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Macias ALD, Alecrim LC, Almeida FCL, Giordano RJ. Understanding the Structural Requirements of Peptide-Protein Interaction and Applications for Peptidomimetic Development. Methods Mol Biol 2024; 2793:65-82. [PMID: 38526724 DOI: 10.1007/978-1-0716-3798-2_5] [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] [Indexed: 03/27/2024]
Abstract
Protein-protein interaction is at the heart of most biological processes, and small peptides that bind to protein binding sites are resourceful tools to explore and understand the structural requirements for these interactions. In that sense, phage display is a well-suited technology to study protein-protein interactions, as it allows for unbiased screening of billions of peptides in search for those that interact with a protein binding domain. Here, we will illustrate how two distinct but complementary approaches, phage display and nuclear magnetic resonance (NMR), can be utilized to unveil structural details of peptide-protein interaction. Finally, knowledge derived from phage mutagenesis and NMR studies can be streamlined for quick peptidomimetic design and synthesis using the retroinversion approach to validate using in vitro and in vivo assays the therapeutic potential of peptides identified by phage display.
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Affiliation(s)
| | - Lilian Costa Alecrim
- Biochemistry Department, Institute of Chemistry, University of Sao Paulo, Sao Paulo, Brazil
| | - Fabio C L Almeida
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ricardo Jose Giordano
- Biochemistry Department, Institute of Chemistry, University of Sao Paulo, Sao Paulo, Brazil.
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2
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Passarini I, Rossiter S, Malkinson J, Zloh M. In Silico Structural Evaluation of Short Cationic Antimicrobial Peptides. Pharmaceutics 2018; 10:E72. [PMID: 29933540 PMCID: PMC6160961 DOI: 10.3390/pharmaceutics10030072] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 06/11/2018] [Accepted: 06/12/2018] [Indexed: 12/26/2022] Open
Abstract
Cationic peptides with antimicrobial properties are ubiquitous in nature and have been studied for many years in an attempt to design novel antibiotics. However, very few molecules are used in the clinic so far, sometimes due to their complexity but, mostly, as a consequence of the unfavorable pharmacokinetic profile associated with peptides. The aim of this work is to investigate cationic peptides in order to identify common structural features which could be useful for the design of small peptides or peptido-mimetics with improved drug-like properties and activity against Gram negative bacteria. Two sets of cationic peptides (AMPs) with known antimicrobial activity have been investigated. The first reference set comprised molecules with experimentally-known conformations available in the protein databank (PDB), and the second one was composed of short peptides active against Gram negative bacteria but with no significant structural information available. The predicted structures of the peptides from the first set were in excellent agreement with those experimentally-observed, which allowed analysis of the structural features of the second group using computationally-derived conformations. The peptide conformations, either experimentally available or predicted, were clustered in an “all vs. all” fashion and the most populated clusters were then analyzed. It was confirmed that these peptides tend to assume an amphipathic conformation regardless of the environment. It was also observed that positively-charged amino acid residues can often be found next to aromatic residues. Finally, a protocol was evaluated for the investigation of the behavior of short cationic peptides in the presence of a membrane-like environment such as dodecylphosphocholine (DPC) micelles. The results presented herein introduce a promising approach to inform the design of novel short peptides with a potential antimicrobial activity.
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Affiliation(s)
- Ilaria Passarini
- School of Life and Medical Sciences, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK.
| | - Sharon Rossiter
- School of Life and Medical Sciences, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK.
| | - John Malkinson
- UCL School of Pharmacy, University College London, 29/39 Brunswick Square, London WC1N 1AX, UK.
| | - Mire Zloh
- School of Life and Medical Sciences, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK.
- Faculty of Pharmacy, University Business Academy, Trg mladenaca 5, 21000 Novi Sad, Serbia.
- NanoPuzzle Medicines Design, Business & Technology Centre, Bessemer Drive, Stevenage SG1 2DX, UK.
