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Strandberg E, Wadhwani P, Bürck J, Anders P, Mink C, van den Berg J, Ciriello RAM, Melo MN, Castanho MARB, Bardají E, Ulmschneider JP, Ulrich AS. Temperature-Dependent Re-alignment of the Short Multifunctional Peptide BP100 in Membranes Revealed by Solid-State NMR Spectroscopy and Molecular Dynamics Simulations. Chembiochem 2023; 24:e202200602. [PMID: 36454659 DOI: 10.1002/cbic.202200602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 12/02/2022]
Abstract
BP100 is a cationic undecamer peptide with antimicrobial and cell-penetrating activities. The orientation of this amphiphilic α-helix in lipid bilayers was examined under numerous conditions using solid-state 19 F, 15 N and 2 H NMR. At high temperatures in saturated phosphatidylcholine lipids, BP100 lies flat on the membrane surface, as expected. Upon lowering the temperature towards the lipid phase transition, the helix is found to flip into an upright transmembrane orientation. In thin bilayers, this inserted state was stable at low peptide concentration, but thicker membranes required higher peptide concentrations. In the presence of lysolipids, the inserted state prevailed even at high temperature. Molecular dynamics simulations suggest that BP100 monomer insertion can be stabilized by snorkeling lysine side chains. These results demonstrate that even a very short helix like BP100 can span (and thereby penetrate through) a cellular membrane under suitable conditions.
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Affiliation(s)
- Erik Strandberg
- Karlsruhe Institute of Technology (KIT), Institute of Biological Interfaces (IBG-2), POB 3640, 76021, Karlsruhe, Germany
| | - Parvesh Wadhwani
- Karlsruhe Institute of Technology (KIT), Institute of Biological Interfaces (IBG-2), POB 3640, 76021, Karlsruhe, Germany
| | - Jochen Bürck
- Karlsruhe Institute of Technology (KIT), Institute of Biological Interfaces (IBG-2), POB 3640, 76021, Karlsruhe, Germany
| | - Patrick Anders
- Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry, Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany
| | - Christian Mink
- Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry, Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany.,Present address: Syngenta Crop Protection AG, 4333, Münchwilen, Switzerland
| | - Jonas van den Berg
- Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry, Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany
| | - Raffaele A M Ciriello
- Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry, Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany
| | - Manuel N Melo
- Instituto de Medicina Molecular Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisbon, Portugal.,Present address: ITQB Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Miguel A R B Castanho
- Instituto de Medicina Molecular Faculdade de Medicina, Universidade de Lisboa, 1649-028, Lisbon, Portugal
| | - Eduard Bardají
- LIPPSO, Department of Chemistry, University of Girona, Campus Montilivi, 17071, Girona, Spain
| | - Jakob P Ulmschneider
- Institute of Natural Sciences and School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Anne S Ulrich
- Karlsruhe Institute of Technology (KIT), Institute of Biological Interfaces (IBG-2), POB 3640, 76021, Karlsruhe, Germany.,Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry, Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany
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2
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Talapko J, Meštrović T, Juzbašić M, Tomas M, Erić S, Horvat Aleksijević L, Bekić S, Schwarz D, Matić S, Neuberg M, Škrlec I. Antimicrobial Peptides-Mechanisms of Action, Antimicrobial Effects and Clinical Applications. Antibiotics (Basel) 2022; 11:antibiotics11101417. [PMID: 36290075 PMCID: PMC9598582 DOI: 10.3390/antibiotics11101417] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 11/07/2022] Open
Abstract
The growing emergence of antimicrobial resistance represents a global problem that not only influences healthcare systems but also has grave implications for political and economic processes. As the discovery of novel antimicrobial agents is lagging, one of the solutions is innovative therapeutic options that would expand our armamentarium against this hazard. Compounds of interest in many such studies are antimicrobial peptides (AMPs), which actually represent the host's first line of defense against pathogens and are involved in innate immunity. They have a broad range of antimicrobial activity against Gram-negative and Gram-positive bacteria, fungi, and viruses, with specific mechanisms of action utilized by different AMPs. Coupled with a lower propensity for resistance development, it is becoming clear that AMPs can be seen as emerging and very promising candidates for more pervasive usage in the treatment of infectious diseases. However, their use in quotidian clinical practice is not without challenges. In this review, we aimed to summarize state-of-the-art evidence on the structure and mechanisms of action of AMPs, as well as to provide detailed information on their antimicrobial activity. We also aimed to present contemporary evidence of clinical trials and application of AMPs and highlight their use beyond infectious diseases and potential challenges that may arise with their increasing availability.
