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Lee TH, Charchar P, Separovic F, Reid GE, Yarovsky I, Aguilar MI. The intricate link between membrane lipid structure and composition and membrane structural properties in bacterial membranes. Chem Sci 2024; 15:3408-3427. [PMID: 38455013 PMCID: PMC10915831 DOI: 10.1039/d3sc04523d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 01/26/2024] [Indexed: 03/09/2024] Open
Abstract
It is now evident that the cell manipulates lipid composition to regulate different processes such as membrane protein insertion, assembly and function. Moreover, changes in membrane structure and properties, lipid homeostasis during growth and differentiation with associated changes in cell size and shape, and responses to external stress have been related to drug resistance across mammalian species and a range of microorganisms. While it is well known that the biomembrane is a fluid self-assembled nanostructure, the link between the lipid components and the structural properties of the lipid bilayer are not well understood. This perspective aims to address this topic with a view to a more detailed understanding of the factors that regulate bilayer structure and flexibility. We describe a selection of recent studies that address the dynamic nature of bacterial lipid diversity and membrane properties in response to stress conditions. This emerging area has important implications for a broad range of cellular processes and may open new avenues of drug design for selective cell targeting.
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Affiliation(s)
- Tzong-Hsien Lee
- Department of Biochemistry and Molecular Biology, Monash University Clayton VIC 3800 Australia
| | - Patrick Charchar
- School of Engineering, RMIT University Melbourne Victoria 3001 Australia
| | - Frances Separovic
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne VIC 3010 Australia
| | - Gavin E Reid
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne VIC 3010 Australia
- Department of Biochemistry and Pharmacology, University of Melbourne Parkville VIC 3010 Australia
| | - Irene Yarovsky
- School of Engineering, RMIT University Melbourne Victoria 3001 Australia
| | - Marie-Isabel Aguilar
- Department of Biochemistry and Molecular Biology, Monash University Clayton VIC 3800 Australia
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2
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Epimers l- and d-Phenylseptin: How the relative stereochemistry affects the peptide-membrane interactions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183708. [PMID: 34310911 DOI: 10.1016/j.bbamem.2021.183708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 11/20/2022]
Abstract
In recent decades, several epimers of peptides containing d-amino acids have been identified in antimicrobial sequences, a feature which has been associated with post-translational modification. Generally, d-isomers present similar or inferior antimicrobial activity, only surpassing their epimers in resistance to peptidases. The naturally occurring l-Phenylseptin (l-Phes) and d-Phenylseptin (d-Phes) peptides (FFFDTLKNLAGKVIGALT-nh2) were reported with d-epimer showing higher activity against Staphylococcus aureus and Xanthomonas axonopodis in comparison with the l-epimer. In this study, we combine structural (CD, solution NMR), orientational (solid-state NMR) and biophysical (ITC, DSC and DLS) studies to understand the role of the d-phenylalanine in the increase of the antimicrobial activity. Although both peptides are structurally similar in the helical region ranging from D4 to the C-terminus, significant structural differences were observed near the peptides' N-termini (which encompasses the FFF motif). Specific aromatic interactions involving the phenylalanine side chains of d-Phes is responsible to maintaining the F1-F3 residues on the hydrophobic face of the peptide, increasing its amphipathicity when compared to the l-epimer. The higher capability of d-Phes to exert an efficient anchoring in the hydrophobic core of the phospholipid bilayer indicates a pivotal role of the N-terminus in enhancing the interaction between the d-peptide and the membrane interface in relation to its epimer.
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Muñoz-López J, Oliveira JCL, Michel DAGR, Ferreira CS, Neto FG, Salnikov ES, Verly RM, Bechinger B, Resende JM. Membrane interactions of Ocellatins. Where do antimicrobial gaps stem from? Amino Acids 2021; 53:1241-1256. [PMID: 34251525 DOI: 10.1007/s00726-021-03029-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 06/25/2021] [Indexed: 10/20/2022]
Abstract
The antimicrobial peptides Ocellatin-LB1, -LB2 and -F1, isolated from frogs, are identical from residue 1 to 22, which correspond to the -LB1 sequence, whereas -LB2 carries an extra N and -F1 additional NKL residues at their C-termini. Despite the similar sequences, previous investigations showed different spectra of activities and biophysical investigations indicated a direct correlation between both membrane-disruptive properties and activities, i.e., ocellatin-F1 > ocellatin-LB1 > ocellatin-LB2. This study presents experimental evidence as well as results from theoretical studies that contribute to a deeper understanding on how these peptides exert their antimicrobial activities and how small differences in the amino acid composition and their secondary structure can be correlated to these activity gaps. Solid-state NMR experiments allied to the simulation of anisotropic NMR parameters allowed the determination of the membrane topologies of these ocellatins. Interestingly, the extra Asn residue at the Ocellatin-LB2 C-terminus results in increased topological flexibility, which is mainly related to wobbling of the helix main axis as noticed by molecular dynamics simulations. Binding kinetics and thermodynamics of the interactions have also been assessed by Surface Plasmon Resonance and Isothermal Titration Calorimetry. Therefore, these investigations allowed to understand in atomic detail the relationships between peptide structure and membrane topology, which are in tune within the series -F1 > > -LB1 ≥ -LB2, as well as how peptide dynamics can affect membrane topology, insertion and binding.
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Affiliation(s)
- José Muñoz-López
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, P.O. Box 486, Belo Horizonte, MG, 31270-901, Brazil.,UMR7177, Institut de Chimie, Université de Strasbourg/CNRS, 4, rue Blaise Pascal , 67000, Strasbourg, France
| | - Jade C L Oliveira
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, P.O. Box 486, Belo Horizonte, MG, 31270-901, Brazil
| | - Daniel A G R Michel
- Departamento de Química, Universidade Federal Dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, 39100-000, Brazil
| | - Carolina S Ferreira
- Departamento de Química, Universidade Federal Dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, 39100-000, Brazil
| | - Francisco Gomes Neto
- Laboratório de Toxinologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, 21040-900, Brazil
| | - Evgeniy S Salnikov
- UMR7177, Institut de Chimie, Université de Strasbourg/CNRS, 4, rue Blaise Pascal , 67000, Strasbourg, France
| | - Rodrigo M Verly
- Departamento de Química, Universidade Federal Dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, 39100-000, Brazil
| | - Burkhard Bechinger
- UMR7177, Institut de Chimie, Université de Strasbourg/CNRS, 4, rue Blaise Pascal , 67000, Strasbourg, France.,Institut Universitaire de France, 75005, Paris, France
| | - Jarbas M Resende
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, P.O. Box 486, Belo Horizonte, MG, 31270-901, Brazil.
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Daskalov A, El Mammeri N, Lends A, Shenoy J, Lamon G, Fichou Y, Saad A, Martinez D, Morvan E, Berbon M, Grélard A, Kauffmann B, Ferber M, Bardiaux B, Habenstein B, Saupe SJ, Loquet A. Structures of Pathological and Functional Amyloids and Prions, a Solid-State NMR Perspective. Front Mol Neurosci 2021; 14:670513. [PMID: 34276304 PMCID: PMC8280340 DOI: 10.3389/fnmol.2021.670513] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 05/26/2021] [Indexed: 12/20/2022] Open
Abstract
Infectious proteins or prions are a remarkable class of pathogens, where pathogenicity and infectious state correspond to conformational transition of a protein fold. The conformational change translates into the formation by the protein of insoluble amyloid aggregates, associated in humans with various neurodegenerative disorders and systemic protein-deposition diseases. The prion principle, however, is not limited to pathogenicity. While pathological amyloids (and prions) emerge from protein misfolding, a class of functional amyloids has been defined, consisting of amyloid-forming domains under natural selection and with diverse biological roles. Although of great importance, prion amyloid structures remain challenging for conventional structural biology techniques. Solid-state nuclear magnetic resonance (SSNMR) has been preferentially used to investigate these insoluble, morphologically heterogeneous aggregates with poor crystallinity. SSNMR methods have yielded a wealth of knowledge regarding the fundamentals of prion biology and have helped to solve the structures of several prion and prion-like fibrils. Here, we will review pathological and functional amyloid structures and will discuss some of the obtained structural models. We will finish the review with a perspective on integrative approaches combining solid-state NMR, electron paramagnetic resonance and cryo-electron microscopy, which can complement and extend our toolkit to structurally explore various facets of prion biology.
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Affiliation(s)
- Asen Daskalov
- CNRS, CBMN UMR 5348, IECB, University of Bordeaux, Pessac, France
| | - Nadia El Mammeri
- CNRS, CBMN UMR 5348, IECB, University of Bordeaux, Pessac, France
| | - Alons Lends
- CNRS, CBMN UMR 5348, IECB, University of Bordeaux, Pessac, France
| | | | - Gaelle Lamon
- CNRS, CBMN UMR 5348, IECB, University of Bordeaux, Pessac, France
| | - Yann Fichou
- CNRS, CBMN UMR 5348, IECB, University of Bordeaux, Pessac, France
| | - Ahmad Saad
- CNRS, CBMN UMR 5348, IECB, University of Bordeaux, Pessac, France
| | - Denis Martinez
- CNRS, CBMN UMR 5348, IECB, University of Bordeaux, Pessac, France
| | - Estelle Morvan
- CNRS, INSERM, IECB, UMS 3033, University of Bordeaux, Pessac, France
| | - Melanie Berbon
- CNRS, CBMN UMR 5348, IECB, University of Bordeaux, Pessac, France
| | - Axelle Grélard
- CNRS, CBMN UMR 5348, IECB, University of Bordeaux, Pessac, France
| | - Brice Kauffmann
- CNRS, INSERM, IECB, UMS 3033, University of Bordeaux, Pessac, France
| | | | | | | | - Sven J. Saupe
- CNRS, IBGC UMR 5095, University of Bordeaux, Bordeaux, France
| | - Antoine Loquet
- CNRS, CBMN UMR 5348, IECB, University of Bordeaux, Pessac, France
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5
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Aisenbrey C, Rifi O, Bechinger B. Structure, membrane topology and influence of cholesterol of the membrane proximal region: transmembrane helical anchor sequence of gp41 from HIV. Sci Rep 2020; 10:22278. [PMID: 33335248 PMCID: PMC7746737 DOI: 10.1038/s41598-020-79327-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 11/30/2020] [Indexed: 11/13/2022] Open
Abstract
During the first steps of HIV infection the Env subunit gp41 is thought to establish contact between the membranes and to be the main driver of fusion. Here we investigated in liquid crystalline membranes the structure and cholesterol recognition of constructs made of a gp41 external region carrying a cholesterol recognition amino acid consensus (CRAC) motif and a hydrophobic membrane anchoring sequence. CD- und ATR-FTIR spectroscopies indicate that the constructs adopt a high degree of helical secondary structure in membrane environments. Furthermore, 15N and 2H solid-state NMR spectra of gp41 polypeptides reconstituted into uniaxially oriented bilayers agree with the CRAC domain being an extension of the transmembrane helix. Upon addition of cholesterol the CRAC NMR spectra remain largely unaffected when being associated with the native gp41 transmembrane sequence but its topology changes when anchored in the membrane by a hydrophobic model sequence. The 2H solid-state NMR spectra of deuterated cholesterol are indicative of a stronger influence of the model sequence on this lipid when compared to the native gp41 sequence. These observations are suggestive of a strong coupling between the transmembrane and the membrane proximal region of gp41 possibly enforced by oligomerization of the transmembrane helical region.
