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Pan F, Li Y, Ding Y, Lv S, You R, Hadianamrei R, Tomeh MA, Zhao X. Anticancer effect of rationally designed α-helical amphiphilic peptides. Colloids Surf B Biointerfaces 2022; 220:112841. [PMID: 36174494 DOI: 10.1016/j.colsurfb.2022.112841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/08/2022] [Accepted: 09/11/2022] [Indexed: 10/14/2022]
Abstract
Anticancer peptides (ACPs) have attracted increasing attention in cancer therapy due to their unique mechanism of action on cancer cells. The main challenge is to establish the correlation between their physicochemical properties and their selectivity and anticancer effect, leading to a clear design strategy. In this study, a series of new α-helical short peptides (coded At1-At12) with different anticancer activities were systematically designed with different amphiphilicity based on a natural α-helical antimicrobial peptide (AMP) derived from ant. Three of the designed peptides, At7, At10 and At11, showed considerable anticancer activity with low toxicity to normal skin fibroblasts. The high selectivity of the peptides is attributed to their balanced amphiphilicity and cationic nature which favours binding to the outer membrane of negatively charged cancer cells over the neutral membrane of normal mammalian cells. In addition to rapid membrane penetration, the designed peptides also damaged the mitochondria and induced mitochondrial membrane depolarization. Moreover, these peptides were found to induce apoptosis in cancer cells by up-regulating the expression of apoptotic proteins Bax and Caspase-3, down-regulating the apoptotic protein Bcl-2, and activating the Caspase enzyme-linked reaction. The results of this study reveal the potential of these peptides for clinical applications, and provide a guidance for further development of highly selective anticancer medications.
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Affiliation(s)
- Fang Pan
- School of Pharmacy, Changzhou University, Changzhou 213164, China
| | - Yueping Li
- School of Pharmacy, Changzhou University, Changzhou 213164, China
| | - Yujie Ding
- School of Pharmacy, Changzhou University, Changzhou 213164, China
| | - Songwei Lv
- School of Pharmacy, Changzhou University, Changzhou 213164, China
| | - Rongrong You
- School of Pharmacy, Changzhou University, Changzhou 213164, China
| | - Roja Hadianamrei
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, UK
| | - Mhd Anas Tomeh
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, UK
| | - Xiubo Zhao
- School of Pharmacy, Changzhou University, Changzhou 213164, China; Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD, UK.
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2
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Akutsu H. Structure and dynamics of phospholipids in membranes elucidated by combined use of NMR and vibrational spectroscopies. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183352. [DOI: 10.1016/j.bbamem.2020.183352] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 05/04/2020] [Accepted: 05/05/2020] [Indexed: 12/17/2022]
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3
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Crown ether modified peptides: Length and crown ring size impact on membrane interactions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183261. [DOI: 10.1016/j.bbamem.2020.183261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/28/2020] [Accepted: 03/04/2020] [Indexed: 11/24/2022]
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4
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Mercurio FA, Scaloni A, Caira S, Leone M. The antimicrobial peptides casocidins I and II: Solution structural studies in water and different membrane-mimetic environments. Peptides 2019; 114:50-58. [PMID: 30243923 DOI: 10.1016/j.peptides.2018.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 09/18/2018] [Accepted: 09/18/2018] [Indexed: 10/28/2022]
Abstract
Antimicrobial peptides (AMPs) represent crucial components of the natural immune defense machinery of different organisms. Generally, they are short and positively charged, and bind to and destabilize bacterial cytoplasmic membranes, ultimately leading to cell death. Natural proteolytic cleavage of αs2-casein in bovine milk generates the antimicrobial peptides casocidin I and II. In the current study, we report for the first time on a detailed structure characterization of casocidins in solution by means of Nuclear Magnetic Resonance spectroscopy (NMR). Structural studies were conducted in H2O and different membrane mimetic environments, including 2,2,2-trifluoroethanol (TFE) and lipid anionic and zwitterionic vesicles. For both peptides, results indicate a mainly disordered conformation in H2O, with a few residues in a partial helical structure. No wide increase of order occurs upon interaction with lipid vesicles. Conversely, peptide conformation becomes highly ordered in presence of TFE, with both casocidins presenting a large helical content. Our data point out a preference of casocidins to interact with model anionic membranes. These results are compatible with possible mechanisms of action underlying the antimicrobial activity of casocidins that ultimately may affect membrane bilayer stability.
