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Kurakin S, Badreeva D, Dushanov E, Shutikov A, Efimov S, Timerova A, Mukhametzyanov T, Murugova T, Ivankov O, Mamatkulov K, Arzumanyan G, Klochkov V, Kučerka N. Arrangement of lipid vesicles and bicelle-like structures formed in the presence of Aβ(25-35) peptide. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184237. [PMID: 37820938 DOI: 10.1016/j.bbamem.2023.184237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 08/31/2023] [Accepted: 10/03/2023] [Indexed: 10/13/2023]
Abstract
Our complementary experimental data and molecular dynamics (MD) simulations results reveal the structure of previously observed lipid bicelle-like structures (BLSs) formed in the presence of amyloid-beta peptide Aβ(25-35) below the main phase transition temperature (Tm) of saturated phosphatidylcholine lipids and small unilamellar vesicles (SUVs) above this temperature. First, we show by using solid-state 31P nuclear magnetic resonance (NMR) spectroscopy that our BLSs being in the lipid gel phase demonstrate magnetic alignment along the magnetic field of NMR spectrometer and undergo a transition to SUVs in the lipid fluid phase when heated through the Tm. Secondly, thanks to the BLS alignment we present their lipid structure. Lipids are found located not only in the flat bilayered part but also around its perimeter, which is corroborated by the results of coarse-grained (CG) MD simulations. Finally, peptides appear to mix randomly with lipids in SUVs while assuming predominantly unordered secondary structures revealed by circular dichroism (CD), Raman spectroscopy, and all-atom MD simulations. Importantly, the former is changing little when the system undergoes morphological transitions between BLSs and SUVs. Our structural results then offer a platform for studying and understanding mechanisms of morphological transformations caused by the disruptive effect of amyloid-beta peptides on the lipid bilayer.
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Affiliation(s)
- Sergei Kurakin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia; Institute of Physics, Kazan Federal University, Kremlevskaya 18, Kazan 420008, Russia.
| | - Dina Badreeva
- Meshcheryakov Laboratory of Information Technologies, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Ermuhammad Dushanov
- Laboratory of Radiation Biology, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Artyom Shutikov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Sergey Efimov
- Institute of Physics, Kazan Federal University, Kremlevskaya 18, Kazan 420008, Russia
| | - Ayzira Timerova
- Institute of Physics, Kazan Federal University, Kremlevskaya 18, Kazan 420008, Russia
| | - Timur Mukhametzyanov
- Butlerov Chemistry Institute, Kazan Federal University, Kremlevskaya 18, Kazan 420008, Russia
| | - Tatiana Murugova
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Oleksandr Ivankov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Kahramon Mamatkulov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Grigory Arzumanyan
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia
| | - Vladimir Klochkov
- Institute of Physics, Kazan Federal University, Kremlevskaya 18, Kazan 420008, Russia
| | - Norbert Kučerka
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Joliot-Curie 6, Dubna, Moscow Region 141980, Russia; Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, Odbojárov 10, Bratislava 832 32, Slovakia.
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2
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Yaacoub C, Wehbe R, Roufayel R, Fajloun Z, Coutard B. Bee Venom and Its Two Main Components-Melittin and Phospholipase A2-As Promising Antiviral Drug Candidates. Pathogens 2023; 12:1354. [PMID: 38003818 PMCID: PMC10674158 DOI: 10.3390/pathogens12111354] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/08/2023] [Accepted: 11/11/2023] [Indexed: 11/26/2023] Open
Abstract
Viruses are known to infect most types of organisms. In humans, they can cause several diseases that range from mild to severe. Although many antiviral therapies have been developed, viral infections continue to be a leading cause of morbidity and mortality worldwide. Therefore, the discovery of new and effective antiviral agents is desperately needed. Animal venoms are a rich source of bioactive molecules found in natural goods that have been used since ancient times in alternative medicine to treat a variety of human diseases. Recently, and with the onset of the COVID-19 pandemic, scientists have regained their interest in the possible use of natural products, such as bee venom (BV), as a potential antiviral agent to treat viral infections. BV is known to exert many therapeutic activities such as anti-proliferative, anti-bacterial, and anti-inflammatory effects. However, there is limited discussion of the antiviral activity of BV in the literature. Therefore, this review aims to highlight the antiviral properties of BV and its two primary constituents, melittin (MEL) and phospholipase A2 (PLA2), against a variety of enveloped and non-enveloped viruses. Finally, the innovative strategies used to reduce the toxicity of BV and its two compounds for the development of new antiviral treatments are also considered.
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Affiliation(s)
- Carole Yaacoub
- Unité des Virus Emergents, Aix-Marseille University, IRD 190-Inserm 1207, IHU Méditerranée Infection, 13005 Marseille, France;
- Laboratory of Applied Biotechnology (LBA3B), Azm Center for Research in Biotechnology and Its Applications, Doctoral School for Sciences and Technology, Lebanese University, Tripoli 1300, Lebanon;
| | - Rim Wehbe
- Biology Department, Faculty of Arts and Sciences, American University of Beirut, Beirut 1107 2020, Lebanon;
| | - Rabih Roufayel
- College of Engineering and Technology, American University of the Middle East, Egaila 54200, Kuwait;
| | - Ziad Fajloun
- Laboratory of Applied Biotechnology (LBA3B), Azm Center for Research in Biotechnology and Its Applications, Doctoral School for Sciences and Technology, Lebanese University, Tripoli 1300, Lebanon;
- Faculty of Sciences III, Department of Biology, Michel Slayman Tripoli Campus, Lebanese University, Tripoli 1352, Lebanon
| | - Bruno Coutard
- Unité des Virus Emergents, Aix-Marseille University, IRD 190-Inserm 1207, IHU Méditerranée Infection, 13005 Marseille, France;
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3
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Guha S, Ferrie RP, Ghimire J, Ventura CR, Wu E, Sun L, Kim SY, Wiedman GR, Hristova K, Wimley WC. Applications and evolution of melittin, the quintessential membrane active peptide. Biochem Pharmacol 2021; 193:114769. [PMID: 34543656 DOI: 10.1016/j.bcp.2021.114769] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 12/12/2022]
Abstract
Melittin, the main venom component of the European Honeybee, is a cationic linear peptide-amide of 26 amino acid residues with the sequence: GIGAVLKVLTTGLPALISWIKRKRQQ-NH2. Melittin binds to lipid bilayer membranes, folds into amphipathic α-helical secondary structure and disrupts the permeability barrier. Since melittin was first described, a remarkable array of activities and potential applications in biology and medicine have been described. Melittin is also a favorite model system for biophysicists to study the structure, folding and function of peptides and proteins in membranes. Melittin has also been used as a template for the evolution of new activities in membranes. Here we overview the rich history of scientific research into the many activities of melittin and outline exciting future applications.
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Affiliation(s)
- Shantanu Guha
- University of Texas Health Science Center at Houston, Department of Microbiology and Molecular Genetics, Houston, TX, USA
| | - Ryan P Ferrie
- Tulane University School of Medicine, Department of Biochemistry and Molecular Biology, New Orleans, LA, USA
| | - Jenisha Ghimire
- Tulane University School of Medicine, Department of Biochemistry and Molecular Biology, New Orleans, LA, USA
| | - Cristina R Ventura
- Seton Hall University, Department of Chemistry and Biochemistry, South Orange, NJ, USA
| | - Eric Wu
- Tulane University School of Medicine, Department of Biochemistry and Molecular Biology, New Orleans, LA, USA
| | - Leisheng Sun
- Tulane University School of Medicine, Department of Biochemistry and Molecular Biology, New Orleans, LA, USA
| | - Sarah Y Kim
- Duke University, Department of Biomedical Engineering, Durham, NC, USA
| | - Gregory R Wiedman
- Seton Hall University, Department of Chemistry and Biochemistry, South Orange, NJ, USA
| | - Kalina Hristova
- Johns Hopkins University, Department of Materials Science and Engineering, Baltimore, MD, USA.
| | - Wimley C Wimley
- University of Texas Health Science Center at Houston, Department of Microbiology and Molecular Genetics, Houston, TX, USA.
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4
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Lee TH, Hall K, Aguilar MI. The Effect of Charge on Melittin-Induced Changes in Membrane Structure and Morphology. Aust J Chem 2020. [DOI: 10.1071/ch19500] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The binding of melittin to a range of phospholipid bilayers was studied using dual polarisation interferometry and atomic force microscopy. The phospholipid model membranes included zwitterionic dimyristylphosphatidylcholine (DMPC), together with mixtures of DMPC/dimyristylphosphatidylglycerol (DMPG) and DMPC/DMPG/cholesterol. Melittin caused significant disruption on all bilayers, but differences in morphological changes during binding were different on each membrane. Overall, the results demonstrate that the process of membrane disruption follows distinct structural changes for different lipid mixtures irrespective of the strength of binding to the membrane surface.
