1
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Zaatouf L, Kumar K, Marcotte I, Warschawski DE. Assessment of membrane labelling mechanisms with exogenous fatty acids and detergents in bacteria. Biochimie 2024:S0300-9084(24)00134-2. [PMID: 38825063 DOI: 10.1016/j.biochi.2024.05.024] [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: 03/29/2024] [Revised: 05/26/2024] [Accepted: 05/30/2024] [Indexed: 06/04/2024]
Abstract
Labelling of bacterial membranes using exogenous fatty acids has proven to be a valuable tool to investigate molecular interactions by in-cell solid-state nuclear magnetic resonance (ssNMR) spectroscopy, notably with antimicrobial peptides. However, the mechanism by which this labelling takes place in non-mutated bacteria has not yet been investigated. In this work, we propose a rapid method to assess the fate of the fatty acids during the labelling of bacteria, involving two different methylation schemes and gas chromatography coupled to mass spectrometry. We applied this approach to Gram(+) and Gram(-) bacteria grown with deuterated palmitic acid under different conditions. We assessed the extent of labelling, then the resulting membrane rigidity by 2H ssNMR. Our results reveal that the labelling mechanism depends on the detergent used to micellize the fatty acids. This labelling can be either active or passive, whether the fatty acids are metabolized and used in the phospholipids biosynthesis, or remain unmodified in the membrane. We discuss the best labelling protocol for studying peptide-membrane interactions.
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Affiliation(s)
- Laila Zaatouf
- Laboratoire des Biomolécules, LBM, CNRS UMR 7203, Sorbonne Université, École normale supérieure, PSL University, 75005, Paris, France
| | - Kiran Kumar
- Departement of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Downtown Station, Montreal, H3C 3P8, Canada
| | - Isabelle Marcotte
- Departement of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Downtown Station, Montreal, H3C 3P8, Canada
| | - Dror E Warschawski
- Laboratoire des Biomolécules, LBM, CNRS UMR 7203, Sorbonne Université, École normale supérieure, PSL University, 75005, Paris, France.
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2
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Sani MA, Rajput S, Keizer DW, Separovic F. NMR techniques for investigating antimicrobial peptides in model membranes and bacterial cells. Methods 2024; 224:10-20. [PMID: 38295893 DOI: 10.1016/j.ymeth.2024.01.012] [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: 10/31/2023] [Revised: 01/07/2024] [Accepted: 01/08/2024] [Indexed: 02/05/2024] Open
Abstract
AMPs are short, mainly cationic membrane-active peptides found in all living organism. They perform diverse roles including signaling and acting as a line of defense against bacterial infections. AMPs have been extensively investigated as templates to facilitate the development of novel antimicrobial therapeutics. Understanding the interplay between these membrane-active peptides and the lipid membranes is considered to be a significant step in elucidating the specific mechanism of action of AMPs against prokaryotic and eukaryotic cells to aid the development of new therapeutics. In this review, we have provided a brief overview of various NMR techniques commonly used for studying AMP structure and AMP-membrane interactions in model membranes and whole cells.
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Affiliation(s)
- Marc-Antoine Sani
- Bio21 Institute, University of Melbourne, Melbourne, VIC 3010, Australia.
| | - Sunnia Rajput
- Bio21 Institute, University of Melbourne, Melbourne, VIC 3010, Australia
| | - David W Keizer
- Bio21 Institute, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Frances Separovic
- Bio21 Institute, University of Melbourne, Melbourne, VIC 3010, Australia; School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia
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3
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Kumar K, Arnold AA, Gauthier R, Mamone M, Paquin JF, Warschawski DE, Marcotte I. 19F solid-state NMR approaches to probe antimicrobial peptide interactions with membranes in whole cells. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184269. [PMID: 38176532 DOI: 10.1016/j.bbamem.2023.184269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 01/06/2024]
Abstract
To address the global problem of bacterial antibiotic resistance, antimicrobial peptides (AMPs) are considered promising therapeutic candidates due to their broad-spectrum and membrane-lytic activity. As preferential interactions with bacteria are crucial, it is equally important to investigate and understand their impact on eukaryotic cells. In this study, we employed 19F solid-state nuclear magnetic resonance (ssNMR) as a novel approach to examine the interaction of AMPs with whole red blood cells (RBCs). We used RBC ghosts (devoid of hemoglobin) and developed a protocol to label their lipid membranes with palmitic acid (PA) monofluorinated at carbon positions 4, 8, or 14 on the acyl chain, allowing us to probe different locations in model and intact RBC ghost membranes. Our work revealed that changes in the 19F chemical shift anisotropy, monitored through a CF bond order parameter (SCF), can provide insights into lipid bilayer dynamics. This information was also obtained using magic-angle spinning 19F ssNMR spectra with and without 1H decoupling, by studying alterations in the second spectral moment (M2) as well as the 19F isotropic chemical shift, linewidth, T1, and T2 relaxation times. The appearance of an additional isotropic peak with a smaller chemical shift anisotropy, a narrower linewidth, and a shorter T1, induced by the AMP caerin 1.1, supports the presence of high-curvature regions in RBCs indicative of pore formation, analogous to its antimicrobial mechanism. In summary, the straightforward incorporation of monofluorinated FAs and rapid signal acquisition offer promising avenues for the study of whole cells using 19F ssNMR.
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Affiliation(s)
- Kiran Kumar
- Departement of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Downtown Station, Montreal H3C 3P8, Canada
| | - Alexandre A Arnold
- Departement of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Downtown Station, Montreal H3C 3P8, Canada
| | - Raphaël Gauthier
- PROTEO, CCVC, Département de chimie, Université Laval, 1045 Avenue de la Médecine, Québec, Québec G1V 0A6, Canada
| | - Marius Mamone
- PROTEO, CCVC, Département de chimie, Université Laval, 1045 Avenue de la Médecine, Québec, Québec G1V 0A6, Canada
| | - Jean-François Paquin
- PROTEO, CCVC, Département de chimie, Université Laval, 1045 Avenue de la Médecine, Québec, Québec G1V 0A6, Canada
| | - Dror E Warschawski
- Departement of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Downtown Station, Montreal H3C 3P8, Canada; Laboratoire des Biomolécules, LBM, CNRS UMR 7203, Sorbonne Université, École normale supérieure, PSL University, 75005 Paris, France.
| | - Isabelle Marcotte
- Departement of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Downtown Station, Montreal H3C 3P8, Canada.