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Affiliation(s)
- Flavia Anna Mercurio
- Institute of Biostructures and Bioimaging (IBB), National Research Council & Interuniversity Research Centre on Bioactive Peptides (CIRPEB), Via Mezzocannone 16, 80134 Naples, Italy
| | - Andrea Scaloni
- Proteomics & Mass Spectrometry Laboratory, ISPAAM, National Research Council, Via Argine 1085, 80147 Naples, Italy
| | - Simonetta Caira
- Proteomics & Mass Spectrometry Laboratory, ISPAAM, National Research Council, Via Argine 1085, 80147 Naples, Italy
| | - Marilisa Leone
- Institute of Biostructures and Bioimaging (IBB), National Research Council & Interuniversity Research Centre on Bioactive Peptides (CIRPEB), Via Mezzocannone 16, 80134 Naples, Italy.
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5
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Paquet-Côté PA, Fillion M, Provencher MÈ, Otis F, Dionne J, Cardinal S, Collignon B, Bürck J, Lagüe P, Ulrich AS, Auger M, Voyer N. Crown ether modified peptide interactions with model membranes‡. Supramol Chem 2019. [DOI: 10.1080/10610278.2019.1574349] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
| | - Matthieu Fillion
- Département de chimie, PROTEO, CERMA and CQMF, Université Laval, Québec, Canada
| | | | - François Otis
- Département de chimie and PROTEO, Université Laval, Québec, Canada
| | - Justine Dionne
- Département de chimie, PROTEO, CERMA and CQMF, Université Laval, Québec, Canada
| | | | - Barbara Collignon
- Département de biochimie, de microbiologie et de bio-informatique and PROTEO, Université Laval, Québec, Canada
| | - Jochen Bürck
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Patrick Lagüe
- Département de biochimie, de microbiologie et de bio-informatique and PROTEO, Université Laval, Québec, Canada
| | - Anne S. Ulrich
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Michèle Auger
- Département de chimie, PROTEO, CERMA and CQMF, Université Laval, Québec, Canada
| | - Normand Voyer
- Département de chimie and PROTEO, Université Laval, Québec, Canada
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6
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Wang S, Wang T, Zhang J, Xu S, Liu H. Disruption of Tumor Cells Using a pH-Activated and Thermosensitive Antitumor Lipopeptide Containing a Leucine Zipper Structure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:8818-8827. [PMID: 29914261 DOI: 10.1021/acs.langmuir.8b00474] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Antitumor peptides may potentially alleviate the problem of chemoresistance but do not yet target tumor cells and would be cytotoxic to normal cells. Here, we designed a pH-activated and thermosensitive lipopeptide (C6-Pep) containing a leucine zipper and an alkyl chain and assessed the ability of C6-Pep to kill cancer cells. Pep, the same sequence without the N-terminal hexanoic acid moiety, was generated as a less hydrophobic control. First, lipopeptide adsorption into lipid monolayers was studied using Langmuir-Blodgett and polarization modulation infrared reflection adsorption spectroscopy. Under weakly acid conditions, electrostatic interactions between C6-Pep and negatively charged phospholipids increased the adsorption/insertion of C6-Pep (vs Pep) into lipid monolayers. Cargo leakage from liposomes was assayed to model lipopeptide-induced lipid membrane disruption. The ability of C6-Pep to disrupt liposomes depended on the peptide molecular structure/hydrophobicity, solution pH, and temperature-induced uncoiling of the zipper structure; the greatest cargo leakage from the liposome with negative charge was observed for C6-Pep at pH 5.5 under mildly hyperthermic conditions (45 °C). In vitro, C6-Pep was significantly more cytotoxic toward HeLa cells at pH 5.5 under hyperthermic conditions than at pH 7.4 and/or 37 °C. Overall, this study demonstrates that amphipathic C6-Pep can insert into cell membranes in the low-pH tumor microenvironment, whereas the application of heat promotes the uncoiling of the zipper structure, leading to the disruption of tumor cell membranes and cell death. pH-activated and thermosensitive C6-Pep represents a promising tool to kill cancer cells via a strategy that does not invoke chemoresistance and may have low side effects.