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5
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Britt HM, Mosely JA, Sanderson JM. The influence of cholesterol on melittin lipidation in neutral membranes. Phys Chem Chem Phys 2019; 21:631-640. [DOI: 10.1039/c8cp06661b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cholesterol inclusion in membranes influences the rate and selectivity of acyl transfer from lipids to a membrane-embedded peptide.
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6
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Florea A, Varga AP, Matei HV. Ultrastructural variability of mitochondrial cristae induced in vitro by bee (Apis mellifera) venom and its derivatives, melittin and phospholipase A2, in isolated rat adrenocortical mitochondria. Micron 2018; 112:42-54. [PMID: 29908421 DOI: 10.1016/j.micron.2018.06.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/08/2018] [Accepted: 06/08/2018] [Indexed: 12/20/2022]
Abstract
We tested the ability of bee venom (BV), melittin (Mlt), and phospholipase A2 (PLA) - used in 5 concentrations each (5, 10, 15, 20 and 40 μg/100 μl) - to promote ultrastructural changes and reorganization of cristae in vitro in mitochondria isolated from rat adrenal cortex after a protocol optimized by us. Thus, apart from two control grups (CI and CS), in which the mitochondria were suspended into saline buffer and isolation medium respectively, 15 more groups of mitochondria were constituted, corresponding to the five different doses of the three substance tested (BV5 to M40; M5 to M40 and P5 to P40). The ultrastructural effects were quantified on transmission electron micrographs using a morphometry software. Values of 84.49 nm and 95.45 nm were calculated for median diameters of mitochondrial cristae in two control groups. Large and very large vesicular cristae, many with 2 or 3 membranes, were generated depending on dose among normal cristae in all treated groups. In the BV and Mlt treated groups, after an initial increase (up to 127.27 nm in V15 group and 151.2 nm in M10 group) due to stimulation of cristae fusion, the cristae diameter diminished as the doses increased, mainly by the collapse of the cristae. In the PLA treated groups, the cristae diameter increased continuously from 83.84 nm to 136.01 nm, by stimulated fusion of cristae, only the two largest doses promoting the collapse of cristae in some mitochondria. The highest percentage of abnormal cristae was found in the Mlt treated groups and next in BV treated groups. All substances tested produced pronounced ultrastructural variability of mitochondrial cristae in vitro: they also changed (depending on dose) mitochondrial shapes, generated matrix debris and the highest concentrations of BV and Mlt were responsible for mitochondrial breakdown. These ultrastructural alterations of mitochondrial criste in the presence of the BV molecules suggest a reduced capacity of adrenocortical mitochondria to synthetize steroid hormones consequently to BV envenomations and partially explain the toxic effects of the BV.
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Affiliation(s)
- Adrian Florea
- Department of Cell and Molecular Biology, Faculty of Medicine, "Iuliu Haţieganu" University of Medicine and Pharmacy, 6 L. Pasteur St., 400349 Cluj-Napoca, Romania.
| | - Andrei Patrick Varga
- Department of Cell and Molecular Biology, Faculty of Medicine, "Iuliu Haţieganu" University of Medicine and Pharmacy, 6 L. Pasteur St., 400349 Cluj-Napoca, Romania; Jibou County Hospital, 28 Libertatii St., 455200 Jibou, Romania.
| | - Horea Vladi Matei
- Department of Cell and Molecular Biology, Faculty of Medicine, "Iuliu Haţieganu" University of Medicine and Pharmacy, 6 L. Pasteur St., 400349 Cluj-Napoca, Romania.
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Abstract
Niosomes are used in studies for drug delivery or gene transfer. However, their physical properties and features relative to liposomes are not well documented. To characterize and more rationally optimize niosome formulations, the properties of these vesicle systems are compared to those of liposomes composed of phosphatidylcholine and phosphatidylethanolamine lipids plus cholesterol. Niosomes are highly stable and only slightly more leaky than liposomes as assayed by calcein leakage; the permeability for ions (KCl) is higher than that of liposomes. Contrary to liposomes, the size of niosomes decreases substantially upon freezing in liquid nitrogen and subsequent thawing, as shown by cryo-EM and dynamic light scattering. The packing of niosomal membranes was determined by laurdan fluorescence and is slightly lower than that of liposomes. We did not succeed in the functional reconstitution of the L-arginine/L-ornithine antiporter ArcD2 in niosomes, which we attribute to the non-ionic nature of the surfactants. The antimicrobial peptides alamethicin and melittin act similarly on niosomes and liposomes composed of unsaturated components, whereas both niosomes and liposomes are unaffected when saturated amphiphiles are used. In conclusion, in terms of stability and permeability for drug-size molecules niosomes are comparable to liposomes and they may offer an excellent, inexpensive alternative for delivery purposes.
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Naito A, Matsumori N, Ramamoorthy A. Dynamic membrane interactions of antibacterial and antifungal biomolecules, and amyloid peptides, revealed by solid-state NMR spectroscopy. Biochim Biophys Acta Gen Subj 2018; 1862:307-323. [PMID: 28599848 PMCID: PMC6384124 DOI: 10.1016/j.bbagen.2017.06.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 05/28/2017] [Accepted: 06/02/2017] [Indexed: 12/12/2022]
Abstract
A variety of biomolecules acting on the cell membrane folds into a biologically active structure in the membrane environment. It is, therefore, important to determine the structures and dynamics of such biomolecules in a membrane environment. While several biophysical techniques are used to obtain low-resolution information, solid-state NMR spectroscopy is one of the most powerful means for determining the structure and dynamics of membrane bound biomolecules such as antibacterial biomolecules and amyloidogenic proteins; unlike X-ray crystallography and solution NMR spectroscopy, applications of solid-state NMR spectroscopy are not limited by non-crystalline, non-soluble nature or molecular size of membrane-associated biomolecules. This review article focuses on the applications of solid-state NMR techniques to study a few selected antibacterial and amyloid peptides. Solid-state NMR studies revealing the membrane inserted bent α-helical structure associated with the hemolytic activity of bee venom melittin and the chemical shift oscillation analysis used to determine the transmembrane structure (with α-helix and 310-helix in the N- and C-termini, respectively) of antibiotic peptide alamethicin are discussed in detail. Oligomerization of an amyloidogenic islet amyloid polypeptide (IAPP, or also known as amylin) resulting from its aggregation in a membrane environment, molecular interactions of the antifungal natural product amphotericin B with ergosterol in lipid bilayers, and the mechanism of lipid raft formation by sphingomyelin studied using solid state NMR methods are also discussed in this review article. This article is part of a Special Issue entitled "Biophysical Exploration of Dynamical Ordering of Biomolecular Systems" edited by Dr. Koichi Kato.
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Affiliation(s)
- Akira Naito
- Graduate School of Engineering, Yokohama National University, Yokohama 240-8501, Japan.
| | - Nobuaki Matsumori
- Department of Chemistry, Graduate School of Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Ayyalusamy Ramamoorthy
- Biophysics Program, University of Michigan, Ann Arbor, MI 48109-1055, USA; Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA
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9
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Norisada K, Javkhlantugs N, Mishima D, Kawamura I, Saitô H, Ueda K, Naito A. Dynamic Structure and Orientation of Melittin Bound to Acidic Lipid Bilayers, As Revealed by Solid-State NMR and Molecular Dynamics Simulation. J Phys Chem B 2017; 121:1802-1811. [DOI: 10.1021/acs.jpcb.6b11207] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kazushi Norisada
- Graduate
School of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Namsrai Javkhlantugs
- Graduate
School of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
- School
of Engineering and Applied Sciences, National University of Mongolia, Ulaanbaatar 14201, Mongolia
| | - Daisuke Mishima
- Graduate
School of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Izuru Kawamura
- Graduate
School of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Hazime Saitô
- Department
of Life Science, University of Hyogo, Harima Science Garden City, Kamigori, Hyogo 678-1297, Japan
| | - Kazuyoshi Ueda
- Graduate
School of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Akira Naito
- Graduate
School of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
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10
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Inhibitory effects of bee venom and its components against viruses in vitro and in vivo. J Microbiol 2016; 54:853-866. [PMID: 27888461 PMCID: PMC7091203 DOI: 10.1007/s12275-016-6376-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 09/13/2016] [Accepted: 10/04/2016] [Indexed: 11/10/2022]
Abstract
Bee venom (BV) from honey bee (Apis Melifera L.) contains at least 18 pharmacologically active components including melittin (MLT), phospholipase A2 (PLA2), and apamin etc. BV is safe for human treatments dose dependently and proven to possess different healing properties including antibacterial and antiparasitidal properties. Nevertheless, antiviral properties of BV have not well investigated. Hence, we identified the potential antiviral properties of BV and its component against a broad panel of viruses. Co-incubation of non-cytotoxic amounts of BV and MLT, the main component of BV, significantly inhibited the replication of enveloped viruses such as Influenza A virus (PR8), Vesicular Stomatitis Virus (VSV), Respiratory Syncytial Virus (RSV), and Herpes Simplex Virus (HSV). Additionally, BV and MLT also inhibited the replication of non-enveloped viruses such as Enterovirus-71 (EV-71) and Coxsackie Virus (H3). Such antiviral properties were mainly explained by virucidal mechanism. Moreover, MLT protected mice which were challenged with lethal doses of pathogenic influenza A H1N1 viruses. Therefore, these results provides the evidence that BV and MLT could be a potential source as a promising antiviral agent, especially to develop as a broad spectrum antiviral agent.
