1
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Understanding the antimicrobial activity of water soluble γ-cyclodextrin/alamethicin complex. Colloids Surf B Biointerfaces 2018; 172:451-458. [DOI: 10.1016/j.colsurfb.2018.08.065] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 08/06/2018] [Accepted: 08/29/2018] [Indexed: 02/03/2023]
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2
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Yong YY, Dykes G, Lee SM, Choo WS. Biofilm inhibiting activity of betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms. J Appl Microbiol 2018; 126:68-78. [PMID: 30153380 DOI: 10.1111/jam.14091] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/17/2018] [Accepted: 08/23/2018] [Indexed: 01/01/2023]
Abstract
AIMS To investigate the biofilm inhibitory activity of betacyanins from red pitahaya (Hylocereus polyrhizus) and red spinach (Amaranthus dubius) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms. METHODS AND RESULTS The pulp of red pitahaya and the leaves of red spinach were extracted using methanol followed by subfractionation to obtain betacyanin fraction. The anti-biofilm activity was examined using broth microdilution assay on polystyrene surfaces and expressed as minimum biofilm inhibitory concentration (MBIC). The betacyanin fraction from red spinach showed better anti-biofilm activity (MBIC: 0·313-1·25 mg ml-1 ) against five Staph. aureus strains while the betacyanin fraction from red pitahaya showed better anti-biofilm activity (MBIC: 0·313-0·625 mg ml-1 ) against four P. aeruginosa strains. Both betacyanin fraction significantly reduced hydrophobicity of Staph. aureus and P. aeruginosa strains. Numbers of Staph. aureus and P. aeruginosa attached to polystyrene were also reduced without affecting their cell viability. CONCLUSION Betacyanins can act as anti-biofilm agents against the initial step of biofilm formation, particularly on a hydrophobic surface like polystyrene. SIGNIFICANCE AND IMPACT OF THE STUDY This study is the first to investigate the use of betacyanin as a biofilm inhibitory agent. Betacyanin could potentially be used to reduce the risk of biofilm-associated infections.
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Affiliation(s)
- Y Y Yong
- School of Science, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| | - G Dykes
- School of Public Health, Curtin University, Bentley, WA, Australia
| | - S M Lee
- School of Science, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
| | - W S Choo
- School of Science, Monash University Malaysia, Bandar Sunway, Selangor, Malaysia
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3
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Kurnik M, Sahin C, Andersen CB, Lorenzen N, Giehm L, Mohammad-Beigi H, Jessen CM, Pedersen JS, Christiansen G, Petersen SV, Staal R, Krishnamurthy G, Pitts K, Reinhart PH, Mulder FAA, Mente S, Hirst WD, Otzen DE. Potent α-Synuclein Aggregation Inhibitors, Identified by High-Throughput Screening, Mainly Target the Monomeric State. Cell Chem Biol 2018; 25:1389-1402.e9. [PMID: 30197194 DOI: 10.1016/j.chembiol.2018.08.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 05/12/2018] [Accepted: 08/06/2018] [Indexed: 12/26/2022]
Abstract
α-Synuclein (αSN) aggregation is central to the etiology of Parkinson's disease (PD). Large-scale screening of compounds to identify aggregation inhibitors is challenged by stochastic αSN aggregation and difficulties in detecting early-stage oligomers (αSOs). We developed a high-throughput screening assay combining SDS-stimulated αSN aggregation with FRET to reproducibly detect initial stages in αSN aggregation. We screened 746,000 compounds, leading to 58 hits that markedly inhibit αSN aggregation and reduce αSOs' membrane permeabilization activity. The most effective aggregation inhibitors were derivatives of (4-hydroxynaphthalen-1-yl)sulfonamide. They interacted strongly with the N-terminal part of monomeric αSN and reduced αSO-membrane interactions, possibly by affecting electrostatic interactions. Several compounds reduced αSO toxicity toward neuronal cell lines. The inhibitors introduced chemical modifications of αSN that were, however, not a prerequisite for inhibitory activity. We also identified several phenyl-benzoxazol compounds that promoted αSN aggregation (proaggregators). These compounds may be useful tools to modulate αSN aggregation in cellula.