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Affiliation(s)
- Sijia Wang
- Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering , East China University of Science and Technology , Shanghai 200237 , PR China
| | - Tong Wang
- Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering , East China University of Science and Technology , Shanghai 200237 , PR China
| | - Junqi Zhang
- Key Laboratory of Medical Molecular Virology (MOE & MOH), School of Basic Medical Sciences , Fudan University , Shanghai 200032 , PR China
| | - Shouhong Xu
- Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering , East China University of Science and Technology , Shanghai 200237 , PR China
| | - Honglai Liu
- Key Laboratory for Advanced Materials, School of Chemistry and Molecular Engineering , East China University of Science and Technology , Shanghai 200237 , PR China
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Laadhari M, Arnold AA, Gravel AE, Separovic F, Marcotte I. Interaction of the antimicrobial peptides caerin 1.1 and aurein 1.2 with intact bacteria by 2 H solid-state NMR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2959-2964. [DOI: 10.1016/j.bbamem.2016.09.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 08/11/2016] [Accepted: 09/12/2016] [Indexed: 11/17/2022]
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8
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Fillion M, Goudreault M, Voyer N, Bechinger B, Auger M. Amphiphilicity Is a Key Determinant in the Membrane Interactions of Synthetic 14-mer Cationic Peptide Analogues. Biochemistry 2016; 55:6919-6930. [DOI: 10.1021/acs.biochem.6b00961] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
| | | | | | - Burkhard Bechinger
- Université de Strasbourg, CNRS, UMR7177, Institut de
Chimie, 4, Rue Blaise
Pascal, 67070 Strasbourg, France
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9
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Sun Z, Barboiu M, Legrand YM, Petit E, Rotaru A. Highly Selective Artificial Cholesteryl Crown Ether K(+)-Channels. Angew Chem Int Ed Engl 2015; 54:14473-7. [PMID: 26437848 DOI: 10.1002/anie.201506430] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 08/10/2015] [Indexed: 11/08/2022]
Abstract
The bacterial KcsA channel conducts K(+) cations at high rates while excluding Na(+) cations. Herein, we report an artificial ion-channel formed by H-bonded stacks of crown-ethers, where K(+) cation conduction is highly preferred to Na(+) cations. The macrocycles aligned along the central pore surround the K(+) cations in a similar manner to the water around the hydrated cation, compensating for the energetic cost of their dehydration. In contrast, the Na(+) cation does not fit the macrocyclic binding sites, so its dehydration is not completely compensated. The present highly K(+)-selective macrocyclic channel may be regarded as a biomimetic of the KcsA channel.
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Affiliation(s)
- Zhanhu Sun
- Adaptive Supramolecular Nanosystems Group, Institut Européen des Membranes, ENSCM-UM-CNRS UMR-5635, Place E. Bataillon, CC 047, F-34095, Montpellier Cedex 5 (France)
| | - Mihail Barboiu
- Adaptive Supramolecular Nanosystems Group, Institut Européen des Membranes, ENSCM-UM-CNRS UMR-5635, Place E. Bataillon, CC 047, F-34095, Montpellier Cedex 5 (France).
