Lipid-protein interactions.
    Mesh-Begriff(e) Animals ; Antimicrobial Cationic Peptides/chemistry ; Antimicrobial Cationic Peptides/metabolism ; Bacterial Outer Membrane Proteins/chemistry ; Bacterial Outer Membrane Proteins/metabolism ; Biophysical Phenomena ; Cell Membrane/chemistry ; Cell Membrane/metabolism ; Humans ; Lipid Bilayers/chemistry ; Lipid Bilayers/metabolism ; Models, Molecular ; Protein Folding ; Protein Structure, Secondary
    Chemische Substanzen Antimicrobial Cationic Peptides ; Bacterial Outer Membrane Proteins ; Lipid Bilayers
    Sprache Englisch
    Erscheinungsdatum 2015-09
    Erscheinungsland Netherlands
    Dokumenttyp Journal Article ; Review
    ZDB-ID 60-7
    ISSN 1879-2596 ; 1879-260X ; 1872-8006 ; 1879-2642 ; 1879-2618 ; 1879-2650 ; 0006-3002 ; 0005-2728 ; 0005-2736 ; 0304-4165 ; 0167-4838 ; 1388-1981 ; 0167-4889 ; 0167-4781 ; 0304-419X ; 1570-9639 ; 0925-4439 ; 1874-9399
    ISSN (online) 1879-2596 ; 1879-260X ; 1872-8006 ; 1879-2642 ; 1879-2618 ; 1879-2650
    ISSN 0006-3002 ; 0005-2728 ; 0005-2736 ; 0304-4165 ; 0167-4838 ; 1388-1981 ; 0167-4889 ; 0167-4781 ; 0304-419X ; 1570-9639 ; 0925-4439 ; 1874-9399
    DOI 10.1016/j.bbamem.2015.02.019
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  7. Artikel ; Online: Terminal charges modulate the pore forming activity of cationic amphipathic helices.

    Strandberg, Erik / Bentz, David / Wadhwani, Parvesh / Bürck, Jochen / Ulrich, Anne S

    Biochimica et biophysica acta. Biomembranes

    2020  Band 1862, Heft 4, Seite(n) 183243

    Abstract: KIA peptides are a series of designer-made cationic amphipathic α-helical antimicrobial peptides of different lengths, based on the repetitive sequence [KIAGKIA]. They can form toroidal pores in membranes, wherein the helices are aligned in a ... ...

    Abstract KIA peptides are a series of designer-made cationic amphipathic α-helical antimicrobial peptides of different lengths, based on the repetitive sequence [KIAGKIA]. They can form toroidal pores in membranes, wherein the helices are aligned in a transmembrane orientation. Solid-state
    Mesh-Begriff(e) Amino Acid Sequence/genetics ; Antimicrobial Cationic Peptides/chemistry ; Cell Membrane/chemistry ; Hydrophobic and Hydrophilic Interactions ; Lipid Bilayers/chemistry ; Nuclear Magnetic Resonance, Biomolecular ; Oligopeptides/chemistry ; Oligopeptides/genetics ; Protein Conformation ; Protein Conformation, alpha-Helical ; Protein Structure, Secondary/genetics
    Chemische Substanzen Antimicrobial Cationic Peptides ; Lipid Bilayers ; Oligopeptides
    Sprache Englisch
    Erscheinungsdatum 2020-02-29
    Erscheinungsland Netherlands
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 60-7
    ISSN 1879-2642 ; 1879-2596 ; 1879-260X ; 1872-8006 ; 1879-2618 ; 1879-2650 ; 0006-3002 ; 0005-2728 ; 0005-2736 ; 0304-4165 ; 0167-4838 ; 1388-1981 ; 0167-4889 ; 0167-4781 ; 0304-419X ; 1570-9639 ; 0925-4439 ; 1874-9399
    ISSN (online) 1879-2642 ; 1879-2596 ; 1879-260X ; 1872-8006 ; 1879-2618 ; 1879-2650
    ISSN 0006-3002 ; 0005-2728 ; 0005-2736 ; 0304-4165 ; 0167-4838 ; 1388-1981 ; 0167-4889 ; 0167-4781 ; 0304-419X ; 1570-9639 ; 0925-4439 ; 1874-9399
    DOI 10.1016/j.bbamem.2020.183243
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  8. Artikel ; Online: Temperature-Dependent Re-alignment of the Short Multifunctional Peptide BP100 in Membranes Revealed by Solid-State NMR Spectroscopy and Molecular Dynamics Simulations.

