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Salnikov E, Aisenbrey C, Bechinger B. Lipid saturation and head group composition have a pronounced influence on the membrane insertion equilibrium of amphipathic helical polypeptides. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183844. [PMID: 34954200 DOI: 10.1016/j.bbamem.2021.183844] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/09/2021] [Accepted: 12/13/2021] [Indexed: 10/19/2022]
Abstract
The histidine-rich peptides of the LAH4 family were designed using cationic antimicrobial peptides such as magainin and PGLa as templates. The LAH4 amphipathic helical sequences exhibit a multitude of interesting biological properties such as antimicrobial activity, cell penetration of a large variety of cargo and lentiviral transduction enhancement. The parent peptide associates with lipid bilayers where it changes from an orientation along the membrane interface into a transmembrane configuration in a pH-dependent manner. Here we show that LAH4 adopts a transmembrane configuration in fully saturated DMPC membranes already at pH 3.5, i.e. much below the pKa of the histidines whereas the transition pH in POPC correlates closely with histidine neutralization. In contrast in POPG membranes the in-planar configuration is stabilized by about one pH unit. The differences in pH can be converted into energetic contributions for the in-plane to transmembrane transition equilibrium, where the shift in the transition pH due to lipid saturation corresponds to energies which are otherwise obtained by the exchange of several cationic with hydrophobic residues. A similar dependence on lipid saturation has also been observed when the PGLa and magainin antimicrobial peptides interact within lipid bilayers suggesting that the quantitative evaluation presented in this paper also applies to other membrane polypeptides.
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Affiliation(s)
- Evgeniy Salnikov
- University of Strasbourg/CNRS, UMR7177 Chemistry Institute, Membrane Biophysics and NMR, Strasbourg, France
| | - Christopher Aisenbrey
- University of Strasbourg/CNRS, UMR7177 Chemistry Institute, Membrane Biophysics and NMR, Strasbourg, France
| | - Burkhard Bechinger
- University of Strasbourg/CNRS, UMR7177 Chemistry Institute, Membrane Biophysics and NMR, Strasbourg, France; Institut Universitaire de France, France.
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2
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Khaliq B, Falke S, Saeed Q, Bilal M, Munawar A, Ali A, Baermann G, Athar HUR, Mahmood S, Betzel C, Ali Q, Akrem A. Eruca sativa seed napin structural insights and thorough functional characterization. Sci Rep 2021; 11:24066. [PMID: 34911985 PMCID: PMC8674280 DOI: 10.1038/s41598-021-02174-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 11/01/2021] [Indexed: 11/09/2022] Open
Abstract
A potent napin protein has been thoroughly characterized from seeds of rocket salad (Eruca sativa). Eruca sativa napin (EsNap) was purified by ammonium sulfate precipitation (70%) and size-exclusion chromatography. Single intact 16 kDa EsNap band was reduced to 11 and 5 kDa bands respectively on SDS-PAGE. Nano LC-MS/MS yielded two fragments comprising of 26 residues which showed 100% sequence identity with napin-3 of Brassica napus. CD spectroscopy indicated a dominant α-helical structure of EsNap. Monodispersity of EsNap was verified by dynamic light scattering, which also confirmed the monomeric status with a corresponding hydrodynamic radius of 2.4 ± 0.2 nm. An elongated ab initio shape of EsNap was calculated based on SAXS data, with an Rg of 1.96 ± 0.1 nm. The ab initio model calculated by DAMMIF with P1 symmetry and a volume of approx. 31,100 nm3, which corresponded to a molecular weight of approximately 15.5 kDa. The comparison of the SAXS and ab initio modeling showed a minimized χ2-value of 1.87, confirming a similar molecular structure. A homology model was predicted using the coordinate information of Brassica napus rproBnIb (PDB ID: 1SM7). EsNap exhibited strong antifungal activity by significantly inhibiting the growth of Fusarium graminearum. EsNap also showed cytotoxicity against the hepatic cell line Huh7 and the obtained IC50 value was 20.49 µM. Further, strong entomotoxic activity was experienced against different life stages of stored grain insect pest T. castaneum. The result of this study shows insights that can be used in developing potential antifungal, anti-cancerous and insect resistance agents in the future using EsNap from E. sativa.
