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Castro TG, Melle-Franco M, Sousa CEA, Cavaco-Paulo A, Marcos JC. Non-Canonical Amino Acids as Building Blocks for Peptidomimetics: Structure, Function, and Applications. Biomolecules 2023; 13:981. [PMID: 37371561 PMCID: PMC10296201 DOI: 10.3390/biom13060981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/05/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
This review provides a fresh overview of non-canonical amino acids and their applications in the design of peptidomimetics. Non-canonical amino acids appear widely distributed in nature and are known to enhance the stability of specific secondary structures and/or biological function. Contrary to the ubiquitous DNA-encoded amino acids, the structure and function of these residues are not fully understood. Here, results from experimental and molecular modelling approaches are gathered to classify several classes of non-canonical amino acids according to their ability to induce specific secondary structures yielding different biological functions and improved stability. Regarding side-chain modifications, symmetrical and asymmetrical α,α-dialkyl glycines, Cα to Cα cyclized amino acids, proline analogues, β-substituted amino acids, and α,β-dehydro amino acids are some of the non-canonical representatives addressed. Backbone modifications were also examined, especially those that result in retro-inverso peptidomimetics and depsipeptides. All this knowledge has an important application in the field of peptidomimetics, which is in continuous progress and promises to deliver new biologically active molecules and new materials in the near future.
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Affiliation(s)
- Tarsila G. Castro
- CEB—Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; (T.G.C.); (A.C.-P.)
- LABBELS—Associate Laboratory, Braga/Guimarães, Portugal
| | - Manuel Melle-Franco
- CICECO—Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal;
| | - Cristina E. A. Sousa
- BioMark Sensor Research—School of Engineering of the Polytechnic Institute of Porto, 4249-015 Porto, Portugal;
| | - Artur Cavaco-Paulo
- CEB—Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; (T.G.C.); (A.C.-P.)
- LABBELS—Associate Laboratory, Braga/Guimarães, Portugal
| | - João C. Marcos
- Centre of Chemistry, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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2
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Tyagi C, Marik T, Szekeres A, Vágvölgyi C, Kredics L, Ötvös F. Tripleurin XIIc: Peptide Folding Dynamics in Aqueous and Hydrophobic Environment Mimic Using Accelerated Molecular Dynamics. Molecules 2019; 24:E358. [PMID: 30669493 PMCID: PMC6359335 DOI: 10.3390/molecules24020358] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 01/14/2019] [Accepted: 01/18/2019] [Indexed: 01/11/2023] Open
Abstract
Peptaibols are a special class of fungal peptides with an acetylated N-terminus and a C-terminal 1,2-amino alcohol along with non-standard amino acid residues. New peptaibols named tripleurins were recently identified from a strain of the filamentous fungal species Trichoderma pleuroti, which is known to cause green mould disease on cultivated oyster mushrooms. To understand the mode of action of these peptaibols, the three-dimensional structure of tripleurin (TPN) XIIc, an 18-mer peptide, was elucidated using an enhanced sampling method, accelerated MD, in water and chloroform solvents. Non-standard residues were parameterized by the Restrained Electrostatic Potential (RESP) charge fitting method. The dihedral distribution indicated towards a right-handed helical formation for TPN XIIc in both solvents. Dihedral angle based principal component analysis revealed a propensity for a slightly bent, helical folded conformation in water solvent, while two distinct conformations were revealed in chloroform: One that folds into highly bent helical structure that resembles a beta-hairpin and another with an almost straight peptide backbone appearing as a rare energy barrier crossing event. The hinge-like movement of the terminals was also observed and is speculated to be functionally relevant. The convergence and efficient sampling is addressed using Cartesian PCA and Kullback-Leibler divergence methods.
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Affiliation(s)
- Chetna Tyagi
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
- Doctoral School of Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
| | - Tamás Marik
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
| | - András Szekeres
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
| | - Csaba Vágvölgyi
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
| | - László Kredics
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
| | - Ferenc Ötvös
- Institute of Biochemistry, Biological Research Centre, Szeged, Temesvári krt. 62, H-6726 Szeged, Hungary.
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3
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Castro TG, Micaêlo NM, Melle-Franco M. Modeling the secondary structures of the peptaibols antiamoebin I and zervamicin II modified with D-amino acids and proline analogues. J Mol Model 2017; 23:313. [DOI: 10.1007/s00894-017-3479-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 09/19/2017] [Indexed: 11/29/2022]
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4
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Morita D, Sawada H, Ogawa W, Miyachi H, Kuroda T. Riccardin C derivatives cause cell leakage in Staphylococcus aureus. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:2057-64. [PMID: 26003535 DOI: 10.1016/j.bbamem.2015.05.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 05/11/2015] [Accepted: 05/13/2015] [Indexed: 10/23/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a major problem in clinical settings, and because it is resistant to most antimicrobial agents, MRSA infections are difficult to treat. We previously reported that synthetic macrocyclic bis(bibenzyl) derivatives, which were originally discovered in liverworts, had anti-MRSA activity. However, the action mechanism responsible was unclear. In the present study, we elucidated the action mechanism of macrocyclic bis(bibenzyl) RC-112 and its partial structure, IDPO-9 (2-phenoxyphenol). Survival experiments demonstrated that RC-112 had a bactericidal effect on MRSA, whereas IDPO-9 had bacteriostatic effects. IDPO-9-resistant mutants exhibited cross-resistance to triclosan, but not to RC-112. The mutation was identified in the fabI, enoyl-acyl carrier protein reductase gene, a target of triclosan. We have not yet isolated the RC-112-resistant mutant. On the other hand, the addition of RC-112, unlike IDPO-9, caused the inflow of ethidium and propidium into S. aureus cells. RC-112-dependent ethidium outflow was observed in ethidium-loaded S. aureus cells. Transmission electron microscopy also revealed that S. aureus cells treated with RC-112 had intracellular lamellar mesosomal-like structures. Intracellular Na+ and K+ concentrations were significantly changed by the RC-112 treatment. These results indicated that RC-112 increased membrane permeability to ethidium, propidium, Na+, and K+, and also that the action mechanism of IDPO-9 was different from those of the other compounds.