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4
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Werby SH, Brčić J, Chosy MB, Sun J, Rendell JT, Neville LF, Wender PA, Cegelski L. Detection of intact vancomycin-arginine as the active antibacterial conjugate in E. coli by whole-cell solid-state NMR. RSC Med Chem 2023; 14:1192-1198. [PMID: 37360389 PMCID: PMC10285746 DOI: 10.1039/d3md00173c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/13/2023] [Indexed: 06/28/2023] Open
Abstract
The introduction of new and improved antibacterial agents based on facile synthetic modifications of existing antibiotics represents a promising strategy to deliver urgently needed antibacterial candidates to treat multi-drug resistant bacterial infections. Using this strategy, vancomycin was transformed into a highly active agent against antibiotic-resistant Gram-negative organisms in vitro and in vivo through the addition of a single arginine to yield vancomycin-arginine (V-R). Here, we report detection of the accumulation of V-R in E. coli by whole-cell solid-state NMR using 15N-labeled V-R. 15N CPMAS NMR revealed that the conjugate remained fully amidated without loss of arginine, demonstrating that intact V-R represents the active antibacterial agent. Furthermore, C{N}REDOR NMR in whole cells with all carbons at natural abundance 13C levels exhibited the sensitivity and selectivity to detect the directly bonded 13C-15N pairs of V-R within E. coli cells. Thus, we also present an effective methodology to directly detect and evaluate active drug agents and their accumulation within bacteria without the need for potentially perturbative cell lysis and analysis protocols.
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Affiliation(s)
- Sabrina H Werby
- Department of Chemistry, Stanford University Stanford CA 94305 USA
| | - Jasna Brčić
- Department of Chemistry, Stanford University Stanford CA 94305 USA
| | - Madeline B Chosy
- Department of Chemistry, Stanford University Stanford CA 94305 USA
| | - Jiuzhi Sun
- Department of Chemistry, Stanford University Stanford CA 94305 USA
| | | | | | - Paul A Wender
- Department of Chemistry, Stanford University Stanford CA 94305 USA
- Department of Chemical and Systems Biology, Stanford University Stanford CA 94305 USA
| | - Lynette Cegelski
- Department of Chemistry, Stanford University Stanford CA 94305 USA
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5
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Avilova IA, Chernyak AV, Soldatova YV, Mumyatov AV, Kraevaya OA, Khakina EA, Troshin PA, Volkov VI. Self-Organization of Fullerene Derivatives in Solutions and Biological Cells Studied by Pulsed Field Gradient NMR. Int J Mol Sci 2022; 23:ijms232113344. [PMID: 36362124 PMCID: PMC9658325 DOI: 10.3390/ijms232113344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 10/24/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022] Open
Abstract
Fullerene derivatives are of great interest in various fields of science and technology. Fullerene derivatives are known to have pronounced anticancer and antiviral activity. They have antibacterial properties. Their properties are largely determined by association processes. Understanding the nature and properties of associates in solvents of various types will make it possible to make significant progress in understanding the mechanisms of aggregation of molecules of fullerene derivatives in solutions. Thus, this work, aimed at studying the size and stability of associates, is relevant and promising for further research. The NMR method in a pulsed field gradient was used, which makes it possible to directly study the translational mobility of molecules. The sizes of individual molecules and associates were calculated based on the Stokes–Einstein model. The lifetime of associates was also estimated. The interaction of water-soluble C60 fullerene derivatives with erythrocytes was also evaluated. The values of self-diffusion coefficients and the lifetime of molecules of their compounds in cell membranes are obtained. It is concluded that the molecules of fullerene derivatives are fixed on the cell surface, and their forward movement is controlled by lateral diffusion.
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Affiliation(s)
- Irina A. Avilova
- Federal Research Center for Problems of Chemical Physics and Medicinal Chemistry RAS, 142432 Chernogolovka, Russia
| | - Alexander V. Chernyak
- Federal Research Center for Problems of Chemical Physics and Medicinal Chemistry RAS, 142432 Chernogolovka, Russia
- Scientific Center in Chernogolovka RAS, 142432 Chernogolovka, Russia
| | - Yuliya V. Soldatova
- Federal Research Center for Problems of Chemical Physics and Medicinal Chemistry RAS, 142432 Chernogolovka, Russia
| | - Alexander V. Mumyatov
- Federal Research Center for Problems of Chemical Physics and Medicinal Chemistry RAS, 142432 Chernogolovka, Russia
| | - Olga A. Kraevaya
- Federal Research Center for Problems of Chemical Physics and Medicinal Chemistry RAS, 142432 Chernogolovka, Russia
| | | | - Pavel A. Troshin
- Federal Research Center for Problems of Chemical Physics and Medicinal Chemistry RAS, 142432 Chernogolovka, Russia
| | - Vitaliy I. Volkov
- Federal Research Center for Problems of Chemical Physics and Medicinal Chemistry RAS, 142432 Chernogolovka, Russia
- Scientific Center in Chernogolovka RAS, 142432 Chernogolovka, Russia
- Correspondence:
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6
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Kumari S, Morrow MR, Booth V. Role of lipopolysaccharide in antimicrobial and cell penetrating peptide membrane interactions probed by deuterium NMR of whole cells. BBA ADVANCES 2022; 2:100057. [PMID: 37082590 PMCID: PMC10074874 DOI: 10.1016/j.bbadva.2022.100057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Abstract
Understanding how non-lipid components of bacteria affect antimicrobial peptide (AMP)-induced membrane disruption is important for a comprehensive understanding of AMP mechanisms and informing AMP-based drug development. This study investigates how lipopolysaccharide (LPS) affects membrane disruption by the AMP MSI-78 and compares the results to the effect of TP2, a cell-penetrating peptide that crosses membrane bilayers without permeabilizing them. We destabilize the LPS layer of Escherichia coli (E. coli) cells via chelation of the stabilizing divalent cations. 2H NMR spectra of E. coli demonstrate that EDTA concentrations of 2.5 mM and 9.0 mM alone have very minor effects on lipid acyl chain order. Interestingly, we find that E. coli pre-treated with 9.0 mM EDTA before treatment with MSI-78 are more sensitive to AMP-induced acyl chain disruption, indicating that intact LPS reduces MSI-78-induced membrane disruption in E. coli. Surprisingly, we also found that at the level of 2H_NMR, the peptide-induced acyl chain disruption is similar for MSI-78 and TP2, although MSI-78 permeabilizes the bilayer and TP2 does not. Furthermore, LPS disruption appears to protect the bacteria from TP2, although it sensitizes them to MSI-78.