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Affiliation(s)
- Martin Kurnik
- iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark
| | - Cagla Sahin
- iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark; Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus, Denmark
| | | | - Nikolai Lorenzen
- iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark
| | - Lise Giehm
- iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark
| | - Hossein Mohammad-Beigi
- iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark; Biotechnology Group, Faculty of Chemical Engineering, Tarbiat Modares University, P.O. Box 14115-143, Tehran, Iran
| | - Christian Moestrup Jessen
- iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark; Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus, Denmark
| | - Jan Skov Pedersen
- iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark; Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus, Denmark
| | | | | | | | | | - Keith Pitts
- Genentech, 1 DNA Way, South San Francisco, CA 94080, USA
| | - Peter H Reinhart
- Forma Therapeutics, Inc.Institute for Applied Life Sciences, University of Massachusetts Amherst, 240 Thatcher Road, Amherst, MA 01003-9364, USA
| | - Frans A A Mulder
- iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark; Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus, Denmark
| | - Scot Mente
- Forma Therapeutics, Inc., 500 Arsenal Street, Suite 100, Watertown, MA 02472, USA
| | | | - Daniel E Otzen
- iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark; Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus, Denmark.
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4
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Zapadka KL, Becher FJ, Gomes Dos Santos AL, Jackson SE. Factors affecting the physical stability (aggregation) of peptide therapeutics. Interface Focus 2017; 7:20170030. [PMID: 29147559 DOI: 10.1098/rsfs.2017.0030] [Citation(s) in RCA: 178] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The number of biological therapeutic agents in the clinic and development pipeline has increased dramatically over the last decade and the number will undoubtedly continue to increase in the coming years. Despite this fact, there are considerable challenges in the development, production and formulation of such biologics particularly with respect to their physical stabilities. There are many cases where self-association to form either amorphous aggregates or highly structured fibrillar species limits their use. Here, we review the numerous factors that influence the physical stability of peptides including both intrinsic and external factors, wherever possible illustrating these with examples that are of therapeutic interest. The effects of sequence, concentration, pH, net charge, excipients, chemical degradation and modification, surfaces and interfaces, and impurities are all discussed. In addition, the effects of physical parameters such as pressure, temperature, agitation and lyophilization are described. We provide an overview of the structures of aggregates formed, as well as our current knowledge of the mechanisms for their formation.
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Affiliation(s)
| | - Frederik J Becher
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | | | - Sophie E Jackson
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
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5
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Wimmer R, Uggerhøj LE. Determination of Structure and Micellar Interactions of Small Antimicrobial Peptides by Solution-State NMR. Methods Mol Biol 2017; 1548:73-88. [PMID: 28013498 DOI: 10.1007/978-1-4939-6737-7_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
NMR spectroscopy is a well-established technique to determine the structure of peptides and small proteins in solution, also when bound to detergent micelles or phospholipid bicelles. The structure of the peptide alone is, however, not conveying the full picture, if the peptide is bound to a micelle, since it does not tell anything about the orientation of the peptide in the micelle. This article describes how to obtain that information together with information on peptide structure.
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Affiliation(s)
- Reinhard Wimmer
- Department of Chemistry and Bioscience, University of Aalborg, Frederik Bajers vej 7H, 9220, Aalborg, Denmark.
| | - Lars Erik Uggerhøj
- Department of Chemistry and Bioscience, University of Aalborg, Frederik Bajers vej 7H, 9220, Aalborg, Denmark
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6
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Madsen JLH, Hjørringgaard CU, Vad BS, Otzen D, Skrydstrup T. Incorporation of β-Silicon-β3-Amino Acids in the Antimicrobial Peptide Alamethicin Provides a 20-Fold Increase in Membrane Permeabilization. Chemistry 2016; 22:8358-67. [DOI: 10.1002/chem.201600445] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Indexed: 12/26/2022]
Affiliation(s)
- Julie L. H. Madsen
- Department of Chemistry and; Interdisciplinary Nanoscience Center; Center for Insoluble Protein Structures; Aarhus University; Gustav Wieds Vej 14 8000 Aarhus C Denmark
| | - Claudia U. Hjørringgaard
- Department of Chemistry and; Interdisciplinary Nanoscience Center; Center for Insoluble Protein Structures; Aarhus University; Gustav Wieds Vej 14 8000 Aarhus C Denmark
| | - Brian S. Vad
- Department of Molecular Biology and Genetics and; Interdisciplinary Nanoscience Center; Center for Insoluble Protein Structures; Aarhus University; Gustav Wieds Vej 14 8000 Aarhus C Denmark
| | - Daniel Otzen
- Department of Molecular Biology and Genetics and; Interdisciplinary Nanoscience Center; Center for Insoluble Protein Structures; Aarhus University; Gustav Wieds Vej 14 8000 Aarhus C Denmark
| | - Troels Skrydstrup
- Department of Chemistry and; Interdisciplinary Nanoscience Center; Center for Insoluble Protein Structures; Aarhus University; Gustav Wieds Vej 14 8000 Aarhus C Denmark
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7
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Hansen SK, Bertelsen K, Paaske B, Nielsen NC, Vosegaard T. Solid-state NMR methods for oriented membrane proteins. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2015; 88-89:48-85. [PMID: 26282196 DOI: 10.1016/j.pnmrs.2015.05.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 04/27/2015] [Indexed: 06/04/2023]
Abstract
Oriented-sample solid-state NMR represents one of few experimental methods capable of characterising the membrane-bound conformation of proteins in the cell membrane. Since the technique was developed 25 years ago, the technique has been applied to study the structure of helix bundle membrane proteins and antimicrobial peptides, characterise protein-lipid interactions, and derive information on dynamics of the membrane anchoring of membrane proteins. We will review the major developments in various aspects of oriented-sample solid-state NMR, including sample-preparation methods, pulse sequences, theory required to interpret the experiments, perspectives for and guidelines to new experiments, and a number of representative applications.