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Affiliation(s)
- Christopher Aisenbrey
- Institut de chimie de Strasbourg, UMR7177, University of Strasbourg/CNRS, 4, Rue Blaise Pascal, 67070, Strasbourg, France
| | - Omar Rifi
- Institut de chimie de Strasbourg, UMR7177, University of Strasbourg/CNRS, 4, Rue Blaise Pascal, 67070, Strasbourg, France
| | - Burkhard Bechinger
- Institut de chimie de Strasbourg, UMR7177, University of Strasbourg/CNRS, 4, Rue Blaise Pascal, 67070, Strasbourg, France.
- Institut Universitaire de France, Paris, France.
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6
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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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7
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Structure, interactions and membrane topology of HIV gp41 ectodomain sequences. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183274. [DOI: 10.1016/j.bbamem.2020.183274] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/06/2020] [Accepted: 03/10/2020] [Indexed: 11/21/2022]
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8
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Aisenbrey C, Douat C, Kichler A, Guichard G, Bechinger B. Characterization of the DNA and Membrane Interactions of a Bioreducible Cell-Penetrating Foldamer in its Monomeric and Dimeric Form. J Phys Chem B 2020; 124:4476-4486. [DOI: 10.1021/acs.jpcb.0c01853] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Christopher Aisenbrey
- Institut de chimie, Université de Strasbourg/CNRS, UMR7177, 4, rue Blaise Pascal, 67070 Strasbourg, France
| | - Céline Douat
- Université Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607 Pessac, France
| | - Antoine Kichler
- Faculté de Pharmacie, Université de Strasbourg/CNRS, UMR7199, 74, route du Rhin, 67401 Illkirch, France
| | - Gilles Guichard
- Université Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, 33607 Pessac, France
| | - Burkhard Bechinger
- Institut de chimie, Université de Strasbourg/CNRS, UMR7177, 4, rue Blaise Pascal, 67070 Strasbourg, France
- Institut Universitaire de France,
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The influence of the stereochemistry and C-end chemical modification of dermorphin derivatives on the peptide-phospholipid interactions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183066. [PMID: 31634444 DOI: 10.1016/j.bbamem.2019.183066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 08/24/2019] [Accepted: 09/11/2019] [Indexed: 11/23/2022]
Abstract
In this work the conformation of dermorphin, Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2, an opioid peptide and its analogues with different stereochemistry of alanine and different C-terminus is studied in aqueous and membrane environments. Using two-dimensional NMR techniques we demonstrate that in D2O/H2O peptides with D-alanine have extended conformation, while for the L-isomers more compact conformation is preferred. The analysis of ROESY HR MAS spectra of the peptides interacting with the DMPC bilayer indicates that both stereoisomers have still more extended conformation compared to aqueous phase, as shown by much weaker intermolecular interactions. The influence of Ala residue stereochemistry is also reflected in the interactions of the studied peptides with model membranes, as shown by the 31P NMR static spectra, in which the shapes of the phosphorus NMR signals originating from D-isomers correspond to spherically shaped vesicles in the presence of external magnetic field, in comparison to a more elongated ones observed for L-isomers, while TEM photographs shows that upon addition of D-isomers larger lipid vesicles are formed, in contrast to smaller ones for L-isomers. The location of aromatic fragments of dermorphins in the membrane is determined based on static 2H NMR and 1H1H RFDR MAS experiments. All aromatic rings were found to be inserted in the hydrophobic part of the bilayer, with the exception of the Tyr5 rings of D-Ala dermorphins. The influence of the C-terminal modification was found to be almost imperceptible.
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Salnikov ES, Aisenbrey C, Pokrandt B, Brügger B, Bechinger B. Structure, Topology, and Dynamics of Membrane-Inserted Polypeptides and Lipids by Solid-State NMR Spectroscopy: Investigations of the Transmembrane Domains of the DQ Beta-1 Subunit of the MHC II Receptor and of the COP I Protein p24. Front Mol Biosci 2019; 6:83. [PMID: 31608287 PMCID: PMC6769064 DOI: 10.3389/fmolb.2019.00083] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 08/23/2019] [Indexed: 01/04/2023] Open
Abstract
MHC class II receptors carry important function in adaptive immunity and their malfunctioning is associated with diabetes type I, chronic inflammatory diseases and other autoimmune diseases. The protein assembles from the DQ alpha-1 and DQ beta-1 subunits where the transmembrane domains of these type I membrane proteins have been shown to be involved in homo- and heterodimer formation. Furthermore, the DQ alpha 1 chain carries a sequence motif that has been first identified in the context of p24, a protein involved in the formation of COPI vesicles of the intracellular transport machinery, to specifically interact with sphingomyelin-C18 (SM-C18). Here we investigated the membrane interactions and dynamics of DQ beta-1 in liquid crystalline POPC phospholipid bilayers by oriented 15N solid-state NMR spectroscopy. The 15N resonances are indicative of a helical tilt angle of the membrane anchor sequence around 20°. Two populations can be distinguished by their differential dynamics probably corresponding the DQ beta-1 mono- and homodimer. Whereas, this equilibrium is hardly affected by the addition of 5 mole% SM-C18 a single population is visible in DMPC lipid bilayers suggesting that the lipid saturation is an important parameter. Furthermore, the DQ alpha-1, DQ beta-1 and p24 transmembrane helical domains were reconstituted into POPC or POPC/SM-C18 lipid bilayers where the fatty acyl chain of either the phosphatidylcholine or of the sphingolipid have been deuterated. Interestingly in the presence of both sphingolipid and polypeptide a strong decrease in the innermost membrane order of the POPC palmitoyl chain is observed, an effect that is strongest for DQ beta-1. In contrast, for the first time the polypeptide interactions were monitored by deuteration of the stearoyl chain of SM-C18. The resulting 2H solid-state NMR spectra show an increase in order for p24 and DQ alpha-1 which both carry the SM recognition motif. Thereby the data are suggestive that SM-C18 together with the transmembrane domains form structures imposing positive curvature strain on the surrounding POPC lipids. This effect is attenuated when SM-C18 is recognized by the protein.
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Affiliation(s)
- Evgeniy S Salnikov
- Université de Strasbourg/CNRS, UMR7177, Institut de Chimie, Strasbourg, France
| | | | - Bianca Pokrandt
- Biochemiezentrum der Universität Heidelberg, Heidelberg, Germany
| | - Britta Brügger
- Biochemiezentrum der Universität Heidelberg, Heidelberg, Germany
| | - Burkhard Bechinger
- Université de Strasbourg/CNRS, UMR7177, Institut de Chimie, Strasbourg, France
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11
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Solid-State NMR Approaches to Study Protein Structure and Protein-Lipid Interactions. Methods Mol Biol 2019. [PMID: 31218633 DOI: 10.1007/978-1-4939-9512-7_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Solid-state NMR spectroscopy has been developed for the investigation of membrane-associated polypeptides and remains one of the few techniques to reveal high-resolution structural information in liquid-disordered phospholipid bilayers. In particular, oriented samples have been used to investigate the structure, dynamics and topology of membrane polypeptides. Much of the previous solid-state NMR work has been developed and performed on peptides but the technique is constantly expanding towards larger membrane proteins. Here, a number of protocols are presented describing among other the reconstitution of membrane proteins into oriented membranes, monitoring membrane alignment by 31P solid-state NMR spectroscopy, investigations of the protein by one- and two-dimensional 15N solid-state NMR and measurements of the lipid order parameters using 2H solid-state NMR spectroscopy. Using such methods solid-state NMR spectroscopy has revealed a detailed picture of the ensemble of both lipids and proteins and their mutual interdependence in the bilayer environment.
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12
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Aisenbrey C, Salnikov ES, Bechinger B. Solid-State NMR Investigations of the MHC II Transmembrane Domains: Topological Equilibria and Lipid Interactions. J Membr Biol 2019; 252:371-384. [PMID: 31187155 DOI: 10.1007/s00232-019-00071-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/25/2019] [Indexed: 10/26/2022]
Abstract
The major histocompatibility complex class II (MHC II) membrane proteins are key players in the adaptive immune response. An aberrant function of these molecules is associated with a large number of autoimmune diseases such as diabetes type I and chronic inflammatory diseases. The MHC class II is assembled from DQ alpha 1 and DQ beta 1 which come together as a heterodimer through GXXXG-mediated protein-protein interactions and a highly specific protein-sphingomyelin-C18 interaction motif located on DQA1. This association can have important consequences in regulating the function of these membrane proteins. Here, we investigated the structure and topology of the DQA1 and DQB1 transmembrane helical domains by CD-, oriented 2H and 15N solid-state NMR spectroscopies. The spectra at peptide-to-lipid ratios of 0.5 to 2 mol% are indicative of a topological equilibrium involving a helix crossing the membrane with a tilt angle of about 20° and another transmembrane topology with around 30° tilt. The latter is probably representing a dimer. Furthermore, at the lowest peptide-to-lipid ratio, a third polypeptide population becomes obvious. Interestingly, the DQB1 and to a lesser extent the DQA1 transmembrane helical domains exhibit a strong fatty acyl chain disordering effect on the inner segments of the 2H-labelled palmitoyl chain of POPC bilayers. This phosphatidylcholine disordering requires the presence of sphingomyelin-C18 suggesting that the ensemble of transmembrane polypeptide and sphingolipid exerts positive curvature strain.
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Affiliation(s)
- Christopher Aisenbrey
- Institut de Chimie, Université de Strasbourg/CNRS, UMR7177, 4, Rue Blaise Pascal, 67070, Strasbourg, France
| | - Evgeniy S Salnikov
- Institut de Chimie, Université de Strasbourg/CNRS, UMR7177, 4, Rue Blaise Pascal, 67070, Strasbourg, France
| | - Burkhard Bechinger
- Institut de Chimie, Université de Strasbourg/CNRS, UMR7177, 4, Rue Blaise Pascal, 67070, Strasbourg, France.
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13
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Aisenbrey C, Kemayo-Koumkoua P, Salnikov ES, Glattard E, Bechinger B. Investigations of the Structure, Topology, and Interactions of the Transmembrane Domain of the Lipid-Sorting Protein p24 Being Highly Selective for Sphingomyelin-C18. Biochemistry 2019; 58:2782-2795. [PMID: 31120242 DOI: 10.1021/acs.biochem.9b00375] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The p24 proteins play an important role in the secretory pathway where they selectively connect various cargo to other proteins, thereby being involved in the controlled assembly and disassembly of the coat protein complexes and lipid sorting. Recently, a highly selective lipid interaction motif has been identified within the p24 transmembrane domain (TMD) that recognizes the combination of the sphingomyelin headgroup and the exact length of the C18 fatty acyl chain (SM-C18). Here, we present investigations of the structure, dynamics, and sphingomyelin interactions of the p24 transmembrane region using circular dichroism, tryptophan fluorescence, and solid-state nuclear magnetic resonance (NMR) spectroscopies of the polypeptides and the surrounding lipids. Membrane insertion and/or conformation of the TMD is strongly dependent on the membrane lipid composition where the transmembrane helical insertion is strongest in the presence of 1-palmitoyl-2-oleoyl- sn-glycero-3-phosphocholine (POPC) and SM-C18. By analyzing solid-state NMR angular restraints from a large number of labeled sites, we have found a tilt angle of 19° for the transmembrane helical domain at a peptide-to-lipid ratio of 1 mol %. Only minor changes in the solid-state NMR spectra are observed due to the presence of SM-C18; the only visible alterations are associated with the SM-C18 recognition motif close to the carboxy-terminal part of the hydrophobic transmembrane region in the proximity of the SM headgroup. Finally, the deuterium order parameters of POPC- d31 were nearly unaffected by the presence of SM-C18 or the polypeptide alone but decreased noticeably when the sphingomyelin and the polypeptide were added in combination.