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7
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Characterization of inositol lipid metabolism in gut-associated Bacteroidetes. Nat Microbiol 2022; 7:986-1000. [PMID: 35725777 PMCID: PMC9246714 DOI: 10.1038/s41564-022-01152-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 05/17/2022] [Indexed: 12/13/2022]
Abstract
Inositol lipids are ubiquitous in eukaryotes and have finely tuned roles in cellular signalling and membrane homoeostasis. In Bacteria, however, inositol lipid production is relatively rare. Recently, the prominent human gut bacterium Bacteroides thetaiotaomicron (BT) was reported to produce inositol lipids and sphingolipids, but the pathways remain ambiguous and their prevalence unclear. Here, using genomic and biochemical approaches, we investigated the gene cluster for inositol lipid synthesis in BT using a previously undescribed strain with inducible control of sphingolipid synthesis. We characterized the biosynthetic pathway from myo-inositol-phosphate (MIP) synthesis to phosphoinositol dihydroceramide, determined the crystal structure of the recombinant BT MIP synthase enzyme and identified the phosphatase responsible for the conversion of bacterially-derived phosphatidylinositol phosphate (PIP-DAG) to phosphatidylinositol (PI-DAG). In vitro, loss of inositol lipid production altered BT capsule expression and antimicrobial peptide resistance. In vivo, loss of inositol lipids decreased bacterial fitness in a gnotobiotic mouse model. We identified a second putative, previously undescribed pathway for bacterial PI-DAG synthesis without a PIP-DAG intermediate, common in Prevotella. Our results indicate that inositol sphingolipid production is widespread in host-associated Bacteroidetes and has implications for symbiosis. The pathways responsible for inositol lipid production in human gut Bacteroides are characterized and these lipids are important for capsule expression and antimicrobial peptide resistance in vitro and colonization in vivo.
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8
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Kumari S, Booth V. Antimicrobial Peptide Mechanisms Studied by Whole-Cell Deuterium NMR. Int J Mol Sci 2022; 23:ijms23052740. [PMID: 35269882 PMCID: PMC8910884 DOI: 10.3390/ijms23052740] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/24/2022] [Accepted: 02/26/2022] [Indexed: 12/29/2022] Open
Abstract
Much of the work probing antimicrobial peptide (AMP) mechanisms has focussed on how these molecules permeabilize lipid bilayers. However, AMPs must also traverse a variety of non-lipid cell envelope components before they reach the lipid bilayer. Additionally, there is a growing list of AMPs with non-lipid targets inside the cell. It is thus useful to extend the biophysical methods that have been traditionally applied to study AMP mechanisms in liposomes to the full bacteria, where the lipids are present along with the full complexity of the rest of the bacterium. This review focusses on what can be learned about AMP mechanisms from solid-state NMR of AMP-treated intact bacteria. It also touches on flow cytometry as a complementary method for measuring permeabilization of bacterial lipid membranes in whole bacteria.
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Affiliation(s)
- Sarika Kumari
- Department of Biochemistry, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada;
| | - Valerie Booth
- Department of Biochemistry, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada;
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada
- Correspondence: ; Tel.: +1-709-864-4523
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9
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Kumar K, Sebastiao M, Arnold AA, Bourgault S, Warschawski DE, Marcotte I. IN SITU SOLID-STATE NMR STUDY OF ANTIMICROBIAL PEPTIDE INTERACTIONs WITH ERYTHROCYTE MEMBRANES. Biophys J 2022; 121:1512-1524. [PMID: 35278426 PMCID: PMC9072582 DOI: 10.1016/j.bpj.2022.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/01/2022] [Accepted: 03/07/2022] [Indexed: 11/02/2022] Open
Abstract
Antimicrobial peptides are promising therapeutic agents to mitigate the global rise of antibiotic resistance. They generally act by perturbing the bacterial cell membrane and are thus less likely to induce resistance. Because they are membrane-active molecules, it is critical to verify and understand their potential action toward eukaryotic cells to help design effective and safe drugs. In this work, we studied the interaction of two antimicrobial peptides, aurein 1.2 and caerin 1.1, with red blood cell (RBC) membranes using in situ 31P and 2H solid-state NMR (SS-NMR). We established a protocol to integrate up to 25% of deuterated fatty acids in the membranes of ghosts, which are obtained when hemoglobin is removed from RBCs. Fatty acid incorporation and the integrity of the lipid bilayer were confirmed by SS-NMR and fluorescence confocal microscopy. Leakage assays were performed to assess the lytic power of the antimicrobial peptides. The in situ perturbation of the ghost membranes by aurein 1.2 and caerin 1.1 revealed by 31P and 2H SS-NMR is consistent with membrane perturbation through a carpet mechanism for aurein 1.2, whereas caerin 1.1 acts on RBCs via pore formation. These results are compatible with fluorescence microscopy images of the ghosts. The peptides interact with eukaryotic membranes following similar mechanisms that take place in bacteria, highlighting the importance of hydrophobicity when determining such interactions. Our work bridges model membranes and in vitro studies and provides an analytical toolbox to assess drug toxicity toward eukaryotic cells.