    Strandberg, Erik / Wadhwani, Parvesh / Bürck, Jochen / Anders, Patrick / Mink, Christian / van den Berg, Jonas / Ciriello, Raffaele A M / Melo, Manuel N / Castanho, Miguel A R B / Bardají, Eduard / Ulmschneider, Jakob P / Ulrich, Anne S

    Chembiochem : a European journal of chemical biology

    2023  Band 24, Heft 4, Seite(n) e202200602

    Abstract: BP100 is a cationic undecamer peptide with antimicrobial and cell-penetrating activities. The orientation of this amphiphilic α-helix in lipid bilayers was examined under numerous conditions using solid- ... ...

    Abstract BP100 is a cationic undecamer peptide with antimicrobial and cell-penetrating activities. The orientation of this amphiphilic α-helix in lipid bilayers was examined under numerous conditions using solid-state
    Mesh-Begriff(e) Temperature ; Molecular Dynamics Simulation ; Peptides/chemistry ; Cell Membrane/chemistry ; Lipid Bilayers/chemistry ; Magnetic Resonance Spectroscopy
    Chemische Substanzen Peptides ; Lipid Bilayers
    Sprache Englisch
    Erscheinungsdatum 2023-01-09
    Erscheinungsland Germany
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2020469-3
    ISSN 1439-7633 ; 1439-4227
    ISSN (online) 1439-7633
    ISSN 1439-4227
    DOI 10.1002/cbic.202200602
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  9. Artikel ; Online: Overlapping Properties of the Short Membrane-Active Peptide BP100 With (i) Polycationic TAT and (ii) α-helical Magainin Family Peptides.

    Mink, Christian / Strandberg, Erik / Wadhwani, Parvesh / Melo, Manuel N / Reichert, Johannes / Wacker, Irene / Castanho, Miguel A R B / Ulrich, Anne S

    Frontiers in cellular and infection microbiology

    2021  Band 11, Seite(n) 609542

    Abstract: BP100 is a short, designer-made membrane-active peptide with multiple functionalities: antimicrobial, cell-penetrating, and fusogenic. Consisting of five lysines and 6 hydrophobic residues, BP100 was shown to bind to lipid bilayers as an amphipathic α- ... ...

    Abstract BP100 is a short, designer-made membrane-active peptide with multiple functionalities: antimicrobial, cell-penetrating, and fusogenic. Consisting of five lysines and 6 hydrophobic residues, BP100 was shown to bind to lipid bilayers as an amphipathic α-helix, but its mechanism of action remains unclear. With these features, BP100 embodies the characteristics of two distinctly different classes of membrane-active peptides, which have been studied in detail and where the mechanism of action is better understood. On the one hand, its amphiphilic helical structure is similar to the pore forming magainin family of antimicrobial peptides, though BP100 is much too short to span the membrane. On the other hand, its length and high charge density are reminiscent of the HIV-TAT family of cell penetrating peptides, for which inverted micelles have been postulated as translocation intermediates, amongst other mechanisms. Assays were performed to test the antimicrobial and hemolytic activity, the induced leakage and fusion of lipid vesicles, and cell uptake. From these results the functional profiles of BP100, HIV-TAT, and the magainin-like peptides magainin 2, PGLa, MSI-103, and MAP were determined and compared. It is observed that the activity of BP100 resembles most closely the much longer amphipathic α-helical magainin-like peptides, with high antimicrobial activity along with considerable fusogenic and hemolytic effects. In contrast, HIV-TAT shows almost no antimicrobial, fusogenic, or hemolytic effects. We conclude that the amphipathic helix of BP100 has a similar membrane-based activity as magainin-like peptides and may have a similar mechanism of action.
    Mesh-Begriff(e) Anti-Bacterial Agents ; Anti-Infective Agents/pharmacology ; Lipid Bilayers ; Magainins ; Protein Conformation, alpha-Helical
    Chemische Substanzen Anti-Bacterial Agents ; Anti-Infective Agents ; Lipid Bilayers ; Magainins
    Sprache Englisch
    Erscheinungsdatum 2021-04-26
    Erscheinungsland Switzerland
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2619676-1
    ISSN 2235-2988 ; 2235-2988
    ISSN (online) 2235-2988
    ISSN 2235-2988
    DOI 10.3389/fcimb.2021.609542
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  10. Artikel: Helix Fraying and Lipid-Dependent Structure of a Short Amphipathic Membrane-Bound Peptide Revealed by Solid-State NMR