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Affiliation(s)
- Binish Khaliq
- Botany Division, Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan, Pakistan.,Botany Division Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
| | - Sven Falke
- Laboratory for Structural Biology of Infection and Inflammation, The Hamburg Centre for Ultrafast Imaging, University of Hamburg, c/o DESY. Build. 22a, Notkestrasse 85, 22607, Hamburg, Germany
| | - Qamar Saeed
- Department of Entomology, Bahauddin Zakariya University, Multan, Pakistan
| | - Muhammad Bilal
- Centre for Applied Molecular Biology, University of Punjab, Lahore, Pakistan
| | - Aisha Munawar
- Department of Chemistry, University of Engineering and Technology, G.T. Road, Lahore, 54890, Pakistan
| | - Arslan Ali
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Gunnar Baermann
- Molekulare Phytopathologie, Universität Hamburg, Biozentrum Klein Flottbek Ohnhorststr, 1822609, Hamburg, Germany
| | - Habib-Ur-Rehman Athar
- Botany Division, Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan, Pakistan
| | - Seema Mahmood
- Botany Division, Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan, Pakistan
| | - Christian Betzel
- Laboratory for Structural Biology of Infection and Inflammation, The Hamburg Centre for Ultrafast Imaging, University of Hamburg, c/o DESY. Build. 22a, Notkestrasse 85, 22607, Hamburg, Germany
| | - Qurban Ali
- Botany Division Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan.
| | - Ahmed Akrem
- Botany Division, Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan, Pakistan.
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Montalbán MG, Víllora G, Licence P. Ecotoxicity assessment of dicationic versus monocationic ionic liquids as a more environmentally friendly alternative. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 150:129-135. [PMID: 29272717 DOI: 10.1016/j.ecoenv.2017.11.073] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 11/03/2017] [Accepted: 11/29/2017] [Indexed: 05/19/2023]
Abstract
One of the reasons why ionic liquids have received growing interest from researchers is their environmentally interesting characteristics, such as their negligible vapour pressure and their good chemical and thermal properties. In particular, dicationic ionic liquids whose thermal and electrochemical stability is higher than that of monocationic ionic liquids have begun to gain attention during recent years. In this work, monocationic and dicationic ionic liquids were synthesized, characterized and tested for their toxicity, which was assessed using the luminescent bacterium Vibrio fischeri. The results revealed that the toxicity of the ionic liquids mainly depends on the head groups and linkage chain length of their cationic structure. Introduction of a new cationic head decreased the EC50 (concentration which leads to 50% reduction in bioluminescence of the bacteria) of the ionic liquids. The results present a promising picture of dicationic ionic liquids as alternatives with lower environmental impact than their monocationic counterparts and underline the significance of designing particular structures for ionic liquids.
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Affiliation(s)
- M G Montalbán
- Department of Chemical Engineering, Faculty of Chemistry, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, P.O. Box 4021, Campus of Espinardo, E-30071 Murcia, Spain
| | - G Víllora
- Department of Chemical Engineering, Faculty of Chemistry, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, P.O. Box 4021, Campus of Espinardo, E-30071 Murcia, Spain.
| | - P Licence
- School of Chemistry, The University of Nottingham, Nottingham NG7 2RD, UK
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Salnikov ES, Raya J, De Zotti M, Zaitseva E, Peggion C, Ballano G, Toniolo C, Raap J, Bechinger B. Alamethicin Supramolecular Organization in Lipid Membranes from 19F Solid-State NMR. Biophys J 2017; 111:2450-2459. [PMID: 27926846 DOI: 10.1016/j.bpj.2016.09.048] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 09/10/2016] [Accepted: 09/29/2016] [Indexed: 11/24/2022] Open
Abstract
Alamethicins (ALMs) are antimicrobial peptides of fungal origin. Their sequences are rich in hydrophobic amino acids and strongly interact with lipid membranes, where they cause a well-defined increase in conductivity. Therefore, the peptides are thought to form transmembrane helical bundles in which the more hydrophilic residues line a water-filled pore. Whereas the peptide has been well characterized in terms of secondary structure, membrane topology, and interactions, much fewer data are available regarding the quaternary arrangement of the helices within lipid bilayers. A new, to our knowledge, fluorine-labeled ALM derivative was prepared and characterized when reconstituted into phospholipid bilayers. As a part of these studies, C19F3-labeled compounds were characterized and calibrated for the first time, to our knowledge, for 19F solid-state NMR distance and oligomerization measurements by centerband-only detection of exchange (CODEX) experiments, which opens up a large range of potential labeling schemes. The 19F-19F CODEX solid-state NMR experiments performed with ALM in POPC lipid bilayers and at peptide/lipid ratios of 1:13 are in excellent agreement with molecular-dynamics calculations of dynamic pentameric assemblies. When the peptide/lipid ratio was lowered to 1:30, ALM was found in the dimeric form, indicating that the supramolecular organization is tuned by equilibria that can be shifted by changes in environmental conditions.