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Affiliation(s)
- Daichi Morita
- Department of Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
| | - Hiromi Sawada
- Medicinal and Bioorganic Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
| | - Wakano Ogawa
- Department of Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
| | - Hiroyuki Miyachi
- Medicinal and Bioorganic Chemistry, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
| | - Teruo Kuroda
- Department of Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
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5
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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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Shenkarev ZO, Paramonov AS, Lyukmanova EN, Gizatullina AK, Zhuravleva AV, Tagaev AA, Yakimenko ZA, Telezhinskaya IN, Kirpichnikov MP, Ovchinnikova TV, Arseniev AS. Peptaibol Antiamoebin I: Spatial Structure, Backbone Dynamics, Interaction with Bicelles and Lipid-Protein Nanodiscs, and Pore Formation in Context of Barrel-Stave Model. Chem Biodivers 2013; 10:838-63. [DOI: 10.1002/cbdv.201200421] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Indexed: 11/12/2022]
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7
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Gessmann R, Axford D, Evans G, Brückner H, Petratos K. The crystal structure of samarosporin I at atomic resolution. J Pept Sci 2012; 18:678-84. [PMID: 23019149 DOI: 10.1002/psc.2454] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 08/24/2012] [Accepted: 08/27/2012] [Indexed: 01/24/2023]
Abstract
The atomic resolution structures of samarosporin I have been determined at 100 and 293 K. This is the first crystal structure of a natural 15-residue peptaibol. The amino acid sequence in samarosporin I is identical to emerimicin IV and stilbellin I. Samarosporin is a peptide antibiotic produced by the ascomycetous fungus Samarospora rostrup and belongs to peptaibol subfamily 2. The structures at both temperatures are very similar to each other adopting mainly a 3₁₀-helical and a minor fraction of α-helical conformation. The helices are significantly bent and packed in an antiparallel fashion in the centered monoclinic lattice leaving among them an approximately 10-Å channel extending along the crystallographic twofold axis. Only two ordered water molecules per peptide molecule were located in the channel. Comparisons have been carried out with crystal structures of subfamily 2 16-residue peptaibols antiamoebin and cephaibols. The repercussion of the structural analysis of samarosporin on membrane function is discussed.
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Ahmed MAM, De Avila M, Polverini E, Bessonov K, Bamm VV, Harauz G. Solution nuclear magnetic resonance structure and molecular dynamics simulations of a murine 18.5 kDa myelin basic protein segment (S72-S107) in association with dodecylphosphocholine micelles. Biochemistry 2012; 51:7475-87. [PMID: 22947219 DOI: 10.1021/bi300998x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The 18.5 kDa myelin basic protein (MBP), the most abundant splice isoform in adult mammalian myelin, is a multifunctional, intrinsically disordered protein involved in the development and compaction of the myelin sheath in the central nervous system. A highly conserved central segment comprises a membrane-anchoring amphipathic α-helix followed by a proline-rich segment that represents a ligand for SH3 domain-containing proteins. Here, we have determined using solution nuclear magnetic resonance spectroscopy the structure of a 36-residue peptide fragment of MBP (murine 18.5 kDa residues S72-S107, denoted the α2-peptide) comprising these two structural motifs, in association with dodecylphosphocholine (DPC) micelles. The structure was calculated using CS-ROSETTA (version 1.01) because the nuclear Overhauser effect restraints were insufficient for this protein. The experimental studies were complemented by molecular dynamics simulations of a corresponding 24-residue peptide fragment (murine 18.5 kDa residues E80-G103, denoted the MD-peptide), also in association with a DPC micelle in silico. The experimental and theoretical results agreed well with one another, despite the independence of the starting structures and analyses, both showing membrane association via the amphipathic α-helix, and a sharp bend in the vicinity of the Pro93 residue (murine 18.5 kDa sequence numbering). Overall, the conformations elucidated here show how the SH3 ligand is presented to the cytoplasm for interaction with SH3 domain-containing proteins such as Fyn and contribute to our understanding of myelin architecture at the molecular level.
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Affiliation(s)
- Mumdooh A M Ahmed
- Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada
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Teixeira V, Feio MJ, Bastos M. Role of lipids in the interaction of antimicrobial peptides with membranes. Prog Lipid Res 2012; 51:149-77. [DOI: 10.1016/j.plipres.2011.12.005] [Citation(s) in RCA: 461] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Galdiero S, Russo L, Falanga A, Cantisani M, Vitiello M, Fattorusso R, Malgieri G, Galdiero M, Isernia C. Structure and orientation of the gH625-644 membrane interacting region of herpes simplex virus type 1 in a membrane mimetic system. Biochemistry 2012; 51:3121-8. [PMID: 22397737 DOI: 10.1021/bi201589m] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Glycoprotein H (gH) of the herpes simplex virus type 1 is involved in the complex mechanism of membrane fusion of the viral envelope with host cells. The virus requires four glycoproteins (gB, gD, gH, gL) to execute fusion and the role played by gH remains mysterious. Mutational studies have revealed several regions of gH ectodomain required for fusion and identified the segment from amino acid 625 to 644 as the most fusogenic region. Here, we studied the behavior in a membrane-mimicking DPC micellar environment of a peptide encompassing this region (gH625-644) and determined its NMR solution structure and its orientation within the micelles.
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Affiliation(s)
- Stefania Galdiero
- Department of Biological Sciences, Division of Biostructures, University of Naples Federico II, Napoli, Italy
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11
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Structure and alignment of the membrane-associated peptaibols ampullosporin A and alamethicin by oriented 15N and 31P solid-state NMR spectroscopy. Biophys J 2010; 96:86-100. [PMID: 18835909 DOI: 10.1529/biophysj.108.136242] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Accepted: 09/03/2008] [Indexed: 11/18/2022] Open
Abstract
Ampullosporin A and alamethicin are two members of the peptaibol family of antimicrobial peptides. These compounds are produced by fungi and are characterized by a high content of hydrophobic amino acids, and in particular the alpha-tetrasubstituted amino acid residue ?-aminoisobutyric acid. Here ampullosporin A and alamethicin were uniformly labeled with (15)N, purified and reconstituted into oriented phophatidylcholine lipid bilayers and investigated by proton-decoupled (15)N and (31)P solid-state NMR spectroscopy. Whereas alamethicin (20 amino acid residues) adopts transmembrane alignments in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) or 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membranes the much shorter ampullosporin A (15 residues) exhibits comparable configurations only in thin membranes. In contrast the latter compound is oriented parallel to the membrane surface in 1,2-dimyristoleoyl-sn-glycero-3-phosphocholine and POPC bilayers indicating that hydrophobic mismatch has a decisive effect on the membrane topology of these peptides. Two-dimensional (15)N chemical shift -(1)H-(15)N dipolar coupling solid-state NMR correlation spectroscopy suggests that in their transmembrane configuration both peptides adopt mixed alpha-/3(10)-helical structures which can be explained by the restraints imposed by the membranes and the bulky alpha-aminoisobutyric acid residues. The (15)N solid-state NMR spectra also provide detailed information on the helical tilt angles. The results are discussed with regard to the antimicrobial activities of the peptides.