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Affiliation(s)
- Christopher Aisenbrey
- Université de Strasbourg/CNRS, UMR7177 , Institut de Chimie , 4, rue Blaise Pascal , 67070 Strasbourg , France
| | - Patricia Kemayo-Koumkoua
- Université de Strasbourg/CNRS, UMR7177 , Institut de Chimie , 4, rue Blaise Pascal , 67070 Strasbourg , France
| | - Evgeniy S Salnikov
- Université de Strasbourg/CNRS, UMR7177 , Institut de Chimie , 4, rue Blaise Pascal , 67070 Strasbourg , France
| | - Elise Glattard
- Université de Strasbourg/CNRS, UMR7177 , Institut de Chimie , 4, rue Blaise Pascal , 67070 Strasbourg , France
| | - Burkhard Bechinger
- Université de Strasbourg/CNRS, UMR7177 , Institut de Chimie , 4, rue Blaise Pascal , 67070 Strasbourg , France
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14
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Juhl DW, van Rensburg W, Bossis X, Vosloo JA, Rautenbach M, Bechinger B. Tyrocidine A interactions with saccharides investigated by CD and NMR spectroscopies. J Pept Sci 2019; 25:e3163. [PMID: 30884009 DOI: 10.1002/psc.3163] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 02/10/2019] [Accepted: 02/12/2019] [Indexed: 01/23/2023]
Abstract
Tyrocidines are a family of cyclic decapeptides produced by the soil bacterium, Brevibacillus parabrevis. These antibiotic peptides can be used to prevent infections in agriculture and food industry but also to prepare antimicrobial lozenges, creams, and dressings for medical applications. It has been observed that the tyrocidines interact with saccharides such as cellulose from their soil environment, as well as sugars in culture media and glycans in fungal cell walls. Here, we investigated the interactions of tyrocidines with glucose, sucrose, and cellotetraose (as cellulose model) in a quantitative fashion utilising CD and NMR spectroscopy. The CD and NMR spectra of tyrocidine A (TrcA) were analysed as a function of solvent composition, and the spectral properties agree with the formation of oligomeric structures that are governed by β-sheet secondary structures once the acetonitrile content of the solvent is increased. Saccharides seem to also induce TrcA spectral changes reverting those induced by organic solvents. The CD spectral changes of TrcA in the presence of glucose agree with new ordered H-bonding, possibly β-sheet structures. The amides involved in intramolecular H-bonding remained largely unaffected by the environmental changes. In contrast, amides exposed to the exterior and/or involved in TrcA intermolecular association show the largest 1 H chemical shift changes. CD and NMR spectroscopic investigations correlated well with TrcA-glucose interactions characterized by a dissociation constant around 200 μM. Interestingly, the association of cellotetraose corresponds closely to the additive effect from four glucose moieties, while a much higher dissociation constant was observed for sucrose. Similar trends to TrcA for binding to the three saccharides were observed for the analogous tyrocidines, tyrocidine B, and tyrocidine C. These results therefore indicate that the tyrocidine interactions with the glucose monosaccharide unit are fairly specific and reversible.
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Affiliation(s)
| | - Wilma van Rensburg
- BIOPEP Peptide Group, Department of Biochemistry, University of Stellenbosch, Matieland, South Africa
| | | | - J Arnold Vosloo
- BIOPEP Peptide Group, Department of Biochemistry, University of Stellenbosch, Matieland, South Africa
| | - Marina Rautenbach
- BIOPEP Peptide Group, Department of Biochemistry, University of Stellenbosch, Matieland, South Africa
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15
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Salnikov ES, Aisenbrey C, Anantharamaiah G, Bechinger B. Solid-state NMR structural investigations of peptide-based nanodiscs and of transmembrane helices in bicellar arrangements. Chem Phys Lipids 2019; 219:58-71. [DOI: 10.1016/j.chemphyslip.2019.01.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/29/2019] [Accepted: 01/29/2019] [Indexed: 02/08/2023]
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16
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Aisenbrey C, Marquette A, Bechinger B. The Mechanisms of Action of Cationic Antimicrobial Peptides Refined by Novel Concepts from Biophysical Investigations. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1117:33-64. [PMID: 30980352 DOI: 10.1007/978-981-13-3588-4_4] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Even 30 years after the discovery of magainins, biophysical and structural investigations on how these peptides interact with membranes can still bear surprises and add new interesting detail to how these peptides exert their antimicrobial action. Early on, using oriented solid-state NMR spectroscopy, it was found that the amphipathic helices formed by magainins are active when being oriented parallel to the membrane surface. More recent investigations indicate that this in-planar alignment is also found when PGLa and magainin in combination exert synergistic pore-forming activities, where studies on the mechanism of synergistic interaction are ongoing. In a related manner, the investigation of dimeric antimicrobial peptide sequences has become an interesting topic of research which bears promise to refine our views how antimicrobial action occurs. The molecular shape concept has been introduced to explain the effects of lipids and peptides on membrane morphology, locally and globally, and in particular of cationic amphipathic helices that partition into the membrane interface. This concept has been extended in this review to include more recent ideas on soft membranes that can adapt to external stimuli including membrane-disruptive molecules. In this manner, the lipids can change their shape in the presence of low peptide concentrations, thereby maintaining the bilayer properties. At higher peptide concentrations, phase transitions occur which lead to the formation of pores and membrane lytic processes. In the context of the molecular shape concept, the properties of lipopeptides, including surfactins, are shortly presented, and comparisons with the hydrophobic alamethicin sequence are made.
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Affiliation(s)
| | - Arnaud Marquette
- Université de Strasbourg/CNRS, UMR7177, Institut de Chimie, Strasbourg, France
| | - Burkhard Bechinger
- Université de Strasbourg/CNRS, UMR7177, Institut de Chimie, Strasbourg, France. .,Faculté de chimie, Institut le Bel, Strasbourg, France.
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17
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Sowińska M, Laskowska A, Guśpiel A, Solecka J, Bochynska-Czyż M, Lipkowski AW, Trzeciak K, Urbanczyk-Lipkowska Z. Bioinspired Amphiphilic Peptide Dendrimers as Specific and Effective Compounds against Drug Resistant Clinical Isolates of E. coli. Bioconjug Chem 2018; 29:3571-3585. [PMID: 30235928 DOI: 10.1021/acs.bioconjchem.8b00544] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Evolution-derived natural compounds have been inspirational for design of numerous pharmaceuticals, e.g., penicillins and tetracyclines. Herein, we present a bioinspired strategy to design peptide dendrimers for the effective therapy of E. coli infections where the selection of appropriate amino acids and the mode of their assembly are based on the information gained from research on membranolytic natural antimicrobial peptides (AMP's). On the molecular level two opposite effects were explored: the effect of multiple positive charges necessary for membrane disintegration was equilibrated by the anchoring role of tryptophanes. Indeed, a series of Trp-terminated dendrimers exhibited high potency against clinical isolates of antibiotic resistant ESBL E. coli strains, stability in human plasma along with very low hemo- and genotoxicity. Investigation of the underlying antimicrobial mechanism indicated that the dendrimers studied at minimal inhibitory concentration showed weak permeability toward membranes. Solid-state 2D NMR studies revealed their presence on and inside the model membranes. Therefore, their biological properties might be explained by targeting of extra- or intracellular receptors. Our results point to a new approach to design novel branched antimicrobials with high therapeutic index.
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Affiliation(s)
- Marta Sowińska
- Institute of Organic Chemistry PAS , Kasprzaka Str. 44/54 , Warsaw 01-224 , Poland
| | - Anna Laskowska
- National Institute of Public Health-National Institute of Hygiene , Chocimska Str. 24 , Warsaw 00-791 , Poland
| | - Adam Guśpiel
- National Institute of Public Health-National Institute of Hygiene , Chocimska Str. 24 , Warsaw 00-791 , Poland
| | - Jolanta Solecka
- National Institute of Public Health-National Institute of Hygiene , Chocimska Str. 24 , Warsaw 00-791 , Poland
| | - Marta Bochynska-Czyż
- Mossakowski Medical Research Centre PAS , Pawinskiego Str. 5 , 02-106 Warsaw , Poland
| | - Andrzej W Lipkowski
- Mossakowski Medical Research Centre PAS , Pawinskiego Str. 5 , 02-106 Warsaw , Poland
| | - Katarzyna Trzeciak
- Institute of Organic Chemistry PAS , Kasprzaka Str. 44/54 , Warsaw 01-224 , Poland.,Centre of Molecular and Macromolecular Studies PAS , Sienkiewicza 112 , 90-363 Lodz , Poland
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18
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Ghosh C, Harmouche N, Bechinger B, Haldar J. Aryl-Alkyl-Lysines Interact with Anionic Lipid Components of Bacterial Cell Envelope Eliciting Anti-Inflammatory and Antibiofilm Properties. ACS OMEGA 2018; 3:9182-9190. [PMID: 31459052 PMCID: PMC6645134 DOI: 10.1021/acsomega.8b01052] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 07/30/2018] [Indexed: 05/05/2023]
Abstract
The emergence of bacterial resistance and hesitance in approving new drugs has bolstered research on membrane-active agents such as antimicrobial peptides and their synthetic derivatives as therapeutic alternatives against bacterial infections. Herein, we document the action of aryl-alkyl-lysines on liposomes mimicking bacterial membranes using solid-state nuclear magnetic resonance spectroscopy. A significant perturbation of the lipid thickness and order parameter of the lipid membrane was observed upon treatment with this class of compounds. Encouraged by these results, the ability of the most active compound (NCK-10) to interact with aggregates of lipopolysaccharides (LPSs) was studied. In vitro experiments showed that NCK-10 was able to prevent the LPS-induced stimulation of proinflammatory cytokines such as tumor necrosis factor-α and interleukin-6. The compound could also disrupt the biofilms of Pseudomonas aeruginosa in vitro and bring down the bacterial burden by more than 99% in a mice model of burn infections caused by the biofilms of P. aeruginosa.
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Affiliation(s)
- Chandradhish Ghosh
- Antimicrobial Research
Laboratory, New Chemistry Unit, Jawaharlal
Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
| | - Nicole Harmouche
- Université
de Strasbourg/CNRS, UMR7177, Institut de Chimie, 67008 Strasbourg, France
| | - Burkhard Bechinger
- Université
de Strasbourg/CNRS, UMR7177, Institut de Chimie, 67008 Strasbourg, France
| | - Jayanta Haldar
- Antimicrobial Research
Laboratory, New Chemistry Unit, Jawaharlal
Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, Karnataka, India
- E-mail: (J.H.)
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19
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Supramolecular Organization of Apolipoprotein-A-I-Derived Peptides within Disc-like Arrangements. Biophys J 2018; 115:467-477. [PMID: 30054032 DOI: 10.1016/j.bpj.2018.06.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 06/18/2018] [Accepted: 06/20/2018] [Indexed: 01/05/2023] Open
Abstract
Apolipoprotein A-I is the major protein component of high-density lipoproteins and fulfils important functions in lipid metabolism. Its structure consists of a chain of tandem domains of amphipathic helices. Using this protein as a template membrane scaffolding protein, class A amphipathic helical peptides were designed to support the amphipathic helix theory and later as therapeutic tools in biomedicine. Here, we investigated the lipid interactions of two apolipoprotein-A-I-derived class A amphipathic peptides, 14A (Ac-DYLKA FYDKL KEAF-NH2) and 18A (Ac-DWLKA FYDKV AEKLK EAF- NH2), including the disc-like supramolecular structures they form with phospholipids. Thus, the topologies of 14A and 18A in phospholipid bilayers have been determined by oriented solid-state NMR spectroscopy. Whereas at a peptide-to-lipid ratio of 2 mol% the peptides align parallel to the bilayer surface, at 7.5 mol% disc-like structures are formed that spontaneously orient in the magnetic field of the NMR spectrometer. From a comprehensive data set of four 15N- or 2H-labeled positions of 14A, a tilt angle, which deviates from perfectly in-planar by 14°, and a model for the peptidic rim structure have been obtained. The tilt and helical pitch angles are well suited to cover the hydrophobic chain region of the bilayer when two peptide helices form a head-to-tail dimer. Thus, the detailed topology found in this work agrees with the peptides forming the rim of nanodiscs in a double belt arrangement.
