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Lakic B, Beh C, Sarkar S, Yap SL, Cardoso P, Valery C, Hung A, Jones NC, Hoffmann SV, Blanch EW, Dyett B, Conn CE. Cubosome lipid nanocarriers for delivery of ultra-short antimicrobial peptides. J Colloid Interface Sci 2024; 677:1080-1097. [PMID: 39137610 DOI: 10.1016/j.jcis.2024.07.232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 07/17/2024] [Accepted: 07/30/2024] [Indexed: 08/15/2024]
Abstract
HYPOTHESIS Although antimicrobial peptides (AMPs) are a promising class of new antibiotics, their inherent susceptibility to degradation requires nanocarrier-mediated delivery. While cubosome nanocarriers have been extensively studied for delivery of AMPs, we do not currently understand why cubosome encapsulation improves antimicrobial efficacy for some compounds but not others. This study therefore aims to investigate the link between the mechanism of action and permeation efficiency of the peptides, their encapsulation efficacy, and the antimicrobial activity of these systems. EXPERIMENTS Encapsulation and delivery of Indolicidin, and its ultra-short derivative, Priscilicidin, were investigated using SAXS, cryo-TEM and circular dichroism. Molecular dynamics simulations were used to understand the loading of these peptides within cubosomes. The antimicrobial efficacy was assessed against gram-negative (E. coli) and gram-positive (MRSA) bacteria. FINDINGS A high ionic strength solution was required to facilitate high loading of the cationic AMPs, with bilayer encapsulation driven by tryptophan and Fmoc moieties. Cubosome encapsulation did not improve the antimicrobial efficacy of the AMPs consistent with their high permeation, as explained by a recent 'diffusion to capture model'. This suggests that cubosome encapsulation may not be an effective strategy for all antimicrobial compounds, paving the way for improved selection of nanocarriers for AMPs, and other antimicrobial compounds.
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Affiliation(s)
- Biserka Lakic
- School of Science, STEM College, RMIT University, Victoria, 3001 Australia
| | - Chia Beh
- School of Science, STEM College, RMIT University, Victoria, 3001 Australia
| | - Sampa Sarkar
- School of Science, STEM College, RMIT University, Victoria, 3001 Australia
| | - Sue-Lyn Yap
- School of Science, STEM College, RMIT University, Victoria, 3001 Australia
| | - Priscila Cardoso
- School of Health and Biomedical Science, Translational Immunology and Nanotechnology Theme, NanoBioPharm Research Group, RMIT University, Bundoora, VIC, Australia
| | - Celine Valery
- School of Health and Biomedical Science, Translational Immunology and Nanotechnology Theme, NanoBioPharm Research Group, RMIT University, Bundoora, VIC, Australia
| | - Andrew Hung
- School of Science, STEM College, RMIT University, Victoria, 3001 Australia
| | - Nykola C Jones
- ISA, Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | | | - Ewan W Blanch
- School of Science, STEM College, RMIT University, Victoria, 3001 Australia.
| | - Brendan Dyett
- School of Science, STEM College, RMIT University, Victoria, 3001 Australia.
| | - Charlotte E Conn
- School of Science, STEM College, RMIT University, Victoria, 3001 Australia.
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Fandiño-Devia E, Santa-González GA, Klaiss-Luna MC, Manrique-Moreno M. Study of the Membrane Activity of the Synthetic Peptide ∆M3 Against Extended-Spectrum β-lactamase Escherichia coli Isolates. J Membr Biol 2024; 257:51-61. [PMID: 38315239 PMCID: PMC11006780 DOI: 10.1007/s00232-024-00306-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 01/03/2024] [Indexed: 02/07/2024]
Abstract
Escherichia coli is the most common microorganism causing nosocomial or community-acquired bacteremia, and extended-spectrum β-lactamase-producing Escherichia coli isolates are identified worldwide with increasing frequency. For this reason, it is necessary to evaluate potential new molecules like antimicrobial peptides. They are recognized for their biological potential which makes them promising candidates in the fight against infections. The goal of this research was to evaluate the potential of the synthetic peptide ΔM3 on several extended-spectrum β-lactamase producing E. coli isolates. The antimicrobial and cytotoxic activity of the peptide was spectrophotometrically determined. Additionally, the capacity of the peptide to interact with the bacterial membrane was monitored by fluorescence microscopy and infrared spectroscopy. The results demonstrated that the synthetic peptide is active against Escherichia coli isolates at concentrations similar to Meropenem. On the other hand, no cytotoxic effect was observed in HaCaT keratinocyte cells even at 10 times the minimal inhibitory concentration. Microscopy results showed a permeabilizing effect of the peptide on the bacteria. The infrared results showed that ΔM3 showed affinity for the lipids of the microorganism's membrane. The results suggest that the ∆M3 interacts with the negatively charged lipids from the E. coli by a disturbing effect on membrane. Finally, the secondary structure experiments of the peptide showed a random structure in solution that did not change during the interaction with the membranes.
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Affiliation(s)
- Estefanía Fandiño-Devia
- Chemistry Institute, Faculty of Exact and Natural Sciences, University of Antioquia, A.A. 1226, Medellin, 050010, Colombia
| | - Gloria A Santa-González
- Grupo de Investigación e Innovación Biomédica, Facultad de Ciencias Exactas y Aplicadas, Instituto Tecnológico Metropolitano, A.A. 54959, Medellín, 050010, Colombia
| | - Maria C Klaiss-Luna
- Chemistry Institute, Faculty of Exact and Natural Sciences, University of Antioquia, A.A. 1226, Medellin, 050010, Colombia
| | - Marcela Manrique-Moreno
- Chemistry Institute, Faculty of Exact and Natural Sciences, University of Antioquia, A.A. 1226, Medellin, 050010, Colombia.