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11
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Therrien A, Lafleur M. Melittin-Induced Lipid Extraction Modulated by the Methylation Level of Phosphatidylcholine Headgroups. Biophys J 2016; 110:400-410. [PMID: 26789763 DOI: 10.1016/j.bpj.2015.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 12/03/2015] [Accepted: 12/07/2015] [Indexed: 01/06/2023] Open
Abstract
Protein- and peptide-induced lipid extraction from membranes is a critical process for many biological events, including reverse cholesterol transport and sperm capacitation. In this work, we examine whether such processes could display specificity for some lipid species. Melittin, the main component of dry bee venom, was used as a model amphipathic α-helical peptide. We specifically determined the modulation of melittin-induced lipid extraction from membranes by the change of the methylation level of phospholipid headgroups. Phosphatidylcholine (PC) bilayers were demethylated either by substitution with phosphatidylethanolamine (PE) or chemically by using mono- and dimethylated PE. It is shown that demethylation reduces the association of melittin with membranes, likely because of the resulting tighter chain packing of the phospholipids, which reduces the capacity of the membranes to accommodate inserted melittin. This reduced binding of the peptide is accompanied by an inhibition of the lipid extraction caused by melittin. We demonstrate that melittin selectively extracts PC from PC/PE membranes. This selectivity is proposed to be a consequence of a PE depletion in the surroundings of bound melittin to minimize disruption of the interphospholipid interactions. The resulting PC-enriched vicinity of melittin would be responsible for the observed formation of PC-enriched lipid/peptide particles resulting from the lipid efflux. These findings reveal that modulating the methylation level of phospholipid headgroups is a simple way to control the specificity of lipid extraction from membranes by peptides/proteins and thereby modulate the lipid composition of the membranes.
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Affiliation(s)
- Alexandre Therrien
- Department of Chemistry, Center for Self-Assembled Chemical Structures, Université de Montréal, Montréal, Québec, Canada
| | - Michel Lafleur
- Department of Chemistry, Center for Self-Assembled Chemical Structures, Université de Montréal, Montréal, Québec, Canada.
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12
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Simple direct formation of self-assembled N-heterocyclic carbene monolayers on gold and their application in biosensing. Nat Commun 2016; 7:12654. [PMID: 27585494 PMCID: PMC5025784 DOI: 10.1038/ncomms12654] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 07/18/2016] [Indexed: 01/14/2023] Open
Abstract
The formation of organic films on gold employing N-heterocyclic carbenes (NHCs) has been previously shown to be a useful strategy for generating stable organic films. However, NHCs or NHC precursors typically require inert atmosphere and harsh conditions for their generation and use. Herein we describe the use of benzimidazolium hydrogen carbonates as bench stable solid precursors for the preparation of NHC films in solution or by vapour-phase deposition from the solid state. The ability to prepare these films by vapour-phase deposition permitted the analysis of the films by a variety of surface science techniques, resulting in the first measurement of NHC desorption energy (158±10 kJ mol−1) and confirmation that the NHC sits upright on the surface. The use of these films in surface plasmon resonance-type biosensing is described, where they provide specific advantages versus traditional thiol-based films. Self-assembled monolayers (SAMs) have shown tremendous number of applications but can suffer from low stability. Here, the authors report air and bench stable carbene precursors allowing facile SAM formation, and furthermore demonstrate an application in biosensing
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13
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Sharma VK, Mamontov E, Tyagi M, Qian S, Rai DK, Urban VS. Dynamical and Phase Behavior of a Phospholipid Membrane Altered by an Antimicrobial Peptide at Low Concentration. J Phys Chem Lett 2016; 7:2394-401. [PMID: 27232190 DOI: 10.1021/acs.jpclett.6b01006] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The mechanism of action of antimicrobial peptides is traditionally attributed to the formation of pores in the lipid cell membranes of pathogens, which requires a substantial peptide to lipid ratio. However, using incoherent neutron scattering, we show that even at a concentration too low for pore formation, an archetypal antimicrobial peptide, melittin, disrupts the regular phase behavior of the microscopic dynamics in a phospholipid membrane, dimyristoylphosphatidylcholine (DMPC). At the same time, another antimicrobial peptide, alamethicin, does not exert a similar effect on the DMPC microscopic dynamics. The melittin-altered lateral motion of DMPC at physiological temperature no longer resembles the fluid-phase behavior characteristic of functional membranes of the living cells. The disruptive effect demonstrated by melittin even at low concentrations reveals a new mechanism of antimicrobial action relevant in more realistic scenarios, when peptide concentration is not as high as would be required for pore formation, which may facilitate treatment with antimicrobial peptides.
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Affiliation(s)
- V K Sharma
- Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
- Solid State Physics Division, Bhabha Atomic Research Centre , Mumbai 400085, India
| | - E Mamontov
- Chemical and Engineering Materials Division, Neutron Sciences Directorate, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - M Tyagi
- National Institute of Standards and Technology Center for Neutron Research , Gaithersburg, Maryland 20899, United States
- Department of Materials Science and Engineering, University of Maryland , College Park, Maryland 20742, United States
| | - S Qian
- Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - D K Rai
- Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - V S Urban
- Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
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14
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Therrien A, Fournier A, Lafleur M. Role of the Cationic C-Terminal Segment of Melittin on Membrane Fragmentation. J Phys Chem B 2016; 120:3993-4002. [PMID: 27054924 DOI: 10.1021/acs.jpcb.5b11705] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The widespread distribution of cationic antimicrobial peptides capable of membrane fragmentation in nature underlines their importance to living organisms. In the present work, we determined the impact of the electrostatic interactions associated with the cationic C-terminal segment of melittin, a 26-amino acid peptide from bee venom (net charge +6), on its binding to model membranes and on the resulting fragmentation. In order to detail the role played by the C-terminal charges, we prepared a melittin analogue for which the four cationic amino acids in positions 21-24 were substituted with the polar residue citrulline, providing a peptide with the same length and amphiphilicity but with a lower net charge (+2). We compared the peptide bilayer affinity and the membrane fragmentation for bilayers prepared from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)/1,2-dipalmitoyl-sn-glycero-3-phospho-l-serine (DPPS) mixtures. It is shown that neutralization of the C-terminal considerably increased melittin affinity for zwitterionic membranes. The unfavorable contribution associated with transferring the cationic C-terminal in a less polar environment was reduced, leaving the hydrophobic interactions, which drive the peptide insertion in bilayers, with limited counterbalancing interactions. The presence of negatively charged lipids (DPPS) in bilayers increased melittin binding by introducing attractive electrostatic interactions, the augmentation being, as expected, greater for native melittin than for its citrullinated analogue. The membrane fragmentation power of the peptide was shown to be controlled by electrostatic interactions and could be modulated by the charge carried by both the membrane and the lytic peptide. The analysis of the lipid composition of the extracted fragments from DPPC/DPPS bilayers revealed no lipid specificity. It is proposed that extended phase separations are more susceptible to lead to the extraction of a lipid species in a specific manner than a specific lipid-peptide affinity. The present work on the lipid extraction by melittin and citrullinated melittin with model membranes emphasizes the complex relation between the affinity, the lipid extraction/membrane fragmentation, and the lipid specificity.