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10
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Booth V. Deuterium Solid State NMR Studies of Intact Bacteria Treated With Antimicrobial Peptides. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 2:621572. [PMID: 35047897 PMCID: PMC8757836 DOI: 10.3389/fmedt.2020.621572] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 12/10/2020] [Indexed: 11/13/2022] Open
Abstract
Solid state NMR has been tremendously useful in characterizing the structure and dynamics of model membranes composed of simple lipid mixtures. Model lipid studies employing solid state NMR have included important work revealing how membrane bilayer structure and dynamics are affected by molecules such as antimicrobial peptides (AMPs). However, solid state NMR need not be applied only to model membranes, but can also be used with living, intact cells. NMR of whole cells holds promise for helping resolve some unsolved mysteries about how bacteria interact with AMPs. This mini-review will focus on recent studies using 2H NMR to study how treatment with AMPs affect membranes in intact bacteria.
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Affiliation(s)
- Valerie Booth
- Department of Biochemistry and Department of Physics and Physical Oceanograpy, Memorial University of Newfoundland, St. John's, NL, Canada
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11
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Ghassemi N, Poulhazan A, Deligey F, Mentink-Vigier F, Marcotte I, Wang T. Solid-State NMR Investigations of Extracellular Matrixes and Cell Walls of Algae, Bacteria, Fungi, and Plants. Chem Rev 2021; 122:10036-10086. [PMID: 34878762 DOI: 10.1021/acs.chemrev.1c00669] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Extracellular matrixes (ECMs), such as the cell walls and biofilms, are important for supporting cell integrity and function and regulating intercellular communication. These biomaterials are also of significant interest to the production of biofuels and the development of antimicrobial treatment. Solid-state nuclear magnetic resonance (ssNMR) and magic-angle spinning-dynamic nuclear polarization (MAS-DNP) are uniquely powerful for understanding the conformational structure, dynamical characteristics, and supramolecular assemblies of carbohydrates and other biomolecules in ECMs. This review highlights the recent high-resolution investigations of intact ECMs and native cells in many organisms spanning across plants, bacteria, fungi, and algae. We spotlight the structural principles identified in ECMs, discuss the current technical limitation and underexplored biochemical topics, and point out the promising opportunities enabled by the recent advances of the rapidly evolving ssNMR technology.
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Affiliation(s)
- Nader Ghassemi
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Alexandre Poulhazan
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States.,Department of Chemistry, Université du Québec à Montréal, Montreal H2X 2J6, Canada
| | - Fabien Deligey
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | | | - Isabelle Marcotte
- Department of Chemistry, Université du Québec à Montréal, Montreal H2X 2J6, Canada
| | - Tuo Wang
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
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12
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Laydevant F, Mahabadi M, Llido P, Bourgouin JP, Caron L, Arnold AA, Marcotte I, Warschawski DE. Growth-phase dependence of bacterial membrane lipid profile and labeling for in-cell solid-state NMR applications. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1864:183819. [PMID: 34800428 DOI: 10.1016/j.bbamem.2021.183819] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/31/2021] [Accepted: 11/05/2021] [Indexed: 10/19/2022]
Abstract
Cell labeling is a preliminary step in multiple biophysical approaches, including the solid-state nuclear magnetic resonance (NMR) study of bacteria in vivo. Deuterium solid-state NMR has been used in the past years to probe bacterial membranes and their interactions with antimicrobial peptides, following a standard labeling protocol. Recent results from our laboratory on a slow-growing bacterium has shown the need to optimize this protocol, especially the bacterial growth time before harvest and the concentration of exogenous labeled fatty acids to be used for both Escherichia coli and Bacillus subtilis. It is also essential for the protocol to remain harmless to cells while providing optimal labeling. We have therefore developed a fast and facile approach to monitor the lipid composition of bacterial membranes under various growth conditions, combining solution 31P NMR and GCMS. Using this approach, the optimized labeling conditions of Escherichia coli and Bacillus subtilis with deuterated palmitic acid were determined. Our results show a modification of B. subtilis phospholipid profile as a function of the growth stage, as opposed to E. coli. Our protocol recommends low concentrations of exogenous palmitic acid in the growth medium, and bacteria harvest after the exponential phase.
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Affiliation(s)
- Florent Laydevant
- Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montreal H3C 3P8, Canada
| | - Mahsa Mahabadi
- Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montreal H3C 3P8, Canada
| | - Pierre Llido
- Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montreal H3C 3P8, Canada
| | - Jean-Philippe Bourgouin
- Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montreal H3C 3P8, Canada
| | - Laurence Caron
- Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montreal H3C 3P8, Canada
| | - Alexandre A Arnold
- Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montreal H3C 3P8, Canada
| | - Isabelle Marcotte
- Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montreal H3C 3P8, Canada.
| | - Dror E Warschawski
- Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montreal H3C 3P8, Canada; Laboratoire des Biomolécules, LBM, CNRS UMR 7203, Sorbonne Université, École normale supérieure, PSL University, 75005 Paris, France.
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13
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Investigating the action of the microalgal pigment marennine on Vibrio splendidus by in vivo 2H and 31P solid-state NMR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183642. [PMID: 34000261 DOI: 10.1016/j.bbamem.2021.183642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/28/2021] [Accepted: 05/04/2021] [Indexed: 11/21/2022]
Abstract
This work investigates the potential probiotic effect of marennine - a natural pigment produced by the diatom Haslea ostrearia - on Vibrio splendidus. These marine bacteria are often considered a threat for aquaculture; therefore, chemical antibiotics can be required to reduce bacterial outbreaks. In vivo2H solid-state NMR was used to probe the effects of marennine on the bacterial membrane in the exponential and stationary phases. Comparisons were made with polymyxin B (PxB) - an antibiotic used in aquaculture and known to interact with Gram(-) bacteria membranes. We also investigated the effect of marennine using 31P solid-state NMR on model membranes. Our results show that marennine has little effect on phospholipid headgroups dynamics, but reduces the acyl chain fluidity. Our data suggest that the two antimicrobial agents perturb V. splendidus membranes through different mechanisms. While PxB would alter the bacterial outer and inner membranes, marennine would act through a membrane stiffening mechanism, without affecting the bilayer integrity. Our study proposes this microalgal pigment, which is harmless for humans, as a potential treatment against vibriosis.