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3
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Tryptophan, more than just an interfacial amino acid in the membrane activity of cationic cell-penetrating and antimicrobial peptides. Q Rev Biophys 2022; 55:e10. [PMID: 35979810 DOI: 10.1017/s0033583522000105] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Trp is unique among the amino acids since it is involved in many different types of noncovalent interactions such as electrostatic and hydrophobic ones, but also in π-π, π-cation, π-anion and π-ion pair interactions. In membranotropic peptides and proteins, Trp locates preferentially at the water-membrane interface. In antimicrobial or cell-penetrating peptides (AMPs and CPPs respectively), Trp is well-known for its strong role in the capacity of these peptides to interact and affect the membrane organisation of both bacteria and animal cells at the level of the lipid bilayer. This essential amino acid can however be involved in other types of interactions, not only with lipids, but also with other membrane partners, that are crucial to understand the functional roles of membranotropic peptides. This review is focused on this latter less known role of Trp and describes in details, both in qualitative and quantitative ways: (i) the physico-chemical properties of Trp; (ii) its effect in CPP internalisation; (iii) its importance in AMP activity; (iv) its role in the interaction of AMPs with glycoconjugates or lipids in bacteria membranes and the consequences on the activity of the peptides; (v) its role in the interaction of CPPs with negatively charged polysaccharides or lipids of animal membranes and the consequences on the activity of the peptides. We intend to bring highlights of the physico-chemical properties of Trp and describe its extensive possibilities of interactions, not only at the well-known level of the lipid bilayer, but with other less considered cell membrane components, such as carbohydrates and the extracellular matrix. The focus on these interactions will allow the reader to reevaluate reported studies. Altogether, our review gathers dedicated studies to show how unique are Trp properties, which should be taken into account to design future membranotropic peptides with expected antimicrobial or cell-penetrating activity.
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Batista Araujo J, Sastre de Souza G, Lorenzon EN. Indolicidin revisited: biological activity, potential applications and perspectives of an antimicrobial peptide not yet fully explored. World J Microbiol Biotechnol 2022; 38:39. [PMID: 35018535 DOI: 10.1007/s11274-022-03227-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 01/02/2022] [Indexed: 11/29/2022]
Abstract
The emergence of multidrug-resistant bacteria, viruses and tumors is a serious threat to public health. Among natural peptides, indolicidin, a 13-residue peptide belonging to the cathelicidin family, deserves special attention. Indolicidin has a broad spectrum of biological activity and is active against a wide range of targets, such as bacteria (Gram+ and Gram-), fungi and viruses. Here, we review the most important features of the biological activity, potential applications and perspectives of indolicidin and its analogs. Although not yet approved for commercialization, this peptide has great potential to be applied in different areas, including the medical, biomedical, food industry and other unexplored areas. To achieve this goal, a multidisciplinary team of researchers must work together to fine tune peptides that overall lead to novel analogs and formulations to combat existing and possibly future diseases.
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Affiliation(s)
| | - Guilherme Sastre de Souza
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, USP, Ribeirão Prêto, São Paulo, Brazil
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5
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Nielsen JE, Prévost SF, Jenssen H, Lund R. Impact of antimicrobial peptides on E. coli-mimicking lipid model membranes: correlating structural and dynamic effects using scattering methods. Faraday Discuss 2021; 232:203-217. [DOI: 10.1039/d0fd00046a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using X-rays and neutrons we address the effect of AMPs on structure and dynamics of lipids in bacterial model membranes.
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Affiliation(s)
| | | | - Håvard Jenssen
- Department of Science and Environment, Roskilde University, 4000 Roskilde, Denmark
| | - Reidar Lund
- Department of Chemistry, University of Oslo, 0315 Oslo, Norway
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6
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Non-Lytic Antibacterial Peptides That Translocate Through Bacterial Membranes to Act on Intracellular Targets. Int J Mol Sci 2019; 20:ijms20194877. [PMID: 31581426 PMCID: PMC6801614 DOI: 10.3390/ijms20194877] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/12/2019] [Accepted: 09/14/2019] [Indexed: 11/28/2022] Open
Abstract
The advent of multidrug resistance among pathogenic bacteria has attracted great attention worldwide. As a response to this growing challenge, diverse studies have focused on the development of novel anti-infective therapies, including antimicrobial peptides (AMPs). The biological properties of this class of antimicrobials have been thoroughly investigated, and membranolytic activities are the most reported mechanisms by which AMPs kill bacteria. Nevertheless, an increasing number of works have pointed to a different direction, in which AMPs are seen to be capable of displaying non-lytic modes of action by internalizing bacterial cells. In this context, this review focused on the description of the in vitro and in vivo antibacterial and antibiofilm activities of non-lytic AMPs, including indolicidin, buforin II PR-39, bactenecins, apidaecin, and drosocin, also shedding light on how AMPs interact with and further translocate through bacterial membranes to act on intracellular targets, including DNA, RNA, cell wall and protein synthesis.
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7
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Dwivedi R, Aggarwal P, Bhavesh NS, Kaur KJ. Design of therapeutically improved analogue of the antimicrobial peptide, indolicidin, using a glycosylation strategy. Amino Acids 2019; 51:1443-1460. [PMID: 31485742 DOI: 10.1007/s00726-019-02779-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 08/27/2019] [Indexed: 02/01/2023]
Abstract
Indolicidin is a member of cathelicidin family which displays broad spectrum antimicrobial activity. Severe toxicity and aggregation propensity associated with indolicidin pose a huge limitation to its probable therapeutic application. We are reporting the use of glycosylation strategy to design an analogue of indolicidin and subsequently explore structural and functional effects of sugar on it. Our study led to the design of a potent antibacterial glycosylated peptide, [βGlc-T9,K7]indolicidin, which showed decreased toxicity against erythrocytes and macrophage cells and thus a higher therapeutic selectivity. The incorporation of sugar also increased the solubility of the peptide. The mode of bacterial killing, functional stability, LPS binding, and cytokine inhibitory potential of the peptide, however, seemed unaffected upon glycosylation. Absence of significant changes in structure upon glycosylation accounts for the possibly retained functions and mode of action of the peptide. Our report thus presents the designing of an indolicidin analogue with improved therapeutic potential by substituting aromatic amino acid with glycosylated amino acid as a promising strategy for the first time.