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Affiliation(s)
- Evgeniy S Salnikov
- Institute of Chemistry, University of Strasbourg/CNRS, UMR7177, Strasbourg, France
| | - Jesus Raya
- Institute of Chemistry, University of Strasbourg/CNRS, UMR7177, Strasbourg, France
| | - Marta De Zotti
- ICB, Padova Unit, CNR, Department of Chemistry, University of Padova, Padova, Italy
| | - Ekaterina Zaitseva
- Department of Membrane Physiology and Technology, Institute of Physiology, University of Freiburg, Freiburg, Germany
| | - Cristina Peggion
- ICB, Padova Unit, CNR, Department of Chemistry, University of Padova, Padova, Italy
| | - Gema Ballano
- ICB, Padova Unit, CNR, Department of Chemistry, University of Padova, Padova, Italy
| | - Claudio Toniolo
- ICB, Padova Unit, CNR, Department of Chemistry, University of Padova, Padova, Italy
| | - Jan Raap
- Leiden Institute of Chemistry, Gorlaeus Laboratories, University of Leiden, Leiden, the Netherlands
| | - Burkhard Bechinger
- Institute of Chemistry, University of Strasbourg/CNRS, UMR7177, Strasbourg, France.
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Gagnon MC, Strandberg E, Grau-Campistany A, Wadhwani P, Reichert J, Bürck J, Rabanal F, Auger M, Paquin JF, Ulrich AS. Influence of the Length and Charge on the Activity of α-Helical Amphipathic Antimicrobial Peptides. Biochemistry 2017; 56:1680-1695. [PMID: 28282123 DOI: 10.1021/acs.biochem.6b01071] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hydrophobic mismatch is important for pore-forming amphipathic antimicrobial peptides, as demonstrated recently [Grau-Campistany, A., et al. (2015) Sci. Rep. 5, 9388]. A series of different length peptides have been generated with the heptameric repeat sequence KIAGKIA, called KIA peptides, and it was found that only those helices sufficiently long to span the hydrophobic thickness of the membrane could induce leakage in lipid vesicles; there was also a clear length dependence of the antimicrobial and hemolytic activities. For the original KIA sequences, the cationic charge increased with peptide length. The goal of this work is to examine whether the charge also has an effect on activity; hence, we constructed two further series of peptides with a sequence similar to those of the KIA peptides, but with a constant charge of +7 for all lengths from 14 to 28 amino acids. For both of these new series, a clear length dependence similar to that of KIA peptides was observed, indicating that charge has only a minor influence. Both series also showed a distinct threshold length for peptides to be active, which correlates directly with the thickness of the membrane. Among the longer peptides, the new series showed activities only slightly lower than those of the original KIA peptides of the same length that had a higher charge. Shorter peptides, in which Gly was replaced with Lys, showed activities similar to those of KIA peptides of the same length, but peptides in which Ile was replaced with Lys lost their helicity and were less active.