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14
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Separovic F, Keizer DW, Sani MA. In-cell Solid-State NMR Studies of Antimicrobial Peptides. FRONTIERS IN MEDICAL TECHNOLOGY 2020; 2:610203. [PMID: 35047891 PMCID: PMC8757805 DOI: 10.3389/fmedt.2020.610203] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/30/2020] [Indexed: 12/23/2022] Open
Abstract
Antimicrobial peptides (AMPs) have attracted attention as alternatives to classic antibiotics due to their expected limited pressure on bacterial resistance mechanisms. Yet, their modes of action, in particular in vivo, remain to be elucidated. In situ atomistic-scale details of complex biomolecular assemblies is a challenging requirement for deciphering the complex modes of action of AMPs. The large diversity of molecules that modulate complex interactions limits the resolution achievable using imaging methodology. Herein, the latest advances in in-cell solid-state NMR (ssNMR) are discussed, which demonstrate the power of this non-invasive technique to provide atomic details of molecular structure and dynamics. Practical requirements for investigations of intact bacteria are discussed. An overview of recent in situ NMR investigations of the architecture and metabolism of bacteria and the effect of AMPs on various bacterial structures is presented. In-cell ssNMR revealed that the studied AMPs have a disruptive action on the molecular packing of bacterial membranes and DNA. Despite the limited number of studies, in-cell ssNMR is emerging as a powerful technique to monitor in situ the interplay between bacteria and AMPs.
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Affiliation(s)
- Frances Separovic
- School of Chemistry, University of Melbourne, Melbourne, VIC, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, Australia
| | - David W. Keizer
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Marc-Antoine Sani
- School of Chemistry, University of Melbourne, Melbourne, VIC, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, Australia
- *Correspondence: Marc-Antoine Sani
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15
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Effect of AMPs MSI-78 and BP100 on the lipid acyl chains of 2H-labeled intact Gram positive bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183199. [DOI: 10.1016/j.bbamem.2020.183199] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/05/2020] [Accepted: 01/15/2020] [Indexed: 01/30/2023]
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16
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Bouhlel Z, Arnold AA, Warschawski DE, Lemarchand K, Tremblay R, Marcotte I. Labelling strategy and membrane characterization of marine bacteria Vibrio splendidus by in vivo 2H NMR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:871-878. [DOI: 10.1016/j.bbamem.2019.01.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/03/2019] [Accepted: 01/31/2019] [Indexed: 01/15/2023]
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17
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Falaise C, Cormier P, Tremblay R, Audet C, Deschênes JS, Turcotte F, François C, Seger A, Hallegraeff G, Lindquist N, Sirjacobs D, Gobert S, Lejeune P, Demoulin V, Mouget JL. Harmful or harmless: Biological effects of marennine on marine organisms. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 209:13-25. [PMID: 30684731 DOI: 10.1016/j.aquatox.2019.01.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 01/16/2019] [Accepted: 01/17/2019] [Indexed: 06/09/2023]
Abstract
Marennine is a water-soluble blue-green pigment produced by the marine diatom Haslea ostrearia. The diatom and its pigment are well known from oyster farming areas as the source of the greening of oyster gills, a natural process increasing their market value in Western France. Blooms of blue Haslea are also present outside oyster ponds and hence marine organisms can be exposed, periodically and locally, to significant amounts of marennine in natural environments. Due to its demonstrated antibacterial activities against marine pathogenic bacteria (e.g. Vibrio) and possible prophylactic effects toward bivalve larvae, marennine is of special interest for the aquaculture industry, especially bivalve hatcheries. The present study aimed to provide new insights into the effects of marennine on a large spectrum of marine organisms belonging to different phyla, including species of aquaculture interest and organisms frequently employed in standardised ecotoxicological assays. Different active solutions containing marennine were tested: partially purified Extracellular Marennine (EMn), and concentrated solutions of marennine present in H. ostrearia culture supernatant; the Blue Water (BW) and a new process called Concentrated Supernatant (CS). Biological effects were meanwhile demonstrated in invertebrate species for the three marennine-based solutions at the highest concentrations tested (e.g., decrease of fertilization success, delay of embryonic developmental stages or larval mortality). Exposure to low concentrations did not impact larval survival or development and even tended to enhance larval physiological state. Furthermore, no effects of marennine were observed on the fish gill cell line tested. Marennine could be viewed as a Jekyll and Hyde molecule, which possibly affects the earliest stages of development of some organisms but with no direct impacts on adults. Our results emphasize the need to determine dosages that optimize beneficial effects and critical concentrations not to be exceeded before considering the use of marennine in bivalve or fish hatcheries.
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Affiliation(s)
- Charlotte Falaise
- Laboratoire Mer Molécule Santé (EA 2160, FR CNRS 3473 IUML), Le Mans Université, Le Mans, France
| | - Patrick Cormier
- Sorbonne Universités (UPMC Paris 06, CNRS, UMR 8227) Biologie Intégrative des Modèles Marins, Station Biologique de Roscoff, Roscoff, France
| | - Réjean Tremblay
- Institut des sciences de la mer, Université du Québec à Rimouski, Rimouski, Canada
| | - Céline Audet
- Institut des sciences de la mer, Université du Québec à Rimouski, Rimouski, Canada
| | | | - François Turcotte
- Institut des sciences de la mer, Université du Québec à Rimouski, Rimouski, Canada
| | - Cyrille François
- Ifremer, RBE-SG2M-LGPMM, Laboratoire de Génétique et de Pathologie des Mollusques Marins, Station La Tremblade, Avenue Mus Loup, F-17390, La Tremblade, France
| | - Andreas Seger
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Hobart, Australia; South Australian Research and Development Institute (SARDI), Urrbrae, South Australia, Australia
| | - Gustaaf Hallegraeff
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Hobart, Australia
| | - Niels Lindquist
- Institute of Marine Sciences, University of North Carolina, Chapel Hill, United States
| | - Damien Sirjacobs
- INBIOS - PHYTOSYSTEMS, Eukaryotic Phylogenomics, Liège University, Liège, Belgium
| | - Sylvie Gobert
- Station de Recherche Sous-marines et Océanographiques (STARESO), 20260, Calvi, France; Université de Liège, MARE, Focus, Océanologie Biologique, Liège, Belgium
| | - Pierre Lejeune
- Station de Recherche Sous-marines et Océanographiques (STARESO), 20260, Calvi, France
| | - Vincent Demoulin
- INBIOS - PHYTOSYSTEMS, Eukaryotic Phylogenomics, Liège University, Liège, Belgium
| | - Jean-Luc Mouget
- Laboratoire Mer Molécule Santé (EA 2160, FR CNRS 3473 IUML), Le Mans Université, Le Mans, France.