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12
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Wang CK, Colgrave ML, Ireland DC, Kaas Q, Craik DJ. Despite a conserved cystine knot motif, different cyclotides have different membrane binding modes. Biophys J 2009; 97:1471-81. [PMID: 19720036 DOI: 10.1016/j.bpj.2009.06.032] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Revised: 06/03/2009] [Accepted: 06/10/2009] [Indexed: 11/19/2022] Open
Abstract
Cyclotides are cyclic proteins produced by plants for defense against pests. Because of their remarkable stability and diverse bioactivities, they have a range of potential therapeutic applications. The bioactivities of cyclotides are believed to be mediated through membrane interactions. To determine the structural basis for the biological activity of the two major subfamilies of cyclotides, we determined the conformation and orientation of kalata B2 (kB2), a Möbius cyclotide, and cycloviolacin O2 (cO2), a bracelet cyclotide, bound to dodecylphosphocholine micelles, using NMR spectroscopy in the presence and absence of 5- and 16-doxylstearate relaxation probes. Analysis of binding curves using the Langmuir isotherm indicated that cO2 and kB2 have association constants of 7.0 x 10(3) M(-1) and 6.0 x 10(3) M(-1), respectively, consistent with the notion that they are bound near the surface, rather than buried deeply within the micelle. This suggestion is supported by the selective broadening of micelle-bound cyclotide NMR signals upon addition of paramagnetic Mn ions. The cyclotides from the different subfamilies exhibited clearly different binding orientations at the micelle surface. Structural analysis of cO2 confirmed that the main element of the secondary structure is a beta-hairpin centered in loop 5. A small helical turn is present in loop 3. Analysis of the surface profile of cO2 shows that a hydrophobic patch stretches over loops 2 and 3, in contrast to the hydrophobic patch of kB2, which predominantly involves loops 2 and 5. The different location of the hydrophobic patches in the two cyclotides explains their different binding orientations and provides an insight into the biological activities of cyclotides.
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Affiliation(s)
- Conan K Wang
- University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland, Australia
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13
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Levtsova OV, Antonov MY, Shaitan AK, Orshanskii IA, Nikolaev IN, Shaitan KV. Molecular dynamics of zervamicin II and its analogs in water and methanol. Biophysics (Nagoya-shi) 2009. [DOI: 10.1134/s000635090904006x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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14
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Langelaan DN, Rainey JK. Headgroup-dependent membrane catalysis of apelin-receptor interactions is likely. J Phys Chem B 2009; 113:10465-71. [PMID: 19708686 PMCID: PMC2736645 DOI: 10.1021/jp904562q] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 06/11/2009] [Indexed: 12/18/2022]
Abstract
Apelin is the peptidic ligand for the G-protein-coupled receptor APJ. The apelin-APJ system is important in cardiovascular regulation, fluid homeostasis, and angiogenesis, among other roles. In this study, we investigate interactions between apelin and membrane-mimetic micelles of the detergents sodium dodecyl sulfate (SDS), dodecylphosphocholine (DPC), and 1-palmitoyl-2-hydroxy-sn-glycero-3-[phospho-rac-(1-glycerol)] (LPPG). Far-ultraviolet circular dichroism spectropolarimetry and diffusion-ordered spectroscopy indicate that apelin peptides bind to micelles of the anionic detergents SDS and LPPG much more favorably than to zwitterionic DPC micelles. Nuclear magnetic resonance spectroscopy allowed full characterization of the interactions of apelin-17 with SDS micelles. Titration with paramagnetic agents and structural determination of apelin-17 in SDS indicate that R6-K12 is highly structured, with R6-L9 directly interacting with headgroups of the micelle. Type I beta-turns are initiated between R6 and L9, and a well-defined type IV beta-turn is initiated at S10. Furthermore, binding of apelin-17 to SDS micelles causes structuring of M15-F17, with no evidence for direct binding of this region to the micelles. These results are placed into the context of the membrane catalysis hypothesis for peptide-receptor binding, and a hypothetical mechanism of APJ binding and activation by apelin is advanced.
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Affiliation(s)
| | - Jan K. Rainey
- To whom correspondence should be addressed. Phone: (902) 494-4632. Fax: (902) 494-1355. E-mail:
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Wang CK, Hu SH, Martin JL, Sjögren T, Hajdu J, Bohlin L, Claeson P, Göransson U, Rosengren KJ, Tang J, Tan NH, Craik DJ. Combined X-ray and NMR analysis of the stability of the cyclotide cystine knot fold that underpins its insecticidal activity and potential use as a drug scaffold. J Biol Chem 2009; 284:10672-83. [PMID: 19211551 DOI: 10.1074/jbc.m900021200] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cyclotides are a family of plant defense proteins that are highly resistant to adverse chemical, thermal, and enzymatic treatment. Here, we present the first crystal structure of a cyclotide, varv F, from the European field pansy, Viola arvensis, determined at a resolution of 1.8 A. The solution state NMR structure was also determined and, combined with measurements of biophysical parameters for several cyclotides, provided an insight into the structural features that account for the remarkable stability of the cyclotide family. The x-ray data confirm the cystine knot topology and the circular backbone, and delineate a conserved network of hydrogen bonds that contribute to the stability of the cyclotide fold. The structural role of a highly conserved Glu residue that has been shown to regulate cyclotide function was also determined, verifying its involvement in a stabilizing hydrogen bond network. We also demonstrate that varv F binds to dodecylphosphocholine micelles, defining the binding orientation and showing that its structure remains unchanged upon binding, further demonstrating that the cyclotide fold is rigid. This study provides a biological insight into the mechanism by which cyclotides maintain their native activity in the unfavorable environment of predator insect guts. It also provides a structural basis for explaining how a cluster of residues important for bioactivity may be involved in self-association interactions in membranes. As well as being important for their bioactivity, the structural rigidity of cyclotides makes them very suitable as a stable template for peptide-based drug design.
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Affiliation(s)
- Conan K Wang
- University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland 4072, Australia
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16
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Aravinda S, Shamala N, Balaram P. Aib Residues in Peptaibiotics and Synthetic Sequences: Analysis of Nonhelical Conformations. Chem Biodivers 2008; 5:1238-62. [PMID: 18649312 DOI: 10.1002/cbdv.200890112] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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17
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Shenkarev ZO, Nadezhdin KD, Lyukmanova EN, Sobol VA, Skjeldal L, Arseniev AS. Divalent cation coordination and mode of membrane interaction in cyclotides: NMR spatial structure of ternary complex Kalata B7/Mn2+/DPC micelle. J Inorg Biochem 2008; 102:1246-56. [PMID: 18295894 DOI: 10.1016/j.jinorgbio.2008.01.018] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Revised: 12/15/2007] [Accepted: 01/10/2008] [Indexed: 10/22/2022]
Abstract
The cyclotides are the family of hydrophobic bioactive plant peptides, characterized by a circular protein backbone and three knot forming disulfide bonds. It is believed that membrane activity of the cyclotides underlines their antimicrobial, cytotoxic and hemolytic properties, but the specific interactions with divalent cations can be also involved. To assess the mode of membrane interaction and divalent cation coordination in cyclotides, the spatial structure of the Möbius cyclotide Kalata B7 from the African perennial plant Oldenlandia affinis was determined in the presence of anisotropic membrane mimetic (dodecylphosphocholine micelles). The model of peptide/cation/micelle complex was built using 5-doxylstearate and Mn2+ relaxation probes. Results show that the peptide binds to the micelle surface with relatively high affinity by two hydrophobic loops (loop 2 - Thr6-Leu7 and loop 5 - Trp19-Ile21). The partially hydrated divalent cation is coordinated by charged side-chain of Glu3, aromatic side chain of Tyr11 and free carbonyls of Thr4 and Thr9, and is located in direct contact with the polar head-groups of detergent. The comparison with data about other cyclotides indicates that divalent cation coordination is the invariant property of all cyclotides, but the mode of peptide/membrane interactions is varied. Probably, the specific cation/peptide interactions play a major, but yet not known, role in the biological activity of the cyclotides.