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20
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Mayo DJ, Sahu ID, Lorigan GA. Assessing topology and surface orientation of an antimicrobial peptide magainin 2 using mechanically aligned bilayers and electron paramagnetic resonance spectroscopy. Chem Phys Lipids 2018; 213:124-130. [DOI: 10.1016/j.chemphyslip.2018.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 04/13/2018] [Accepted: 04/20/2018] [Indexed: 12/13/2022]
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21
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Gomes KAGG, Dos Santos DM, Santos VM, Piló-Veloso D, Mundim HM, Rodrigues LV, Lião LM, Verly RM, de Lima ME, Resende JM. NMR structures in different membrane environments of three ocellatin peptides isolated from Leptodactylus labyrinthicus. Peptides 2018; 103:72-83. [PMID: 29596881 DOI: 10.1016/j.peptides.2018.03.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 03/21/2018] [Accepted: 03/23/2018] [Indexed: 10/17/2022]
Abstract
The peptides ocellatin-LB1, -LB2 and -F1 have previously been isolated from anurans of the Leptodactylus genus and the sequences are identical from residue 1-22, which correspond to ocellatin-LB1 sequence (GVVDILKGAAKDIAGHLASKVM-NH2), whereas ocellatin-LB2 carries an extra N and ocellatin-F1 extra NKL residues at their C-termini. These peptides showed different spectra of activities and biophysical investigations indicated a direct correlation between membrane-disruptive properties and antimicrobial activities, i.e. ocellatin-F1 > ocellatin-LB1 > ocellatin-LB2. To better characterize their membrane interactions, we report here the detailed three-dimensional NMR structures of these peptides in TFE-d2:H2O (60:40) and in the presence of zwitterionic DPC-d38 and anionic SDS-d25 micellar solutions. Although the three peptides showed significant helical contents in the three mimetic environments, structural differences were noticed. When the structures of the three peptides in the presence of DPC-d38 micelles are compared to each other, a more pronounced curvature is observed for ocellatin-F1 and the bent helix, with the concave face composed mostly of hydrophobic residues, is consistent with the micellar curvature and the amphipathic nature of the molecule. Interestingly, an almost linear helical segment was observed for ocellatin-F1 in the presence of SDS-d25 micelles and the conformational differences in the two micellar environments are possibly related to the presence of the extra Lys residue near the peptide C-terminus, which increases the affinity of ocellatin-F1 to anionic membranes in comparison with ocellatin-LB1 and -LB2, as proved by isothermal titration calorimetry. To our knowledge, this work reports for the first time the three-dimensional structures of ocellatin peptides.
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Affiliation(s)
- Karla A G G Gomes
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, P.O. Box 486, 31270-901 Belo Horizonte, MG, Brazil; Instituto de Engenharia, Ciência e Tecnologia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 39440-000 Janaúba, MG, Brazil
| | - Daniel M Dos Santos
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, P.O. Box 486, 31270-901 Belo Horizonte, MG, Brazil
| | - Virgílio M Santos
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, P.O. Box 486, 31270-901 Belo Horizonte, MG, Brazil
| | - Dorila Piló-Veloso
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, P.O. Box 486, 31270-901 Belo Horizonte, MG, Brazil
| | - Higor M Mundim
- Instituto de Química, Universidade Federal de Goiás, Av. Esperança, s/n, Campus Samambaia, 74690-900 Goiânia, GO, Brazil
| | - Leticia V Rodrigues
- Instituto de Química, Universidade Federal de Goiás, Av. Esperança, s/n, Campus Samambaia, 74690-900 Goiânia, GO, Brazil
| | - Luciano M Lião
- Instituto de Química, Universidade Federal de Goiás, Av. Esperança, s/n, Campus Samambaia, 74690-900 Goiânia, GO, Brazil
| | - Rodrigo M Verly
- Departamento de Química, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 39100-000 Diamantina, MG, Brazil
| | - Maria Elena de Lima
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, P.O. Box 486, 31270-901 Belo Horizonte, MG, Brazil
| | - Jarbas M Resende
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, P.O. Box 486, 31270-901 Belo Horizonte, MG, Brazil.
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22
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Abstract
Various recent developments in solid-state nuclear magnetic resonance (ssNMR) spectroscopy have enabled an array of new insights regarding the structure, dynamics, and interactions of biomolecules. In the ever more integrated world of structural biology, ssNMR studies provide structural and dynamic information that is complementary to the data accessible by other means. ssNMR enables the study of samples lacking a crystalline lattice, featuring static as well as dynamic disorder, and does so independent of higher-order symmetry. The present study surveys recent applications of biomolecular ssNMR and examines how this technique is increasingly integrated with other structural biology techniques, such as (cryo) electron microscopy, solution-state NMR, and X-ray crystallography. Traditional ssNMR targets include lipid bilayer membranes and membrane proteins in a lipid bilayer environment. Another classic application has been in the area of protein misfolding and aggregation disorders, where ssNMR has provided essential structural data on oligomers and amyloid fibril aggregates. More recently, the application of ssNMR has expanded to a growing array of biological assemblies, ranging from non-amyloid protein aggregates, protein–protein complexes, viral capsids, and many others. Across these areas, multidimensional magic angle spinning (MAS) ssNMR has, in the last decade, revealed three-dimensional structures, including many that had been inaccessible by other structural biology techniques. Equally important insights in structural and molecular biology derive from the ability of MAS ssNMR to probe information beyond comprehensive protein structures, such as dynamics, solvent exposure, protein–protein interfaces, and substrate–enzyme interactions.
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23
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Itkin A, Salnikov ES, Aisenbrey C, Raya J, Glattard E, Raussens V, Ruysschaert JM, Bechinger B. Structural Characterization of the Amyloid Precursor Protein Transmembrane Domain and Its γ-Cleavage Site. ACS OMEGA 2017; 2:6525-6534. [PMID: 31457253 PMCID: PMC6645296 DOI: 10.1021/acsomega.7b00619] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 08/16/2017] [Indexed: 06/10/2023]
Abstract
Alzheimer's disease is the most common form of dementia that affects about 50 million of sufferers worldwide. A major role for the initiation and progression of Alzheimer's disease has been associated with the amyloid β-peptide (Aβ), which is a protease cleavage product of the amyloid precursor protein. The amyloid precursor protein is an integral membrane protein with a single transmembrane domain. Here, we assessed the structural integrity of the transmembrane domain within oriented phosphatidylcholine lipid bilayers and determined the tilt angle distribution and dynamics of various subdomains using solid-state NMR and attenuated total reflectance Fourier transform infrared spectroscopies. Although the overall secondary structure of the transmembrane domain is α-helical, pronounced conformational and topological heterogeneities were observed for the γ- and, to a lesser extent, the ζ-cleavage site, with pronounced implications for the production of Aβ and related peptides, the development of the disease, and pharmaceutical innovation.
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Affiliation(s)
- Anna Itkin
- University
of Strasbourg/CNRS, UMR7177 Chemistry Institute, Membrane Biophysics
and NMR, 4, rue Blaise
Pascal, F-67070 Strasbourg, France
- Center
for Structural Biology and Bioinformatics, Laboratory of Structure
and Function of Biological Membranes, Université
Libre de Bruxelles, Campus
Plaine - Acces 2 - Batiment BC - Niveau 4, Boulevard du Triomphe -
CP 206/2, B-1050 Brussels, Belgium
| | - Evgeniy S. Salnikov
- University
of Strasbourg/CNRS, UMR7177 Chemistry Institute, Membrane Biophysics
and NMR, 4, rue Blaise
Pascal, F-67070 Strasbourg, France
| | - Christopher Aisenbrey
- University
of Strasbourg/CNRS, UMR7177 Chemistry Institute, Membrane Biophysics
and NMR, 4, rue Blaise
Pascal, F-67070 Strasbourg, France
| | - Jesus Raya
- University
of Strasbourg/CNRS, UMR7177 Chemistry Institute, Membrane Biophysics
and NMR, 4, rue Blaise
Pascal, F-67070 Strasbourg, France
| | - Elise Glattard
- University
of Strasbourg/CNRS, UMR7177 Chemistry Institute, Membrane Biophysics
and NMR, 4, rue Blaise
Pascal, F-67070 Strasbourg, France
| | - Vincent Raussens
- Center
for Structural Biology and Bioinformatics, Laboratory of Structure
and Function of Biological Membranes, Université
Libre de Bruxelles, Campus
Plaine - Acces 2 - Batiment BC - Niveau 4, Boulevard du Triomphe -
CP 206/2, B-1050 Brussels, Belgium
| | - Jean-Marie Ruysschaert
- Center
for Structural Biology and Bioinformatics, Laboratory of Structure
and Function of Biological Membranes, Université
Libre de Bruxelles, Campus
Plaine - Acces 2 - Batiment BC - Niveau 4, Boulevard du Triomphe -
CP 206/2, B-1050 Brussels, Belgium
| | - Burkhard Bechinger
- University
of Strasbourg/CNRS, UMR7177 Chemistry Institute, Membrane Biophysics
and NMR, 4, rue Blaise
Pascal, F-67070 Strasbourg, France
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24
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Molugu TR, Lee S, Brown MF. Concepts and Methods of Solid-State NMR Spectroscopy Applied to Biomembranes. Chem Rev 2017; 117:12087-12132. [PMID: 28906107 DOI: 10.1021/acs.chemrev.6b00619] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Concepts of solid-state NMR spectroscopy and applications to fluid membranes are reviewed in this paper. Membrane lipids with 2H-labeled acyl chains or polar head groups are studied using 2H NMR to yield knowledge of their atomistic structures in relation to equilibrium properties. This review demonstrates the principles and applications of solid-state NMR by unifying dipolar and quadrupolar interactions and highlights the unique features offered by solid-state 2H NMR with experimental illustrations. For randomly oriented multilamellar lipids or aligned membranes, solid-state 2H NMR enables direct measurement of residual quadrupolar couplings (RQCs) due to individual C-2H-labeled segments. The distribution of RQC values gives nearly complete profiles of the segmental order parameters SCD(i) as a function of acyl segment position (i). Alternatively, one can measure residual dipolar couplings (RDCs) for natural abundance lipid samples to obtain segmental SCH order parameters. A theoretical mean-torque model provides acyl-packing profiles representing the cumulative chain extension along the normal to the aqueous interface. Equilibrium structural properties of fluid bilayers and various thermodynamic quantities can then be calculated, which describe the interactions with cholesterol, detergents, peptides, and integral membrane proteins and formation of lipid rafts. One can also obtain direct information for membrane-bound peptides or proteins by measuring RDCs using magic-angle spinning (MAS) in combination with dipolar recoupling methods. Solid-state NMR methods have been extensively applied to characterize model membranes and membrane-bound peptides and proteins, giving unique information on their conformations, orientations, and interactions in the natural liquid-crystalline state.