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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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Structural and Dynamic Insights of the Interaction between Tritrpticin and Micelles: An NMR Study. Biophys J 2017; 111:2676-2688. [PMID: 28002744 DOI: 10.1016/j.bpj.2016.10.034] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 10/14/2016] [Accepted: 10/27/2016] [Indexed: 01/02/2023] Open
Abstract
A large number of antimicrobial peptides (AMPs) acts with high selectivity and specificity through interactions with membrane lipid components. These peptides undergo complex conformational changes in solution; upon binding to an interface, one major conformation is stabilized. Here we describe a study of the interaction between tritrpticin (TRP3), a cathelicidin AMP, and micelles of different chemical composition. The peptide's structure and dynamics were examined using one-dimensional and two-dimensional NMR. Our data showed that the interaction occurred by conformational selection and the peptide acquired similar structures in all systems studied, despite differences in detergent headgroup charge or dipole orientation. Fluorescence and paramagnetic relaxation enhancement experiments showed that the peptide is located in the interface region and is slightly more deeply inserted in 1-myristoyl-2-hydroxy-sn-glycero-3-phospho-1'-rac-glycerol (LMPG, anionic) than in 1-lauroyl-2-hydroxy-sn-glycero-3-phosphocholine (LLPC, zwitterionic) micelles. Moreover, the tilt angle of an assumed helical portion of the peptide is similar in both systems. In previous work we proposed that TRP3 acts by a toroidal pore mechanism. In view of the high hydrophobic core exposure, hydration, and curvature presented by micelles, the conformation of TRP3 in these systems could be related to the peptide's conformation in the toroidal pore.
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Gomes-Neto F, Valente AP, Almeida FCL. Modeling the interaction of dodecylphosphocholine micelles with the anticoccidial peptide PW2 guided by NMR data. Molecules 2013; 18:10056-80. [PMID: 23966088 PMCID: PMC6270265 DOI: 10.3390/molecules180810056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 08/05/2013] [Accepted: 08/07/2013] [Indexed: 11/16/2022] Open
Abstract
Antimicrobial peptides are highly dynamic entities that acquire structure upon binding to a membrane interface. To better understand the structure and the mechanism for the molecular recognition of dodecylphosphocholine (DPC) micelles by the anticoccidial peptide PW2, we performed molecular dynamics (MD) simulations guided by NMR experimental data, focusing on strategies to explore the transient nature of micelles, which rearrange on a millisecond to second timescale. We simulated the association of PW2 with a pre-built DPC micelle and with free-DPC molecules that spontaneously forms micelles in the presence of the peptide along the simulation. The simulation with spontaneous micelle formation provided the adequate environment which replicated the experimental data. The unrestrained MD simulations reproduced the NMR structure for the entire 100 ns MD simulation time. Hidden discrete conformational states could be described. Coulomb interactions are important for initial approximation and hydrogen bonds for floating the aromatic region at the interface, being essential for the stabilization of the interaction. Arg9 is strongly attached with phosphate. We observed a helix elongation process stabilized by the intermolecular peptide-micelle association. Full association that mimics the experimental data only happens after complete micelle re-association. Fast micelle dynamics without dissociation of surfactants leads to only superficial binding.
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Affiliation(s)
- Francisco Gomes-Neto
- Laboratory of Toxinology, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21045-900, Brazil; E-Mail:
- Institute of Medical Biochemistry, National Center of Nuclear Magnetic Resonance Jiri Jonas, Federal University of Rio de Janeiro - Institute of Structural Biology and Bioimaging, Rio de Janeiro 21941-920, Brazil; E-Mail:
| | - Ana Paula Valente
- Institute of Medical Biochemistry, National Center of Nuclear Magnetic Resonance Jiri Jonas, Federal University of Rio de Janeiro - Institute of Structural Biology and Bioimaging, Rio de Janeiro 21941-920, Brazil; E-Mail:
| | - Fabio C. L. Almeida
- Institute of Medical Biochemistry, National Center of Nuclear Magnetic Resonance Jiri Jonas, Federal University of Rio de Janeiro - Institute of Structural Biology and Bioimaging, Rio de Janeiro 21941-920, Brazil; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +55-21-3104-2326; Fax: +55-21-3104-2326
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Lim SB, Rubinstein I, Sadikot RT, Artwohl JE, Önyüksel H. A novel peptide nanomedicine against acute lung injury: GLP-1 in phospholipid micelles. Pharm Res 2010; 28:662-72. [PMID: 21108040 DOI: 10.1007/s11095-010-0322-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 11/08/2010] [Indexed: 12/25/2022]
Abstract
PURPOSE Treatment of acute lung injury (ALI) observed in Gram-negative sepsis represents an unmet medical need due to a high mortality rate and lack of effective treatment. Accordingly, we developed and characterized a novel nanomedicine against ALI. We showed that when human glucagon-like peptide 1(7-36) (GLP-1) self-associated with PEGylated phospholipid micelles (SSM), the resulting GLP1-SSM (hydrodynamic size, ~15 nm) exerted effective anti-inflammatory protection against lipopolysaccharide (LPS)-induced ALI in mice. METHODS GLP1-SSM was prepared by incubating GLP-1 with SSM dispersion in saline and characterized using fluorescence spectroscopy and circular dichroism. Bioactivity was tested by in vitro cAMP induction, while in vivo anti-inflammatory effects were determined by lung neutrophil cell count, myeloperoxidase activity and pro-inflammatory cytokine levels in LPS-induced ALI mice. RESULTS Amphipathic GLP-1 interacted spontaneously with SSM as indicated by increased α-helicity and fluorescence emission. This association elicited increased bioactivity as determined by in vitro cAMP production. Correspondingly, subcutaneous GLP1-SSM (5-30 nmol/mouse) manifested dose-dependent decrease in lung neutrophil influx, myeloperoxidase activity and interleukin-6 in ALI mice. By contrast, GLP-1 in saline showed no significant anti-inflammatory effects against LPS-induced lung hyper-inflammatory responses. CONCLUSIONS GLP1-SSM is a promising novel anti-inflammatory nanomedicine against ALI and should be further developed for its transition to clinics.