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Affiliation(s)
- Marie-Claude Gagnon
- Department of Chemistry, PROTEO, CGCC, Université Laval , 1045 avenue de la Médecine, Québec, Canada G1V 0A6.,Department of Chemistry, PROTEO, CERMA, CQMF, Université Laval , 1045 avenue de la Médecine, Québec, Canada G1V 0A6
| | - Erik Strandberg
- Karlsruhe Institute of Technology (KIT) , Institute of Biological Interfaces (IBG-2), P.O. Box 3640, 76021 Karlsruhe, Germany
| | - Ariadna Grau-Campistany
- Secció de Química Orgànica, Departament de Química Inorgànica i Orgànica, Facultat de Química, Universitat de Barcelona , Barcelona, Spain
| | - Parvesh Wadhwani
- Karlsruhe Institute of Technology (KIT) , Institute of Biological Interfaces (IBG-2), P.O. Box 3640, 76021 Karlsruhe, Germany
| | - Johannes Reichert
- Karlsruhe Institute of Technology (KIT) , Institute of Biological Interfaces (IBG-2), P.O. Box 3640, 76021 Karlsruhe, Germany
| | - Jochen Bürck
- Karlsruhe Institute of Technology (KIT) , Institute of Biological Interfaces (IBG-2), P.O. Box 3640, 76021 Karlsruhe, Germany
| | - Francesc Rabanal
- Secció de Química Orgànica, Departament de Química Inorgànica i Orgànica, Facultat de Química, Universitat de Barcelona , Barcelona, Spain
| | - Michèle Auger
- Department of Chemistry, PROTEO, CERMA, CQMF, Université Laval , 1045 avenue de la Médecine, Québec, Canada G1V 0A6
| | - Jean-François Paquin
- Department of Chemistry, PROTEO, CGCC, Université Laval , 1045 avenue de la Médecine, Québec, Canada G1V 0A6
| | - Anne S Ulrich
- Karlsruhe Institute of Technology (KIT) , Institute of Biological Interfaces (IBG-2), P.O. Box 3640, 76021 Karlsruhe, Germany.,KIT , Institute of Organic Chemistry, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
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7
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Tian X, Sun F, Zhou XR, Luo SZ, Chen L. Role of peptide self-assembly in antimicrobial peptides. J Pept Sci 2015; 21:530-9. [DOI: 10.1002/psc.2788] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 05/05/2015] [Accepted: 05/05/2015] [Indexed: 12/31/2022]
Affiliation(s)
- Xibo Tian
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology; Beijing University of Chemical Technology; Beijing 100029 China
| | - Fude Sun
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology; Beijing University of Chemical Technology; Beijing 100029 China
| | - Xi-Rui Zhou
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology; Beijing University of Chemical Technology; Beijing 100029 China
| | - Shi-Zhong Luo
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology; Beijing University of Chemical Technology; Beijing 100029 China
| | - Long Chen
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology; Beijing University of Chemical Technology; Beijing 100029 China
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8
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Bechinger B. The SMART model: Soft Membranes Adapt and Respond, also Transiently, in the presence of antimicrobial peptides. J Pept Sci 2014; 21:346-55. [PMID: 25522713 DOI: 10.1002/psc.2729] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 11/21/2014] [Accepted: 11/26/2014] [Indexed: 12/22/2022]
Abstract
Biophysical and structural studies of peptide-lipid interactions, peptide topology and dynamics have changed our view on how antimicrobial peptides insert and interact with membranes. Clearly, both the peptides and the lipids are highly dynamic, change and mutually adapt their conformation, membrane penetration and detailed morphology on a local and a global level. As a consequence, the peptides and lipids can form a wide variety of supramolecular assemblies in which the more hydrophobic sequences preferentially, but not exclusively, adopt transmembrane alignments and have the potential to form oligomeric structures similar to those suggested by the transmembrane helical bundle model. In contrast, charged amphipathic sequences tend to stay intercalated at the membrane interface where they cause pronounced disruptions of the phospholipid fatty acyl packing. At increasing local or global concentrations, the peptides result in transient membrane openings, rupture and ultimately lysis. Depending on peptide-to-lipid ratio, lipid composition and environmental factors (temperature, buffer composition, ionic strength, etc.), the same peptide sequence can result in a variety of those responses. Therefore, the SMART model has been introduced to cover the full range of possibilities. With such a view in mind, novel antimicrobial compounds have been designed from amphipathic polymers, peptide mimetics, combinations of ultra-short polypeptides with hydrophobic anchors or small designer molecules.