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Affiliation(s)
- Zakhar O Shenkarev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Str. 16/10, 117997 Moscow, Russia
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18
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Ovchinnikova TV, Murashev AN. The peptaibol antibiotic zervamicin displays neurotropic activity. DOKL BIOCHEM BIOPHYS 2007; 414:146-8. [PMID: 17695323 DOI: 10.1134/s1607672907030143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- T V Ovchinnikova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117991 Russia
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Milov AD, Tsvetkov YD, Gorbunova EY, Mustaeva LG, Ovchinnikova TV, Handgraaf JW, Raap J. Solvent effects on the secondary structure of the membrane-active zervamicin determined by PELDOR spectroscopy. Chem Biodivers 2007; 4:1243-55. [PMID: 17589863 DOI: 10.1002/cbdv.200790107] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Zervamicin is a voltage-gated ion-channel-forming peptide. Channels are generally considered to be formed by first insertion of amphipathic molecules into the phospholipid bilayer, followed by self-assembly of a variable number of transmembrane helices. We have studied the length of the peptide structure to address the question whether this peptide is long enough to span the phospholipid bilayer. The pulsed electron-electron double resonance (PELDOR) spectroscopic technique was used to determine the length of the helical molecule in membrane-mimicking solvents. This was achieved from the distance-related dipole-dipole interaction between spin labels, which were located at both ends of the linear peptide chain. The data were obtained by using samples of frozen glassy solutions of MeOH, MeOH/toluene, and MeOH/CHCl(3). Contributions of inter- and intramolecular interactions of spin labels were separated to analyze the intramolecular interaction and the distance distribution function between the labels. It is shown that the main maximum of the distribution functions is located at a distance of ca. 3.3 nm, and this distance appears to be only slightly dependent on the solvent composition. The distribution function was observed to narrow after addition of either CHCl(3) or toluene to MeOH. This effect is rationalized in terms of a decreased mobility of the terminal amino acid residues. By molecular-dynamics simulations, it was shown that the conformation, corresponding with the predominant distance found by PELDOR, agrees well with the mixed alpha/3(10)-helical that was previously determined by NMR. However, in the case toluene was added to the MeOH solution to further increase the hydrophobicity of the environment of the membrane-active peptide, the distribution function gives rise to a minor fraction (7-8%) with a distance of 4.2 nm. This distance corresponds most likely to the more extended 2(7)-helix structure.
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Affiliation(s)
- Alexander D Milov
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk, Russian Federation
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20
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Shenkarev ZO, Paramonov AS, Nadezhdin KD, Bocharov EV, Kudelina IA, Skladnev DA, Tagaev AA, Yakimenko ZA, Ovchinnikova TV, Arseniev AS. Antiamoebin I in Methanol Solution: Rapid Exchange between Right-Handed and Left-Handed310-Helical Conformations. Chem Biodivers 2007; 4:1219-42. [PMID: 17589862 DOI: 10.1002/cbdv.200790106] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Antiamoebin I (Aam-I) is a membrane-active peptaibol antibiotic isolated from fungal species belonging to the genera Cephalosporium, Emericellopsis, Gliocladium, and Stilbella. Antiamoebin I has the amino acid sequence: Ac-Phe(1)-Aib-Aib-Aib-Iva-Gly-Leu-Aib(8)-Aib-Hyp-Gln-Iva-Hyp-Aib-Pro-Phl(16). By using the uniformly (13)C,(15)N-labeled sample of Aam-I, the set of conformationally dependent J couplings and (3h)J(NC) couplings through H-bonds were measured. Analysis of these data along with the data on magnetic nonequivalence of the (13)C(beta) nuclei (Deltadelta((13)C(beta))) in Aib and Iva residues allowed us to draw the univocal conclusion that the N-terminal part (Phe(1)-Gly(6)) of Aam-I in MeOH solution is in fast exchange between the right-handed and left-handed 3(10)-helical conformations, with an approximately equal population of both states. An additional conformational exchange process was found at the Aib(8) residue. The (15)N-NMR-relaxation and CD-spectroscopy measurements confirmed these findings. Molecular modeling and Monte Carlo simulations revealed that both exchange processes are correlated and coupled with significant hinge-bending motions around the Aib(8) residue. Our results explain relatively low activity of Aam-I with respect to other 15-amino acid residue peptaibols (for example, zervamicin) in functional and biological tests. The high dynamic 'propensity' possibly prevents both initial binding of the antiamoebin to the membrane and subsequent formation of stable ionic channels according to the barrel-stave mechanism.
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Affiliation(s)
- Zakhar O Shenkarev
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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21
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Ovchinnikova TV, Levitskaya NG, Voskresenskaya OG, Yakimenko ZA, Tagaev AA, Ovchinnikova AY, Murashev AN, Kamenskii AA. Neuroleptic Properties of the Ion-Channel-Forming Peptaibol Zervamicin: Locomotor Activity and Behavioral Effects. Chem Biodivers 2007; 4:1374-87. [PMID: 17589870 DOI: 10.1002/cbdv.200790117] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Zervamicins IIA and IIB are members of the peptaibol family of peptide antibiotics. They are produced by the fungus Emericellopsis salmosynnemata. Peptaibols are known to be of potential usefulness for chemotherapeutic applications, as are other secondary fungal metabolites. Previously, we have found zervamicins to decrease spontaneous locomotor activity in mice, suggesting their neurotropic properties on an equal footing with antimicrobial activity. The current study deals with behavioral effects of zervamicins IIA and IIB in mice. According to our results, both zervamicins induce a reliable decrease in locomotion and exploratory activity measured in the hole-board test. The behavioral effects of zervamicin IIA become apparent at lower dosages (0.05-2.0 mg/kg) as compared with zervamicin IIB (0.5-12.0 mg/kg). The experiments on behavioral effects in the elevated plus maze test showed that both zervamicins caused a reliable decrease in the number of head-dippings, open-arm entries, and rearings. The observed behavioral effects may be rather associated with a decrease in the exploratory activity than with anxiety-related responses in mice. Zervamicins induced depression-like behavior of experimental animals in the forced-swim test. Both peptaibols reduce physical endurance and change motor coordination of experimental animals in the bar-holding test. Taken together, the data obtained clearly indicate that both zervamicins possess neuroleptic activity.