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Affiliation(s)
- Alexandre Therrien
- Department of Chemistry, Center for Self-Assembled Chemical Structures (CSACS), Université de Montréal , C.P. 6128, Succ. Centre Ville, Montréal (Québec) H3C 3J7, Canada
| | - Alain Fournier
- Centre INRS-Institut Armand-Frappier, Institut National de la Recherche Scientifique, 531 Boul. des Prairies, Ville de Laval (Québec) H7V 1B7, Canada
| | - Michel Lafleur
- Department of Chemistry, Center for Self-Assembled Chemical Structures (CSACS), Université de Montréal , C.P. 6128, Succ. Centre Ville, Montréal (Québec) H3C 3J7, Canada
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Sharma VK, Mamontov E, Anunciado DB, O'Neill H, Urban VS. Effect of antimicrobial peptide on the dynamics of phosphocholine membrane: role of cholesterol and physical state of bilayer. SOFT MATTER 2015. [PMID: 26212615 DOI: 10.1039/c5sm01562f] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Antimicrobial peptides are universal in all forms of life and are well known for their strong interaction with the cell membrane. This makes them a popular target for investigation of peptide-lipid interactions. Here we report the effect of melittin, an important antimicrobial peptide, on the dynamics of membranes based on 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) lipid in both the solid gel and fluid phases. To probe the phase transition, elastic neutron intensity temperature scans have been carried out on DMPC-based unilamellar vesicles (ULV) with and without melittin. We have found that addition of a small amount (0.2 mol%) melittin eliminates the steep fall in the elastic intensity at 296 K associated with the solid gel to fluid phase transition, which is observed for pure DMPC vesicles. Quasielastic neutron scattering (QENS) experiments have been carried out on DMPC ULV in the solid gel and fluid phases with and without 0.2 mol% melittin. The data analysis invariably shows the presence of lateral and internal motions of the DMPC molecule. We found that melittin does have a profound effect on the dynamics of lipid molecules, especially on the lateral motion, and affects it in a different way, depending on the phase of the bilayers. In the solid gel phase, it acts as a plasticizer, enhancing the lateral motion of DMPC. However, in the fluid phase it acts as a stiffening agent, restricting the lateral motion of the lipid molecules. These observations are consistent with the mean squared displacements extracted from the elastic intensity temperature scans. Their importance lies in the fact that many membrane processes, including signaling and energy transduction pathways, are controlled to a great extent by the lateral diffusion of lipids in the membrane. To investigate the effect of melittin on vesicles supplemented with cholesterol, QENS experiments have also been carried out on DMPC ULV with cholesterol in the presence and absence of 0.2 mol% melittin. Remarkably, the effects of melittin on the membrane dynamics disappear in the presence of 20 mol% cholesterol. Our measurements indicate that the destabilizing effect of the peptide melittin on membranes can be mitigated by the presence of cholesterol. This study might provide new insights into the mechanism of action of antimicrobial peptides and their selective toxicity towards foreign microorganisms.
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Affiliation(s)
- V K Sharma
- Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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Pott T, Gerbeaud C, Barbier N, Méléard P. Melittin modifies bending elasticity in an unexpected way. Chem Phys Lipids 2015; 185:99-108. [DOI: 10.1016/j.chemphyslip.2014.05.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 04/28/2014] [Accepted: 05/18/2014] [Indexed: 12/22/2022]
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17
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Manzini MC, Perez KR, Riske KA, Bozelli JC, Santos TL, da Silva MA, Saraiva GK, Politi MJ, Valente AP, Almeida FC, Chaimovich H, Rodrigues MA, Bemquerer MP, Schreier S, Cuccovia IM. Peptide:lipid ratio and membrane surface charge determine the mechanism of action of the antimicrobial peptide BP100. Conformational and functional studies. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1985-99. [DOI: 10.1016/j.bbamem.2014.04.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 03/21/2014] [Accepted: 04/05/2014] [Indexed: 02/06/2023]
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Mäler L. Solution NMR studies of cell-penetrating peptides in model membrane systems. Adv Drug Deliv Rev 2013; 65:1002-11. [PMID: 23137785 DOI: 10.1016/j.addr.2012.10.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 10/17/2012] [Accepted: 10/22/2012] [Indexed: 12/29/2022]
Abstract
Cell-penetrating peptides (CPPs) are a class of short, often cationic peptides that have the capability to translocate across cellular membranes, and although the translocation most likely involves several pathways, they interact directly with membranes, as well as with model bilayers. Most CPPs attain a three-dimensional structure when interacting with bilayers, while they are more or less unstructured in aqueous solution. To understand the relationship between structure and the effect that CPPs have on membranes it is of great importance to investigate CPPs at atomic resolution in a suitable membrane model. Moreover, the location in bilayers is likely to be correlated with the translocation mechanism. Solution-state NMR offers a unique possibility to investigate structure, dynamics and location of proteins and peptides in bilayers. This review focuses on solution NMR as a tool for investigating CPP-lipid interactions. Structural propensities and cell-penetrating capabilities can be derived from a combination of CPP solution structures and studies of the effect that the peptides have on bilayers and the localization in a bilayer.
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Affiliation(s)
- Lena Mäler
- Department of Biochemistry and Biophysics, The Arrhenius Laboratory, Stockholm University, Stockholm, Sweden.
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Multiple membrane interactions and versatile vesicle deformations elicited by melittin. Toxins (Basel) 2013; 5:637-64. [PMID: 23594437 PMCID: PMC3705284 DOI: 10.3390/toxins5040637] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 04/02/2013] [Accepted: 04/10/2013] [Indexed: 01/11/2023] Open
Abstract
Melittin induces various reactions in membranes and has been widely studied as a model for membrane-interacting peptide; however, the mechanism whereby melittin elicits its effects remains unclear. Here, we observed melittin-induced changes in individual giant liposomes using direct real-time imaging by dark-field optical microscopy, and the mechanisms involved were correlated with results obtained using circular dichroism, cosedimentation, fluorescence quenching of tryptophan residues, and electron microscopy. Depending on the concentration of negatively charged phospholipids in the membrane and the molecular ratio between lipid and melittin, melittin induced the “increasing membrane area”, “phased shrinkage”, or “solubilization” of liposomes. In phased shrinkage, liposomes formed small particles on their surface and rapidly decreased in size. Under conditions in which the increasing membrane area, phased shrinkage, or solubilization were mainly observed, the secondary structure of melittin was primarily estimated as an α-helix, β-like, or disordered structure, respectively. When the increasing membrane area or phased shrinkage occurred, almost all melittin was bound to the membranes and reached more hydrophobic regions of the membranes than when solubilization occurred. These results indicate that the various effects of melittin result from its ability to adopt various structures and membrane-binding states depending on the conditions.
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Wang G, Zhang X, Geng J, Li K, Ding D, Pu KY, Cai L, Lai YH, Liu B. Glycosylated Star-Shaped Conjugated Oligomers for Targeted Two-Photon Fluorescence Imaging. Chemistry 2012; 18:9705-13. [DOI: 10.1002/chem.201200849] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Indexed: 11/07/2022]
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Verdon J, Labanowski J, Sahr T, Ferreira T, Lacombe C, Buchrieser C, Berjeaud JM, Héchard Y. Fatty acid composition modulates sensitivity of Legionella pneumophila to warnericin RK, an antimicrobial peptide. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1808:1146-53. [PMID: 21182824 DOI: 10.1016/j.bbamem.2010.12.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 11/25/2010] [Accepted: 12/13/2010] [Indexed: 11/16/2022]
Abstract
Warnericin RK is an antimicrobial peptide, produced by a Staphyloccocus warneri strain, described to be specifically active against Legionella, the pathogenic bacteria responsible for Legionnaires' disease. Warnericin RK is an amphiphilic alpha-helical peptide, which possesses a detergent-like mode of action. Two others peptides, δ-hemolysin I and II, produced by the same S. warneri strain, are highly similar to S. aureus δ-hemolysin and also display anti-Legionella activity. It has been recently reported that S. aureus δ-hemolysin activity on vesicles is likewise related to phospholipid acyl-chain structure, such as chain length and saturation. As staphylococcal δ-hemolysins were highly similar, we thus hypothesized that fatty acid composition of Legionella's membrane might influence the sensitivity of the bacteria to warnericin RK. Relationship between sensitivity to the peptide and fatty acid composition was then followed in various conditions. Cells in stationary phase, which were already described as less resistant than cells in exponential phase, displayed higher amounts of branched-chain fatty acids (BCFA) and short chain fatty acids. An adapted strain, able to grow at a concentration 33 fold higher than minimal inhibitory concentration of the wild type (i.e. 1μM), was isolated after repeated transfers of L. pneumophila in the presence of increased concentrations of warnericin RK. The amount of BCFA was significantly higher in the adapted strain than in the wild type strain. Also, a transcriptomic analysis of the wild type and adapted strains showed that two genes involved in fatty acid biosynthesis were repressed in the adapted strain. These genes encode enzymes involved in desaturation and elongation of fatty acids respectively. Their repression was in agreement with the decrease of unsaturated fatty acids and fatty acid chain length in the adapted strain. Conclusively, our results indicate that the increase of BCFA and the decrease of fatty acid chain length in membrane were correlated with the increase in resistance to warnericin RK. Therefore, fatty acid profile seems to play a critical role in the sensitivity of L. pneumophila to warnericin RK.