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Affiliation(s)
- Rohini Dwivedi
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Priyanka Aggarwal
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Neel S Bhavesh
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Kanwal J Kaur
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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8
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A biophysical study of the interactions between the antimicrobial peptide indolicidin and lipid model systems. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:1355-1364. [DOI: 10.1016/j.bbamem.2019.04.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/22/2019] [Accepted: 04/07/2019] [Indexed: 12/19/2022]
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Nielsen JE, Bjørnestad VA, Lund R. Resolving the structural interactions between antimicrobial peptides and lipid membranes using small-angle scattering methods: the case of indolicidin. SOFT MATTER 2018; 14:8750-8763. [PMID: 30358793 DOI: 10.1039/c8sm01888j] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Using small angle X-ray and neutron scattering (SAXS/SANS) and detailed theoretical modelling we have elucidated the structure of the antimicrobial peptide, indolicidin, and the interaction with model lipid membranes of different anionic lipid compositions mimicking typical charge densities found in the cytoplasmic membrane of bacteria. First, we show that indolicidin displays a predominantly disordered, random chain conformation in solution with a small fraction (≈1%) of fiber-like nanostructures that are not dissolved at higher temperatures. The peptide is shown to strongly interact with the membranes at all charge densities without significantly perturbing the lipid bilayer structure. Instead, the results show that indolicidin inserts into the outer leaflet of the lipid vesicles causing a reduced local order of the lipid packing. This result is supported by an observed change in the melting point of the lipids upon addition of the peptide, as seen by differential scanning calorimetry experiments. The peptide does not to our observation affect the thickness of the membrane or form distinct structural pores in the membrane at physiologically relevant concentrations as has been previously suggested as an important mode of action. Finally, using sophisticated contrast variation SANS, we show that the peptide does not affect the random lateral distribution of anionic lipids in the membrane. Together, these results demonstrate that the structural aspects of the mode of action of antimicrobial peptides can be elucidated in detail using SAS techniques with liposomes as model systems.
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10
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Tsai CW, Lin ZW, Chang WF, Chen YF, Hu WW. Development of an indolicidin-derived peptide by reducing membrane perturbation to decrease cytotoxicity and maintain gene delivery ability. Colloids Surf B Biointerfaces 2018; 165:18-27. [DOI: 10.1016/j.colsurfb.2018.02.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 01/30/2018] [Accepted: 02/03/2018] [Indexed: 11/28/2022]
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11
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Latza VM, Rodriguez-Loureiro I, Kiesel I, Halperin A, Fragneto G, Schneck E. Neutron Reflectometry Elucidates Protein Adsorption from Human Blood Serum onto PEG Brushes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:12708-12718. [PMID: 29023130 DOI: 10.1021/acs.langmuir.7b03048] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Poly(ethylene glycol) (PEG) brushes are reputed for their ability to prevent undesired protein adsorption to material surfaces exposed to biological fluids. Here, protein adsorption out of human blood serum onto PEG brushes anchored to solid-supported lipid monolayers was characterized by neutron reflectometry, yielding volume fraction profiles of lipid headgroups, PEG, and adsorbed proteins at subnanometer resolution. For both PEGylated and non-PEGylated lipid surfaces, serum proteins adsorb as a thin layer of approximately 10 Å, overlapping with the headgroup region. This layer corresponds to primary adsorption at the grafting surface and resists rinsing. A second diffuse protein layer overlaps with the periphery of the PEG brush and is attributed to ternary adsorption due to protein-PEG attraction. This second layer disappears upon rinsing, thus providing a first observation of the structural effect of rinsing on protein adsorption to PEG brushes.
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Affiliation(s)
- Victoria M Latza
- Max Planck Institute of Colloids and Interfaces , Am Mühlenberg 1, 14476 Potsdam, Germany
| | | | - Irena Kiesel
- Institut Laue-Langevin , 71 avenue des Martyrs, 38042 Grenoble Cedex 9, France
- TU Dortmund University , Otto-Hahn-Straße 4a, 44227 Dortmund, Germany
| | | | - Giovanna Fragneto
- Institut Laue-Langevin , 71 avenue des Martyrs, 38042 Grenoble Cedex 9, France
| | - Emanuel Schneck
- Max Planck Institute of Colloids and Interfaces , Am Mühlenberg 1, 14476 Potsdam, Germany
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Mo GCH, Yip CM. Structural templating of J-aggregates: Visualizing bis(monoacylglycero)phosphate domains in live cells. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1687-1695. [PMID: 28844737 DOI: 10.1016/j.bbapap.2017.07.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/13/2017] [Accepted: 07/24/2017] [Indexed: 12/23/2022]
Abstract
Identifying the key structural and dynamical determinants that drive the association of biomolecules, whether in solution, or perhaps more importantly in a membrane environment, has critical implications for our understanding of cellular dynamics, processes, and signaling. With recent advances in high-resolution imaging techniques, from the development of new molecular labels to technical advances in imaging methodologies and platforms, researchers are now reaping the benefits of being able to directly characterize and quantify local dynamics, structures, and conformations in live cells and tissues. These capabilities are providing unique insights into association stoichiometries, interactions, and structures on sub-micron length scales. We previously examined the role of lipid headgroup chemistry and phase state in guiding the formation of pseudoisocyanine (PIC) dye J-aggregates on supported planar bilayers [Langmuir, 25, 10719]. We describe here how these same J-aggregates can report on the in situ formation of organellar membrane domains in live cells. Live cell hyperspectral confocal microscopy using GFP-conjugated GTPase markers of early (Rab5) and late (Rab7) endosomes revealed that the PIC J-aggregates were confined to domains on either the limiting membrane or intralumenal vesicles (ILV) of late endosomes, known to be enriched in the anionic lipid bis(monoacylglycero)phosphate (BMP). Correlated confocal fluorescence - atomic force microscopy performed on endosomal membrane-mimetic supported planar lipid bilayers confirmed BMP-specific templating of the PIC J-aggregates. These data provide strong evidence for the formation of BMP-rich lipid domains during multivesicular body formation and portend the application of structured dye aggregates as markers of cellular membrane domain structure, size, and formation.