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Affiliation(s)
- Tatiana V Ovchinnikova
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation.
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22
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Rainey JK, Fliegel L, Sykes BD. Strategies for dealing with conformational sampling in structural calculations of flexible or kinked transmembrane peptides. Biochem Cell Biol 2007; 84:918-29. [PMID: 17215879 DOI: 10.1139/o06-178] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Peptides corresponding to transmembrane (TM) segments from membrane proteins provide a potential route for the determination of membrane protein structure. We have determined that 2 functionally critical TM segments from the mammalian Na+/H+ exchanger display well converged structure in regions separated by break points. The flexibility of these break points results in conformational sampling in solution. A brief review of available NMR structures of helical membrane proteins demonstrates that there are a number of published structures showing similar properties. Such flexibility is likely indicative of kinks in the full-length protein. This minireview focuses on methods and protocols for NMR structure calculation and analysis of peptide structures under conditions of conformational sampling. The methods outlined allow the identification and analysis of structured peptides containing break points owing to conformational sampling and the differentiation between oligomerization and ensemble-averaged observation of multiple peptide conformations.
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Affiliation(s)
- Jan K Rainey
- Protein Engineering Network of Centres of Excellence and Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
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23
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Campagna S, Saint N, Molle G, Aumelas A. Structure and Mechanism of Action of the Antimicrobial Peptide Piscidin. Biochemistry 2007; 46:1771-8. [PMID: 17253775 DOI: 10.1021/bi0620297] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Piscidin, an antibacterial peptide isolated from the mast cells of striped bass, has potent antimicrobial activity against a broad spectrum of pathogens in vitro. We investigated the mechanism of action of this 22-residue cationic peptide by carrying out structural studies and electrophysiological experiments in lipid bilayers. Circular dichroism experiments showed that piscidin was unstructured in water but had a high alpha-helix content in dodecylphosphocholine (DPC) micelles. 1H NMR data in water and TFE confirmed these results and demonstrated that the segment of residues 8-17 adopted an alpha-helical structure in a micellar environment. This molecule has a marked amphipathic character, due to well-defined hydrophobic and hydrophilic sectors. This structure is similar to those determined for other cationic peptides involved in permeabilization of the bacterial membrane. Multichannel experiments with piscidin incorporated into azolectin planar bilayers gave reproducible I-V curves at various peptide concentrations and unambiguously showed that this peptide permeabilized the membrane. This pore forming activity was confirmed by single-channel experiments, with well-defined ion channels obtained at different voltages. The characteristics of the ion channels (voltage dependence, only one or two states of conductance) clearly suggest that piscidin is more likely to permeabilize the membrane by toroidal pore formation rather than via the "barrel-stave" mechanism.
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Affiliation(s)
- Sylvie Campagna
- CNRS UMR5048, Centre de Biochimie Structurale, F34090 Montpellier, France
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24
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Shenkarev ZO, Nadezhdin KD, Sobol VA, Sobol AG, Skjeldal L, Arseniev AS. Conformation and mode of membrane interaction in cyclotides. Spatial structure of kalata B1 bound to a dodecylphosphocholine micelle. FEBS J 2006; 273:2658-72. [PMID: 16817894 DOI: 10.1111/j.1742-4658.2006.05282.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cyclotides are a family of bioactive plant peptides that are characterized by a circular protein backbone and three conserved tightly packed disulfide bonds. The antimicrobial and hemolytic properties of cyclotides, along with the relative hydrophobicity of the peptides, point to the biological membrane as a target for cyclotides. To assess the membrane-induced conformation and orientation of cyclotides, the interaction of the Möbius cyclotide, kalata B1, from the African perennial plant Oldenlandia affinis, with dodecylphosphocholine micelles was studied using NMR spectroscopy. Under conditions where the cyclotide formed a well-defined complex with micelles, the spatial structure of kalata B1 was calculated from NOE and J couplings data, and the model for the peptide-micelle complex was built using 5- and 16-doxylstearate relaxation probes. The binding of divalent cations to the peptide-micelle complex was quantified by Mn2+ titration. The results show that the peptide binds to the micelle surface, with relatively high affinity, via two hydrophobic loops (loop 5, Trp19-Val21; and loop6, Leu27-Val29). The charged residues (Glu3 and Arg24), along with the cation-binding site (near Glu3) are segregated on the other side of the molecule and in contact with polar head groups of detergent. The spatial structure of kalata B1 is only slightly changed during incorporation into micelles and represents a distorted triple-stranded beta-sheet cross-linked by a cystine knot. Detailed structural analysis and comparison with other knottins revealed structural conservation of the two-disulfide motif in cyclic and acyclic peptides. The results thus obtained provide the first model for interaction of cyclotides with membranes and permit consideration of the cyclotides as membrane-active cationic antimicrobial peptides.
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Affiliation(s)
- Zakhar O Shenkarev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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25
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Raap J, Hollander J, Ovchinnikova TV, Swischeva NV, Skladnev D, Kiihne S. Trans and surface membrane bound zervamicin IIB: 13C-MAOSS-NMR at high spinning speed. JOURNAL OF BIOMOLECULAR NMR 2006; 35:285-93. [PMID: 16937243 DOI: 10.1007/s10858-006-9045-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Accepted: 06/21/2006] [Indexed: 05/11/2023]
Abstract
Interactions between (15)N-labelled peptides or proteins and lipids can be investigated using membranes aligned on a thin polymer film, which is rolled into a cylinder and inserted into the MAS-NMR rotor. This can be spun at high speed, which is often useful at high field strengths. Unfortuantely, substrate films like commercially available polycarbonate or PEEK produce severe overlap with peptide and protein signals in (13)C-MAOSS NMR spectra. We show that a simple house hold foil support allows clear observation of the carbonyl, aromatic and C(alpha) signals of peptides and proteins as well as the ester carbonyl and choline signals of phosphocholine lipids. The utility of the new substrate is validated in applications to the membrane active peptide zervamicin IIB. The stability and macroscopic ordering of thin PC10 bilayers was compared with that of thicker POPC bilayers, both supported on the household foil. Sidebands in the (31)P-spectra showed a high degree of alignment of both the supported POPC and PC10 lipid molecules. Compared with POPC, the PC10 lipids are slightly more disordered, most likely due to the increased mobilities of the shorter lipid molecules. This mobility prevents PC10 from forming stable vesicles for MAS studies. The (13)C-peptide peaks were selectively detected in a (13)C-detected (1)H-spin diffusion experiment. Qualitative analysis of build-up curves obtained for different mixing times allowed the transmembrane peptide in PC10 to be distinguished from the surface bound topology in POPC. The (13)C-MAOSS results thus independently confirms previous findings from (15)N spectroscopy [Bechinger, B., Skladnev, D.A., Ogrel, A., Li, X., Rogozhkina, E.V., Ovchinnikova, T.V., O'Neil, J.D.J. and Raap, J. (2001) Biochemistry, 40, 9428-9437]. In summary, application of house hold foil opens the possibility of measuring high resolution (13)C-NMR spectra of peptides and proteins in well ordered membranes, which are required to determine the secondary and supramolecular structures of membrane active peptides, proteins and aggregates.