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Affiliation(s)
- Julien Verdon
- Laboratoire de Chimie et Microbiologie de l'Eau, UMR CNRS 6008, Université de Poitiers, Poitiers, France
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23
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Toraya S, Javkhlantugs N, Mishima D, Nishimura K, Ueda K, Naito A. Dynamic structure of bombolitin II bound to lipid bilayers as revealed by solid-state NMR and molecular-dynamics simulation. Biophys J 2010; 99:3282-9. [PMID: 21081076 PMCID: PMC2980745 DOI: 10.1016/j.bpj.2010.09.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2010] [Revised: 09/15/2010] [Accepted: 09/20/2010] [Indexed: 01/19/2023] Open
Abstract
Bombolitin II (BLT2) is one of the hemolytic heptadecapeptides originally isolated from the venom of a bumblebee. Structure and orientation of BLT2 bound to 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) membranes were determined by solid-state (31)P and (13)C NMR spectroscopy. (31)P NMR spectra showed that BLT2-DPPC membranes were disrupted into small particles below the gel-to-liquid crystalline phase transition temperature (T(c)) and fused to form a magnetically oriented vesicle system where the membrane surface is parallel to the magnetic fields above the T(c). (13)C NMR spectra of site-specifically (13)C-labeled BLT2 at the carbonyl carbons were observed and the chemical shift anisotropies were analyzed to determine the dynamic structure of BLT2 bound to the magnetically oriented vesicle system. It was revealed that the membrane-bound BLT2 adopted an α-helical structure, rotating around the membrane normal with the tilt angle of the helical axis at 33°. Interatomic distances obtained from rotational-echo double-resonance experiments further showed that BLT2 adopted a straight α-helical structure. Molecular dynamics simulation performed in the BLT2-DPPC membrane system showed that the BLT2 formed a straight α-helix and that the C-terminus was inserted into the membrane. The α-helical axis is tilted 30° to the membrane normal, which is almost the same as the value obtained from solid-state NMR. These results suggest that the membrane disruption induced by BLT2 is attributed to insertion of BLT2 into the lipid bilayers.
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Affiliation(s)
- Shuichi Toraya
- Faculty of Engineering, Yokohama National University, Yokohama, Japan
| | | | - Daisuke Mishima
- Faculty of Engineering, Yokohama National University, Yokohama, Japan
| | | | - Kazuyoshi Ueda
- Faculty of Engineering, Yokohama National University, Yokohama, Japan
| | - Akira Naito
- Faculty of Engineering, Yokohama National University, Yokohama, Japan
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Chen J, Lariviere WR. The nociceptive and anti-nociceptive effects of bee venom injection and therapy: a double-edged sword. Prog Neurobiol 2010; 92:151-83. [PMID: 20558236 DOI: 10.1016/j.pneurobio.2010.06.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Revised: 03/31/2010] [Accepted: 06/08/2010] [Indexed: 12/23/2022]
Abstract
Bee venom injection as a therapy, like many other complementary and alternative medicine approaches, has been used for thousands of years to attempt to alleviate a range of diseases including arthritis. More recently, additional theraupeutic goals have been added to the list of diseases making this a critical time to evaluate the evidence for the beneficial and adverse effects of bee venom injection. Although reports of pain reduction (analgesic and antinociceptive) and anti-inflammatory effects of bee venom injection are accumulating in the literature, it is common knowledge that bee venom stings are painful and produce inflammation. In addition, a significant number of studies have been performed in the past decade highlighting that injection of bee venom and components of bee venom produce significant signs of pain or nociception, inflammation and many effects at multiple levels of immediate, acute and prolonged pain processes. This report reviews the extensive new data regarding the deleterious effects of bee venom injection in people and animals, our current understanding of the responsible underlying mechanisms and critical venom components, and provides a critical evaluation of reports of the beneficial effects of bee venom injection in people and animals and the proposed underlying mechanisms. Although further studies are required to make firm conclusions, therapeutic bee venom injection may be beneficial for some patients, but may also be harmful. This report highlights key patterns of results, critical shortcomings, and essential areas requiring further study.
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Affiliation(s)
- Jun Chen
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, The Fourth Military Medical University, 1 Xinsi Road, Baqiao District, Xi'an 710038, PR China.
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25
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Arseneault M, Bédard S, Boulet-Audet M, Pézolet M. Study of the interaction of lactoferricin B with phospholipid monolayers and bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:3468-3478. [PMID: 20112931 DOI: 10.1021/la903014w] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Bovine lactoferricin (LfcinB) is an antimicrobial peptide obtained from the pepsin cleavage of lactoferrin. The activity of LfcinB has been extensively studied on diverse pathogens, but its mechanism of action still has to be elucidated. Because of its nonspecificity, its mode of action is assumed to be related to interactions with membranes. In this study, the interaction of LfcinB with a negatively charged monolayer of dipalmitoylphosphatidylglycerol has been investigated as a function of the surface pressure of the lipid film using in situ Brewster angle and polarization modulation infrared reflection absorption spectroscopy and on transferred monolayers by atomic force microscopy and polarized attenuated total reflection infrared spectroscopy. The data show clearly that LfcinB forms stable films at the air-water interface. They also reveal that the interaction of LfcinB with the lipid monolayer is modulated by the surface pressure. At low surface pressure, LfcinB inserts within the lipid film with its long molecular axis oriented mainly parallel to the acyl chains, while at high surface pressure, LfcinB is adsorbed under the lipid film, the hairpin being preferentially aligned parallel to the plane of the interface. The threshold for which the behavior changes is 20 mN/m. At this critical surface pressure, LfcinB interacts with the monolayer to form discoidal lipid-peptide assemblies. This structure may actually represent the mechanism of action of this peptide. The results obtained on monolayers are correlated by fluorescent probe release measurements of dye-containing vesicles made of lipids in different phases and support the important role of the lipid fluidity and packing on the activity of LfcinB.
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Affiliation(s)
- Marjolaine Arseneault
- Centre de recherche sur les matériaux avancés, Département de chimie, Université Laval, Québec, Québec Canada, G1V OA6
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26
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Biophysical studies of the membrane location of the voltage-gated sensors in the HsapBK and KvAP K+ channels. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:1976-86. [DOI: 10.1016/j.bbamem.2009.07.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 06/30/2009] [Accepted: 07/01/2009] [Indexed: 11/22/2022]
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27
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Ouellet M, Voyer N, Auger M. Membrane interactions and dynamics of a 21-mer cytotoxic peptide: a solid-state NMR study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1798:235-43. [PMID: 19703408 DOI: 10.1016/j.bbamem.2009.07.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Revised: 07/06/2009] [Accepted: 07/30/2009] [Indexed: 11/29/2022]
Abstract
We have investigated the membrane interactions and dynamics of a 21-mer cytotoxic model peptide that acts as an ion channel by solid-state NMR spectroscopy. To shed light on its mechanism of membrane perturbation, (31)P and (2)H NMR experiments were performed on 21-mer peptide-containing bicelles. (31)P NMR results indicate that the 21-mer peptide stabilizes the bicelle structure and orientation in the magnetic field and perturbs the lipid polar head group conformation. On the other hand, (2)H NMR spectra reveal that the 21-mer peptide orders the lipid acyl chains upon binding. (15)N NMR experiments performed in DMPC bilayers stacked between glass plates also reveal that the 21-mer peptide remains at the bilayer surface. (15)N NMR experiments in perpendicular DMPC bicelles indicate that the 21-mer peptide does not show a circular orientational distribution in the bicelle planar region. Finally, (13)C NMR experiments were used to study the 21-mer peptide dynamics in DMPC multilamellar vesicles. By analyzing the (13)CO spinning sidebands, the results show that the 21-mer peptide is immobilized upon membrane binding. In light of these results, we propose a model of membrane interaction for the 21-mer peptide where it lies at the bilayer surface and perturbs the lipid head group conformation.