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Affiliation(s)
- Jasminka Talapko
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
- Correspondence: (J.T.); (I.Š.)
| | - Tomislav Meštrović
- University Centre Varaždin, University North, 42000 Varaždin, Croatia
- Institute for Health Metrics and Evaluation, University of Washington, 3980 15th Ave. NE, Seattle, WA 98195, USA
| | - Martina Juzbašić
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
| | - Matej Tomas
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
| | - Suzana Erić
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Josipa Huttlera 4, 31000 Osijek, Croatia
| | - Lorena Horvat Aleksijević
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
| | - Sanja Bekić
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Josipa Huttlera 4, 31000 Osijek, Croatia
- Family Medicine Practice, 31000 Osijek, Croatia
| | - Dragan Schwarz
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
| | - Suzana Matić
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Josipa Huttlera 4, 31000 Osijek, Croatia
| | - Marijana Neuberg
- University Centre Varaždin, University North, 42000 Varaždin, Croatia
| | - Ivana Škrlec
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia
- Correspondence: (J.T.); (I.Š.)
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Membranolytic Mechanism of Amphiphilic Antimicrobial β-Stranded [KL]n Peptides. Biomedicines 2022; 10:biomedicines10092071. [PMID: 36140173 PMCID: PMC9495826 DOI: 10.3390/biomedicines10092071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/19/2022] [Accepted: 08/21/2022] [Indexed: 11/17/2022] Open
Abstract
Amphipathic peptides can act as antibiotics due to membrane permeabilization. KL peptides with the repetitive sequence [Lys-Leu]n-NH2 form amphipathic β-strands in the presence of lipid bilayers. As they are known to kill bacteria in a peculiar length-dependent manner, we suggest here several different functional models, all of which seem plausible, including a carpet mechanism, a β-barrel pore, a toroidal wormhole, and a β-helix. To resolve their genuine mechanism, the activity of KL peptides with lengths from 6–26 amino acids (plus some inverted LK analogues) was systematically tested against bacteria and erythrocytes. Vesicle leakage assays served to correlate bilayer thickness and peptide length and to examine the role of membrane curvature and putative pore diameter. KL peptides with 10–12 amino acids showed the best therapeutic potential, i.e., high antimicrobial activity and low hemolytic side effects. Mechanistically, this particular window of an optimum β-strand length around 4 nm (11 amino acids × 3.7 Å) would match the typical thickness of a lipid bilayer, implying the formation of a transmembrane pore. Solid-state 15N- and 19F-NMR structure analysis, however, showed that the KL backbone lies flat on the membrane surface under all conditions. We can thus refute any of the pore models and conclude that the KL peptides rather disrupt membranes by a carpet mechanism. The intriguing length-dependent optimum in activity can be fully explained by two counteracting effects, i.e., membrane binding versus amyloid formation. Very short KL peptides are inactive, because they are unable to bind to the lipid bilayer as flexible β-strands, whereas very long peptides are inactive due to vigorous pre-aggregation into β-sheets in solution.