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Affiliation(s)
- J Raap
- Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands.
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26
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Brunecky R, Lee S, Rzepecki PW, Overduin M, Prestwich GD, Kutateladze AG, Kutateladze TG. Investigation of the binding geometry of a peripheral membrane protein. Biochemistry 2006; 44:16064-71. [PMID: 16331966 PMCID: PMC2516348 DOI: 10.1021/bi051127+] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A growing number of modules including FYVE domains target key signaling proteins to membranes through specific recognition of lipid headgroups and hydrophobic insertion into bilayers. Despite the critical role of membrane insertion in the function of these modules, the structural mechanism of membrane docking and penetration remains unclear. In particular, the three-dimensional orientation of the inserted proteins with respect to the membrane surface is difficult to define quantitatively. Here, we determined the geometry of the micelle penetration of the early endosome antigen 1 (EEA1) FYVE domain by obtaining NMR-derived restraints that correlate with the distances between protein backbone amides and spin-labeled probes. The 5- and 14-doxyl-phosphatidylcholine spin-labels were incorporated into dodecylphosphocholine (DPC) micelles, and the reduction of amide signal intensities of the FYVE domain due to paramagnetic relaxation enhancement was measured. The vector of the FYVE domain insertion was estimated relative to the molecular axis by minimizing the paramagnetic restraints obtained in phosphatidylinositol 3-phosphate (PI3P)-enriched micelles containing only DPC or mixed with phosphatidylserine (PS). Additional distance restraints were obtained using a novel spin-label mimetic of PI(3)P that contains a nitroxyl radical near the threitol group of the lipid. Conformational changes indicative of elongation of the membrane insertion loop (MIL) were detected upon micelle interaction, in which the hydrophobic residues of the loop tend to move deeper into the nonpolar core of micelles. The micelle insertion mechanism of the FYVE domain defined in this study is consistent with mutagenesis data and chemical shift perturbations and demonstrates the advantage of using the spin-label NMR approach for investigating the binding geometry by peripheral membrane proteins.
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Affiliation(s)
- Roman Brunecky
- Department of Pharmacology, University of Colorado Health Sciences Center, Aurora, Colorado 80045, USA
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27
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Kropacheva TN, Salnikov ES, Nguyen HH, Reissmann S, Yakimenko ZA, Tagaev AA, Ovchinnikova TV, Raap J. Membrane association and activity of 15/16-membered peptide antibiotics: zervamicin IIB, ampullosporin A and antiamoebin I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2005; 1715:6-18. [PMID: 16084799 DOI: 10.1016/j.bbamem.2005.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2004] [Revised: 06/14/2005] [Accepted: 07/07/2005] [Indexed: 11/23/2022]
Abstract
Permeabilization of the phospholipid membrane, induced by the antibiotic peptides zervamicin IIB (ZER), ampullosporin A (AMP) and antiamoebin I (ANT) was investigated in a vesicular model system. Membrane-perturbing properties of these 15/16 residue peptides were examined by measuring the K(+) transport across phosphatidyl choline (PC) membrane and by dissipation of the transmembrane potential. The membrane activities are found to decrease in the order ZER>AMP>>ANT, which correlates with the sequence of their binding affinities. To follow the insertion of the N-terminal Trp residue of ZER and AMP, the environmental sensitivity of its fluorescence was explored as well as the fluorescence quenching by water-soluble (iodide) and membrane-bound (5- and 16-doxyl stearic acids) quenchers. In contrast to AMP, the binding affinity of ZER as well as the depth of its Trp penetration is strongly influenced by the thickness of the membrane (diC(16:1)PC, diC(18:1)PC, C(16:0)/C(18:1)PC, diC(20:1)PC). In thin membranes, ZER shows a higher tendency to transmembrane alignment. In thick membranes, the in-plane surface association of these peptaibols results in a deeper insertion of the Trp residue of AMP which is in agreement with model calculations on the localization of both peptide molecules at the hydrophilic-hydrophobic interface. The observed differences between the membrane affinities/activities of the studied peptaibols are discussed in relation to their hydrophobic and amphipathic properties.
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Affiliation(s)
- T N Kropacheva
- Chemistry Department, Udmurt State University, Izhevsk, Russia
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28
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Farès C, Qian J, Davis JH. Magic angle spinning and static oriented sample NMR studies of the relaxation in the rotating frame of membrane peptides. J Chem Phys 2005. [DOI: 10.1063/1.1899645] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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29
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Kristiansen PE, Fimland G, Mantzilas D, Nissen-Meyer J. Structure and mode of action of the membrane-permeabilizing antimicrobial peptide pheromone plantaricin A. J Biol Chem 2005; 280:22945-50. [PMID: 15805109 DOI: 10.1074/jbc.m501620200] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The three-dimensional structure in dodecyl phosphocholine micelles of the 26-mer membrane-permeabilizing bacteriocin-like pheromone plantaricin A (PlnA) has been determined by use of nuclear magnetic resonance spectroscopy. The peptide was unstructured in water but became partly structured upon exposure to micelles. An amphiphilic alpha-helix stretching from residue 12 to 21 (possibly also including residues 22 and 23) was then formed in the C-terminal part of the peptide, whereas the N-terminal part remained largely unstructured. PlnA exerted its membrane-permeabilizing antimicrobial activity through a nonchiral interaction with the target cell membrane because the d-enantiomeric form had the same activity as the natural l-form. This nonchiral interaction involved the amphiphilic alpha-helical region in the C-terminal half of PlnA because a 17-mer fragment that contains the amphiphilic alpha-helical part of the peptide had antimicrobial potency that was similar to that of the l- and d-enantiomeric forms of PlnA. Also the pheromone activity of PlnA depended on this nonchiral interaction because both the l- and d-enantiomeric forms of the 17-mer fragment inhibited the pheromone activity. The pheromone activity also involved, however, a chiral interaction between the N-terminal part of PlnA and its receptor because high concentrations of the l-form (but not the d-form) of a 5-mer fragment derived from the N-terminal part of PlnA had pheromone activity. The results thus reveal a novel mechanism whereby peptide pheromones such as PlnA may function. An initial nonchiral interaction with membrane lipids induces alpha-helical structuring in a segment of the peptide pheromone. The peptide becomes thereby sufficiently structured and properly positioned in the membrane interface, thus enabling it to engage in a chiral interaction with its receptor in or near the membrane water interface. This membrane-interacting mode of action explains why some peptide pheromones/hormones such as PlnA sometimes display antimicrobial activity in addition to their pheromone activity.