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Affiliation(s)
- Gary C H Mo
- Department of Chemical Engineering and Applied Chemistry, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College St., Toronto M5S 3E1, Canada; Department of Pharmacology, University of California San Diego, La Jolla, CA 92093, USA
| | - Christopher M Yip
- Department of Biochemistry, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College St., Toronto M5S 3E1, Canada; Department of Chemical Engineering and Applied Chemistry, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College St., Toronto M5S 3E1, Canada; Institute of Biomaterials and Biomedical Engineering, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College St., Toronto M5S 3E1, Canada.
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Tsai CW, Hu WW, Liu CI, Ruaan RC, Tsai BC, Jin SLC, Chang Y, Chen WY. The consideration of indolicidin modification to balance its hemocompatibility and delivery efficiency. Int J Pharm 2015; 494:498-505. [DOI: 10.1016/j.ijpharm.2015.08.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 07/24/2015] [Accepted: 08/13/2015] [Indexed: 01/21/2023]
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14
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Bera S, Ghosh A, Sharma S, Debnath T, Giri B, Bhunia A. Probing the role of Proline in the antimicrobial activity and lipopolysaccharide binding of indolicidin. J Colloid Interface Sci 2015; 452:148-159. [PMID: 25935286 DOI: 10.1016/j.jcis.2015.04.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 04/12/2015] [Accepted: 04/13/2015] [Indexed: 01/28/2023]
Abstract
HYPOTHESIS Indolicidin (ILPWKWPWWPWRR-NH2), an antimicrobial peptide from bovine neutrophils, possesses significant antibacterial activity. An interesting feature of indolicidin is its unusually high content of Tryptophan and Proline residues. While the involvement of Tryptophan has been studied for its hemolytic and antibacterial activity, little is known about the roles played by Proline in these aspects. We herein investigate the structure and biological activities of indolicidin, where Proline at either one or more of the 3rd, 7th, 10th positions has been replaced by Alanine to better understand its structure and biological function. EXPERIMENTS Structural aspects of Proline residues of indolicidin and its effect on antimicrobial activity were elucidated by replacing Proline residues with Alanine. Minimum inhibitory concentration (MIC) and scanning electron microscopy (SEM) experiments provide substantial evidence for the importance of Proline residues for antimicrobial activity and cell wall disintegration. Binding affinity of the peptides to Lipopolysaccharide (LPS) was investigated using fluorescence spectroscopy and dynamic light scattering (DLS) in conjunction with (31)PNMR spectroscopy and confirmed the disintegration of LPS layer. FINDINGS Our study reveals that Proline residues are necessary for interaction of indolicidin with LPS and establishes the significance of the third and tenth Proline residues for its antimicrobial activity. We believe that the presence of so many Proline residues provides the molecule a selective advantage of adopting different conformations varying from a globular, closed conformation to an open extended conformation, and even to a wedge-shaped conformation, which account for the diverse mechanisms of action of indolicidin.
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Affiliation(s)
- Swapna Bera
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Anirban Ghosh
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Shruti Sharma
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Tanmoy Debnath
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Banabihari Giri
- Central Instrument Facility, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Anirban Bhunia
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India.
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15
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Esmaili E, Shahlaei M. Analysis of the flexibility and stability of the structure of magainin in a bilayer, and in aqueous and nonaqueous solutions using molecular dynamics simulations. J Mol Model 2015; 21:73. [PMID: 25750019 DOI: 10.1007/s00894-015-2622-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 02/15/2015] [Indexed: 11/25/2022]
Abstract
The precise mode of the antimicrobial activity of Magainin (Mag)-an antimicrobial peptide (AMP)-is still unclear. In this study, the conformation of Mag was characterized in water, and in a methanol and lipid bilayer [palmitoyl-oleoylphosphatidylcholine (POPC)] using a molecular dynamics (MD) simulation technique. To describe the role conformation plays in Mag function, the global conformational differences within three systems were studied. Through analysis of the resulting configuration ensembles, the differences in the three systems, such as overall flexibility and average secondary structure, were studied. It is suggested that these differences may be important enough to influence interactions with lipid biomembranes, thereby influencing key properties such as penetration into cell membrane and stability.
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Affiliation(s)
- Elham Esmaili
- Department of Biochemistry, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran
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3D hydrophobic moment vectors as a tool to characterize the surface polarity of amphiphilic peptides. Biophys J 2015; 106:2385-94. [PMID: 24896117 DOI: 10.1016/j.bpj.2014.04.020] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 04/02/2014] [Accepted: 04/07/2014] [Indexed: 11/22/2022] Open
Abstract
The interaction of membranes with peptides and proteins is largely determined by their amphiphilic character. Hydrophobic moments of helical segments are commonly derived from their two-dimensional helical wheel projections, and the same is true for β-sheets. However, to the best of our knowledge, there exists no method to describe structures in three dimensions or molecules with irregular shape. Here, we define the hydrophobic moment of a molecule as a vector in three dimensions by evaluating the surface distribution of all hydrophilic and lipophilic regions over any given shape. The electrostatic potential on the molecular surface is calculated based on the atomic point charges. The resulting hydrophobic moment vector is specific for the instantaneous conformation, and it takes into account all structural characteristics of the molecule, e.g., partial unfolding, bending, and side-chain torsion angles. Extended all-atom molecular dynamics simulations are then used to calculate the equilibrium hydrophobic moments for two antimicrobial peptides, gramicidin S and PGLa, under different conditions. We show that their effective hydrophobic moment vectors reflect the distribution of polar and nonpolar patches on the molecular surface and the calculated electrostatic surface potential. A comparison of simulations in solution and in lipid membranes shows how the peptides undergo internal conformational rearrangement upon binding to the bilayer surface. A good correlation with solid-state NMR data indicates that the hydrophobic moment vector can be used to predict the membrane binding geometry of peptides. This method is available as a web application on http://www.ibg.kit.edu/HM/.