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Affiliation(s)
- Burkhard Bechinger
- Université de Strasbourg/CNRS, UMR7177, Institut de Chimie, 4, rue Blaise Pascal, 67070, Strasbourg, France
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Abstract
Antimicrobial peptides (AMPs) provide a primordial source of immunity, conferring upon eukaryotic cells resistance against bacteria, protozoa, and viruses. Despite a few examples of anionic peptides, AMPs are usually relatively short positively charged polypeptides, consisting of a dozen to about a hundred amino acids, and exhibiting amphipathic character. Despite significant differences in their primary and secondary structures, all AMPs discovered to date share the ability to interact with cellular membranes, thereby affecting bilayer stability, disrupting membrane organization, and/or forming well-defined pores. AMPs selectively target infectious agents without being susceptible to any of the common pathways by which these acquire resistance, thereby making AMPs prime candidates to provide therapeutic alternatives to conventional drugs. However, the mechanisms of AMP actions are still a matter of intense debate. The structure-function paradigm suggests that a better understanding of how AMPs elicit their biological functions could result from atomic resolution studies of peptide-lipid interactions. In contrast, more strict thermodynamic views preclude any roles for three-dimensional structures. Indeed, the design of selective AMPs based solely on structural parameters has been challenging. In this chapter, we will focus on selected AMPs for which studies on the corresponding AMP-lipid interactions have helped reach an understanding of how AMP effects are mediated. We will emphasize the roles of both liquid- and solid-state NMR spectroscopy for elucidating the mechanisms of action of AMPs.
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Membrane interactions of ionic liquids: possible determinants for biological activity and toxicity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:2967-74. [PMID: 22877704 DOI: 10.1016/j.bbamem.2012.07.025] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 07/24/2012] [Accepted: 07/27/2012] [Indexed: 11/22/2022]
Abstract
Ionic liquids (ILs) are a class of diverse organic salts with relatively low melting points (below 100°C) which have attracted considerable interest as a promising "green" substitute for organic solvents. The broad solvation properties of ILs and their high solubility in water, however, present health risks, in particular since it was shown that many ILs exhibit cytotoxic properties. In this context, interactions of ILs with the cellular membrane are believed to constitute a primary culprit for toxicity. We present a comprehensive biophysical and microscopy study of membrane interactions of a series of ILs having different side-chain compositions and lengths, and cationic head-group structures and orientations. The experimental data reveal that the ILs studied exhibit distinct mechanisms of membrane binding, insertion, and disruption which could be correlated with their biological activities. The results indicate, in particular, that both the side chain composition and particularly the head-groups of ILs constitute determinants for membrane activity and consequent cell toxicity. This work suggests that tuning membrane interactions of ILs should be an important factor for designing future compounds with benign environmental impact.
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Lopes SC, Neves CS, Eaton P, Gameiro P. Improved model systems for bacterial membranes from differing species: Theimportance of varying composition in PE/PG/cardiolipin ternary mixtures. Mol Membr Biol 2012; 29:207-17. [DOI: 10.3109/09687688.2012.700491] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Scorciapino MA, Pirri G, Vargiu AV, Ruggerone P, Giuliani A, Casu M, Buerck J, Wadhwani P, Ulrich AS, Rinaldi AC. A novel dendrimeric peptide with antimicrobial properties: structure-function analysis of SB056. Biophys J 2012; 102:1039-48. [PMID: 22404926 DOI: 10.1016/j.bpj.2012.01.048] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 01/17/2012] [Accepted: 01/30/2012] [Indexed: 01/15/2023] Open
Abstract
The novel antimicrobial peptide with a dimeric dendrimer scaffold, SB056, was empirically optimized by high-throughput screening. This procedure produced an intriguing primary sequence whose structure-function analysis is described here. The alternating pattern of hydrophilic and hydrophobic amino acids suggests the possibility that SB056 is a membrane-active peptide that forms amphiphilic β-strands in a lipid environment. Circular dichroism confirmed that the cationic SB056 folds as β-sheets in the presence of anionic vesicles. Lipid monolayer surface pressure experiments revealed unusual kinetics of monolayer penetration, which suggest lipid-induced aggregation as a membranolytic mechanism. NMR analyses of the linear monomer and the dendrimeric SB056 in water and in 30% trifluoroethanol, on the other hand, yielded essentially unstructured conformations, supporting the excellent solubility and storage properties of this compound. However, simulated annealing showed that many residues lie in the β-region of the Ramachandran plot, and molecular-dynamics simulations confirmed the propensity of this peptide to fold as a β-type conformation. The excellent solubility in water and the lipid-induced oligomerization characteristics of this peptide thus shed light on its mechanism of antimicrobial action, which may also be relevant for systems that can form toxic β-amyloid fibrils when in contact with cellular membranes. Functionally, SB056 showed high activity against Gram-negative bacteria and some limited activity against Gram-positive bacteria. Its potency against Gram-negative strains was comparable (on a molar basis) to that of colistin and polymyxin B, with an even broader spectrum of activity than numerous other reference compounds.