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Complex Relationships between the Blue Pigment Marennine and Marine Bacteria of the Genus Vibrio. Mar Drugs 2019; 17:md17030160. [PMID: 30857186 PMCID: PMC6471480 DOI: 10.3390/md17030160] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 02/28/2019] [Accepted: 03/04/2019] [Indexed: 12/15/2022] Open
Abstract
Marennine, the water-soluble blue pigment produced by the marine diatom Haslea ostrearia, is known to display antibacterial activities. Previous studies have demonstrated a prophylactic effect of marennine on bivalve larvae challenged with a pathogenic Vibrio splendidus, suggesting that the blue Haslea is a good candidate for applications in aquaculture as a source of a natural antimicrobial agent. Indeed, the genus Vibrio is ubiquitous in aquaculture ecosystems, and regular events of pathogenic invasion cause some of the biggest losses worldwide. To better characterize the effects of marennine on Vibrios, a panel of 30 Vibrio strains belonging to 10 different species was tested, including bivalve pathogenic species (e.g., Vibrio crassostreae and Vibrio harveyi). Vibrio strains were first exposed to 10 and 25 µg mL-1 of Blue Water (BW), a concentrated culture supernatant of H. ostrearia containing marennine. This screening evidenced a great diversity in responses, from growth stimulation to a total inhibition, at both the interspecific or intraspecific level. In a second series of experiments, 10 Vibrio strains were exposed to BW at concentrations ranging from 5 to 80 µg mL-1. The highest concentrations of BW did not systematically result in the highest growth inhibition as hormetic responses-opposite effects regarding the concentration-were occasionally evidenced. The relationships between marennine and Vibrio strains appear more complex than expected and justify further study-in particular, on the mechanisms of action-before considering applications as a natural prophylactic or antibiotic agent in aquaculture.
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Avilova I, Khakina E, Kraevaya O, Kotelnikov A, Kotelnikova R, Troshin P, Volkov V. Self-diffusion of water-soluble fullerene derivatives in mouse erythrocytes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1537-1543. [PMID: 29792833 DOI: 10.1016/j.bbamem.2018.05.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 05/15/2018] [Accepted: 05/18/2018] [Indexed: 02/02/2023]
Abstract
Self-diffusion of water-soluble fullerene derivative (WSFD) C60[S(CH2)3SO3Na]5H in mouse red blood cells (RBC) was characterized by 1H pulsed field gradient NMR technique. It was found that a fraction of fullerene molecules (~13% of the fullerene derivative added in aqueous RBC suspension) shows a self-diffusion coefficient of (5.5 ± 0.8)·10-12 m2/s, which is matching the coefficient of the lateral diffusion of lipids in the erythrocyte membrane (DL = (5.4 ± 0.8)·10-12 m2/s). This experimental finding evidences the absorption of the fullerene derivative by RBC. Fullerene derivative molecules are also absorbed by RBC ghosts and phosphatidylcholine liposomes as manifested in self-diffusion coefficients of (7.9 ± 1.2)·10-12 m2/s and (7.7 ± 1.2)·10-12 m2/s, which are also close to the lateral diffusion coefficients of (6.5 ± 1.0)·10-12 m2/s and (8.5 ± 1.3)·10-12 m2/s, respectively. The obtained results suggest that fullerene derivative molecules are, probably, fixed on the RBC surface. The average residence time of the fullerene derivative molecule on RBC was estimated as 440 ± 70 ms. Thus, the pulsed field gradient NMR was shown to be a versatile technique for investigation of the interactions of the fullerene derivatives with blood cells providing essential information, which can be projected on their behavior in-vivo after intravenous administration while screening as potential drug candidates.
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Affiliation(s)
- Irina Avilova
- Institute of Problems of Chemical Physics, RAS, Academician Semenov avenue 1, Chernogolovka 142432, Moscow Region, Russia
| | - Ekaterina Khakina
- Institute of Problems of Chemical Physics, RAS, Academician Semenov avenue 1, Chernogolovka 142432, Moscow Region, Russia
| | - Ol''ga Kraevaya
- Institute of Problems of Chemical Physics, RAS, Academician Semenov avenue 1, Chernogolovka 142432, Moscow Region, Russia; Higher Chemical College, Russian Academy of Sciences, D. I. Mendeleev University of Chemical Technology, Miusskaya 9, 125047 Moscow, Russia
| | - Alexander Kotelnikov
- Institute of Problems of Chemical Physics, RAS, Academician Semenov avenue 1, Chernogolovka 142432, Moscow Region, Russia
| | - Raisa Kotelnikova
- Institute of Problems of Chemical Physics, RAS, Academician Semenov avenue 1, Chernogolovka 142432, Moscow Region, Russia
| | - Pavel Troshin
- Skolkovo Institute of Science and Technology, Nobel st. 3, 143026 Moscow, Russia; Institute of Problems of Chemical Physics, RAS, Academician Semenov avenue 1, Chernogolovka 142432, Moscow Region, Russia
| | - Vitaliy Volkov
- Institute of Problems of Chemical Physics, RAS, Academician Semenov avenue 1, Chernogolovka 142432, Moscow Region, Russia; Science Center in Chernogolovka, RAS, Lesnaya str. 9, Chernogolovka 142432, Moscow Region, Russia.