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Affiliation(s)
- Trivikram R Molugu
- Department of Chemistry & Biochemistry and ‡Department of Physics, University of Arizona , Tucson, Arizona 85721, United States
| | - Soohyun Lee
- Department of Chemistry & Biochemistry and ‡Department of Physics, University of Arizona , Tucson, Arizona 85721, United States
| | - Michael F Brown
- Department of Chemistry & Biochemistry and ‡Department of Physics, University of Arizona , Tucson, Arizona 85721, United States
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25
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Harmouche N, Aisenbrey C, Porcelli F, Xia Y, Nelson SED, Chen X, Raya J, Vermeer L, Aparicio C, Veglia G, Gorr SU, Bechinger B. Solution and Solid-State Nuclear Magnetic Resonance Structural Investigations of the Antimicrobial Designer Peptide GL13K in Membranes. Biochemistry 2017; 56:4269-4278. [DOI: 10.1021/acs.biochem.7b00526] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nicole Harmouche
- Université de Strasbourg/CNRS, UMR7177, Institut de
Chimie, 1, rue Blaise
Pascal, 67070 Strasbourg, France
| | - Christopher Aisenbrey
- Université de Strasbourg/CNRS, UMR7177, Institut de
Chimie, 1, rue Blaise
Pascal, 67070 Strasbourg, France
| | - Fernando Porcelli
- DIBAF-University of Tuscia-Viterbo, Largo dell’Universita’, Blocco D, 01100 Viterbo, Italy
| | - Youlin Xia
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, 321 Church Street Southeast, Minneapolis, Minnesota 55455, United States
| | - Sarah E. D. Nelson
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, 321 Church Street Southeast, Minneapolis, Minnesota 55455, United States
| | - Xi Chen
- Minnesota
Dental Research Center for Biomaterials and Biomechanics and Department
of Restorative Sciences, University of Minnesota School of Dentistry, 515 Delaware Street Southeast, Minneapolis, Minnesota 55455, United States
| | - Jesus Raya
- Université de Strasbourg/CNRS, UMR7177, Institut de
Chimie, 1, rue Blaise
Pascal, 67070 Strasbourg, France
| | - Louic Vermeer
- Université de Strasbourg/CNRS, UMR7177, Institut de
Chimie, 1, rue Blaise
Pascal, 67070 Strasbourg, France
| | - Conrado Aparicio
- Minnesota
Dental Research Center for Biomaterials and Biomechanics and Department
of Restorative Sciences, University of Minnesota School of Dentistry, 515 Delaware Street Southeast, Minneapolis, Minnesota 55455, United States
| | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, 321 Church Street Southeast, Minneapolis, Minnesota 55455, United States
| | - Sven-Ulrik Gorr
- Department
of Diagnostic and Biological Sciences, University of Minnesota School of Dentistry, 515 Delaware Street Southeast, Minneapolis, Minnesota 55455, United States
| | - Burkhard Bechinger
- Université de Strasbourg/CNRS, UMR7177, Institut de
Chimie, 1, rue Blaise
Pascal, 67070 Strasbourg, France
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26
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Wolf J, Aisenbrey C, Harmouche N, Raya J, Bertani P, Voievoda N, Süss R, Bechinger B. pH-Dependent Membrane Interactions of the Histidine-Rich Cell-Penetrating Peptide LAH4-L1. Biophys J 2017; 113:1290-1300. [PMID: 28734478 DOI: 10.1016/j.bpj.2017.06.053] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 06/01/2017] [Accepted: 06/23/2017] [Indexed: 01/17/2023] Open
Abstract
The histidine-rich designer peptide LAH4-L1 exhibits antimicrobial and potent cell-penetrating activities for a wide variety of cargo including nucleic acids, polypeptides, adeno-associated viruses, and nanodots. The non-covalent complexes formed between the peptide and cargo enter the cell via an endosomal pathway where the pH changes from neutral to acidic. Here, we investigated the membrane interactions of the peptide with phospholipid bilayers and its membrane topology using static solid-state NMR spectroscopy. Oriented 15N solid-state NMR indicates that in membranes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (POPS) 3:1 mol/mole and at neutral pH, the peptide adopts transmembrane topologies. Furthermore, 31P and 2H solid-state NMR spectra show that liquid crystalline 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and POPC/POPS 3:1 liposomes retain a bilayer macroscopic phase even at the highest peptide concentrations investigated, with an oblate orientational distribution of the phospholipids at a peptide/lipid ratio of 1:5. At pH 5, as it occurs in the endosome, the alignment of LAH4-L1 at a peptide/lipid ratio of 1:25 is predominantly parallel to POPC/POPS 3:1 bilayers (prolate deformation) when at the same time it induces a considerable decrease of the deuterium order parameter of POPC/2H31-POPS 3:1. In addition, when studied in mechanically supported lipid membranes, a pronounced disordering of the phospholipid alignment is observed. In the presence of even higher peptide concentrations, lipid spectra are observed that suggest the formation of magnetically oriented or isotropic bicelles. This membrane-disruptive effect is enhanced for gel phase DMPC membranes. By protonation of the four histidines in acidic environments, the overall charge and hydrophobic moment of LAH4-L1 considerably change, and much of the peptide is released from the cargo. Thus, the amphipathic peptide sequences become available to disrupt the endosomal membrane and to assure highly efficient release from this organelle.
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Affiliation(s)
- Justine Wolf
- Institut de Chimie, UMR7177, Université de Strasbourg, CNRS, Strasbourg, France
| | | | - Nicole Harmouche
- Institut de Chimie, UMR7177, Université de Strasbourg, CNRS, Strasbourg, France
| | - Jesus Raya
- Institut de Chimie, UMR7177, Université de Strasbourg, CNRS, Strasbourg, France
| | - Philippe Bertani
- Institut de Chimie, UMR7177, Université de Strasbourg, CNRS, Strasbourg, France
| | - Natalia Voievoda
- Institut de Chimie, UMR7177, Université de Strasbourg, CNRS, Strasbourg, France
| | - Regine Süss
- Albert-Ludwigs-Universität Freiburg, Pharmazeutische Technologie und Biopharmazie, Freiburg, Germany
| | - Burkhard Bechinger
- Institut de Chimie, UMR7177, Université de Strasbourg, CNRS, Strasbourg, France.
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Gusmão KAG, Dos Santos DM, Santos VM, Cortés ME, Reis PVM, Santos VL, Piló-Veloso D, Verly RM, de Lima ME, Resende JM. Ocellatin peptides from the skin secretion of the South American frog Leptodactylus labyrinthicus (Leptodactylidae): characterization, antimicrobial activities and membrane interactions. J Venom Anim Toxins Incl Trop Dis 2017; 23:4. [PMID: 28115922 PMCID: PMC5244724 DOI: 10.1186/s40409-017-0094-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 01/06/2017] [Indexed: 12/04/2022] Open
Abstract
Background The availability of antimicrobial peptides from several different natural sources has opened an avenue for the discovery of new biologically active molecules. To the best of our knowledge, only two peptides isolated from the frog Leptodactylus labyrinthicus, namely pentadactylin and ocellatin-F1, have shown antimicrobial activities. Therefore, in order to explore the antimicrobial potential of this species, we have investigated the biological activities and membrane interactions of three peptides isolated from the anuran skin secretion. Methods Three peptide primary structures were determined by automated Edman degradation. These sequences were prepared by solid-phase synthesis and submitted to activity assays against gram-positive and gram-negative bacteria and against two fungal strains. The hemolytic properties of the peptides were also investigated in assays with rabbit blood erythrocytes. The conformational preferences of the peptides and their membrane interactions have been investigated by circular dichroism spectroscopy and liposome dye release assays. Results The amino acid compositions of three ocellatins were determined and the sequences exhibit 100% homology for the first 22 residues (ocellatin-LB1 sequence). Ocellatin-LB2 carries an extra Asn residue and ocellatin-F1 extra Asn-Lys-Leu residues at C-terminus. Ocellatin-F1 presents a stronger antibiotic potential and a broader spectrum of activities compared to the other peptides. The membrane interactions and pore formation capacities of the peptides correlate directly with their antimicrobial activities, i.e., ocellatin-F1 > ocellatin-LB1 > ocellatin-LB2. All peptides acquire high helical contents in membrane environments. However, ocellatin-F1 shows in average stronger helical propensities. Conclusions The obtained results indicate that the three extra amino acid residues at the ocellatin-F1 C-terminus play an important role in promoting stronger peptide-membrane interactions and antimicrobial properties. The extra Asn-23 residue present in ocellatin-LB2 sequence seems to decrease its antimicrobial potential and the strength of the peptide-membrane interactions. Electronic supplementary material The online version of this article (doi:10.1186/s40409-017-0094-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Karla A G Gusmão
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG Brazil.,Instituto de Engenharia, Ciência e Tecnologia, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Janaúba, MG Brazil
| | - Daniel M Dos Santos
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG Brazil
| | - Virgílio M Santos
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG Brazil
| | - María Esperanza Cortés
- Departamento de Odontologia Restauradora, Faculdade de Odontologia, Universidade Federal de Minas Gerais, Belo Horizonte, MG Brazil
| | - Pablo V M Reis
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG Brazil
| | - Vera L Santos
- Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG Brazil
| | - Dorila Piló-Veloso
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG Brazil
| | - Rodrigo M Verly
- Departamento de Química, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG Brazil
| | - Maria Elena de Lima
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG Brazil
| | - Jarbas M Resende
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG Brazil
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28
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Rabe M, Aisenbrey C, Pluhackova K, de Wert V, Boyle AL, Bruggeman DF, Kirsch SA, Böckmann RA, Kros A, Raap J, Bechinger B. A Coiled-Coil Peptide Shaping Lipid Bilayers upon Fusion. Biophys J 2016; 111:2162-2175. [PMID: 27851940 PMCID: PMC5113151 DOI: 10.1016/j.bpj.2016.10.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/08/2016] [Accepted: 10/06/2016] [Indexed: 12/19/2022] Open
Abstract
A system based on two designed peptides, namely the cationic peptide K, (KIAALKE)3, and its complementary anionic counterpart called peptide E, (EIAALEK)3, has been used as a minimal model for membrane fusion, inspired by SNARE proteins. Although the fact that docking of separate vesicle populations via the formation of a dimeric E/K coiled-coil complex can be rationalized, the reasons for the peptides promoting fusion of vesicles cannot be fully explained. Therefore it is of significant interest to determine how the peptides aid in overcoming energetic barriers during lipid rearrangements leading to fusion. In this study, investigations of the peptides' interactions with neutral PC/PE/cholesterol membranes by fluorescence spectroscopy show that tryptophan-labeled K∗ binds to the membrane (KK∗ ∼6.2 103 M-1), whereas E∗ remains fully water-solvated. 15N-NMR spectroscopy, depth-dependent fluorescence quenching, CD-spectroscopy experiments, and MD simulations indicate a helix orientation of K∗ parallel to the membrane surface. Solid-state 31P-NMR of oriented lipid membranes was used to study the impact of peptide incorporation on lipid headgroup alignment. The membrane-immersed K∗ is found to locally alter the bilayer curvature, accompanied by a change of headgroup orientation relative to the membrane normal and of the lipid composition in the vicinity of the bound peptide. The NMR results were supported by molecular dynamics simulations, which showed that K reorganizes the membrane composition in its vicinity, induces positive membrane curvature, and enhances the lipid tail protrusion probability. These effects are known to be fusion relevant. The combined results support the hypothesis for a twofold role of K in the mechanism of membrane fusion: 1) to bring opposing membranes into close proximity via coiled-coil formation and 2) to destabilize both membranes thereby promoting fusion.