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Affiliation(s)
- Marise Ouellet
- Département de Chimie, PROTEO (Regroupement Québécois de Recherche sur la Fonction, la Structure et l'Ingénierie des Protéines), CERMA (Centre de Recherche sur les Matériaux Avancés), Université Laval, Québec, Québec, Canada G1V 0A6
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Shi L, Cembran A, Gao J, Veglia G. Tilt and azimuthal angles of a transmembrane peptide: a comparison between molecular dynamics calculations and solid-state NMR data of sarcolipin in lipid membranes. Biophys J 2009; 96:3648-62. [PMID: 19413970 DOI: 10.1016/j.bpj.2009.02.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 02/03/2009] [Accepted: 02/12/2009] [Indexed: 02/04/2023] Open
Abstract
We report molecular dynamics simulations in the explicit membrane environment of a small membrane-embedded protein, sarcolipin, which regulates the sarcoplasmic reticulum Ca-ATPase activity in both cardiac and skeletal muscle. In its monomeric form, we found that sarcolipin adopts a helical conformation, with a computed average tilt angle of 28 +/- 6 degrees and azymuthal angles of 66 +/- 22 degrees, in reasonable accord with angles determined experimentally (23 +/- 2 degrees and 50 +/- 4 degrees, respectively) using solid-state NMR with separated-local-field experiments. The effects of time and spatial averaging on both (15)N chemical shift anisotropy and (1)H/(15)N dipolar couplings have been analyzed using short-time averages of fast amide out-of-plane motions and following principal component dynamic trajectories. We found that it is possible to reproduce the regular oscillatory patterns observed for the anisotropic NMR parameters (i.e., PISA wheels) employing average amide vectors. This work highlights the role of molecular dynamics simulations as a tool for the analysis and interpretation of solid-state NMR data.
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Affiliation(s)
- Lei Shi
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota, USA
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29
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Kumar T, Pandian S, Srisailam S, Yu C. Structure and Function of Snake Venom Cardiotoxins. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/15569549809009249] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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30
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Verly RM, de Moraes CM, Resende JM, Aisenbrey C, Bemquerer MP, Piló-Veloso D, Valente AP, Almeida FCL, Bechinger B. Structure and membrane interactions of the antibiotic peptide dermadistinctin K by multidimensional solution and oriented 15N and 31P solid-state NMR spectroscopy. Biophys J 2009; 96:2194-203. [PMID: 19289046 DOI: 10.1016/j.bpj.2008.11.063] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Revised: 10/18/2008] [Accepted: 11/06/2008] [Indexed: 01/05/2023] Open
Abstract
DD K, a peptide first isolated from the skin secretion of the Phyllomedusa distincta frog, has been prepared by solid-phase chemical peptide synthesis and its conformation was studied in trifluoroethanol/water as well as in the presence of sodium dodecyl sulfate and dodecylphosphocholine micelles or small unilamellar vesicles. Multidimensional solution NMR spectroscopy indicates an alpha-helical conformation in membrane environments starting at residue 7 and extending to the C-terminal carboxyamide. Furthermore, DD K has been labeled with (15)N at a single alanine position that is located within the helical core region of the sequence. When reconstituted into oriented phosphatidylcholine membranes the resulting (15)N solid-state NMR spectrum shows a well-defined helix alignment parallel to the membrane surface in excellent agreement with the amphipathic character of DD K. Proton-decoupled (31)P solid-state NMR spectroscopy indicates that the peptide creates a high level of disorder at the level of the phospholipid headgroup suggesting that DD K partitions into the bilayer where it severely disrupts membrane packing.
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Affiliation(s)
- Rodrigo M Verly
- Departamento de Química Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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Verdon J, Girardin N, Lacombe C, Berjeaud JM, Héchard Y. delta-hemolysin, an update on a membrane-interacting peptide. Peptides 2009; 30:817-23. [PMID: 19150639 DOI: 10.1016/j.peptides.2008.12.017] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Revised: 12/17/2008] [Accepted: 12/18/2008] [Indexed: 11/16/2022]
Abstract
delta-hemolysin is a hemolytic peptide produced by Staphylococcus, and it has been studied for nearly 50 years. Therefore, it has become a model in the study of peptides interacting with membranes. In this review, we report some recent findings and compare them with previous works. delta-hemolysin is a 26 amino acid peptide, somewhat hydrophobic and presenting a zero net charge. Study of its structure has shown that delta-hemolysin is alpha-helical and amphipathic, such as many antimicrobial peptides (e.g. magainin and melittin). However, delta-hemolysin had not displayed any reported antimicrobial activity until a recent publication showed its high potency against Legionella. Its mode of action is based on direct interaction with target membranes. In accordance with its concentration, delta-hemolysin may slightly perturb a membrane or lead to cell lysis. Peptide charge plays an important role in its interaction with membranes, as is shown in the study of peptide variants. Some positively charged variants become highly hemolytic and even active against Escherichia coli and Staphylococcus aureus. Finally, it has recently been demonstrated that peptide preferentially binds to lipid-disordered domains. It has been postulated that as a result, enrichment in lipid-ordered domains might increase peptide concentration in lipid-disordered domains and thereby improve its activity.
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Sengupta D, Leontiadou H, Mark AE, Marrink SJ. Toroidal pores formed by antimicrobial peptides show significant disorder. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:2308-17. [DOI: 10.1016/j.bbamem.2008.06.007] [Citation(s) in RCA: 381] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Revised: 05/27/2008] [Accepted: 06/02/2008] [Indexed: 01/02/2023]
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Lundquist A, Wessman P, Rennie AR, Edwards K. Melittin–Lipid interaction: A comparative study using liposomes, micelles and bilayerdisks. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:2210-6. [DOI: 10.1016/j.bbamem.2008.05.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Revised: 05/09/2008] [Accepted: 05/27/2008] [Indexed: 10/22/2022]
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Abstract
The membrane-destabilizing effect of the peptide melittin on phosphatidylcholine membranes is modulated by the presence of cholesterol. This investigation shows that inclusion of 40 mol % cholesterol in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine or 1,2-dioleoyl-sn-glycero-3-phosphocholine liposomes reduces melittin's affinity for the membrane. It is significant that the presence of cholesterol does not increase the amount of membrane-associated melittin needed to cause maximum leakage from, or major structural rearrangements of, the liposomes. Furthermore, comparison of microscopy and leakage data suggests that melittin-induced leakage occurs via different mechanisms in the cholesterol-free and cholesterol-supplemented systems. In the absence of cholesterol, leakage of carboxyfluorescein takes place from intact liposomes in a manner compatible with the presence of small melittin-induced pores. In the presence of cholesterol, on the other hand, adsorption of the peptide causes complete membrane disruption and the formation of long-lived open-bilayer structures. Moreover, in the case of cholesterol-supplemented systems, melittin induces pronounced liposome aggregation. Cryotransmission electron microscopy was used, together with ellipsometry, circular dichroism, turbidity, and leakage measurements, to investigate the effects of melittin on phosphatidylcholine membranes in the absence and presence of cholesterol. The melittin partitioning behavior in the membrane systems was estimated by means of steady-state fluorescence spectroscopy measurements.
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Lohner K, Sevcsik E, Pabst G. Chapter Five Liposome-Based Biomembrane Mimetic Systems: Implications for Lipid–Peptide Interactions. ADVANCES IN PLANAR LIPID BILAYERS AND LIPOSOMES 2008. [DOI: 10.1016/s1554-4516(07)06005-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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36
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Abstract
Melittin is the principal toxic component in the venom of the European honey bee Apis mellifera and is a cationic, hemolytic peptide. It is a small linear peptide composed of 26 amino acid residues in which the amino-terminal region is predominantly hydrophobic whereas the carboxy-terminal region is hydrophilic due to the presence of a stretch of positively charged amino acids. This amphiphilic property of melittin has resulted in melittin being used as a suitable model peptide for monitoring lipid-protein interactions in membranes. In this review, the solution and membrane properties of melittin are highlighted, with an emphasis on melittin-membrane interaction using biophysical approaches. The recent applications of melittin in various cellular processes are discussed.
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Affiliation(s)
- H Raghuraman
- Centre for Cellular and Molecular Biology, Hyderabad, India
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37
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Sevcsik E, Pabst G, Jilek A, Lohner K. How lipids influence the mode of action of membrane-active peptides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:2586-95. [PMID: 17662236 DOI: 10.1016/j.bbamem.2007.06.015] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Revised: 06/01/2007] [Accepted: 06/14/2007] [Indexed: 11/18/2022]
Abstract
The human, multifunctional peptide LL-37 causes membrane disruption by distinctly different mechanisms strongly dependent on the nature of the membrane lipid composition, varying not only with lipid headgroup charge but also with hydrocarbon chain length. Specifically, LL-37 induces a peptide-associated quasi-interdigitated phase in negatively charged phosphatidylglycerol (PG) model membranes, where the hydrocarbon chains are shielded from water by the peptide. In turn, LL-37 leads to a disintegration of the lamellar organization of zwitterionic dipalmitoyl-phosphatidylcholine (DPPC) into disk-like micelles. Interestingly, interdigitation was also observed for the longer-chain C18 and C20 PCs. This dual behavior of LL-37 can be attributed to a balance between electrostatic interactions reflected in different penetration depths of the peptide and hydrocarbon chain length. Thus, our observations indicate that there is a tight coupling between the peptide properties and those of the lipid bilayer, which needs to be considered in studies of lipid/peptide interaction. Very similar effects were also observed for melittin and the frog skin peptide PGLa. Therefore, we propose a phase diagram showing different lipid/peptide arrangements as a function of hydrocarbon chain length and LL-37 concentration and suggest that this phase diagram is generally applicable to membrane-active peptides localized parallel to the membrane surface.