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17
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Wang KF, Nagarajan R, Camesano TA. Differentiating antimicrobial peptides interacting with lipid bilayer: Molecular signatures derived from quartz crystal microbalance with dissipation monitoring. Biophys Chem 2014; 196:53-67. [PMID: 25307196 DOI: 10.1016/j.bpc.2014.09.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 09/16/2014] [Accepted: 09/16/2014] [Indexed: 10/24/2022]
Abstract
Many antimicrobial peptides (AMPs) kill bacteria by disrupting the lipid bilayer structure of their inner membrane. However, there is only limited quantitative information in the literature to differentiate between AMPs of differing molecular properties, in terms of how they interact with the membrane. In this study, we have used quartz crystal microbalance with dissipation monitoring (QCM-D) to probe the interactions between a supported bilayer membrane of egg phosphatidylcholine (egg PC) and four structurally different AMPs: alamethicin, chrysophsin-3, indolicidin, and sheep myeloid antimicrobial peptide (SMAP-29). Multiple signatures from the QCM-D measurements were extracted, differentiating the AMPs, that provide information on peptide addition to and lipid removal from the membrane, the dynamics of peptide-membrane interactions and the rates at which the peptide actions are initiated. The mechanistic variations in peptide action were related to the fundamental structural properties of the peptides including the hydrophobicity, hydrophobic moment, and the probability of α-helical secondary structures.
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Affiliation(s)
- Kathleen F Wang
- Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, United States
| | - Ramanathan Nagarajan
- Molecular Sciences and Engineering Team, Natick Soldier Research, Development and Engineering Center, Natick, MA 01760, United States.
| | - Terri A Camesano
- Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, United States
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18
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Leitgeb B. Characteristic Structural Features of Indolicidin: Effects of thecis-transIsomerism on its Conformation. Chem Biol Drug Des 2013; 83:132-40. [DOI: 10.1111/cbdd.12238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 09/03/2013] [Accepted: 09/23/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Balázs Leitgeb
- Institute of Biophysics; Biological Research Centre; Hungarian Academy of Sciences; Temesvári krt. 62 H-6726 Szeged Hungary
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19
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Rahmanpour A, Ghahremanpour MM, Mehrnejad F, Moghaddam ME. Interaction of Piscidin-1 with zwitterionic versus anionic membranes: a comparative molecular dynamics study. J Biomol Struct Dyn 2013; 31:1393-403. [DOI: 10.1080/07391102.2012.737295] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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20
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Haney EF, Petersen AP, Lau CK, Jing W, Storey DG, Vogel HJ. Mechanism of action of puroindoline derived tryptophan-rich antimicrobial peptides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:1802-13. [DOI: 10.1016/j.bbamem.2013.03.023] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 03/24/2013] [Accepted: 03/25/2013] [Indexed: 02/06/2023]
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21
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Yeh IC, Ripoll DR, Wallqvist A. Free energy difference in indolicidin attraction to eukaryotic and prokaryotic model cell membranes. J Phys Chem B 2012; 116:3387-96. [PMID: 22376120 DOI: 10.1021/jp211883u] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We analyzed the thermodynamic and structural determinants of indolicidin interactions with eukaryotic and prokaryotic cell membranes using a series of atomistically detailed molecular dynamics simulations. We used quartz-supported bilayers with two different compositions of zwitterionic and anionic phospholipids as model eukaryotic and prokaryotic cell membranes. Indolicidin was preferentially attracted to the model prokaryotic cell membrane in contrast to the weak adsorption on the eukaryotic membrane. The nature of the indolicidin surface adsorption depended on an electrostatic guiding component, an attractive enthalpic component derived from van der Waals interactions, and a balance between entropic factors related to peptide confinement at the interface and counterion release from the bilayer surface. Thus, whereas we attributed the specificity of the indolicidin/membrane interaction to electrostatics, these interactions were not the sole contributors to the free energy of adsorption. Instead, a balance between an attractive van der Waals enthalpic component and a repulsive entropic component determined the overall strength of indolicidin adsorption.
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Affiliation(s)
- In-Chul Yeh
- Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland, USA.
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22
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Wang Y, Schlamadinger DE, Kim JE, McCammon JA. Comparative molecular dynamics simulations of the antimicrobial peptide CM15 in model lipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:1402-9. [PMID: 22387432 DOI: 10.1016/j.bbamem.2012.02.017] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 02/01/2012] [Accepted: 02/15/2012] [Indexed: 10/28/2022]
Abstract
We report altogether 3-μs molecular dynamics (MD) simulations of the antimicrobial peptide CM15 to systematically investigate its interaction with two model lipid bilayers, pure POPC and mixed POPG:POPC (1:2). Starting with either an α-helical or a random-coil conformation, CM15 is found to insert into both bilayers. Peptide-lipid interaction is stronger with the anionic POPG:POPC than the zwitterionic POPC, which is largely attributed to the electrostatic attraction between CM15 and the negatively charged POPG. Simulations initiated with CM15 as a random coil allowed us to study peptide folding at the lipid-water interface. Interestingly, CM15 folding appears to be faster in POPC than POPG:POPC, which may be explained by a lower activation energy barrier of structural rearrangement in the former system. Our data also suggest that compared with the random-coil conformation, CM15 in a pre-folded α-helix has significantly reduced interactions with the lipids, indicating that peptide initial structures may bias the simulation results considerably on the 100-ns timescale. The implications of this result should be considered when preparing and interpreting future AMP simulations.
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Affiliation(s)
- Yi Wang
- Howard Hughes Medical Institute, Department of Chemistry and Biochemistry, Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA.