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Shenkarev ZO, Paramonov AS, Balashova TA, Yakimenko ZA, Baru MB, Mustaeva LG, Raap J, Ovchinnikova TV, Arseniev AS. High stability of the hinge region in the membrane-active peptide helix of zervamicin: paramagnetic relaxation enhancement studies. Biochem Biophys Res Commun 2005; 325:1099-105. [PMID: 15541401 DOI: 10.1016/j.bbrc.2004.10.115] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2004] [Indexed: 10/26/2022]
Abstract
Zervamicin IIB is a 16 amino acid peptaibol that forms voltage dependent ion channels with multilevel conductance states in planar lipid bilayers and vesicular systems. Stability of the hinge region and intermolecular interactions were investigated in the N- and C-terminally spin-labelled peptide analogues. Intermolecular and intramolecular paramagnetic enhancement indicates that zervamicin behaves as a rigid helical rod in methanol solution. There are no high amplitude hinge-bending motions, and the peptaibol is monomeric up to concentration 1.5 mM. Stability of the hinge region illustrates the helix stabilising propensity of the Pro residue in membrane mimic environments and implies absence of significant conformational rearrangement due to voltage peptaibol activation.
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Affiliation(s)
- Zakhar O Shenkarev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia
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31
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Raap J, Erkelens K, Ogrel A, Skladnev DA, Brückner H. Fungal biosynthesis of non-ribosomal peptide antibiotics and α, α-dialkylated amino acid constituents. J Pept Sci 2005; 11:331-8. [PMID: 15635654 DOI: 10.1002/psc.621] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Zervamicins (Zrv) IIA and IIB are membrane modifying peptide antibiotics of fungal origin, characterized by a sequence of 15 amino acid residues. The primary structure of Zrv-IIA contains five alpha-aminoisobutyric acid residues at positions 4, 7, 9, 12 and 14 of the linear peptide. The sequence of Zrv-IIB is similar, but contains a D-isovaline at position 4. When the free amino acid Aib was added to the peptone-glucose culture medium, the fungus Emericellopsis salmosynnemata produced Zrv-IIA as the major secondary metabolite, whereas addition of DL-Iva to the culture led to a high production of Zrv-IIB. This observation is rationalized by a lack of selectivity of the non-ribosomal peptide synthetase with respect to the thiolester activated amino acid substrates during step 12 of peptide synthesis. Analysis of the configuration of the Iva residue of Zrv-IIB showed a high enantiomeric purity of the D-enantiomer, indicating a high stereoselectivity of the peptide synthetase for this substrate.When the culture was supplemented with [(15)N]DL-Iva, the nitrogen isotope was not only found at the D-Iva residue, but surprisingly also at the Aib residues as well as at the proteinogenic residues of Zrv. The partial catabolism of exogenous [(15)N]DL-Iva is explained by the assumption of a decarboxylation-dependent transamination reaction, catalysed by 2,2-dimethylglycine decarboxylase. The same enzyme might also be involved in the reversed carboxylation reactions of acetone and 2-butanone, during the anabolic biosynthesis of Aib and Iva, respectively. Zrv might possibly act as a thermodynamic sink to shift these equilibrium reactions towards the reversed side.
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Affiliation(s)
- Jan Raap
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Leiden, The Netherlands.
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32
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Kronen M, Görls H, Nguyen HH, Reissmann S, Bohl M, Sühnel J, Gräfe U. Crystal structure and conformational analysis of ampullosporin A. J Pept Sci 2004; 9:729-44. [PMID: 14658792 DOI: 10.1002/psc.495] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Ampullosporin A is a 15-mer peptaibol type polypeptide that induces pigment formation by the fungus Phoma destructiva, forms voltage-dependent ion channels in membranes and exhibits hypothermic effects in mice. The structure of ampullosporin A has been determined by x-ray crystallography. This is the first three-dimensional (3D) structure of the peptaibol subfamily SF6. From the N-terminus to residue 13 the molecule adopts an approximate right-handed alpha-helical geometry, whereas a less regular structure pattern with beta-turn characteristics is found in the C-terminus. Even though ampullosporin A does not contain a single proline or hydroxyproline it is significantly bent. It belongs to both the shortest and the most strongly bent peptaibol 3D structures. The straight structure part encompasses residues Ac-Trp(1)-Aib(10) and is thus less extended than the alpha-helical subunit. The 3D structure of ampullosporin A is discussed in relation to other experimentally determined peptaibol structures and in the context of its channel-forming properties. As a part of this comparison a novel bending analysis based on a 3D curvilinear axis describing the global structural characteristics has been proposed and applied to all 3D peptaibol structures. A sampling of 2500 conformations using different molecular dynamics protocols yields, for the complete ampullosporin A structure, an alpha-helix as the preferred conformation in vacuo with almost no bend. This indicates that solvent or crystal effects may be important for the experimentally observed peptide backbone bending characteristics of ampullosporin A.
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Affiliation(s)
- Matthias Kronen
- Hans-Knöll-Institut für Naturstoff-Forschung, Beutenbergstrasse 11, D-07745 Jena, Germany
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Abstract
The crystal structures of the peptaibol antibiotics cephaibol A, cephaibol B and cephaibol C have been determined at ca. 0.9 A resolution. All three adopt a helical conformation with a sharp bend (of about 55 degrees) at the central hydroxyproline. All isovalines were found to possess the D configuration, superposition of all four models (there are two independent molecules in the cephaibol B structure) shows that the N-terminal helix is rigid and the C-terminus is flexible. There are differences in the hydrogen bonding patterns for the three structures that crystallize in different space groups despite relatively similar unit cell dimensions, but only in the case of cephaibol C does the packing emulate the formation of a membrane channel believed to be important for their biological function.