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Affiliation(s)
- E Sevcsik
- Institute of Biophysics and Nanosystems Research, Austrian Academy of Sciences, Schmiedlstrasse 6, 8042 Graz, Austria
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38
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van den Bogaart G, Mika JT, Krasnikov V, Poolman B. The lipid dependence of melittin action investigated by dual-color fluorescence burst analysis. Biophys J 2007; 93:154-63. [PMID: 17434946 PMCID: PMC1914432 DOI: 10.1529/biophysj.107.106005] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dual-color fluorescence-burst analysis was used to study melittin-induced leakage of macromolecules from liposomes of various lipid compositions. To perform dual-color fluorescence-burst analysis, fluorescently labeled size-marker molecules were encapsulated into liposomes, labeled with a second lipid-attached fluorophore. By correlating the fluorescence bursts, resulting from the liposomes diffusing through the detection volume of a dual-color confocal microscope, the distribution of size-marker molecules over the liposomes was determined. It was found that melittin causes leakage via two different mechanisms: 1), For liposomes composed of neutral bilayer-forming lipids, low melittin concentrations induced pore formation with the pore size depending on the melittin concentration. 2), For liposomes containing anionic and/or nonbilayer forming lipids, melittin induced fusion or aggregation of liposomes accompanied by a-specific leakage. Experiments with liposomes prepared from Escherichia coli lipid extracts and intact cells of Lactococcus lactis indicate that both mechanisms are physiologically relevant.
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Affiliation(s)
- Geert van den Bogaart
- Biochemistry Department, Groningen Biomolecular Science and Biotechnology Institute & Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
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39
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Dufourcq J, Dufourc EJ, Maillet JC, Cornut I, Thiaudiere E, Bonmatin JM. Peptide-Induced Changes in Structure, Dynamic and Barrier Properties of Liposomes and Membranes. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426509308045632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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40
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Andersson A, Biverståhl H, Nordin J, Danielsson J, Lindahl E, Mäler L. The membrane-induced structure of melittin is correlated with the fluidity of the lipids. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1768:115-21. [PMID: 16949029 DOI: 10.1016/j.bbamem.2006.07.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Revised: 06/28/2006] [Accepted: 07/17/2006] [Indexed: 11/30/2022]
Abstract
The effect of the bee toxin melittin on DMPC dynamics in fast-tumbling bicelles has been investigated. The (13)C R(1) and (13)C-(1)H NOE relaxation parameters for DMPC were used to monitor the effect of melittin and cholesterol on lipid dynamics. It was found that melittin has the largest effect on the DMPC mobility in DMPC/DHPC bicelles, while less effect was observed in cholesterol-doped bicelles, or in bicelles made with CHAPS, indicating that the rigidity of the membrane affects the melittin-membrane interaction. CD spectra were analysed in terms of cooperativity of the alpha-helix to random coil transition in melittin, and these results also indicated similar differences between the bicelles. The study shows that bicelles can be used to investigate lipid dynamics by spin relaxation, and in particular of peptide-induced changes in membrane fluidity.
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Affiliation(s)
- August Andersson
- Department of Biochemistry and Biophysics, The Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden
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41
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Detergent-like actions of linear amphipathic cationic antimicrobial peptides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1758:1529-39. [PMID: 16928357 DOI: 10.1016/j.bbamem.2006.07.001] [Citation(s) in RCA: 429] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 06/30/2006] [Accepted: 07/06/2006] [Indexed: 12/25/2022]
Abstract
Antimicrobial peptides have raised much interest as pathogens become resistant against conventional antibiotics. We review biophysical studies that have been performed to better understand the interactions of linear amphipathic cationic peptides such as magainins, cecropins, dermaseptin, delta-lysin or melittin. The amphipathic character of these peptides and their interactions with membranes resemble the properties of detergent molecules and analogies between membrane-active peptide and detergents are presented. Several models have been suggested to explain the pore-forming, membrane-lytic and antibiotic activities of these peptides. Here we suggest that these might be 'special cases' within complicated phase diagrams describing the morphological plasticity of peptide/lipid supramolecular assemblies.
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42
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García-Sáez AJ, Coraiola M, Serra MD, Mingarro I, Müller P, Salgado J. Peptides corresponding to helices 5 and 6 of Bax can independently form large lipid pores. FEBS J 2006; 273:971-81. [PMID: 16478471 DOI: 10.1111/j.1742-4658.2006.05123.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Proteins of the B-cell lymphoma protein 2 (Bcl2) family are key regulators of the apoptotic cascade, controlling the release of apoptotic factors from the mitochondrial intermembrane space. A helical hairpin found in the core of water-soluble folds of these proteins has been reported to be the pore-forming domain. Here we show that peptides including any of the two alpha-helix fragments of the hairpin of Bcl2 associated protein X (Bax) can independently induce release of large labelled dextrans from synthetic lipid vesicles. The permeability promoted by these peptides is influenced by intrinsic monolayer curvature and accompanied by fast transbilayer redistribution of lipids, supporting a toroidal pore mechanism as in the case of the full-length protein. However, compared with the pores made by complete Bax, the pores made by the Bax peptides are smaller and do not need the concerted action of tBid. These data indicate that the sequences of both fragments of the hairpin contain the principal physicochemical requirements for pore formation, showing a parallel between the permeabilization mechanism of a complex regulated protein system, such as Bax, and the much simpler pore-forming antibiotic peptides.
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Affiliation(s)
- Ana J García-Sáez
- Department of Biochemistry and Molecular Biology, University of Valencia, Spain
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43
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Chevalier C, Galloux M, Pous J, Henry C, Denis J, Da Costa B, Navaza J, Lepault J, Delmas B. Structural peptides of a nonenveloped virus are involved in assembly and membrane translocation. J Virol 2005; 79:12253-63. [PMID: 16160151 PMCID: PMC1211518 DOI: 10.1128/jvi.79.19.12253-12263.2005] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The capsid of infectious bursal disease virus (IBDV), a nonenveloped virus of the family Birnaviridae, has a T=13l icosahedral shell constituted by a single protein, VP2, and several disordered peptides, all derived from the precursor pVP2. In this study, we show that two of the peptides, pep11 and pep46, control virus assembly and cell entry. Deletion of pep11 or even simple substitution of most of its residues blocks the capsid morphogenesis. Removal of pep46 also prevents capsid assembly but leads to the formation of subviral particles formed by unprocessed VP2 species. Fitting with the VP2 atomic model into three-dimensional reconstructions of these particles demonstrates that the presence of uncleaved pep46 causes a steric hindrance at the vertices, blocking fivefold axis formation. Mutagenesis of the pVP2 maturation sites confirms that C terminus processing is necessary for VP2 to acquire the correct icosahedral architecture. All peptides present on virions are accessible to proteases or biochemical labeling. One of them, pep46, is shown to induce large structural rearrangements in liposomes and to destabilize target membranes, demonstrating its implication in cell entry.
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Affiliation(s)
- Christophe Chevalier
- Unité de Recherche de Virologie et Immunologie Moléculaires, INRA, F-78350 Jouy-en-Josas, France
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44
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Toraya S, Nagao T, Norisada K, Tuzi S, Saitô H, Izumi S, Naito A. Morphological behavior of lipid bilayers induced by melittin near the phase transition temperature. Biophys J 2005; 89:3214-22. [PMID: 16113109 PMCID: PMC1366817 DOI: 10.1529/biophysj.105.059311] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Morphological changes of DMPC, DLPC, and DPPC bilayers containing melittin (lecithin/melittin molar ratio of 10:1) around the gel-to-liquid crystalline phase transition temperatures (Tc) were examined by a variety of biophysical methods. First, giant vesicles with the diameters of approximately 20 microm were observed by optical microscopy for melittin-DMPC bilayers at 27.9 degrees C. When the temperature was lowered to 24.9 degrees C (Tc = 23 degrees C for the neat DMPC bilayers), the surface of vesicles became blurred and dynamic pore formation was visible in the microscopic picture taken at different exposure times. Phase separation and association of melittin molecules in the bilayers were further detected by fluorescent microscopy and mass spectrometry, respectively. These vesicles disappeared completely at 22.9 degrees C. It was thus found that the melittin-lecithin bilayers reversibly undergo their fusion and disruption near the respective Tcs. The fluctuation of lipids is, therefore, responsible for the membrane fusion above the Tc, and the association of melittin molecules causes membrane fragmentation below the Tc. Subsequent magnetic alignments were observed by solid-state (31)P NMR spectra for the melittin-lecithin vesicles at a temperature above the respective Tcs. On the other hand, additional large amplitude motion induced by melittin at a temperature near the Tc breaks down the magnetic alignment.