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Wurl A, Ott M, Plato E, Meister A, Hamdi F, Kastritis PL, Blume A, Ferreira TM. Filling the Gap with Long n-Alkanes: Incorporation of C20 and C30 into Phospholipid Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:8595-8606. [PMID: 35786894 DOI: 10.1021/acs.langmuir.2c00872] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Investigating how hydrophobic molecules mix with phospholipid bilayers and how they affect membrane properties is commonplace in biophysics. Despite this, a molecular-level empirical description of a membrane model as simple as a phospholipid bilayer with long linear hydrophobic chains incorporated is still missing. Here, we present an unprecedented molecular characterization of the incorporation of two long n-alkanes, n-eicosane (C20) and n-triacontane (C30) with 20 and 30 carbons, respectively, in phosphatidylcholine (PC) bilayers using a combination of experimental techniques (2H NMR, 31P NMR, 1H-13C dipolar recoupling solid-state NMR, X-ray scattering, and cryogenic electron microscopy) and atomistic molecular dynamics (MD) simulations. At low hydration, deuterated C20 and C30 yield 2H NMR spectra evidencing anisotropic-motion, which demonstrates their miscibility in PC membranes up to a critical alkane-to-acyl-chain volume fraction, ϕc. The acquired 2H NMR spectra of C20 and C30 have notably different lineshapes. At low alkane volume fractions below ϕc, CHARMM36 MD simulations predict such 2H NMR spectra qualitatively and thus enable an atomistic-level interpretation of the spectra. Above ϕc, the 2H NMR lineshapes become characteristic of motions in the intermediate-regime that, together with the MD simulation results, suggest the onset of immiscibility between the alkane molecules and the acyl chains. For all the systems investigated, the phospholipid molecular structure is unperturbed by the presence of the alkanes. However, at conditions of excess hydration and at surprisingly low alkane fractions below ϕc, a peak characteristic of isotropic motion is observed in both the 2H spectra of the alkanes and 31P spectra of the phospholipids, strongly indicating that the incorporation of the alkanes induces a reduction on the average radius of the lipid vesicles.
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Affiliation(s)
- Anika Wurl
- NMR Group - Institute of Physics, Martin Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany
| | - Maria Ott
- Department of Biotechnology and Biochemistry, Martin Luther University Halle-Wittenberg, 06099 Halle, Saale, Germany
| | - Eric Plato
- NMR Group - Institute of Physics, Martin Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany
| | - Annette Meister
- Department of Biotechnology and Biochemistry, Martin Luther University Halle-Wittenberg, 06099 Halle, Saale, Germany
| | - Farzad Hamdi
- Department of Biotechnology and Biochemistry, Martin Luther University Halle-Wittenberg, 06099 Halle, Saale, Germany
| | - Panagiotis L Kastritis
- Department of Biotechnology and Biochemistry, Martin Luther University Halle-Wittenberg, 06099 Halle, Saale, Germany
| | - Alfred Blume
- Insitute of Chemistry, Martin Luther University Halle-Wittenberg, 06099 Halle, Saale, Germany
| | - Tiago M Ferreira
- NMR Group - Institute of Physics, Martin Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany
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5
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Probing and Manipulating the Lateral Pressure Profile in Lipid Bilayers Using Membrane-Active Peptides-A Solid-State 19F NMR Study. Int J Mol Sci 2022; 23:ijms23094544. [PMID: 35562938 PMCID: PMC9101910 DOI: 10.3390/ijms23094544] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/14/2022] [Accepted: 04/18/2022] [Indexed: 02/04/2023] Open
Abstract
The lateral pressure profile constitutes an important physical property of lipid bilayers, influencing the binding, insertion, and function of membrane-active peptides, such as antimicrobial peptides. In this study, we demonstrate that the lateral pressure profile can be manipulated using the peptides residing in different regions of the bilayer. A 19F-labeled analogue of the amphiphilic peptide PGLa was used to probe the lateral pressure at different depths in the membrane. To evaluate the lateral pressure profile, we measured the orientation of this helical peptide with respect to the membrane using solid-state 19F-NMR, which is indicative of its degree of insertion into the bilayer. Using this experimental approach, we observed that the depth of insertion of the probe peptide changed in the presence of additional peptides and, furthermore, correlated with their location in the membrane. In this way, we obtained a tool to manipulate, as well as to probe, the lateral pressure profile in membranes.
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Wadhwani P, Sekaran S, Strandberg E, Bürck J, Chugh A, Ulrich AS. Membrane Interactions of Latarcins: Antimicrobial Peptides from Spider Venom. Int J Mol Sci 2021; 22:ijms221810156. [PMID: 34576320 PMCID: PMC8470881 DOI: 10.3390/ijms221810156] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 11/26/2022] Open
Abstract
A group of seven peptides from spider venom with diverse sequences constitute the latarcin family. They have been described as membrane-active antibiotics, but their lipid interactions have not yet been addressed. Using circular dichroism and solid-state 15N-NMR, we systematically characterized and compared the conformation and helix alignment of all seven peptides in their membrane-bound state. These structural results could be correlated with activity assays (antimicrobial, hemolysis, fluorescence vesicle leakage). Functional synergy was not observed amongst any of the latarcins. In the presence of lipids, all peptides fold into amphiphilic α-helices as expected, the helices being either surface-bound or tilted in the bilayer. The most tilted peptide, Ltc2a, possesses a novel kind of amphiphilic profile with a coiled-coil-like hydrophobic strip and is the most aggressive of all. It indiscriminately permeabilizes natural membranes (antimicrobial, hemolysis) as well as artificial lipid bilayers through the segregation of anionic lipids and possibly enhanced motional averaging. Ltc1, Ltc3a, Ltc4a, and Ltc5a are efficient and selective in killing bacteria but without causing significant bilayer disturbance. They act rather slowly or may even translocate towards intracellular targets, suggesting more subtle lipid interactions. Ltc6a and Ltc7, finally, do not show much antimicrobial action but can nonetheless perturb model bilayers.