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Affiliation(s)
- Sara K Hansen
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Kresten Bertelsen
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Berit Paaske
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Niels Chr Nielsen
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Thomas Vosegaard
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark.
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8
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Phospholipid Ether Linkages Significantly Modulate the Membrane Affinity of the Antimicrobial Peptide Novicidin. J Membr Biol 2015; 248:487-96. [DOI: 10.1007/s00232-015-9792-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/12/2015] [Indexed: 02/06/2023]
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9
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The natural, peptaibolic peptide SPF-5506-A4 adopts a β-bend spiral structure, shows low hemolytic activity and targets membranes through formation of large pores. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:882-9. [PMID: 25796141 DOI: 10.1016/j.bbapap.2015.03.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 03/04/2015] [Accepted: 03/06/2015] [Indexed: 12/23/2022]
Abstract
The medium-length fungal peptaibol SPF-5506-A(4) has been shown to inhibit formation of the Aβ peptide involved in Alzheimer''s disease. As Aβ is a cleavage-product from the membrane-bound APP protein, we hypothesized that SPF-5506-A(4)'s activity might be linked to membrane interactions in general. Here we describe the synthesis, structure and membrane interactions of SPF-5506-A4. The challenging synthesis was carried out on solid phase and a detailed conformational analysis in solution revealed a β-bend ribbon spiral core structure with flexible termini. Investigations of its membrane activity revealed low hemolytic activity, limited inhibition of both Gram-positive and Gram-negative cell growth and a preference for an overall negatively charged membrane surface mimicking the bacterial cell surface. SPF-5506-A(4) is the first peptaibol to be shown to facilitate leakage of large (4.6 nm diameter) fluorescence-labeled dextran from vesicles while leaving the vesicles intact. We conclude that SPF-5506-A(4) follows the toroidal pore model in its mode of action.
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10
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Liu L, Niu L, Xu M, Han Q, Duan H, Dong M, Besenbacher F, Wang C, Yang Y. Molecular tethering effect of C-terminus of amyloid peptide aβ42. ACS NANO 2014; 8:9503-9510. [PMID: 25192556 DOI: 10.1021/nn503737r] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Amyloid peptides are considered to be the main contributor for the membrane disruption related to the pathogenesis of degenerative diseases. The variation of amino acids at the carboxylic terminus of amyloid peptide has revealed significant effects on the modulation of abnormal assemblies of amyloid peptides. In this work, molecular binding agents were tethered to the C-terminus of β-amyloid peptide 1-42 (Aβ42). The molecular interaction between Aβ42 and molecule tethers was identified at single molecule level by using scanning tunneling microscopy (STM). The mechanistic insight into the feature variation of the self-assembly of Aβ42 peptide caused by molecular tethering at C-terminus was clearly revealed, which could appreciably affect the nucleation of amyloid peptide, thus reducing the membrane disruptions.