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Affiliation(s)
- Gábor Bunkóczi
- Lehrstuhl für Strukturchemie, Georg-August Universität, Tammannstr. 4, 37077 Göttingen, Germany
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Shenkarev ZO, Balashova TA, Yakimenko ZA, Ovchinnikova TV, Arseniev AS. Peptaibol zervamicin IIb structure and dynamics refinement from transhydrogen bond J couplings. Biophys J 2004; 86:3687-99. [PMID: 15189865 PMCID: PMC1304270 DOI: 10.1529/biophysj.103.036798] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2003] [Accepted: 03/05/2004] [Indexed: 11/18/2022] Open
Abstract
Zervamicin IIB (Zrv-IIB) is a channel-forming peptaibol antibiotic of fungal origin. The measured transhydrogen bond (3h)J(NC') couplings in methanol solution heaving average value of -0.41 Hz indicate that the stability of the Zrv-IIB helix in this milieu is comparable to the stability of helices in globular proteins. The N-terminus of the peptide forms an alpha-helix, whereas 3(10)-helical hydrogen bonds stabilize the C-terminus. However, two weak transhydrogen bond peaks are observed in a long-range HNCO spectrum for HN Aib(12). Energy calculations using the Empirical Conformation Energy Program for Peptides (ECEPP)/2 force field and the implicit solvent model show that the middle of the peptide helix accommodates a bifurcated hydrogen bond that is simultaneously formed between HN Aib(12) and CO Leu(8) and CO Aib(9). Several lowered (3h)J(NC') on a polar face of the helix correlate with the conformational exchange process observed earlier and imply dynamic distortions of a hydrogen bond pattern with the predominant population of a properly folded helical structure. The refined structure of Zrv-IIB on the basis of the observed hydrogen bond pattern has a small ( approximately 20 degrees ) angle of helix bending that is virtually identical to the angle of bending in dodecylphosphocholine (DPC) micelles, indicating the stability of a hinge region in different environments. NMR parameters ((1)HN chemical shifts and transpeptide bond (1)J(NC') couplings) sensitive to hydrogen bonding along with the solvent accessible surface area of carbonyl oxygens indicate a large polar patch on the convex side of the helix formed by three exposed backbone carbonyls of Aib(7), Aib(9), and Hyp(10) and polar side chains of Hyp(10), Gln(11), and Hyp(13). The unique structural features, high helix stability and the enhanced polar patch, set apart Zrv-IIB from other peptaibols (for example, alamethicin) and possibly underlie its biological and physiological properties.
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Affiliation(s)
- Z O Shenkarev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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Galbraith TP, Harris R, Driscoll PC, Wallace BA. Solution NMR studies of antiamoebin, a membrane channel-forming polypeptide. Biophys J 2003; 84:185-94. [PMID: 12524274 PMCID: PMC1302602 DOI: 10.1016/s0006-3495(03)74841-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Antiamoebin I is a membrane-active peptaibol produced by fungi of the species Emericellopsis which is capable of forming ion channels in membranes. Previous structure determinations by x-ray crystallography have shown the molecule is mostly helical, with a deep bend in the center of the polypeptide, and that the backbone structure is independent of the solvent used for crystallization. In this study, the solution structure of antiamoebin was determined by NMR spectroscopy in methanol, a solvent from which one of the crystal structures was determined. The ensemble of structures produced exhibit a right-handed helical C terminus and a left-handed helical conformation toward the N-terminus, in contrast to the completely right-handed helices found in the crystal structures. The NMR results also suggest that a "hinge" region exists, which gives flexibility to the polypeptide in the central region, and which could have functional implications for the membrane insertion process. A model for the membrane insertion and assembly process is proposed based on the antiamoebin solution and crystal structures, and is contrasted with the assembly and insertion mechanism proposed for other ion channel-forming polypeptides.
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Affiliation(s)
- T P Galbraith
- School of Crystallography, Birkbeck College, University of London, UK
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Ovchinnikova TV, Shenkarev ZO, Yakimenko ZA, Svishcheva NV, Tagaev AA, Skladnev DA, Arseniev AS. Biosynthetic uniform13C,15N-labelling of zervamicin IIB. Complete13C and15N NMR assignment. J Pept Sci 2003; 9:817-26. [PMID: 14658801 DOI: 10.1002/psc.499] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Zervamicin IIB is a member of the alpha-aminoisobutyric acid containing peptaibol antibiotics. A new procedure for the biosynthetic preparation of the uniformly 13C- and 15N-enriched peptaibol is described This compound was isolated from the biomass of the fungus-producer Emericellopsis salmosynnemata strain 336 IMI 58330 obtained upon cultivation in the totally 13C, 15N-labelled complete medium. To prepare such a medium the autolysed biomass and the exopolysaccharides of the obligate methylotrophic bacterium Methylobacillus flagellatus KT were used. This microorganism was grown in totally 13C, 15N-labelled minimal medium containing 13C-methanol and 15N-ammonium chloride as the only carbon and nitrogen sources. Preliminary NMR spectroscopic analysis indicated a high extent of isotope incorporation (> 90%) and led to the complete 13C- and 15N-NMR assignment including the stereospecific assignment of Aib residues methyl groups. The observed pattern of the structurally important secondary chemical shifts of 1H(alpha), 13C=O and 13C(alpha) agrees well with the previously determined structure of zervamicin IIB in methanol solution.
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Affiliation(s)
- Tatyana V Ovchinnikova
- Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.
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Kropacheva TN, Raap J. Ion transport across a phospholipid membrane mediated by the peptide trichogin GA IV. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1567:193-203. [PMID: 12488053 DOI: 10.1016/s0005-2736(02)00616-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Trichogin GA IV is a special member of a class of peptaibols that are linear peptide antibiotics of fungal origin, characterised by the presence of a variable number of alpha-aminoisobutyric acid residues, an acyl group at the N-terminus and a 1,2-amino alcohol at the C-terminus. Most of the peptaibols display ion-channel-forming or at least membrane-modifying properties. The 11-residue-long trichogin GA IV is not only one of shortest peptaibols, but it is also unique for its n-octanoyl group instead of the more common found acetyl group at the N-terminus. For the first time we have found that this lipopeptaibol is able to enhance conduction of monovalent cations through membranes of large unilamellar vesicles (LUVs). The influence of the [Leu-OMe]trichogin GA IV analogue (TRI) on ion permeation was studied under a variety of conditions (lipid composition, lipid-to-peptide ratio and a transmembrane potential). Parallel experiments were performed with the 16-residue long, channel-forming peptaibol, zervamicin (ZER). For the two peptides, the permeability between K(+) and Na(+) was found to be different. In addition, the ion diffusion rate dependencies on the peptide concentration are observed to be different. This might indicate that a different number of aggregated molecules are involved in the rate-limiting step, i.e. 3-4 (TRI) and 4-7 (ZER). In the presence of TRI, dissipation of the transmembrane potential, Delta psi, was observed with a rate to be dependent on the magnitude of both initial Delta psi and peptide concentration. Both peptides were activated by a cis-positive but not by cis-negative Delta psi. Under identical conditions the ion-conducting efficiency of zervamicin was 100-200 times higher than that of trichogin. Our results show that, unlike for zervamicin, the membrane-modifying activity of trichogin is not associated with a channel mechanism.
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Affiliation(s)
- T N Kropacheva
- Department of Chemistry, Udmurt State University, Izhevsk, Russia
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