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Affiliation(s)
- Sok Bee Lim
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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Kamiya M, Oyauchi K, Sato Y, Yokoyama T, Wang M, Aizawa T, Kumaki Y, Mizuguchi M, Imai K, Demura M, Suzuki K, Kawano K. Structure-activity relationship of a novel pentapeptide with cancer cell growth-inhibitory activity. J Pept Sci 2010; 16:242-8. [PMID: 20401925 DOI: 10.1002/psc.1225] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We previously reported that yamamarin, a pentapeptide with an amidated C-terminus (DILRG-NH(2)) isolated from larvae of the silkmoth, and its palmitoylated analog (C16-DILRG-NH(2)) suppressed proliferation of rat hepatoma (liver cancer) cells. In this study, we investigated the structure-activity relationship of yamamarin by in vitro assay and spectroscopic methods (CD and NMR) for various analogs. The in vitro assay results demonstrated that the chemical structure of the C-terminal part (-RG-NH(2)) of yamamarin is essential for its activity. The CD and NMR results indicated that yamamarin and its analog adopt predominantly a random coil conformation. Moreover, a comparison of NMR spectra of DILRG-NH(2) and C16-DILRG-NH(2) revealed that the N-terminal palmitoyl group of C16-DILRG-NH(2) did not affect the conformation of the C-terminal part, which is essential for activity. Together, these results should assist in the design of more sophisticated anticancer drugs.
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Affiliation(s)
- Masakatsu Kamiya
- Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
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de Medeiros LN, Angeli R, Sarzedas CG, Barreto-Bergter E, Valente AP, Kurtenbach E, Almeida FCL. Backbone dynamics of the antifungal Psd1 pea defensin and its correlation with membrane interaction by NMR spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA 2010; 1798:105-13. [PMID: 19632194 DOI: 10.1016/j.bbamem.2009.07.013] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Revised: 06/25/2009] [Accepted: 07/08/2009] [Indexed: 11/26/2022]
Abstract
Plant defensins are cysteine-rich cationic peptides, components of the innate immune system. The antifungal sensitivity of certain exemplars was correlated to the level of complex glycosphingolipids in the membrane of fungi strains. Psd1 is a 46 amino acid residue defensin isolated from pea seeds which exhibit antifungal activity. Its structure is characterized by the so-called cysteine-stabilized alpha/beta motif linked by three loops as determined by two-dimensional NMR. In the present work we explored the measurement of heteronuclear Nuclear Overhauser Effects, R1 and R2 (15)N relaxation ratios, and chemical shift to probe the backbone dynamics of Psd1 and its interaction with membrane mimetic systems with phosphatidylcholine (PC) or dodecylphosphocholine (DPC) with glucosylceramide (CMH) isolated from Fusarium solani. The calculated R2 values predicted a slow motion around the highly conserved among Gly12 residue and also in the region of the Turn3 His36-Trp38. The results showed that Psd1 interacts with vesicles of PC or PC:CMH in slightly different forms. The interaction was monitored by chemical shift perturbation and relaxation properties. Using this approach we could map the loops as the binding site of Psd1 with the membrane. The major binding epitope showed conformation exchange properties in the mus-ms timescale supporting the conformation selection as the binding mechanism. Moreover, the peptide corresponding to part of Loop1 (pepLoop1: Gly12 to Ser19) is also able to interact with DPC micelles acquiring a stable structure and in the presence of DPC:CMH the peptide changes to an extended conformation, exhibiting NOE mainly with the carbohydrate and ceramide parts of CMH.