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23
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Effect of antimicrobial peptide-amide: indolicidin on biological membranes. J Biomed Biotechnol 2011; 2011:670589. [PMID: 21765635 PMCID: PMC3134306 DOI: 10.1155/2011/670589] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 03/24/2011] [Accepted: 04/29/2011] [Indexed: 11/18/2022] Open
Abstract
Indolicidin, a cationic antimicrobial tridecapeptide amide, is rich in proline and tryptophan residues. Its biological activity is intensively studied, but the details how indolicidin interacts with membranes are not fully understood yet. We report here an in situ atomic force microscopic study describing the effect of indolicidin on an artificial supported planar bilayer membrane of dipalmitoyl phosphatidylcholine (DPPC) and on purple membrane of Halobacterium salinarum. Concentration dependent interaction of the peptide and membranes was found in case of DPPC resulting the destruction of the membrane. Purple membrane was much more resistant against indolicidin, probably due to its high protein content. Indolicidin preferred the border of membrane disks, where the lipids are more accessible. These data suggest that the atomic force microscope is a powerful tool in the study of indolicidin-membrane interaction.
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24
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Nguyen LT, de Boer L, Zaat SAJ, Vogel HJ. Investigating the cationic side chains of the antimicrobial peptide tritrpticin: hydrogen bonding properties govern its membrane-disruptive activities. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:2297-303. [PMID: 21641334 DOI: 10.1016/j.bbamem.2011.05.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2011] [Revised: 05/15/2011] [Accepted: 05/16/2011] [Indexed: 11/27/2022]
Abstract
The positively charged side chains of cationic antimicrobial peptides are generally thought to provide the initial long-range electrostatic attractive forces that guide them towards the negatively charged bacterial membranes. Peptide analogs were designed to examine the role of the four Arg side chains in the cathelicidin peptide tritrpticin (VRRFPWWWPFLRR). The analogs include several noncoded Arg and Lys derivatives that offer small variations in side chain length and methylation state. The peptides were tested for bactericidal and hemolytic activities, and their membrane insertion and permeabilization properties were characterized by leakage assays and fluorescence spectroscopy. A net charge of +5 for most of the analogs maintains their high antimicrobial activity and directs them towards preferential insertion into model bacterial membrane systems with a similar extent of burial of the Trp side chains. However the peptides exhibit significant functional differences. Analogs with methylated cationic side chains cause lower levels of membrane leakage and are associated with lower hemolytic activities, making them potentially attractive pharmaceutical candidates. Analogs containing the Arg guanidinium groups cause more membrane disruption than those containing the Lys amino groups. Peptides in the latter group with shorter side chains have increased membrane activity and conversely, elongating the Arg residue causes slightly higher membrane activity. Altogether, the potential for strong hydrogen bonding between the four positive Arg side chains with the phospholipid head groups seems to be a determinant for the membrane disruptive properties of tritrpticin and many related cationic antimicrobial peptides.
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Affiliation(s)
- Leonard T Nguyen
- Biochemistry Research Group, Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
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25
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Fuzo CA, Degrève L. Study of the antimicrobial peptide indolicidin and mutants in eukaryotic modelled membrane by molecular dynamics simulations. Mol Phys 2011. [DOI: 10.1080/00268976.2010.520753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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Mondal J, Zhu X, Cui Q, Yethiraj A. Sequence-Dependent Interaction of β-Peptides with Membranes. J Phys Chem B 2010; 114:13585-92. [DOI: 10.1021/jp1070242] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Jagannath Mondal
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin, 53706
| | - Xiao Zhu
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin, 53706
| | - Qiang Cui
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin, 53706
| | - Arun Yethiraj
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin, 53706
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27
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Tsai HHG, Lee JB, Tseng SS, Pan XA, Shih YC. Folding and membrane insertion of amyloid-beta (25-35) peptide and its mutants: Implications for aggregation and neurotoxicity. Proteins 2010; 78:1909-25. [DOI: 10.1002/prot.22705] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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28
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Podorieszach AP, Huttunen-Hennelly HEK. The effects of tryptophan and hydrophobicity on the structure and bioactivity of novel indolicidin derivatives with promising pharmaceutical potential. Org Biomol Chem 2010; 8:1679-87. [DOI: 10.1039/b921248e] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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29
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Oreopoulos J, Yip CM. Combinatorial microscopy for the study of protein–membrane interactions in supported lipid bilayers: Order parameter measurements by combined polarized TIRFM/AFM. J Struct Biol 2009; 168:21-36. [DOI: 10.1016/j.jsb.2009.02.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Revised: 02/23/2009] [Accepted: 02/24/2009] [Indexed: 02/06/2023]
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30
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Mo GCH, Yip CM. Supported lipid bilayer templated J-aggregate growth: role of stabilizing cation-pi interactions and headgroup packing. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:10719-10729. [PMID: 19645500 DOI: 10.1021/la901227h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Controlling the self-assembly of molecules into specific structural motifs has important implications for the design of materials with specific optical properties. We report here the results of a correlated confocal fluorescence-atomic force microscopy (AFM) study of pseudoisocyanine iodide (PIC) self-assembly on supported lipid bilayers. Through judicious selection of bilayer headgroup packing and chemistry, two types of PIC J-aggregates, distinguishable by their absorbance spectra, and both exhibiting strong resonant fluorescence and bathochromic shifts in absorbance relative to the monomer, were isolated. Remarkably, selective templating can be achieved using different zwitterionic headgroups, producing J-aggregates that display a larger bathochromic shift than their solution counterparts. Our correlated confocal-AFM studies coupled with FT-IR spectroscopy suggested that zwitterionic phospholipids mediate J-aggregate formation through specific cation-pi interactions between PIC and the lipid headgroups with the PIC molecules oriented largely perpendicular to the bilayer normal. The existence of the two isoforms further suggests that bilayer headgroup packing plays a key role in controlling interchromophore organization and subsequent aggregate nucleation and growth.