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Affiliation(s)
- Lei Liu
- National Center for Nanoscience and Technology , Beijing 100190, China
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11
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Structural features of peptoid-peptide hybrids in lipid-water interfaces. FEBS Lett 2014; 588:3291-7. [DOI: 10.1016/j.febslet.2014.07.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/24/2014] [Accepted: 07/14/2014] [Indexed: 12/15/2022]
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12
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Balakrishnan VS, Vad BS, Otzen DE. Novicidin's membrane permeabilizing activity is driven by membrane partitioning but not by helicity: a biophysical study of the impact of lipid charge and cholesterol. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:996-1002. [PMID: 23562965 DOI: 10.1016/j.bbapap.2013.03.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 03/05/2013] [Accepted: 03/25/2013] [Indexed: 12/11/2022]
Abstract
We have investigated the interactions between the antimicrobial peptide Novicidin (Nc) and vesicles containing the phospholipid DOPC, with various amounts of DOPG and cholesterol using circular dichroism spectroscopy, calcein release, equilibrium dialysis and isothermal titration calorimetry. Nc adopts a random coil structure in the absence of lipids and in the presence of vesicles containing 100% DOPC. Lipids with 25-40% DOPG induce the highest level of helicity in Nc; higher DOPG levels lead to lower helicity levels and an altered tertiary arrangement of the peptide. However, the ability of Nc to permeabilize vesicles correlates not with helicity but rather with its overall membrane affinity, which is enthalpically favorable but opposed by entropy. Permeabilization declines with increasing mole percentage PG. Changes in helicity correlate with changes in enthalpy, reflecting the enthalpy of helix formation, but not with affinity. There is also a large favorable enthalpic interaction between Nc and lipids in the absence of negative charge and structural changes. Cholesterol slightly reduces membrane permeabilization but has little effect on Nc affinity and secondary structure, and probably protects the membrane by inducing the liquid ordered state. We conclude that helicity is not a prerequisite for activity, and charge-charge interactions are not the only major driving force for AMP interactions with membranes. Our data are compatible with a model in which a superficial binding mode with a large membrane surface binding area per peptide is more efficient than a more intimate embedding within the membrane environment.
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Affiliation(s)
- Vijay S Balakrishnan
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
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13
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Oeemig JS, Lynggaard C, Knudsen DH, Hansen FT, Nørgaard KD, Schneider T, Vad BS, Sandvang DH, Nielsen LA, Neve S, Kristensen HH, Sahl HG, Otzen DE, Wimmer R. Eurocin, a new fungal defensin: structure, lipid binding, and its mode of action. J Biol Chem 2012; 287:42361-72. [PMID: 23093408 DOI: 10.1074/jbc.m112.382028] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Antimicrobial peptides are a new class of antibiotics that are promising for pharmaceutical applications because they have retained efficacy throughout evolution. One class of antimicrobial peptides are the defensins, which have been found in different species. Here we describe a new fungal defensin, eurocin. Eurocin acts against a range of Gram-positive human pathogens but not against Gram-negative bacteria. Eurocin consists of 42 amino acids, forming a cysteine-stabilized α/β-fold. The thermal denaturation data point shows the disulfide bridges being responsible for the stability of the fold. Eurocin does not form pores in cell membranes at physiologically relevant concentrations; it does, however, lead to limited leakage of a fluorophore from small unilamellar vesicles. Eurocin interacts with detergent micelles, and it inhibits the synthesis of cell walls by binding equimolarly to the cell wall precursor lipid II.
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Affiliation(s)
- Jesper S Oeemig
- Department of Biotechnology, Chemistry, and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark
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14
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Bertelsen K, Dorosz J, Hansen SK, Nielsen NC, Vosegaard T. Mechanisms of peptide-induced pore formation in lipid bilayers investigated by oriented 31P solid-state NMR spectroscopy. PLoS One 2012; 7:e47745. [PMID: 23094079 PMCID: PMC3475706 DOI: 10.1371/journal.pone.0047745] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 09/17/2012] [Indexed: 01/30/2023] Open
Abstract
There is a considerable interest in understanding the function of antimicrobial peptides (AMPs), but the details of their mode of action is not fully understood. This motivates extensive efforts in determining structural and mechanistic parameters for AMP’s interaction with lipid membranes. In this study we show that oriented-sample 31P solid-state NMR spectroscopy can be used to probe the membrane perturbations and -disruption by AMPs. For two AMPs, alamethicin and novicidin, we observe that the majority of the lipids remain in a planar bilayer conformation but that a number of lipids are involved in the peptide anchoring. These lipids display reduced dynamics. Our study supports previous studies showing that alamethicin adopts a transmembrane arrangement without significant disturbance of the surrounding lipids, while novicidin forms toroidal pores at high concentrations leading to more extensive membrane disturbance.