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20
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Cardoso MH, Oshiro KG, Rezende SB, Cândido ES, Franco OL. The Structure/Function Relationship in Antimicrobial Peptides: What Can we Obtain From Structural Data? THERAPEUTIC PROTEINS AND PEPTIDES 2018; 112:359-384. [DOI: 10.1016/bs.apcsb.2018.01.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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21
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Booth V, Warschawski DE, Santisteban NP, Laadhari M, Marcotte I. Recent progress on the application of 2H solid-state NMR to probe the interaction of antimicrobial peptides with intact bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1500-1511. [PMID: 28844739 DOI: 10.1016/j.bbapap.2017.07.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Revised: 07/13/2017] [Accepted: 07/25/2017] [Indexed: 10/19/2022]
Abstract
Discoveries relating to innate immunity and antimicrobial peptides (AMPs) granted Bruce Beutler and Jules Hoffmann a Nobel prize in medicine in 2011, and opened up new avenues for the development of therapies against infections, and even cancers. The mechanisms by which AMPs interact with, and ultimately disrupt, bacterial cell membranes is still, to a large extent, incompletely understood. Up until recently, this mechanism was studied using model lipid membranes that failed to reproduce the complexity of molecular interactions present in real cells comprising lipids but also membrane proteins, a cell wall containing peptidoglycan or lipopolysaccharides, and other molecules. In this review, we focus on recent attempts to study, at the molecular level, the interaction between cationic AMPs and intact bacteria, by 2H solid-state NMR. Specifically-labeled lipids allow us to focus on the interaction of AMPs with the heart of the bacterial membrane, and measure the lipid order and its variation upon interaction with various peptides. We will review the important parameters to consider in such a study, and summarize the results obtained in the past 5years on various peptides, in particular aurein 1.2, caerin 1.1, MSI-78 and CA(1-8)M(1-10). This article is part of a Special Issue entitled: Biophysics in Canada, edited by Lewis Kay, John Baenziger, Albert Berghuis and Peter Tieleman.
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Affiliation(s)
- Valerie Booth
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada; Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL A1B 3X7, Canada
| | - Dror E Warschawski
- UMR 7099, CNRS - Université Paris Diderot, IBPC, 13 rue Pierre et Marie Curie, F-75005 Paris, France; Department of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Downtown Station, Montréal H3C 3P8, Canada
| | - Nury P Santisteban
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL A1B 3X7, Canada
| | - Marwa Laadhari
- Department of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Downtown Station, Montréal H3C 3P8, Canada
| | - Isabelle Marcotte
- Department of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Downtown Station, Montréal H3C 3P8, Canada.
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22
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Auger M. Membrane solid-state NMR in Canada: A historical perspective. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:1483-1489. [PMID: 28652206 DOI: 10.1016/j.bbapap.2017.06.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 06/17/2017] [Accepted: 06/21/2017] [Indexed: 11/18/2022]
Abstract
This manuscript presents an overview of more than 40years of membrane solid-state nuclear magnetic resonance (NMR) research in Canada. This technique is a method of choice for the study of the structure and dynamics of lipid bilayers; bilayer interactions with a variety of molecules such as membrane peptides, membrane proteins and drugs; and to investigate membrane peptide and protein structure, dynamics, and topology. Canada has a long tradition in this field of research, starting with pioneering work on natural and model membranes in the 1970s in a context of emergence of biophysics in the country. The 1980s and 1990s saw an emphasis on studying lipid structures and dynamics, and peptide-lipid and protein-lipid interactions. The study of bicelles began in the 1990s, and in the 2000s there was a rise in the study of membrane protein structures. Novel perspectives include using dynamic nuclear polarization (DNP) for membrane studies and using NMR in live cells. This article is part of a Special Issue entitled: Biophysics in Canada, edited by Lewis Kay, John Baenziger, Albert Berghuis and Peter Tieleman.
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Affiliation(s)
- Michèle Auger
- Département de chimie, PROTEO, CERMA, CQMF, Université Laval, Québec, Québec G1V 0A6, Canada.
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23
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Beaugrand M, Arnold AA, Bourgault S, Williamson PTF, Marcotte I. Comparative study of the structure and interaction of the pore helices of the hERG and Kv1.5 potassium channels in model membranes. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2017; 46:549-559. [PMID: 28314880 DOI: 10.1007/s00249-017-1201-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 02/15/2017] [Accepted: 02/17/2017] [Indexed: 10/19/2022]
Abstract
The hERG channel is a voltage-gated potassium channel found in cardiomyocytes that contributes to the repolarization of the cell membrane following the cardiac action potential, an important step in the regulation of the cardiac cycle. The lipids surrounding K+ channels have been shown to play a key role in their regulation, with anionic lipids shown to alter gating properties. In this study, we investigate how anionic lipids interact with the pore helix of hERG and compare the results with those from Kv1.5, which possesses a pore helix more typical of K+ channels. Circular dichroism studies of the pore helix secondary structure reveal that the presence of the anionic lipid DMPS within the bilayer results in a slight unfolding of the pore helices from both hERG and Kv1.5, albeit to a lesser extent for Kv1.5. In the presence of anionic lipids, the two pore helices exhibit significantly different interactions with the lipid bilayer. We demonstrate that the pore helix from hERG causes significant perturbation to the order in lipid bicelles, which contrasts with only small changes observed for Kv1.5. These observations suggest that the atypical sequence of the pore helix of hERG may play a key role in determining how anionic lipids influence its gating.
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Affiliation(s)
- Maïwenn Beaugrand
- Department of Chemistry, Université du Québec à Montréal, Downtown Station, PO Box 8888, Montreal, H3C 3P8, Canada
| | - Alexandre A Arnold
- Department of Chemistry, Université du Québec à Montréal, Downtown Station, PO Box 8888, Montreal, H3C 3P8, Canada
| | - Steve Bourgault
- Department of Chemistry, Université du Québec à Montréal, Downtown Station, PO Box 8888, Montreal, H3C 3P8, Canada
| | - Philip T F Williamson
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, SO17 1BJ, UK
| | - Isabelle Marcotte
- Department of Chemistry, Université du Québec à Montréal, Downtown Station, PO Box 8888, Montreal, H3C 3P8, Canada.