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Affiliation(s)
- Parvesh Wadhwani
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021 Karlsruhe, Germany; (P.W.); (E.S.); (J.B.)
| | - Saiguru Sekaran
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, Delhi 110016, India; (S.S.); (A.C.)
| | - Erik Strandberg
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021 Karlsruhe, Germany; (P.W.); (E.S.); (J.B.)
| | - Jochen Bürck
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021 Karlsruhe, Germany; (P.W.); (E.S.); (J.B.)
| | - Archana Chugh
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, Delhi 110016, India; (S.S.); (A.C.)
| | - Anne S. Ulrich
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021 Karlsruhe, Germany; (P.W.); (E.S.); (J.B.)
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
- Correspondence:
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7
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Talandashti R, Mehrnejad F, Rostamipour K, Doustdar F, Lavasanifar A. Molecular Insights into Pore Formation Mechanism, Membrane Perturbation, and Water Permeation by the Antimicrobial Peptide Pleurocidin: A Combined All-Atom and Coarse-Grained Molecular Dynamics Simulation Study. J Phys Chem B 2021; 125:7163-7176. [PMID: 34171196 DOI: 10.1021/acs.jpcb.1c01954] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The antimicrobial peptide (AMP) pleurocidin has a broad antimicrobial activity against Gram-negative and Gram-positive bacteria by perturbation and permeabilizing their membranes; however, understanding the mechanism of action of pleurocidin, a promising AMP for replacing current antibiotic agents, has tremendous importance for future applications. Hence, we applied all-atom (AA) and coarse-grained (CG) molecular dynamics (MD) simulations to provide molecular-level insights into the pore-forming process. The early stages of pore formation were examined by 500 ns AA simulations. The results demonstrated that pleurocidin has the ability to create a pore with two peptides through which water molecules can flow. However, the results of the 25 μs CG simulations indicate that the final pore will be created by accumulation of more than two peptides. The results show that after 2.5 μs of simulations, peptides will aggregate and create a channel-like pore across the membrane. Pleurocidin can construct a more efficient and stable pore in the anionic membranes than in the zwitterionic membranes. Moreover, the structure amphipathicity, polarity, and basic residues play crucial roles in the pore formation and flow of water molecules across the lipid bilayers. In general, the findings revealed that based on the lipid compositions of the membranes, pleurocidin could act by forming either toroidal or disordered toroidal pores with different peptide arrangements.