| | - Yves-Marie Legrand
- Adaptive Supramolecular Nanosystems Group, Institut Européen des Membranes, ENSCM-UM-CNRS UMR-5635, Place E. Bataillon, CC 047, F-34095, Montpellier Cedex 5 (France)
| | - Eddy Petit
- Adaptive Supramolecular Nanosystems Group, Institut Européen des Membranes, ENSCM-UM-CNRS UMR-5635, Place E. Bataillon, CC 047, F-34095, Montpellier Cedex 5 (France)
| | - Alexandru Rotaru
- Petru Poni Institute of Macromolecular Chemistry of Romanian Academy, 41A Aleea Gr. Ghica Voda, Iasi (Romania)
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10
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Sun Z, Barboiu M, Legrand YM, Petit E, Rotaru A. Highly Selective Artificial Cholesteryl Crown Ether K+-Channels. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201506430] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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11
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Fillion M, Auger M. Oriented samples: a tool for determining the membrane topology and the mechanism of action of cationic antimicrobial peptides by solid-state NMR. Biophys Rev 2015; 7:311-320. [PMID: 28510228 PMCID: PMC5425733 DOI: 10.1007/s12551-015-0167-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 02/05/2015] [Indexed: 01/12/2023] Open
Abstract
Overuse and misuse of antibiotics have led bacteria to acquire several mechanisms of resistance. In response to this, researchers have identified natural antimicrobial peptides as promising candidates to fight against multiresistant bacteria. However, their mode of action is still unclear, and a better understanding of the mode of action of these peptides is of primary importance to develop new peptides displaying high antibacterial activity and low hemolytic activity. One of the main features that defines the mechanism of action is the membrane topology of the peptide. Among the spectroscopic techniques, solid-state NMR is the technique of choice for determining the location of the peptide within the membrane. It can be achieved by performing experiments with oriented samples. In the literature, the two most common types of oriented samples are bicelles and phospholipids mechanically oriented between glass plates. The mode of perturbation of the membrane-active peptide can be studied by phosphorus-31 and deuterium NMR. On the other hand, several experiments such as nitrogen-15 and fluorine solid-state NMR, that require labeled peptides, can give valuable information on the membrane topology of the peptide. The combination of the latter techniques allows the determination of a precise topology, thus a better knowledge of the molecular determinants involved in the membrane interactions of antimicrobial peptides.
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Affiliation(s)
- Matthieu Fillion
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, G1V 0A6, Canada
| | - Michèle Auger
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC, G1V 0A6, Canada.
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12
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Kuroda K, Okumura K, Isogai H, Isogai E. The Human Cathelicidin Antimicrobial Peptide LL-37 and Mimics are Potential Anticancer Drugs. Front Oncol 2015; 5:144. [PMID: 26175965 PMCID: PMC4485164 DOI: 10.3389/fonc.2015.00144] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 06/15/2015] [Indexed: 01/08/2023] Open
Abstract
Antimicrobial peptides (AMPs) play a critical role in innate host defense against microbial pathogens in many organisms. The human cathelicidin, LL-37, has a net positive charge and is amphiphilic, and can eliminate pathogenic microbes directly via electrostatic attraction toward negatively charged bacterial membranes. A number of studies have shown that LL-37 participates in various host immune systems, such as inflammatory responses and tissue repair, in addition to its antibacterial properties. Moreover, recent evidence suggests that it is also involved in the regulation of cancer. Indeed, previous studies have suggested that human LL-37 is involved in carcinogenesis via multiple reporters, such as FPR2 (FPRL1), epidermal growth factor receptor, and ERBb2, although LL-37 and its fragments and analogs also show anticancer effects in various cancer cell lines. This discrepancy can be attributed to peptide-based factors, host membrane-based factors, and signal regulation. Here, we describe the association between AMPs and cancer with a focus on anticancer peptide functions and selectivity in an effort to understand potential therapeutic implications.