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Affiliation(s)
- Shuichi Toraya
- Graduate School of Engineering, Yokohama National University, Yokohama 240-8501, Japan
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45
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Bechinger B. Detergent-like properties of magainin antibiotic peptides: a 31P solid-state NMR spectroscopy study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2005; 1712:101-8. [PMID: 15869740 DOI: 10.1016/j.bbamem.2005.03.003] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Revised: 03/11/2005] [Accepted: 03/11/2005] [Indexed: 12/11/2022]
Abstract
(31)P solid-state NMR spectroscopy has been used to investigate the macroscopic phase behavior of phospholipid bilayers in the presence of increasing amounts of magainin antibiotic peptides. Addition of >1 mol% magainin 2 to gel-phase DMPC or liquid crystalline POPC membranes respectively, results in (31)P NMR spectra that are characterized by the coexistence of isotropic signals and line shapes typical for phospholipid bilayers. The isotropic signal intensity is a function of temperature and peptide concentration. At peptide concentrations >4 mol% of the resulting phospholipid (31)P NMR spectra are characteristic of magnetically oriented POPC bilayers suggesting the formation of small disk-like micelles or perforated sheets. In contrast, addition of magainin to acidic phospholipids results in homogenous bilayer-type (31)P NMR spectra with reduced chemical shift anisotropies. The results presented are in good agreement with the interfacial insertion of magainin helices with an alignment parallel to the surface of the phospholipid bilayers. The resulting curvature strain results in detergent-like properties of the amphipathic helical peptides.
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46
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Wang E, Han X. Electrochemical Study of the Bilayer Lipid Membrane. ADVANCES IN PLANAR LIPID BILAYERS AND LIPOSOMES 2005. [DOI: 10.1016/s1554-4516(05)02009-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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47
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Abstract
Antimicrobial peptides (AMPs) of innate origin are agents of the most ancient form of defense systems. They can be found in a wide variety of species ranging from bacteria through insects to humans. Through the course of evolution, host organisms developed arsenals of AMPs that protect them against a large variety of invading pathogens including both Gram-negative and Gram-positive bacteria. At a time of increasing bacterial resistance, AMPs have been the focus of investigation in a number of laboratories worldwide. Although recent studies show that some of the peptides are likely to have intracellular targets, the vast majority of AMPs appear to act by permeabilization of the bacterial cell membrane. Their activity and selectivity are governed by the physicochemical parameters of the peptide chains as well as the properties of the membrane system itself. In this review, we will summarize some of the recent developments that provide us with a better understanding of the mode of action of this unique family of antibacterial agents. Particular attention will be given to the determinants of AMP-lipid bilayer interactions as well as to the different pore formation mechanisms. The emphasis will be on linear AMPs but representatives of cysteine-bridged AMPs will also be discussed.
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Affiliation(s)
- Orsolya Toke
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
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48
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Toraya S, Nishimura K, Naito A. Dynamic structure of vesicle-bound melittin in a variety of lipid chain lengths by solid-state NMR. Biophys J 2004; 87:3323-35. [PMID: 15339796 PMCID: PMC1304800 DOI: 10.1529/biophysj.104.046102] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2004] [Accepted: 08/20/2004] [Indexed: 11/18/2022] Open
Abstract
Solid-state 31P- and 13C-NMR spectra were recorded in melittin-lecithin vesicles composed of 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) or 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). Highly ordered magnetic alignments were achieved with the membrane surface parallel to the magnetic field above the gel-to-liquid crystalline phase transition temperature (Tc). Using these magnetically oriented vesicle systems, dynamic structures of melittin bound to the vesicles were investigated by analyzing the 13C anisotropic and isotropic chemical shifts of selectively 13C-labeled carbonyl carbons of melittin under the static and magic-angle spinning conditions. These results indicate that melittin molecules adopt an alpha-helical structure and laterally diffuse to rotate rapidly around the membrane normal with tilt angles of the N-terminal helix being -33 degrees and -36 degrees and those of the C-terminal helix being 21 degrees and 25 degrees for DLPC and DPPC vesicles, respectively. The rotational-echo double-resonance method was used to measure the interatomic distance between [1-13C]Val8 and [15N]Leu13 to further identify the bending alpha-helical structure of melittin to possess the interhelical angles of 126 degrees and 119 degrees in DLPC and DPPC membranes, respectively. These analyses further lead to the conclusion that the alpha-helices of melittin molecules penetrate the hydrophobic cores of the bilayers incompletely as a pseudo-trans-membrane structure and induce fusion and disruption of vesicles.
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Affiliation(s)
- Shuichi Toraya
- Faculty of Engineering, Yokohama National University, Yokohama, Japan
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49
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Constantinescu I, Lafleur M. Influence of the lipid composition on the kinetics of concerted insertion and folding of melittin in bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2004; 1667:26-37. [PMID: 15533303 DOI: 10.1016/j.bbamem.2004.08.012] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2004] [Revised: 08/16/2004] [Accepted: 08/30/2004] [Indexed: 11/21/2022]
Abstract
We have examined the kinetics of the adsorption of melittin, a secondary amphipathic peptide extracted from bee venom, on lipid membranes using three independent and complementary approaches. We probed (i) the change in the polarity of the 19Trp of the peptide upon binding, (ii) the insertion of this residue in the apolar core of the membrane, measuring the 19Trp-fluorescence quenching by bromine atoms attached on lipid acyl chains, and (iii) the folding of the peptide, by circular dichroism (CD). We report a tight coupling of the insertion of the peptide with its folding as an alpha-helix. For all the investigated membrane systems (cholesterol-containing, phosphoglycerol-containing, and pure phosphocholine bilayers), the decrease in the polarity of 19Trp was found to be significantly faster than the increase in the helical content of melittin. Therefore, from a kinetics point of view, the formation of the alpha-helix is a consequence of the insertion of melittin. The rate of melittin folding was found to be influenced by the lipid composition of the bilayer and we propose that this was achieved by the modulation of the kinetics of insertion. The study reports a clear example of the coupling existing between protein penetration and folding, an interconnection that must be considered in the general scheme of membrane protein folding.
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Affiliation(s)
- Iren Constantinescu
- Department of Chemistry, Université de Montréal, CP 6128, Succ. Centre Ville, Montréal, Québec, Canada, H3C 3J7
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50
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Porcelli F, Buck B, Lee DK, Hallock KJ, Ramamoorthy A, Veglia G. Structure and orientation of pardaxin determined by NMR experiments in model membranes. J Biol Chem 2004; 279:45815-23. [PMID: 15292173 PMCID: PMC1513189 DOI: 10.1074/jbc.m405454200] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pardaxins are a class of ichthyotoxic peptides isolated from fish mucous glands. Pardaxins physically interact with cell membranes by forming pores or voltage-gated ion channels that disrupt cellular functions. Here we report the high-resolution structure of synthetic pardaxin Pa4 in sodium dodecylphosphocholine micelles, as determined by (1)H solution NMR spectroscopy. The peptide adopts a bend-helix-bend-helix motif with an angle between the two structure helices of 122 +/- 9 degrees , making this structure substantially different from the one previously determined in organic solvents. In addition, paramagnetic solution NMR experiments on Pa4 in micelles reveal that except for the C terminus, the peptide is not solvent-exposed. These results are complemented by solid-state NMR experiments on Pa4 in lipid bilayers. In particular, (13)C-(15)N rotational echo double-resonance experiments in multilamellar vesicles support the helical conformation of the C-terminal segment, whereas (2)H NMR experiments show that the peptide induces considerable disorder in both the head-groups and the hydrophobic core of the bilayers. These solid-state NMR studies indicate that the C-terminal helix has a transmembrane orientation in DMPC bilayers, whereas in POPC bilayers, this domain is heterogeneously oriented on the lipid surface and undergoes slow motion on the NMR time scale. These new data help explain how the non-covalent interactions of Pa4 with lipid membranes induce a stable secondary structure and provide an atomic view of the membrane insertion process of Pa4.
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Affiliation(s)
- Fernando Porcelli
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA
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