    Strandberg, Erik / Anne S. Ulrich / Ariadna Grau-Campistany / Francesc Rabanal / Jochen Bürck / Parvesh Wadhwani

    Journal of physical chemistry. 2018 June 01, v. 122, no. 23

    2018  

    Abstract: The amphipathic α-helical peptide KIA14 [(KIAGKIA)2-NH2] was studied in membranes using circular dichroism and solid-state NMR spectroscopy to obtain global as well as local structural information. By analyzing 2H NMR data from 10 analogues of KIA14 that ...

    Abstract The amphipathic α-helical peptide KIA14 [(KIAGKIA)2-NH2] was studied in membranes using circular dichroism and solid-state NMR spectroscopy to obtain global as well as local structural information. By analyzing 2H NMR data from 10 analogues of KIA14 that were selectively labeled with Ala-d3, those positions that are properly folded into a helix could be determined within the membrane-bound peptide. The N-terminus was found to be unraveled, whereas positions 4–14 formed an ideal helix all the way to the C-terminus. The helicity did not change when Gly residues were replaced by Ala-d3 but was reduced when Ile was replaced, indicating that large hydrophobic residues are required for membrane binding and helix formation. The reduced helicity was strongly correlated with a decrease in peptide-induced leakage from lipid vesicles. The orientation of the short KIA14 peptide was assessed in several lipid systems and compared with that of the longer KIA21 sequence [(KIAGKIA)3-NH2]. In 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine, both peptides are aligned flat on the membrane surface, whereas in 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC)/1-myristoyl-2-hydroxy-sn-glycero-3-phosphatidylcholine (lyso-MPC) both are inserted into the membrane in an upright orientation. These two types of lipid systems had been selected for their strongly negative and positive spontaneous curvature, respectively. We propose that in these cases, the peptide orientation is largely determined by the lipid properties. On the other hand, in plain DMPC and 1,2-dilauroyl-sn-glycero-3-phosphatidylcholine, which have only a slight positive curvature, a marked difference in orientation is evident: the short KIA14 lies almost flat on the membrane surface, whereas the longer KIA21 is more tilted. We thus propose that out of the lipid systems tested here, DMPC (with hardly any curvature) is the least biased lipid system in which peptide orientation and realignment can be studied, allowing to compare and discriminate the intrinsic effects of the properties of the peptides as such.
    Schlagwörter circular dichroism spectroscopy ; deuterium ; hydrophobicity ; lipids ; nuclear magnetic resonance spectroscopy ; peptides ; physical chemistry ; surfactants
    Sprache Englisch
    Erscheinungsverlauf 2018-0601
    Umfang p. 6236-6250.
    Erscheinungsort American Chemical Society
    Dokumenttyp Artikel
    ISSN 1520-5207
    DOI 10.1021/acs.jpcb.8b02661
    Datenquelle NAL Katalog (AGRICOLA)

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