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Affiliation(s)
- Mariano A Scorciapino
- Department of Chemical Sciences, Istituto Officina dei Materiali del Consiglio Nazionale delle Ricerche, UOS SLACS, Italy
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13
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Mullen DG, Verardi R, Porcelli F, Scaloni A, Barany G, Veglia G. Synthesis and characterization of the 47-residue heterodimeric antimicrobial peptide distinctin, featuring directed disulfide bridge formation. Biopolymers 2012; 98:479-84. [PMID: 23203692 PMCID: PMC3551542 DOI: 10.1002/bip.22087] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 04/17/2012] [Accepted: 04/20/2012] [Indexed: 11/09/2022]
Abstract
Distinctin, a 47-residue heterodimeric peptide with potent antimicrobial activity, comprises two monomeric units linked covalently by a disulfide bond between Cys19 from the 22-residue A chain and Cys23 from the 25-residue B chain. Previous synthetic strategies involved assemblies of the two individual chains, followed by their co-oxidation to form the connecting disulfide bridge, and resulted in a mixture of three species: two homodimers and one heterodimer. Here, we report synthesis of exclusively heterodimeric distinctin, using recently developed tactics for directed disulfide bridge formation. Material prepared this way was characterized and found to be suitable for more detailed structural studies.
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Affiliation(s)
- Daniel G. Mullen
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Raffaello Verardi
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Fernando Porcelli
- Department for Innovation in Biological, Agro-Food and Forest Systems, DIBAF, University of Tuscia, Viterbo, Italy
| | - Andrea Scaloni
- Proteomics & Mass Spectrometry Laboratory, ISPAAM, National Research Council, 80147 Naples, Italy
| | - George Barany
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
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Maria-Neto S, Honorato RV, Costa FT, Almeida RG, Amaro DS, Oliveira JTA, Vasconcelos IM, Franco OL. Bactericidal activity identified in 2S Albumin from sesame seeds and in silico studies of structure-function relations. Protein J 2011; 30:340-50. [PMID: 21691771 DOI: 10.1007/s10930-011-9337-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pathogenic bacteria constitute an important cause of hospital-acquired infections. However, the misuse of available bactericidal agents has led to the appearance of antibiotic-resistant strains. Thus, efforts to seek new antimicrobials with different action mechanisms would have an enormous impact. Here, a novel antimicrobial protein (SiAMP2) belonging to the 2S albumin family was isolated from Sesamum indicum kernels and evaluated against several bacteria and fungi. Furthermore, in silico analysis was conducted in order to identify conserved residues through other 2S albumin antimicrobial proteins (2S-AMPs). SiAMP2 specifically inhibited Klebsiella sp. Specific regions in the molecule surface where cationic (RR/RRRK) and hydrophobic (MEYWPR) residues are exposed and conserved were proposed as being involved in antimicrobial activity. This study reinforces the hypothesis that plant storage proteins might also play as pathogen protection providing an insight into the mechanism of action for this novel 2S-AMP and evolutionary relations between antimicrobial activity and 2S albumins.
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Affiliation(s)
- Simone Maria-Neto
- Centro de Análises Proteômicas e Bioquímicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, SGAN Quadra, Modulo B, Brasília, Distrito Federal, Brazil.
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Abstract
Traditional approaches of medicinal chemistry focus on finding novel structures possessing desired biological properties, or on relating chemical details to a particular biological function. Here the aim is to hit the therapeutic target of interest rather than to understand and exploit its origin. Consequently, molecular mechanisms underlying the disease are of much lesser concern, with intuitive designs continuing to be most successful. Physical sciences can offer alternative ways of tackling the problem by establishing structural continuums between different time and length scales spanning physical phenomena of life processes and their disorders. This can be achieved by the use of approximated physical models providing a rationale for interconversions between different but related scales, which can further be extended with chemical details obtained from complementary experimental data.
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16
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Bechinger B. Insights into the mechanisms of action of host defence peptides from biophysical and structural investigations. J Pept Sci 2011; 17:306-14. [DOI: 10.1002/psc.1343] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 11/12/2010] [Accepted: 11/15/2010] [Indexed: 01/09/2023]
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