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Affiliation(s)
- Gary C H Mo
- Department of Biochemistry, Institute of Biomaterials and Biomedical Engineering, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada
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31
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Pimthon J, Willumeit R, Lendlein A, Hofmann D. Membrane association and selectivity of the antimicrobial peptide NK-2: a molecular dynamics simulation study. J Pept Sci 2009; 15:654-67. [DOI: 10.1002/psc.1165] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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32
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Waegele MM, Tucker MJ, Gai F. 5-Cyanotryptophan as an Infrared Probe of Local Hydration Status of Proteins. Chem Phys Lett 2009; 478:249-253. [PMID: 20161057 DOI: 10.1016/j.cplett.2009.07.058] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The nitrile (C≡N) stretching vibration is sensitive to environment, making nitrile-derivatized amino acids an increasingly utilized tool to study various biological processes. Herein, we show that the bandwidth of the C≡N stretching vibration of 5-cyanotryptophan is particularly sensitive to water, rendering it an attractive infrared probe of local hydration status. We confirm the utility of this probe in biological applications by using it to examine how the hydration status of individual tryptophan sidechains of an antimicrobial peptide, indolicidin, changes upon peptide binding to model membranes. Furthermore, we show that p-cyanophenylalanine and 5-cyanotryptophan constitute a useful fluorescence energy transfer pair.
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Affiliation(s)
- Matthias M Waegele
- Department of Chemistry, University of Pennsylvania, 231 South 34 Street, Philadelphia, PA 19104, USA
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33
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Coupling molecular dynamics simulations with experiments for the rational design of indolicidin-analogous antimicrobial peptides. J Mol Biol 2009; 392:837-54. [PMID: 19576903 DOI: 10.1016/j.jmb.2009.06.071] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 06/08/2009] [Accepted: 06/27/2009] [Indexed: 11/21/2022]
Abstract
Antimicrobial peptides (AMPs) have attracted much interest in recent years because of their potential use as new-generation antibiotics. Indolicidin (IL) is a 13-residue cationic AMP that is effective against a broad spectrum of bacteria, fungi, and even viruses. Unfortunately, its high hemolytic activity retards its clinical applications. In this study, we adopted molecular dynamics (MD) simulations as an aid toward the rational design of IL analogues exhibiting high antimicrobial activity but low hemolysis. We employed long-timescale, multi-trajectory all-atom MD simulations to investigate the interactions of the peptide IL with model membranes. The lipid bilayer formed by the zwitterionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) was chosen as the model erythrocyte membrane; lipid bilayers formed from a mixture of POPC and the negatively charged 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol were chosen to model bacterial membranes. MD simulations with a total simulation time of up to 4 micros revealed the mechanisms of the processes of IL adsorption onto and insertion into the membranes. The packing order of these lipid bilayers presumably correlated to the membrane stability upon IL adsorption and insertion. We used the degree of local membrane thinning and the reduction in the order parameter of the acyl chains of the lipids to characterize the membrane stability. The order of the mixed 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol/POPC lipid bilayer reduced significantly upon the adsorption of IL. On the other hand, although the order of the pure-POPC lipid bilayer was perturbed slightly during the adsorption stage, the value was reduced more dramatically upon the insertion of IL into the membrane's hydrophobic region. The results imply that enhancing IL adsorption on the microbial membrane may amplify its antimicrobial activity, while the degree of hemolysis may be reduced through inhibition of IL insertion into the hydrophobic region of the erythrocyte membrane. In addition, through simulations, we identified the amino acids that are most responsible for the adsorption onto or insertion into the two model membranes. Positive charges are critical to the peptide's adsorption, whereas the presence of hydrophobic Trp8 and Trp9 leads to its deeper insertion. Combining the hypothetical relationships between the membrane disordering and the antimicrobial and hemolytical activities with the simulated results, we designed three new IL-analogous peptides: IL-K7 (Pro7-->Lys), IL-F89 (Trp8 and Trp9-->Phe), and IL-K7F89 (Pro7-->Lys; Trp8 and Trp9-->Phe). The hemolytic activity of IL-F89 is considerably lower than that of IL, whereas the antimicrobial activity of IL-K7 is greatly enhanced. In particular, the de novo peptide IL-K7F89 exhibits higher antimicrobial activity against Escherichia coli; its hemolytic activity decreased to only 10% of that of IL. Our simulated and experimental results correlated well. This approach-coupling MD simulations with experimental design-is a useful strategy toward the rational design of AMPs for potential therapeutic use.
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34
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Fotakis C, Christodouleas D, Chatzigeorgiou P, Zervou M, Benetis NP, Viras K, Mavromoustakos T. Development of a CP 31P NMR broadline simulation methodology for studying the interactions of antihypertensive AT1 antagonist losartan with phospholipid bilayers. Biophys J 2009; 96:2227-36. [PMID: 19289049 DOI: 10.1016/j.bpj.2008.11.057] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2008] [Revised: 10/30/2008] [Accepted: 11/20/2008] [Indexed: 11/16/2022] Open
Abstract
A cross-polarization (CP) (31)P NMR broadline simulation methodology was developed for studying the effects of drugs in phospholipids bilayers. Based on seven-parameter fittings, this methodology provided information concerning the conformational changes and dynamics effects of losartan in the polar region of the dipalmitoylphosphatidylcholine bilayers. The test molecule for this study was losartan, an antihypertensive drug known to exert its effect on AT(1) transmembrane receptors. The results were complemented and compared with those of differential scanning calorimetry, solid-state (13)C NMR spectroscopy, Raman spectroscopy, and electron spin resonance. More specifically, these physical chemical methodologies indicated that the amphipathic losartan molecule interacts with the hydrophilic-head zone of the lipid bilayers. The CP (31)P NMR broadline simulations showed that the lipid molecules in the bilayers containing losartan displayed greater collective tilt compared to the tilt displayed by the load-free bilayers, indicating improved packing. The Raman results displayed a decrease in the trans/gauche ratio and increased intermolecular interactions of the acyl chains in the liquid crystalline phase. Additional evidence, suggesting that losartan possibly anchors in the realm of the headgroup, was derived from upfield shift of the average chemical shift sigma(iso) of the (31)P signal in the presence of losartan and from shift of the observed peak at 715 cm(-1) attributed to C-N stretching in the Raman spectra.