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Affiliation(s)
- Kresten Bertelsen
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, University of Aarhus, Aarhus, Denmark
| | - Jerzy Dorosz
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, University of Aarhus, Aarhus, Denmark
| | - Sara Krogh Hansen
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, University of Aarhus, Aarhus, Denmark
| | - Niels Chr. Nielsen
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, University of Aarhus, Aarhus, Denmark
- * E-mail: (NCN); (TV)
| | - Thomas Vosegaard
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, University of Aarhus, Aarhus, Denmark
- Department of Engineering, School of Engineering, University of Aarhus, Aarhus, Denmark
- * E-mail: (NCN); (TV)
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15
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Pedersen LRL, Hansted JG, Nielsen SB, Petersen TE, Sørensen US, Otzen D, Sørensen ES. Proteolytic activation of proteose peptone component 3 by release of a C-terminal peptide with antibacterial properties. J Dairy Sci 2012; 95:2819-29. [PMID: 22612919 DOI: 10.3168/jds.2011-4837] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 01/29/2012] [Indexed: 02/02/2023]
Abstract
The milk protein proteose peptone component 3 (PP3, also known as lactophorin) is a small phosphoglycoprotein, which is exclusively expressed in the lactating mammary gland. A 23-residue synthetic peptide (lactophoricin, Lpcin S), corresponding to the C-terminal amphipathic α-helix of PP3, has previously been shown to permeabilize membranes and display antibacterial activity. Lactophorin readily undergoes proteolytic cleavage in milk and during dairy processing, and it has been suggested that PP3-derived peptides are part of milk's endogenous defense system against bacteria. Here, we report that a 26-residue C-terminal peptide (Lpcin P) can be generated by trypsin proteolysis of PP3 and that structural and functional studies of Lpcin P indicate that the peptide has antibacterial properties. The Lpcin P showed α-helical structure in both anionic and organic solvents, and the amount of α-helical structure was increased in the presence of lipid vesicles. Oriented circular dichroism showed that Lpcin P oriented parallel to the membrane surface. However, the peptide permeabilized calcein-containing vesicles efficiently. Lpcin P displayed antibacterial activity against Streptococcus thermophilus, but not against Staphylococcus aureus and Escherichia coli. The PP3 full-length protein did not display the same properties, which could indicate that PP3 functions as a precursor protein that upon proteolysis, releases a bioactive antibacterial peptide.
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Affiliation(s)
- L R L Pedersen
- Protein Chemistry Laboratory, Aarhus University, DK-8000 Aarhus, Denmark
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16
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Hjørringgaard CU, Vad BS, Matchkov VV, Nielsen SB, Vosegaard T, Nielsen NC, Otzen DE, Skrydstrup T. Cyclodextrin-scaffolded alamethicin with remarkably efficient membrane permeabilizing properties and membrane current conductance. J Phys Chem B 2012; 116:7652-9. [PMID: 22676384 DOI: 10.1021/jp2098679] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Bacterial resistance to classical antibiotics is a serious medical problem, which continues to grow. Small antimicrobial peptides represent a potential solution and are increasingly being developed as novel therapeutic agents. Many of these peptides owe their antibacterial activity to the formation of trans-membrane ion-channels resulting in cell lysis. However, to further develop the field of peptide antibiotics, a thorough understanding of their mechanism of action is needed. Alamethicin belongs to a class of peptides called peptaibols and represents one of these antimicrobial peptides. To examine the dynamics of assembly and to facilitate a thorough structural evaluation of the alamethicin ion-channels, we have applied click chemistry for the synthesis of templated alamethicin multimers covalently attached to cyclodextrin-scaffolds. Using oriented circular dichroism, calcein release assays, and single-channel current measurements, the α-helices of the templated multimers were demonstrated to insert into lipid bilayers forming highly efficient and remarkably stable ion-channels.