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Affiliation(s)
- Martin Rabe
- Leiden Institute of Chemistry - Supramolecular and Biomaterials Chemistry, Leiden University, Leiden, the Netherlands.
| | | | - Kristyna Pluhackova
- Computational Biology, Department of Biology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Vincent de Wert
- Leiden Institute of Chemistry - Supramolecular and Biomaterials Chemistry, Leiden University, Leiden, the Netherlands
| | - Aimee L Boyle
- Leiden Institute of Chemistry - Supramolecular and Biomaterials Chemistry, Leiden University, Leiden, the Netherlands
| | - Didjay F Bruggeman
- Leiden Institute of Chemistry - Supramolecular and Biomaterials Chemistry, Leiden University, Leiden, the Netherlands
| | - Sonja A Kirsch
- Computational Biology, Department of Biology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Rainer A Böckmann
- Computational Biology, Department of Biology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Alexander Kros
- Leiden Institute of Chemistry - Supramolecular and Biomaterials Chemistry, Leiden University, Leiden, the Netherlands
| | - Jan Raap
- Leiden Institute of Chemistry - Supramolecular and Biomaterials Chemistry, Leiden University, Leiden, the Netherlands
| | - Burkhard Bechinger
- Université de Strasbourg/CNRS UMR7177, Institut de Chimie, Strasbourg, France.
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Dicke A, Gopinath T, Wang Y, Veglia G. Probing Residue-Specific Water-Protein Interactions in Oriented Lipid Membranes via Solid-State NMR Spectroscopy. J Phys Chem B 2016; 120:10959-10968. [PMID: 27704861 DOI: 10.1021/acs.jpcb.6b08282] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Water plays a central role in membrane protein folding and function. It not only catalyzes lipid membrane self-assembly but also affects the structural integrity and conformational dynamics of membrane proteins. Magic angle spinning (MAS) solid-state NMR (ssNMR) is the technique of choice for measuring water accessibility of membrane proteins, providing a measure for membrane protein topology and insertion within lipid bilayers. However, the sensitivity and resolution of membrane protein samples for MAS experiments are often dictated by hydration levels, which affect the structural dynamics of membrane proteins. Oriented-sample ssNMR (OS-ssNMR) is a complementary technique to determine both structure and topology of membrane proteins in liquid crystalline bilayers. Recent advancements in OS-ssNMR involve the use of oriented bicellar phases that have improved both sensitivity and resolution. Importantly, for bicelle formation and orientation, lipid bilayers must be well organized and hydrated, resulting in the protein's topology being similar to that found in native membranes. Under these conditions, the NMR resonances become relatively narrow, enabling a better separation of 1H-15N dipolar couplings and anisotropic 15N chemical shifts with separated local field (SLF) experiments. Here, we report a residue-specific water accessibility experiment for a small membrane protein, sarcolipin (SLN), embedded in oriented lipid bicelles as probed by new water-edited SLF (WE-SLF) experiments. We show that SLN's residues belonging to the juxtamembrane region are more exposed to the water-lipid interface than the corresponding membrane-embedded residues. The information that can be obtained from the WE-SLF experiments can be interpreted using a simple theoretical model based on spin-diffusion theory and offers a complete characterization of membrane proteins in realistic membrane bilayer systems.
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Affiliation(s)
- Alysha Dicke
- Department of Biochemistry, Molecular Biology, and Biophysics and ‡Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - T Gopinath
- Department of Biochemistry, Molecular Biology, and Biophysics and ‡Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Yingjie Wang
- Department of Biochemistry, Molecular Biology, and Biophysics and ‡Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology, and Biophysics and ‡Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455, United States
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30
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Malanovic N, Lohner K. Antimicrobial Peptides Targeting Gram-Positive Bacteria. Pharmaceuticals (Basel) 2016; 9:E59. [PMID: 27657092 PMCID: PMC5039512 DOI: 10.3390/ph9030059] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/07/2016] [Accepted: 09/13/2016] [Indexed: 01/01/2023] Open
Abstract
Antimicrobial peptides (AMPs) have remarkably different structures as well as biological activity profiles, whereupon most of these peptides are supposed to kill bacteria via membrane damage. In order to understand their molecular mechanism and target cell specificity for Gram-positive bacteria, it is essential to consider the architecture of their cell envelopes. Before AMPs can interact with the cytoplasmic membrane of Gram-positive bacteria, they have to traverse the cell wall composed of wall- and lipoteichoic acids and peptidoglycan. While interaction of AMPs with peptidoglycan might rather facilitate penetration, interaction with anionic teichoic acids may act as either a trap for AMPs or a ladder for a route to the cytoplasmic membrane. Interaction with the cytoplasmic membrane frequently leads to lipid segregation affecting membrane domain organization, which affects membrane permeability, inhibits cell division processes or leads to delocalization of essential peripheral membrane proteins. Further, precursors of cell wall components, especially the highly conserved lipid II, are directly targeted by AMPs. Thereby, the peptides do not inhibit peptidoglycan synthesis via binding to proteins like common antibiotics, but form a complex with the precursor molecule, which in addition can promote pore formation and membrane disruption. Thus, the multifaceted mode of actions will make AMPs superior to antibiotics that act only on one specific target.
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Affiliation(s)
- Nermina Malanovic
- Institute of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Austria.
| | - Karl Lohner
- Institute of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Austria.
- BioTechMed Graz, Humboldtstrasse 50/III, 8010 Graz, Austria.
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31
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Côté S, Binette V, Salnikov ES, Bechinger B, Mousseau N. Probing the Huntingtin 1-17 membrane anchor on a phospholipid bilayer by using all-atom simulations. Biophys J 2016; 108:1187-98. [PMID: 25762330 DOI: 10.1016/j.bpj.2015.02.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 01/18/2015] [Accepted: 02/02/2015] [Indexed: 12/12/2022] Open
Abstract
Mislocalization and aggregation of the huntingtin protein are related to Huntington's disease. Its first exon-more specifically the first 17 amino acids (Htt17)-is crucial for the physiological and pathological functions of huntingtin. It regulates huntingtin's activity through posttranslational modifications and serves as an anchor to membrane-containing organelles of the cell. Recently, structure and orientation of the Htt17 membrane anchor were determined using a combined solution and solid-state NMR approach. This prompted us to refine this model by investigating the dynamics and thermodynamics of this membrane anchor on a POPC bilayer using all-atom, explicit solvent molecular dynamics and Hamiltonian replica exchange. Our simulations are combined with various experimental measurements to generate a high-resolution atomistic model for the huntingtin Htt17 membrane anchor on a POPC bilayer. More precisely, we observe that the single α-helix structure is more stable in the phospholipid membrane than the NMR model obtained in the presence of dodecylphosphocholine detergent micelles. The resulting Htt17 monomer has its hydrophobic plane oriented parallel to the bilayer surface. Our results further unveil the key residues interacting with the membrane in terms of hydrogen bonds, salt-bridges, and nonpolar contributions. We also observe that Htt17 equilibrates at a well-defined insertion depth and that it perturbs the physical properties-order parameter, thickness, and area per lipid-of the bilayer in a manner that could favor its dimerization. Overall, our observations reinforce and refine the NMR measurements on the Htt17 membrane anchor segment of huntingtin that is of fundamental importance to its biological functions.
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Affiliation(s)
- Sébastien Côté
- Département de Physique and Groupe de Recherche sur les Protéines Membranaires, Université de Montréal, Montréal, Québec, Canada.
| | - Vincent Binette
- Département de Physique and Groupe de Recherche sur les Protéines Membranaires, Université de Montréal, Montréal, Québec, Canada
| | - Evgeniy S Salnikov
- Université de Strasbourg/Centre National de la Recherche Scientifique, UMR7177, Institut de Chimie, Strasbourg, France
| | - Burkhard Bechinger
- Université de Strasbourg/Centre National de la Recherche Scientifique, UMR7177, Institut de Chimie, Strasbourg, France
| | - Normand Mousseau
- Département de Physique and Groupe de Recherche sur les Protéines Membranaires, Université de Montréal, Montréal, Québec, Canada.
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32
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Fillion M, Auger M. Oriented samples: a tool for determining the membrane topology and the mechanism of action of cationic antimicrobial peptides by solid-state NMR. Biophys Rev 2015; 7:311-320. [PMID: 28510228 PMCID: PMC5425733 DOI: 10.1007/s12551-015-0167-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 02/05/2015] [Indexed: 01/12/2023] Open
Abstract
Overuse and misuse of antibiotics have led bacteria to acquire several mechanisms of resistance. In response to this, researchers have identified natural antimicrobial peptides as promising candidates to fight against multiresistant bacteria. However, their mode of action is still unclear, and a better understanding of the mode of action of these peptides is of primary importance to develop new peptides displaying high antibacterial activity and low hemolytic activity. One of the main features that defines the mechanism of action is the membrane topology of the peptide. Among the spectroscopic techniques, solid-state NMR is the technique of choice for determining the location of the peptide within the membrane. It can be achieved by performing experiments with oriented samples. In the literature, the two most common types of oriented samples are bicelles and phospholipids mechanically oriented between glass plates. The mode of perturbation of the membrane-active peptide can be studied by phosphorus-31 and deuterium NMR. On the other hand, several experiments such as nitrogen-15 and fluorine solid-state NMR, that require labeled peptides, can give valuable information on the membrane topology of the peptide. The combination of the latter techniques allows the determination of a precise topology, thus a better knowledge of the molecular determinants involved in the membrane interactions of antimicrobial peptides.
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Affiliation(s)
- Matthieu Fillion
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, G1V 0A6, Canada
| | - Michèle Auger
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, G1V 0A6, Canada.
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Zhu Y, Negmi A, Moran-Mirabal J. Multi-Stacked Supported Lipid Bilayer Micropatterning through Polymer Stencil Lift-Off. MEMBRANES 2015; 5:385-98. [PMID: 26343733 PMCID: PMC4584287 DOI: 10.3390/membranes5030385] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 08/25/2015] [Indexed: 01/07/2023]
Abstract
Complex multi-lamellar structures play a critical role in biological systems, where they are present as lamellar bodies, and as part of biological assemblies that control energy transduction processes. Multi-lamellar lipid layers not only provide interesting systems for fundamental research on membrane structure and bilayer-associated polypeptides, but can also serve as components in bioinspired materials or devices. Although the ability to pattern stacked lipid bilayers at the micron scale is of importance for these purposes, limited work has been done in developing such patterning techniques. Here, we present a simple and direct approach to pattern stacked supported lipid bilayers (SLBs) using polymer stencil lift-off and the electrostatic interactions between cationic and anionic lipids. Both homogeneous and phase-segregated stacked SLB patterns were produced, demonstrating that the stacked lipid bilayers retain lateral diffusivity. We demonstrate patterned SLB stacks of up to four bilayers, where fluorescence resonance energy transfer (FRET) and quenching was used to probe the interactions between lipid bilayers. Furthermore, the study of lipid phase behaviour showed that gel phase domains align between adjacent layers. The proposed stacked SLB pattern platform provides a robust model for studying lipid behaviour with a controlled number of bilayers, and an attractive means towards building functional bioinspired materials or devices.
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Affiliation(s)
- Yujie Zhu
- Department of Chemistry and Chemical Biology, McMaster Univerisity, 1280 Main Street West,Hamilton, Ontario L8S 4M8, Canada
| | - Ahmed Negmi
- Department of Chemistry and Chemical Biology, McMaster Univerisity, 1280 Main Street West,Hamilton, Ontario L8S 4M8, Canada
| | - Jose Moran-Mirabal
- Department of Chemistry and Chemical Biology, McMaster Univerisity, 1280 Main Street West,Hamilton, Ontario L8S 4M8, Canada.