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35
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Zipfel PF, Reuter M. Complement Activation Products C3a and C4a as Endogenous Antimicrobial Peptides. Int J Pept Res Ther 2009. [DOI: 10.1007/s10989-009-9180-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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36
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Fleming E, Maharaj NP, Chen JL, Nelson RB, Elmore DE. Effect of lipid composition on buforin II structure and membrane entry. Proteins 2009; 73:480-91. [PMID: 18452210 DOI: 10.1002/prot.22074] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Buforin II is a 21-amino acid polycationic antimicrobial peptide derived from a peptide originally isolated from the stomach tissue of the Asian toad Bufo bufo gargarizans. It is hypothesized to target a wide range of bacteria by translocating into cells without membrane permeabilization and binding to nucleic acids. Previous research found that the structure and membrane interactions of buforin II are related to lipid composition. In this study, we used molecular dynamics (MD) simulations along with lipid vesicle experiments to gain insight into how buforin II interacts differently with phosphatidylcholine (PC), phosphatidylglycerol (PG), and phosphatidylethanolamine (PE) lipids. Fluorescent spectroscopic measurements agreed with the previous assertion that buforin II does not interact with pure PC vesicles. Nonetheless, the reduced entry of the peptide into anionic PG membranes versus neutral PC membranes during simulations correlates with the experimentally observed reduction in BF2 translocation through pure PG membranes. Simulations showing membrane entry into PC also provide insight into how buforin II may initially penetrate cell membranes. Our MD simulations also allowed us to consider how neutral PE lipids affect the peptide differently than PC. In particular, the peptide had a more helical secondary structure in simulations with PE lipids. A change in structure was also apparent in circular dichroism measurements. PE also reduced membrane entry in simulations, which correlates with decreased translocation in the presence of PE observed in previous studies. Together, these results provide molecular-level insight into how lipid composition can affect buforin II structure and function and will be useful in efforts to design peptides with desired antimicrobial and cell-penetrating properties.
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Affiliation(s)
- Eleanor Fleming
- Department of Chemistry, Wellesley College, Wellesley, Massachusetts 02481, USA
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37
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Melo MN, Ferre R, Castanho MARB. Antimicrobial peptides: linking partition, activity and high membrane-bound concentrations. Nat Rev Microbiol 2009; 7:245-50. [PMID: 19219054 DOI: 10.1038/nrmicro2095] [Citation(s) in RCA: 492] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An increasing amount of information on the action of antimicrobial peptides (AMPs) at the molecular level has not yet been translated into a comprehensive understanding of effects in bacteria. Although some biophysical attributes of AMPs have been correlated with macroscopic features, the physiological relevance of other properties has not yet been addressed. Pertinent and surprising conclusions have therefore been left unstated. Strong membrane-binding and micromolar therapeutic concentrations of AMPs indicate that membrane-bound concentrations may be reached that are higher than intuitively expected, triggering disruptive effects on bacteria.
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Affiliation(s)
- Manuel N Melo
- Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Av. Professor Egas Moniz, Lisbon, Portugal
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38
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Cationic peptide-induced remodelling of model membranes: Direct visualization by in situ atomic force microscopy. J Struct Biol 2008; 162:121-38. [DOI: 10.1016/j.jsb.2007.11.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 10/01/2007] [Accepted: 11/06/2007] [Indexed: 02/04/2023]
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39
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Langham AA, Ahmad AS, Kaznessis YN. On the nature of antimicrobial activity: a model for protegrin-1 pores. J Am Chem Soc 2008; 130:4338-46. [PMID: 18335931 DOI: 10.1021/ja0780380] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
We conducted over 150 ns of simulation of a protegrin-1 octamer pore in a lipid bilayer composed of palmitoyloleoyl-phosphatidylethanolamine (POPE) and palmitoyloleoyl-phosphatidylglycerol (POPG) lipids mimicking the inner membrane of a bacterial cell. The simulations improve on a model of a pore proposed from recent NMR experiments and provide a coherent understanding of the molecular mechanism of antimicrobial activity. Although lipids tilt somewhat toward the peptides, the simulated protegrin-1 pore more closely follows the barrel-stave model than the toroidal-pore model. The movement of ions is investigated through the pore. The pore selectively allows negatively charged chloride ions to pass through at an average rate of one ion every two nanoseconds. Only two events are observed of sodium ions crossing through the pore. The potential of mean force is calculated for the water and both ion types. It is determined that the chloride ions move through the pore with ease, similarly to the water molecules with the exception of a zone of restricted movement midway through the pore. In bacteria, ions moving through the pore will compromise the integrity of the transmembrane potential. Without the transmembrane potential as a countermeasure, water will readily flow inside the higher osmolality cytoplasm. We determine that the diffusivity of water through a single PG-1 pore is sufficient to cause fast cell death by osmotic lysis.
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Affiliation(s)
- Allison A Langham
- Department of Chemical Engineering and Materials Science, 421 Washington Avenue SE, Minneapolis, Minnesota 55455, USA
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40
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Khandelia H, Ipsen JH, Mouritsen OG. The impact of peptides on lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:1528-36. [PMID: 18358231 DOI: 10.1016/j.bbamem.2008.02.009] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 02/22/2008] [Accepted: 02/24/2008] [Indexed: 11/26/2022]
Abstract
We review the fundamental strategies used by small peptides to associate with lipid membranes and how the different strategies impact on the structure and dynamics of the lipids. In particular we focus on the binding of amphiphilic peptides by electrostatic and hydrophobic forces, on the anchoring of peptides to the bilayer by acylation and prenylation, and on the incorporation of small peptides that form well-defined channels. The effect of lipid-peptide interactions on the lipids is characterized in terms of lipid acyl-chain order, membrane thickness, membrane elasticity, permeability, lipid-domain and annulus formation, as well as acyl-chain dynamics. The different situations are illustrated by specific cases for which experimental observations can be interpreted and supplemented by theoretical modeling and simulations. A comparison is made with the effect on lipids of trans-membrane proteins. The various cases are discussed in the context of the possible roles played by lipid-peptide interactions for the biological, physiological, and pharmacological function of peptides.
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Affiliation(s)
- Himanshu Khandelia
- MEMPHYS-Center for Biomembrane Physics, Department of Physics and Chemistry, University of Southern Denmark, Campusvej 55, Odense M, Denmark
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