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Affiliation(s)
- Claudia U Hjørringgaard
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C, Denmark
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17
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Influence of stearyl and trifluoromethylquinoline modifications of the cell penetrating peptide TP10 on its interaction with a lipid membrane. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:915-24. [DOI: 10.1016/j.bbamem.2011.12.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Revised: 12/23/2011] [Accepted: 12/27/2011] [Indexed: 11/20/2022]
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18
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Eckert R. Road to clinical efficacy: challenges and novel strategies for antimicrobial peptide development. Future Microbiol 2011; 6:635-51. [PMID: 21707311 DOI: 10.2217/fmb.11.27] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Since the discovery of magainins, cecropins and defensins 30 years ago, antimicrobial peptides (AMPs) have been hailed as a potential solution to the dearth of novel antibiotic development. AMPs have shown robust activity against a wide variety of pathogens, including drug-resistant bacteria. Unlike small-molecule antibiotics, however, AMPs have failed to translate this success to the clinic. Only the polymyxins, gramicidins, nisin and daptomycin are currently approved for medical use; the latter is the only example to have been developed in the last several decades. Nonetheless, researchers continue to isolate, modify and develop novel AMPs for therapeutic applications. Efforts have focused on increasing stability, reducing cytotoxicity, improving antimicrobial activity and incorporating AMPs in novel formulations, including nanoscale particles. As peptide synthesis and recombinant production methodologies improve, and more relevant bioassays become available, it becomes increasingly likely that AMPs will break the regulatory barrier and enter the marketplace as valuable antimicrobial weapons in the next 10 years.
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Affiliation(s)
- Randal Eckert
- C3 Jian, Inc., 423 Hindry Ave, Unit D, Inglewood, CA 90301, USA.
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Bertelsen K, Vad B, Nielsen EH, Hansen SK, Skrydstrup T, Otzen DE, Vosegaard T, Nielsen NC. Long-term-stable ether-lipid vs conventional ester-lipid bicelles in oriented solid-state NMR: altered structural information in studies of antimicrobial peptides. J Phys Chem B 2011; 115:1767-74. [PMID: 21309516 DOI: 10.1021/jp110866g] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recently, ether lipids have been introduced as long-term stable alternatives to the more natural, albeit easier degradable, ester lipids in the preparation of oriented lipid bilayers and bicelles for oriented-sample solid-state NMR spectroscopy. Here we report that ether lipids such as the frequently used 14-O-PC (1,2-di-O-tetradecyl-sn-glycero-3-phosphocholine) may induce significant changes in the structure and dynamics, including altered interaction between peptides and lipids relative to what is observed with the more conventionally used DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) bilayers. Such effects are demonstrated for the antimicrobial peptide novicidin, for which 2D separate-local-field NMR and circular dichroism experiments reveal significant structural/conformational differences for the peptide in the two different lipid systems. Likewise, we observe altered secondary structure and different temperature-dependent membrane anchoring for the antimicrobial peptide alamethicin depending on whether the peptide is reconstituted into ester or ether lipids. Such observations are not particularly surprising considering the significant difference of the lipids in the phosphorus headgroup and they may provide important new insight into the delicate peptide-membrane interactions in the systems studied. In contrast, these observations reinforce the need to carefully consider potential structural changes in addition to long-term stability prior to the selection of membrane environment of membrane proteins in the analysis of their structure and dynamics. In more general terms, the results underscore the necessity in structural biology to address both the protein and its environments in studies relating structure to function.
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Affiliation(s)
- Kresten Bertelsen
- Center for Insoluble Protein Structures (inSPIN), Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000 Aarhus C, Denmark
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Dorosz J, Gofman Y, Kolusheva S, Otzen D, Ben-Tal N, Nielsen NC, Jelinek R. Membrane interactions of novicidin, a novel antimicrobial peptide: phosphatidylglycerol promotes bilayer insertion. J Phys Chem B 2010; 114:11053-60. [PMID: 20690652 DOI: 10.1021/jp1052248] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Novicidin is an antimicrobial peptide derived from ovispirin, a cationic peptide which originated from the ovine cathelicidin SMAP-29. Novicidin, however, has been designed to minimize the cytotoxic properties of SMAP-29 and ovisipirin toward achieving potential therapeutic applications. We present an analysis of membrane interactions and lipid bilayer penetration of novicidin, using an array of biophysical techniques and biomimetic membrane assemblies, complemented by Monte Carlo (MC) simulations. The data indicate that novicidin interacts minimally with zwitterionic bilayers, accounting for its low hemolytic activity. Negatively charged phosphatidylglycerol, on the other hand, plays a significant role in initiating membrane binding of novicidin, and promotes peptide insertion into the interface between the lipid headgroups and the acyl chains. The significant insertion into bilayers containing negative phospholipids might explain the enhanced antibacterial properties of novicidin. Overall, this study highlights two distinct outcomes for membrane interactions of novicidin, and points to a combination between electrostatic attraction to the lipid/water interface and penetration into the subsurface lipid headgroups region as important determinants for the biological activity of novicidin.
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Affiliation(s)
- Jerzy Dorosz
- Department of Chemistry and Ilse Katz Institute for Nanotechnology, Ben Gurion University, Beer Sheva 84105, Israel
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