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Affiliation(s)
- Kengo Kuroda
- Laboratory of Animal Microbiology, Graduate School of Agricultural Science, Tohoku University , Sendai , Japan
| | - Kazuhiko Okumura
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Health Sciences University of Hokkaido , Hokkaido , Japan
| | - Hiroshi Isogai
- Animal Research Center, Sapporo Medical University , Sapporo , Japan
| | - Emiko Isogai
- Laboratory of Animal Microbiology, Graduate School of Agricultural Science, Tohoku University , Sendai , Japan
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Fillion M, Valois-Paillard G, Lorin A, Noël M, Voyer N, Auger M. Membrane Interactions of Synthetic Peptides with Antimicrobial Potential: Effect of Electrostatic Interactions and Amphiphilicity. Probiotics Antimicrob Proteins 2014; 7:66-74. [DOI: 10.1007/s12602-014-9177-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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Fillion M, Noël M, Lorin A, Voyer N, Auger M. Investigation of the mechanism of action of novel amphipathic peptides: insights from solid-state NMR studies of oriented lipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2173-9. [PMID: 24508758 DOI: 10.1016/j.bbamem.2014.01.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 01/26/2014] [Accepted: 01/29/2014] [Indexed: 12/12/2022]
Abstract
We have investigated in the present study the effect of both non-selective and selective cationic 14-mer peptides on the lipid orientation of DMPC bilayers by (31)P solid-state nuclear magnetic resonance (NMR) spectroscopy. Depending on the position of substitution, these peptides adopt mainly either an α-helical structure able to permeabilize DMPC and DMPG vesicles (non-selective peptides) or an intermolecular β-sheet structure only able to permeabilize DMPG vesicles (selective peptides). Several systems have been investigated, namely bilayers mechanically oriented between glass plates as well as bicelles oriented with their normal perpendicular or parallel to the external magnetic field. The results have been compared with spectral simulations with the goal of elucidating the difference in the interaction of these two types of peptides with zwitterionic lipid bilayers. The results indicate that the perturbation induced by selective peptides is much greater than that induced by non-selective peptides in all the lipid systems investigated, and this perturbation has been associated to the aggregation of the selective β-sheet peptides in these systems. On the other hand, the oriented lipid spectra obtained in the presence of non-selective peptides suggest the presence of toroidal pores. This article is part of a Special Issue entitled: Interfacially Active Peptides and Proteins. Guest Editors: William C. Wimley and Kalina Hristova.
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Affiliation(s)
- Matthieu Fillion
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC G1V 0A6, Canada
| | - Mathieu Noël
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC G1V 0A6, Canada
| | - Aurélien Lorin
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC G1V 0A6, Canada
| | - Normand Voyer
- Department of Chemistry, PROTEO, Université Laval, Québec, QC G1V 0A6, Canada
| | - Michèle Auger
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF), Université Laval, Québec, QC G1V 0A6, Canada.
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15
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Lorin A, Noël M, Provencher MÈ, Turcotte V, Cardinal S, Lagüe P, Voyer N, Auger M. Determining the mode of action involved in the antimicrobial activity of synthetic peptides: a solid-state NMR and FTIR study. Biophys J 2012; 103:1470-9. [PMID: 23062339 DOI: 10.1016/j.bpj.2012.08.055] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 08/20/2012] [Accepted: 08/28/2012] [Indexed: 10/27/2022] Open
Abstract
We have previously shown that leucine to lysine substitution(s) in neutral synthetic crown ether containing 14-mer peptide affect the peptide structure and its ability to permeabilize bilayers. Depending on the substitution position, the peptides adopt mainly either a α-helical structure able to permeabilize dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylglycerol (DMPG) vesicles (nonselective peptides) or an intermolecular β-sheet structure only able to permeabilize DMPG vesicles (selective peptides). In this study, we have used a combination of solid-state NMR and Fourier transform infrared spectroscopy to investigate the effects of nonselective α-helical and selective intermolecular β-sheet peptides on both types of bilayers. (31)P NMR results indicate that both types of peptides interact with the headgroups of DMPC and DMPG bilayers. (2)H NMR and Fourier transform infrared results reveal an ordering of the hydrophobic core of bilayers when leakage is noted, i.e., for DMPG vesicles in the presence of both types of peptides and DMPC vesicles in the presence of nonselective peptides. However, selective peptides have no significant effect on the ordering of DMPC acyl chains. The ability of these 14-mer peptides to permeabilize lipid vesicles therefore appears to be related to their ability to increase the order of the bilayer hydrophobic core.
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Affiliation(s)
- Aurélien Lorin
- Département de chimie, PROTEO (Regroupement Québécois de Recherche sur la Fonction, la Structure et l'Ingénierie des Protéines), CERMA (Centre de Recherche sur les Matériaux Avancés), Université Laval, Québec, Québec, Canada
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