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Membrane interactions of phylloseptin-1, -2, and -3 peptides by oriented solid-state NMR spectroscopy. Biophys J 2015; 107:901-11. [PMID: 25140425 DOI: 10.1016/j.bpj.2014.07.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 06/30/2014] [Accepted: 07/07/2014] [Indexed: 01/10/2023] Open
Abstract
Phylloseptin-1, -2, and -3 are three members of the family of linear cationic antimicrobial peptides found in tree frogs. The highly homologous peptides encompass 19 amino acids, and only differ in the amino acid composition and charge at the six most carboxy-terminal residues. Here, we investigated how such subtle changes are reflected in their membrane interactions and how these can be correlated to their biological activities. To this end, the three peptides were labeled with stable isotopes, reconstituted into oriented phospholipid bilayers, and their detailed topology determined by a combined approach using (2)H and (15)N solid-state NMR spectroscopy. Although phylloseptin-2 and -3 adopt perfect in-plane alignments, the tilt angle of phylloseptin-1 deviates by 8° probably to assure a more water exposed localization of the lysine-17 side chain. Furthermore, different azimuthal angles are observed, positioning the amphipathic helices of all three peptides with the charged residues well exposed to the water phase. Interestingly, our studies also reveal that two orientation-dependent (2)H quadrupolar splittings from methyl-deuterated alanines and one (15)N amide chemical shift are sufficient to unambiguously determine the topology of phylloseptin-1, where quadrupolar splittings close to the maximum impose the most stringent angular restraints. As a result of these studies, a strategy is proposed where the topology of a peptide structure can be determined accurately from the labeling with (15)N and (2)H isotopes of only a few amino acid residues.
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35
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Molecular dynamics methods to predict peptide locations in membranes: LAH4 as a stringent test case. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:581-92. [DOI: 10.1016/j.bbamem.2014.11.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/22/2014] [Accepted: 11/05/2014] [Indexed: 01/07/2023]
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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: 79] [Impact Index Per Article: 7.9] [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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37
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Shalom-Elazari H, Zazrin-Greenspon H, Shaked H, Chill JH. Global fold and backbone dynamics of the hepatitis C virus E2 glycoprotein transmembrane domain determined by NMR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2919-28. [PMID: 25109935 DOI: 10.1016/j.bbamem.2014.07.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 06/30/2014] [Accepted: 07/22/2014] [Indexed: 01/13/2023]
Abstract
E1 and E2 are two hepatitis C viral envelope glycoproteins that assemble into a heterodimer that is essential for membrane fusion and penetration into the target cell. Both extracellular and transmembrane (TM) glycoprotein domains contribute to this interaction, but study of TM-TM interactions has been limited because synthesis and structural characterization of these highly hydrophobic segments present significant challenges. In this NMR study, by successful expression and purification of the E2 transmembrane domain as a fusion construct we have determined the global fold and characterized backbone motions for this peptide incorporated in phospholipid micelles. Backbone resonance frequencies, relaxation rates and solvent exposure measurements concur in showing this domain to adopt a helical conformation, with two helical segments spanning residues 717-726 and 732-746 connected by an unstructured linker containing the charged residues D728 and R730 involved in E1 binding. Although this linker exhibits increased local motions on the ps timescale, the dominating contribution to its relaxation is the global tumbling motion with an estimated correlation time of 12.3ns. The positioning of the helix-linker-helix architecture within the mixed micelle was established by paramagnetic NMR spectroscopy and phospholipid-peptide cross relaxation measurements. These indicate that while the helices traverse the hydrophobic interior of the micelle, the linker lies closer to the micelle perimeter to accommodate its charged residues. These results lay the groundwork for structure determination of the E1/E2 complex and a molecular understanding of glycoprotein heterodimerization.
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Affiliation(s)
| | | | - Hadassa Shaked
- Department of Chemistry, Bar Ilan University, Ramat Gan 52900, Israel
| | - Jordan H Chill
- Department of Chemistry, Bar Ilan University, Ramat Gan 52900, Israel.
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38
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Pogozheva ID, Mosberg HI, Lomize AL. Life at the border: adaptation of proteins to anisotropic membrane environment. Protein Sci 2014; 23:1165-96. [PMID: 24947665 DOI: 10.1002/pro.2508] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 06/17/2014] [Accepted: 06/18/2014] [Indexed: 12/25/2022]
Abstract
This review discusses main features of transmembrane (TM) proteins which distinguish them from water-soluble proteins and allow their adaptation to the anisotropic membrane environment. We overview the structural limitations on membrane protein architecture, spatial arrangement of proteins in membranes and their intrinsic hydrophobic thickness, co-translational and post-translational folding and insertion into lipid bilayers, topogenesis, high propensity to form oligomers, and large-scale conformational transitions during membrane insertion and transport function. Special attention is paid to the polarity of TM protein surfaces described by profiles of dipolarity/polarizability and hydrogen-bonding capacity parameters that match polarity of the lipid environment. Analysis of distributions of Trp resides on surfaces of TM proteins from different biological membranes indicates that interfacial membrane regions with preferential accumulation of Trp indole rings correspond to the outer part of the lipid acyl chain region-between double bonds and carbonyl groups of lipids. These "midpolar" regions are not always symmetric in proteins from natural membranes. We also examined the hydrophobic effect that drives insertion of proteins into lipid bilayer and different free energy contributions to TM protein stability, including attractive van der Waals forces and hydrogen bonds, side-chain conformational entropy, the hydrophobic mismatch, membrane deformations, and specific protein-lipid binding.
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Affiliation(s)
- Irina D Pogozheva
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan, 48109-1065
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39
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Bertani P, Raya J, Bechinger B. 15N chemical shift referencing in solid state NMR. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2014; 61-62:15-18. [PMID: 24746715 DOI: 10.1016/j.ssnmr.2014.03.003] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 03/19/2014] [Accepted: 03/29/2014] [Indexed: 06/03/2023]
Abstract
Solid-state NMR spectroscopy has much advanced during the last decade and provides a multitude of data that can be used for high-resolution structure determination of biomolecules, polymers, inorganic compounds or macromolecules. In some cases the chemical shift referencing has become a limiting factor to the precision of the structure calculations and we have therefore evaluated a number of methods used in proton-decoupled (15)N solid-state NMR spectroscopy. For (13)C solid-state NMR spectroscopy adamantane is generally accepted as an external standard, but to calibrate the (15)N chemical shift scale several standards are in use. As a consequence the published chemical shift values exhibit considerable differences (up to 22 ppm). In this paper we report the (15)N chemical shift of several commonly used references compounds in order to allow for comparison and recalibration of published data and future work. We show that (15)NH4Cl in its powdered form (at 39.3 ppm with respect to liquid NH3) is a suitable external reference as it produces narrow lines when compared to other reference compounds and at the same time allows for the set-up of cross-polarization NMR experiments. The compound is suitable to calibrate magic angle spinning and static NMR experiments. Finally the temperature variation of (15)NH4Cl chemical shift is reported.
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Affiliation(s)
- Philippe Bertani
- Université de Strasbourg/CNRS, UMR7177, Institut de Chimie de Strasbourg, 1 rue Blaise Pascal, 67070 Strasbourg, France.
| | - Jésus Raya
- Université de Strasbourg/CNRS, UMR7177, Institut de Chimie de Strasbourg, 1 rue Blaise Pascal, 67070 Strasbourg, France
| | - Burkhard Bechinger
- Université de Strasbourg/CNRS, UMR7177, Institut de Chimie de Strasbourg, 1 rue Blaise Pascal, 67070 Strasbourg, France
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40
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Kemayo Koumkoua P, Aisenbrey C, Salnikov E, Rifi O, Bechinger B. On the design of supramolecular assemblies made of peptides and lipid bilayers. J Pept Sci 2014; 20:526-36. [PMID: 24909405 DOI: 10.1002/psc.2656] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 04/29/2014] [Accepted: 04/29/2014] [Indexed: 02/02/2023]
Abstract
Peptides confer interesting properties to materials, supramolecular assemblies and to lipid membranes and are used in analytical devices or within delivery vehicles. Their relative ease of production combined with a high degree of versatility make them attractive candidates to design new such products. Here, we review and demonstrate how CD- and solid-state NMR spectroscopic approaches can be used to follow the reconstitution of peptides into membranes and to describe some of their fundamental characteristics. Whereas CD spectroscopy is used to monitor secondary structure in different solvent systems and thereby aggregation properties of the highly hydrophobic domain of p24, a protein involved in vesicle trafficking, solid-state NMR spectroscopy was used to deduce structural information and the membrane topology of a variety of peptide sequences found in nature or designed. (15)N chemical shift solid-state NMR spectroscopy indicates that the hydrophobic domain of p24 as well as a designed sequence of 19 hydrophobic amino acid residues adopt transmembrane alignments in phosphatidylcholine membranes. In contrast, the amphipathic antimicrobial peptide magainin 2 and the designed sequence LK15 align parallel to the bilayer surface. Additional angular information is obtained from deuterium solid-state NMR spectra of peptide sites labelled with (2)H3-alanine, whereas (31)P and (2)H solid-state NMR spectra of the lipids furnish valuable information on the macroscopic order and phase properties of the lipid matrix. Using these approaches, peptides and reconstitution protocols can be elaborated in a rational manner, and the analysis of a great number of peptide sequences is reviewed. Finally, a number of polypeptides with membrane topologies that are sensitive to a variety of environmental conditions such as pH, lipid composition and peptide-to-lipid ratio will be presented.
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Affiliation(s)
- Patricia Kemayo Koumkoua
- Université de Strasbourg / CNRS, UMR7177, Institut de Chimie, 1, rue Blaise Pascal, 67070, Strasbourg, France
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41
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Middleton DA, Madine J, Castelletto V, Hamley IW. Insights into the molecular architecture of a peptide nanotube using FTIR and solid-state NMR spectroscopic measurements on an aligned sample. Angew Chem Int Ed Engl 2013; 52:10537-40. [PMID: 23955926 PMCID: PMC4672711 DOI: 10.1002/anie.201301960] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Indexed: 11/05/2022]
Abstract
Queuing up: Molecular orientation within macroscopically aligned nanotubes of the peptide AAAAAAK can be studied by solid-state NMR and IR spectroscopy. Line shape analysis of the NMR spectra indicates that the peptide N-H bonds are tilted 65-70° relative to the nanotube long axis. Re-evaluation of earlier X-ray fiber diffraction data suggests that the peptide molecules are hydrogen-bonded in a helical arrangement along the nanotube axis.
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Affiliation(s)
- David A Middleton
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB (UK).
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42
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Peptide-lipid interactions: experiments and applications. Int J Mol Sci 2013; 14:18758-89. [PMID: 24036440 PMCID: PMC3794806 DOI: 10.3390/ijms140918758] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 08/27/2013] [Accepted: 08/28/2013] [Indexed: 02/06/2023] Open
Abstract
The interactions between peptides and lipids are of fundamental importance in the functioning of numerous membrane-mediated cellular processes including antimicrobial peptide action, hormone-receptor interactions, drug bioavailability across the blood-brain barrier and viral fusion processes. Moreover, a major goal of modern biotechnology is obtaining new potent pharmaceutical agents whose biological action is dependent on the binding of peptides to lipid-bilayers. Several issues need to be addressed such as secondary structure, orientation, oligomerization and localization inside the membrane. At the same time, the structural effects which the peptides cause on the lipid bilayer are important for the interactions and need to be elucidated. The structural characterization of membrane active peptides in membranes is a harsh experimental challenge. It is in fact accepted that no single experimental technique can give a complete structural picture of the interaction, but rather a combination of different techniques is necessary.