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Santisteban NP, Morrow MR, Booth V. Protocols for Studying the Interaction of MSI-78 with the Membranes of Whole Gram-Positive and Gram-Negative Bacteria by NMR. Methods Mol Biol 2017; 1548:217-230. [PMID: 28013507 DOI: 10.1007/978-1-4939-6737-7_15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Antimicrobial peptides (AMPs) may interact with a variety of target cell components, including the lipid bilayer, non-lipidic cell envelope components, and/or intracellular targets. However, most biophysical experiments aimed at elucidating the detailed mechanism of AMPs are limited to simple model membrane systems and neglect potentially functional interactions between AMPs and non-lipidic cell components. One of the biophysical techniques commonly used to study how AMPs interact with lipid bilayers is solid-state deuterium NMR. In this chapter we provide protocols to prepare deuterium-labeled intact Gram-negative and Gram-positive bacteria and to observe these samples using solid-state deuterium NMR. Such experiments have the potential to provide important information about how non-lipidic cell envelope components modulate AMP interactions with the cytoplasmic membrane of bacteria.
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Affiliation(s)
- Nury P Santisteban
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland and Labrador, St. John's, NL, Canada
| | - Michael R Morrow
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland and Labrador, St. John's, NL, Canada
| | - Valerie Booth
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland and Labrador, St. John's, NL, Canada.
- Department of Biochemistry, Memorial University of Newfoundland and Labrador, St. John's, NL, Canada, A1B 3X9.
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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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In-Cell Solid-State NMR: An Emerging Technique for the Study of Biological Membranes. Biophys J 2016; 109:2461-2466. [PMID: 26682804 DOI: 10.1016/j.bpj.2015.10.041] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 10/20/2015] [Accepted: 10/30/2015] [Indexed: 11/22/2022] Open
Abstract
Biological molecular processes are often studied in model systems, which simplifies their inherent complexity but may cause investigators to lose sight of the effects of the molecular environment. Information obtained in this way must therefore be validated by experiments in the cell. NMR has been used to study biological cells since the early days of its development. The first NMR structural studies of a protein inside a cell (by solution-state NMR) and of a membrane protein (by solid-state NMR) were published in 2001 and 2011, respectively. More recently, dynamic nuclear polarization, which has been used to enhance the signal in solid-state NMR, has also been applied to the study of frozen cells. Much progress has been made in the past 5 years, and in this review we take stock of this new technique, which is particularly appropriate for the study of biological membranes.
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Faghihzadeh F, Anaya NM, Schifman LA, Oyanedel-Craver V. Fourier transform infrared spectroscopy to assess molecular-level changes in microorganisms exposed to nanoparticles. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s41204-016-0001-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Warnet XL, Laadhari M, Arnold AA, Marcotte I, Warschawski DE. A 2H magic-angle spinning solid-state NMR characterisation of lipid membranes in intact bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:146-52. [DOI: 10.1016/j.bbamem.2015.10.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/06/2015] [Accepted: 10/26/2015] [Indexed: 10/22/2022]
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Shen M, Roopchand R, Mananga ES, Amoureux JP, Chen Q, Boutis GS, Hu B. Revisiting NMR composite pulses for broadband (2)H excitation. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2015; 66-67:45-48. [PMID: 25583576 PMCID: PMC4375013 DOI: 10.1016/j.ssnmr.2014.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 12/02/2014] [Accepted: 12/10/2014] [Indexed: 06/04/2023]
Abstract
Quadrupolar echo NMR spectroscopy of static solids often requires RF excitation that covers spectral widths exceeding 100 kHz, which is difficult to obtain due to instrumental limitations. In this work we revisit four well-known composite pulses (COM-I, II, III and IV) for broadband excitation in deuterium quadrupolar echo spectroscopy. These composite pulses are combined with several phase cycling schemes that were previously shown to decrease finite pulse width distortions in deuterium solid-echo experiments performed with two single pulses. The simulations and experiments show that COM-II and IV composite pulses combined with an 8-step phase cycling aid in achieving broadband excitation with limited pulse width distortions.
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Affiliation(s)
- Ming Shen
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China; UCCS, University Lille North of France, Villeneuve d׳Ascq 59652, France
| | - Rabia Roopchand
- Department of Physics, Hunter College, New York, NY 10065, USA
| | - Eugene S Mananga
- Center for Advanced Radiological Sciences, Division of Nuclear Medicine and Molecular Imaging Physics, Department of Radiology, Harvard Medical School and Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA; Department of Physics and Technology, The City University of New York, 2155 University Avenue, CPH 118, Bronx, New York, NY 10453, USA.
| | - Jean-Paul Amoureux
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China; UCCS, University Lille North of France, Villeneuve d׳Ascq 59652, France
| | - Qun Chen
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China
| | - Gregory S Boutis
- Physics Department, Brooklyn College, 2900 Bedford Avenue, Brooklyn, NY 11210, USA.
| | - Bingwen Hu
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai 200062, China.
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Arnold AA, Genard B, Zito F, Tremblay R, Warschawski DE, Marcotte I. Identification of lipid and saccharide constituents of whole microalgal cells by 13C solid-state NMR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:369-77. [DOI: 10.1016/j.bbamem.2014.07.017] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 07/02/2014] [Accepted: 07/15/2014] [Indexed: 11/15/2022]
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31
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Marennine, promising blue pigments from a widespread Haslea diatom species complex. Mar Drugs 2014; 12:3161-89. [PMID: 24879542 PMCID: PMC4071570 DOI: 10.3390/md12063161] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 04/29/2014] [Accepted: 04/29/2014] [Indexed: 11/21/2022] Open
Abstract
In diatoms, the main photosynthetic pigments are chlorophylls a and c, fucoxanthin, diadinoxanthin and diatoxanthin. The marine pennate diatom Haslea ostrearia has long been known for producing, in addition to these generic pigments, a water-soluble blue pigment, marennine. This pigment, responsible for the greening of oysters in western France, presents different biological activities: allelopathic, antioxidant, antibacterial, antiviral, and growth-inhibiting. A method to extract and purify marennine has been developed, but its chemical structure could hitherto not be resolved. For decades, H. ostrearia was the only organism known to produce marennine, and can be found worldwide. Our knowledge about H. ostrearia-like diatom biodiversity has recently been extended with the discovery of several new species of blue diatoms, the recently described H. karadagensis, H. silbo sp. inedit. and H. provincialis sp. inedit. These blue diatoms produce different marennine-like pigments, which belong to the same chemical family and present similar biological activities. Aside from being a potential source of natural blue pigments, H. ostrearia-like diatoms thus present a commercial potential for aquaculture, cosmetics, food and health industries.
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