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Affiliation(s)
- Reza Talandashti
- Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, P. O. Box: 1985717443 Tehran, Iran.,Department of Life Sciences Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran 14395-1561, Iran
| | - Faramarz Mehrnejad
- Department of Life Sciences Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran 14395-1561, Iran
| | - Kiana Rostamipour
- Department of Life Sciences Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran 14395-1561, Iran
| | - Farahnoosh Doustdar
- Department of Life Sciences Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran 14395-1561, Iran.,Department of Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran 19839-63113, Iran
| | - Afsaneh Lavasanifar
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
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Mink C, Strandberg E, Wadhwani P, Melo MN, Reichert J, Wacker I, Castanho MARB, Ulrich AS. Overlapping Properties of the Short Membrane-Active Peptide BP100 With (i) Polycationic TAT and (ii) α-helical Magainin Family Peptides. Front Cell Infect Microbiol 2021; 11:609542. [PMID: 33981626 PMCID: PMC8107365 DOI: 10.3389/fcimb.2021.609542] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 04/09/2021] [Indexed: 01/04/2023] Open
Abstract
BP100 is a short, designer-made membrane-active peptide with multiple functionalities: antimicrobial, cell-penetrating, and fusogenic. Consisting of five lysines and 6 hydrophobic residues, BP100 was shown to bind to lipid bilayers as an amphipathic α-helix, but its mechanism of action remains unclear. With these features, BP100 embodies the characteristics of two distinctly different classes of membrane-active peptides, which have been studied in detail and where the mechanism of action is better understood. On the one hand, its amphiphilic helical structure is similar to the pore forming magainin family of antimicrobial peptides, though BP100 is much too short to span the membrane. On the other hand, its length and high charge density are reminiscent of the HIV-TAT family of cell penetrating peptides, for which inverted micelles have been postulated as translocation intermediates, amongst other mechanisms. Assays were performed to test the antimicrobial and hemolytic activity, the induced leakage and fusion of lipid vesicles, and cell uptake. From these results the functional profiles of BP100, HIV-TAT, and the magainin-like peptides magainin 2, PGLa, MSI-103, and MAP were determined and compared. It is observed that the activity of BP100 resembles most closely the much longer amphipathic α-helical magainin-like peptides, with high antimicrobial activity along with considerable fusogenic and hemolytic effects. In contrast, HIV-TAT shows almost no antimicrobial, fusogenic, or hemolytic effects. We conclude that the amphipathic helix of BP100 has a similar membrane-based activity as magainin-like peptides and may have a similar mechanism of action.
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Affiliation(s)
- Christian Mink
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Erik Strandberg
- Institute of Biological Interfaces (IBG-2), KIT, Karlsruhe, Germany
| | - Parvesh Wadhwani
- Institute of Biological Interfaces (IBG-2), KIT, Karlsruhe, Germany
| | - Manuel N Melo
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | | | - Irene Wacker
- Cryo EM, Centre for Advanced Materials, Universität Heidelberg, Heidelberg, Germany
| | - Miguel A R B Castanho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Anne S Ulrich
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.,Institute of Biological Interfaces (IBG-2), KIT, Karlsruhe, Germany
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9
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Afrose F, Martfeld AN, Greathouse DV, Koeppe RE. Examination of pH dependency and orientation differences of membrane spanning alpha helices carrying a single or pair of buried histidine residues. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183501. [PMID: 33130099 DOI: 10.1016/j.bbamem.2020.183501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 01/08/2023]
Abstract
We have employed the peptide framework of GWALP23 (acetyl-GGALWLALALALALALALWLAGA-amide) to examine the orientation, dynamics and pH dependence of peptides having buried single or pairs of histidine residues. When residue L8 is substituted to yield GWALP23-H8, acetyl-GGALWLAH8ALALALALALWLAGA-amide, the deuterium NMR spectra of 2H-labeled core alanine residues reveal a helix that occupies a single transmembrane orientation in DLPC, or in DMPC at low pH, yet shows multiple states at higher pH or in bilayers of DOPC. Moreover, a single histidine at position 8 or 16 in the GWALP23 framework is sensitive to pH. Titration points are observed near pH 3.5 for the deprotonation of H8 in lipid bilayers of DLPC or DMPC, and for H16 in DOPC. When residues L8 and L16 both are substituted to yield GWALP23-H8,16, the 2H NMR spectra show, interestingly, no titration dependence from pH 2-8, yet bilayer thickness-dependent orientation differences. The helix with H8 and H16 is found to adopt a transmembrane orientation in thin bilayers of DLPC, a combination of transmembrane and surface orientations in DMPC, and then a complete transition to a surface bound orientation in the thicker DPoPC and DOPC lipid bilayers. In the surface orientations, alanine A7 no longer fits within the core helix. These results along with previous studies with different locations of histidine residues suggest that lipid hydrophobic thickness is a first determinant and pH a second determinant for the helical orientation, along with possible side-chain snorkeling, when the His residues are incorporated into the hydrophobic region of a lipid membrane-associated helix.
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Affiliation(s)
- Fahmida Afrose
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Ashley N Martfeld
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Denise V Greathouse
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Roger E Koeppe
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
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10
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León Madrazo A, Segura Campos MR. Review of antimicrobial peptides as promoters of food safety: Limitations and possibilities within the food industry. J Food Saf 2020. [DOI: 10.1111/jfs.12854] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Anaí León Madrazo
- Facultad de Ingeniería Química Universidad Autónoma de Yucatán Mérida Yucatán Mexico
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