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Affiliation(s)
- Luciano Neves de Medeiros
- Instituto de Biofísica Carlos Chagas Filho, Programa de Biologia Molecular e Estrutural, Universidade Federal do Rio de Janeiro, Brazil
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Page RC, Lee S, Moore JD, Opella SJ, Cross TA. Backbone structure of a small helical integral membrane protein: A unique structural characterization. Protein Sci 2009; 18:134-46. [PMID: 19177358 DOI: 10.1002/pro.24] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The structural characterization of small integral membrane proteins pose a significant challenge for structural biology because of the multitude of molecular interactions between the protein and its heterogeneous environment. Here, the three-dimensional backbone structure of Rv1761c from Mycobacterium tuberculosis has been characterized using solution NMR spectroscopy and dodecylphosphocholine (DPC) micelles as a membrane mimetic environment. This 127 residue single transmembrane helix protein has a significant (10 kDa) C-terminal extramembranous domain. Five hundred and ninety distance, backbone dihedral, and orientational restraints were employed resulting in a 1.16 A rmsd backbone structure with a transmembrane domain defined at 0.40 A. The structure determination approach utilized residual dipolar coupling orientation data from partially aligned samples, long-range paramagnetic relaxation enhancement derived distances, and dihedral restraints from chemical shift indices to determine the global fold. This structural model of Rv1761c displays some influences by the membrane mimetic illustrating that the structure of these membrane proteins is dictated by a combination of the amino acid sequence and the protein's environment. These results demonstrate both the efficacy of the structural approach and the necessity to consider the biophysical properties of membrane mimetics when interpreting structural data of integral membrane proteins and, in particular, small integral membrane proteins.
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Affiliation(s)
- Richard C Page
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, USA
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Anderluh G, Lakey JH. Disparate proteins use similar architectures to damage membranes. Trends Biochem Sci 2008; 33:482-90. [PMID: 18778941 DOI: 10.1016/j.tibs.2008.07.004] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Revised: 06/22/2008] [Accepted: 07/24/2008] [Indexed: 01/30/2023]
Abstract
Membrane disruption can efficiently alter cellular function; indeed, pore-forming toxins (PFTs) are well known as important bacterial virulence factors. However, recent data have revealed that structures similar to those found in PFTs are found in membrane active proteins across disparate phyla. Many similarities can be identified only at the 3D-structural level. Of note, domains found in membrane-attack complex proteins of complement and perforin (MACPF) resemble cholesterol-dependent cytolysins from Gram-positive bacteria, and the Bcl family of apoptosis regulators share similar architectures with Escherichia coli pore-forming colicins. These and other correlations provide considerable help in understanding the structural requirements for membrane binding and pore formation.
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Affiliation(s)
- Gregor Anderluh
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111, 1000, Ljubljana, Slovenia.
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Cruzeiro-Silva C, Gomes-Neto F, Tinoco LW, Cilli EM, Barros PVR, Lapido-Loureiro PA, Bisch PM, Almeida FCL, Valente AP. Structural biology of membrane-acting peptides: conformational plasticity of anticoccidial peptide PW2 probed by solution NMR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:3182-92. [PMID: 17927950 DOI: 10.1016/j.bbamem.2007.08.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Revised: 08/22/2007] [Accepted: 08/24/2007] [Indexed: 10/22/2022]
Abstract
The bottleneck for the complete understanding of the structure-function relationship of flexible membrane-acting peptides is its dynamics. At the same time, not only the structure but also the dynamics are the key points for their mechanism of action. Our model is PW2, a TRP-rich, cationic peptide selected from phage display libraries that shows anticoccidial activity against Eimeria acervulina. In this manuscript we used a combination of several NMR techniques to tackle these difficulties. The structural features of the membrane-acting peptide PW2 was studied in several membrane mimetic environments: we compared the structural features of PW2 in SDS and DPC micelles, that were reported earlier, with the structure properties in different lipid vesicles and the peptide free in water. We were able to unify the structural information obtained in each of these systems. The structural constraints of the peptide free in water were fundamental for the understanding of plasticity necessary for the membrane interaction. Our data suggested that the WWR sequence is the region responsible for anchoring the peptide to the interfaces, and that this same region displays some degree of conformational order in solution. For PW2, we found that affinity is related to the aromatic region, by anchoring the peptide to the membrane, and specificity is related to the N- and C-termini, which are able to accommodate in the membrane due to its plasticity.
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Affiliation(s)
- C Cruzeiro-Silva
- Centro Nacional de Ressonância Magnética Nuclear Jiri Jonas, Programa de Biologia Estrutural, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil
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