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43
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Middleton DA, Madine J, Castelletto V, Hamley IW. Insights into the Molecular Architecture of a Peptide Nanotube Using FTIR and Solid-State NMR Spectroscopic Measurements on an Aligned Sample. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201301960] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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44
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Xia Y, Peng L. Photoactivatable Lipid Probes for Studying Biomembranes by Photoaffinity Labeling. Chem Rev 2013; 113:7880-929. [DOI: 10.1021/cr300419p] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Yi Xia
- Aix-Marseille Université, Centre Interdisciplinaire de Nanoscience de Marseille, CNRS UMR 7325, Campus de Luminy, 13288 Marseille, France
| | - Ling Peng
- Aix-Marseille Université, Centre Interdisciplinaire de Nanoscience de Marseille, CNRS UMR 7325, Campus de Luminy, 13288 Marseille, France
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45
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Michalek M, Salnikov E, Bechinger B. Structure and topology of the huntingtin 1-17 membrane anchor by a combined solution and solid-state NMR approach. Biophys J 2013; 105:699-710. [PMID: 23931318 PMCID: PMC3736738 DOI: 10.1016/j.bpj.2013.06.030] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 06/07/2013] [Accepted: 06/17/2013] [Indexed: 10/26/2022] Open
Abstract
The very amino-terminal domain of the huntingtin protein is directly located upstream of the protein's polyglutamine tract, plays a decisive role in several important properties of this large protein and in the development of Huntington's disease. This huntingtin 1-17 domain is on the one hand known to markedly increase polyglutamine aggregation rates and on the other hand has been shown to be involved in cellular membrane interactions. Here, we determined the high-resolution structure of huntingtin 1-17 in dodecyl phosphocholine micelles and the topology of its helical domain in oriented phosphatidylcholine bilayers. Using two-dimensional solution NMR spectroscopy the low-energy conformations of the polypeptide were identified in the presence of dodecyl phosphocholine detergent micelles. In a next step a set of four solid-state NMR angular restraints was obtained from huntingtin 1-17 labeled with (15)N and (2)H at selected sites. Of the micellar ensemble of helical conformations only a limited set agrees in quantitative detail with the solid-state angular restraints of huntingtin 1-17 obtained in supported planar lipid bilayers. Thereby, the solid-state NMR data were used to further refine the domain structure in phospholipid bilayers. At the same time its membrane topology was determined and different motional regimes of this membrane-associated domain were explored. The pronounced structural transitions of huntingtin 1-17 upon membrane-association result in a α-helical conformation from K6 to F17, i.e., up to the very start of the polyglutamine tract. This amphipathic helix is aligned nearly parallel to the membrane surface (tilt angle ∼77°) and is characterized by a hydrophobic ridge on one side and an alternation of cationic and anionic residues that run along the hydrophilic face of the helix. This arrangement facilitates electrostatic interactions between huntingtin 1-17 domains and possibly with the proximal polyglutamine tract.
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Affiliation(s)
| | | | - Burkhard Bechinger
- Université de Strasbourg/CNRS, UMR7177, Institut de Chimie, Strasbourg, France
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46
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Shaghaghi H, Ebrahimi HP, Bahrami Panah N, Tafazzoli M. Layer selection effect on solid state 13C and 15N chemical shifts calculation using ONIOM approach. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2013; 51-52:31-36. [PMID: 23414630 DOI: 10.1016/j.ssnmr.2013.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 01/15/2013] [Accepted: 01/21/2013] [Indexed: 06/01/2023]
Abstract
Solid state (13)C and (15)N chemical shifts of uracil and imidazole have been calculated using a 2-layer ONIOM approach at 32 levels of theory. The effect of electron correlation between two layers has been investigated by choosing two different kinds of layer selection. Factorial design has been applied as a multivariate technique to analyze the effect of wave function and layer selection on solid state (13)C and (15)N chemical shifts calculations. PBEPBE/6-311+G(d,p) was recommended as an optimally selected level of theory for high layer in both models. It is illustrated that considering the electron correlation of two layers of ONIOM models is important factor to calculate solid state (15)N chemical shifts. The agreement between the calculated and experimental values of solid state (13)C and (15)N chemical shifts using ONIOM (PBEPBE/6-311+G(d,p):AM1) for both uracil and imidazole confirmed the reliability of the selected wave functions and layer selection.
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Affiliation(s)
- Hoora Shaghaghi
- Department of Chemistry, Sharif University of Technology, Tehran, Iran
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47
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Song C, Weichbrodt C, Salnikov ES, Dynowski M, Forsberg BO, Bechinger B, Steinem C, de Groot BL, Zachariae U, Zeth K. Crystal structure and functional mechanism of a human antimicrobial membrane channel. Proc Natl Acad Sci U S A 2013; 110:4586-91. [PMID: 23426625 PMCID: PMC3607029 DOI: 10.1073/pnas.1214739110] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Multicellular organisms fight bacterial and fungal infections by producing peptide-derived broad-spectrum antibiotics. These host-defense peptides compromise the integrity of microbial cell membranes and thus evade pathways by which bacteria develop rapid antibiotic resistance. Although more than 1,700 host-defense peptides have been identified, the structural and mechanistic basis of their action remains speculative. This impedes the desired rational development of these agents into next-generation antibiotics. We present the X-ray crystal structure as well as solid-state NMR spectroscopy, electrophysiology, and MD simulations of human dermcidin in membranes that reveal the antibiotic mechanism of this major human antimicrobial, found to suppress Staphylococcus aureus growth on the epidermal surface. Dermcidin forms an architecture of high-conductance transmembrane channels, composed of zinc-connected trimers of antiparallel helix pairs. Molecular dynamics simulations elucidate the unusual membrane permeation pathway for ions and show adjustment of the pore to various membranes. Our study unravels the comprehensive mechanism for the membrane-disruptive action of this mammalian host-defense peptide at atomistic level. The results may form a foundation for the structure-based design of peptide antibiotics.
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Affiliation(s)
- Chen Song
- Computational Biomolecular Dynamics Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Conrad Weichbrodt
- Institute for Organic and Biomolecular Chemistry, Georg August University Göttingen, 37077 Göttingen, Germany
| | - Evgeniy S. Salnikov
- Membrane Biophysics and NMR, Chemistry Institute, Unité Mixte de Recherche 7177, University of Strasbourg and Centre National de la Recherche Scientifique, 67000 Strasbourg, France
| | - Marek Dynowski
- Research and Development, Computing Centre, Freiburg University, 79104 Freiburg, Germany
- Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Björn O. Forsberg
- Computational Biomolecular Dynamics Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Burkhard Bechinger
- Membrane Biophysics and NMR, Chemistry Institute, Unité Mixte de Recherche 7177, University of Strasbourg and Centre National de la Recherche Scientifique, 67000 Strasbourg, France
| | - Claudia Steinem
- Institute for Organic and Biomolecular Chemistry, Georg August University Göttingen, 37077 Göttingen, Germany
| | - Bert L. de Groot
- Computational Biomolecular Dynamics Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Ulrich Zachariae
- Scottish Universities' Physics Alliance, School of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom; and
| | - Kornelius Zeth
- Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
- Unidad de Biofisica, University of Basque Country and Spanish Science Research Council, 48940 Leioa, Vizcaya, Spain
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48
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Michalek M, Salnikov ES, Werten S, Bechinger B. Membrane interactions of the amphipathic amino terminus of huntingtin. Biochemistry 2013; 52:847-58. [PMID: 23305455 DOI: 10.1021/bi301325q] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The amino-terminal domain of huntingtin (Htt17), located immediately upstream of the decisive polyglutamine tract, strongly influences important properties of this large protein and thereby the development of Huntington's disease. Htt17 markedly increases polyglutamine aggregation rates and the level of huntingtin's interactions with biological membranes. Htt17 adopts a largely helical conformation in the presence of membranes, and this structural transition was used to quantitatively analyze membrane association as a function of lipid composition. The apparent membrane partitioning constants increased in the presence of anionic lipids but decreased with increasing amounts of cholesterol. When membrane permeabilization was tested, a pronounced dye release was observed from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) vesicles and 75:25 (molar ratio) POPC/1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-l-serine vesicles but not across bilayers that better mimic cellular membranes. Solid-state nuclear magnetic resonance structural investigations indicated that the Htt17 α-helix adopts an alignment parallel to the membrane surface, and that the tilt angle (∼75°) was nearly constant in all of the membranes that were investigated. Furthermore, the addition of Htt17 resulted in a decrease in the lipid order parameter in all of the membranes that were investigated. The lipid interactions of Htt17 have pivotal implications for membrane anchoring and functional properties of huntingtin and concomitantly the development of the disease.
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Affiliation(s)
- Matthias Michalek
- Membrane Biophysics and NMR Chemistry Institute UMR7177, University of Strasbourg/CNRS International Center for Frontier Research in Chemistry, 1 rue Blaise Pascal, Strasbourg, France
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49
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Zhang Y, Romsted LS, Zhuang L, de Jong S. Simultaneous determination of interfacial molarities of amide bonds, carboxylate groups, and water by chemical trapping in micelles of amphiphiles containing peptide bond models. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:534-544. [PMID: 23237147 DOI: 10.1021/la3040819] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Chemical trapping is a powerful approach for obtaining experimental estimates of interfacial molarities of weakly basic nucleophiles in the interfacial regions of amphiphile aggregates. Here, we demonstrate that the chemical probe 4-hexadecyl-2,6-dimethylbenzenediazonium ion (16-ArN(2)(+)) reacts competitively with interfacial water, with the amide carbonyl followed by cleavage of the headgroups from the tail at the amide oxygen, and with the terminal carboxylate groups in micelles of two N-acyl amino-acid amphiphiles, sodium N-lauroylsarcosinate (SLS) and sodium N-lauroylglycinate (SLG), simple peptide bond model amphiphiles. Interfacial molarities (in moles per liter of interfacial volume) of these three groups were obtained from product yields, assuming that selectivity toward a particular nucleophile compared to water is the same in an aqueous reference solution and in the interfacial region. Interfacial carboxylate group molarities are ~1.5 M in both SLS and SLG micelles, but the concentration of the amide carbonyl for SLS micelles is ~4.6-5 times less (ca. 0.7 M) than that of SLG micelles (~3 M). The proton on the secondary N of SLG helps solubilize the amide bond in the aqueous region, but the methyl on the tertiary N of SLS helps solubilize the amide bond in the micellar core, reducing its reaction with 16-ArN(2)(+). Application of chemical trapping to proteins in membrane mimetic interfaces should provide insight into the topology of the protein within the interface because trapping of the amide carbonyl and cleavage at the C-N bond occurs only within the interface, and fragment characterization marks those peptide bonds located within the interface.
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Affiliation(s)
- Yongliang Zhang
- Department of Chemistry and Chemical Biology, Wright-Rieman Laboratories, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08903, United States
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50
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Aisenbrey C, Michalek M, Salnikov ES, Bechinger B. Solid-state NMR approaches to study protein structure and protein-lipid interactions. Methods Mol Biol 2013; 974:357-387. [PMID: 23404284 DOI: 10.1007/978-1-62703-275-9_16] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Solid-state NMR spectroscopy has been developed for the investigation of membrane-associated polypeptides and remains one of the few techniques to reveal high-resolution structural information in liquid-disordered phospholipid bilayers. In particular, oriented samples have been used to investigate the structure, dynamics, and topology of membrane polypeptides. Much of the previous solid-state NMR work has been developed and performed on peptides, but the technique is constantly expanding towards larger membrane proteins. Here, a number of protocols are presented describing among other the reconstitution of membrane proteins into oriented membranes, monitoring membrane alignment by (31)P solid-state NMR spectroscopy; investigations of the protein by one- and two-dimensional (15)N solid-state NMR; and measurements of the lipid order parameters using (2)H solid-state NMR spectroscopy. Using such methods solid-state NMR spectroscopy has revealed a detailed picture of the ensemble of both lipids and proteins and their mutual interdependence in the bilayer environment.
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