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Buchholz KR, Reichelt M, Johnson MC, Robinson SJ, Smith PA, Rutherford ST, Quinn JG. Potent activity of polymyxin B is associated with long-lived super-stoichiometric accumulation mediated by weak-affinity binding to lipid A. Nat Commun 2024; 15:4733. [PMID: 38830951 PMCID: PMC11148078 DOI: 10.1038/s41467-024-49200-5] [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] [Received: 11/15/2022] [Accepted: 05/23/2024] [Indexed: 06/05/2024] Open
Abstract
Polymyxins are gram-negative antibiotics that target lipid A, the conserved membrane anchor of lipopolysaccharide in the outer membrane. Despite their clinical importance, the molecular mechanisms underpinning polymyxin activity remain unresolved. Here, we use surface plasmon resonance to kinetically interrogate interactions between polymyxins and lipid A and derive a phenomenological model. Our analyses suggest a lipid A-catalyzed, three-state mechanism for polymyxins: transient binding, membrane insertion, and super-stoichiometric cluster accumulation with a long residence time. Accumulation also occurs for brevicidine, another lipid A-targeting antibacterial molecule. Lipid A modifications that impart polymyxin resistance and a non-bactericidal polymyxin derivative exhibit binding that does not evolve into long-lived species. We propose that transient binding to lipid A permeabilizes the outer membrane and cluster accumulation enables the bactericidal activity of polymyxins. These findings could establish a blueprint for discovery of lipid A-targeting antibiotics and provide a generalizable approach to study interactions with the gram-negative outer membrane.
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Affiliation(s)
- Kerry R Buchholz
- Department of Infectious Diseases, Genentech, Inc., South San Francisco, CA, USA.
| | - Mike Reichelt
- Department of Pathology, Genentech, Inc., South San Francisco, CA, USA
| | - Matthew C Johnson
- Department of Structural Biology, Genentech, Inc., South San Francisco, CA, USA
| | - Sarah J Robinson
- Department of Discovery Chemistry, Genentech, Inc., South San Francisco, CA, USA
| | - Peter A Smith
- Department of Infectious Diseases, Genentech, Inc., South San Francisco, CA, USA
- Revagenix, Inc., San Mateo, CA, USA
| | - Steven T Rutherford
- Department of Infectious Diseases, Genentech, Inc., South San Francisco, CA, USA.
| | - John G Quinn
- Department of Biochemical and Cellular Pharmacology, Genentech, Inc., South San Francisco, CA, USA.
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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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Malec K, Monaco S, Delso I, Nestorowicz J, Kozakiewicz-Latała M, Karolewicz B, Khimyak YZ, Angulo J, Nartowski KP. Unravelling the mechanisms of drugs partitioning phenomena in micellar systems via NMR spectroscopy. J Colloid Interface Sci 2023; 638:135-148. [PMID: 36736115 DOI: 10.1016/j.jcis.2023.01.063] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 01/12/2023] [Indexed: 01/22/2023]
Abstract
Despite extensive use of micelles in materials and colloidal science, their supramolecular organization as well as host-guest interactions within these dynamic assemblies are poorly understood. Small guest molecules in the presence of micelles undergo constant exchange between a micellar aggregate and the surrounding solution, posing a considerable challenge for their molecular level characterisation. In this work we reveal the interaction maps between small guest molecules and surfactants forming micelles via novel applications of NMR techniques supported with state-of-the-art analytical methods used in colloidal science. Model micelles composed of structurally distinct surfactants (block non-ionic polymer Pluronic® F-127, non-ionic surfactant Tween 20 or Tween 80, and ionic surfactant sodium lauryl sulphate, SLS) were selected and loaded with model small molecules of biological relevance (i.e. the drugs fluconazole, FLU or indomethacin, IMC) known to have different partition coefficients. Molecular level organization of FLU or IMC within hydrophilic and hydrophobic domains of micellar aggregates was established using the combination of NMR methods (1D 1H NMR, 1D 19F NMR, 2D 1H-1H NOESY and 2D 1H-19F HOESY, and the multifrequency-STD NMR) and corroborated with molecular dynamics (MD) simulations. This is the first application of multifrequency-STD NMR to colloidal systems, enabling us to elucidate intricately detailed patterns of drug/micelle interactions in a single NMR experiment within minutes. Importantly, our results indicate that flexible surfactants, such as block copolymers and polysorbates, form micellar aggregates with a surface composed of both hydrophilic and hydrophobic domains and do not follow the classical core-shell model of the micelle. We propose that the magnitude of changes in 1H chemical shifts corroborated with interaction maps obtained from DEEP-STD NMR and 2D NMR experiments can be used as an indicator of the strength of the guest-surfactant interactions. This NMR toolbox can be adopted for the analysis of broad range of colloidal host-guest systems from soft materials to biological systems.
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Affiliation(s)
- Katarzyna Malec
- Department of Drug Form Technology, Faculty of Pharmacy, Wroclaw Medical University, 211a Borowska Str, 50-556 Wroclaw, Poland
| | - Serena Monaco
- School of Pharmacy, University of East Anglia, Chancellors Drive, NR4 7TJ Norwich, UK
| | - Ignacio Delso
- School of Pharmacy, University of East Anglia, Chancellors Drive, NR4 7TJ Norwich, UK
| | - Justyna Nestorowicz
- Department of Drug Form Technology, Faculty of Pharmacy, Wroclaw Medical University, 211a Borowska Str, 50-556 Wroclaw, Poland
| | - Marta Kozakiewicz-Latała
- Department of Drug Form Technology, Faculty of Pharmacy, Wroclaw Medical University, 211a Borowska Str, 50-556 Wroclaw, Poland
| | - Bożena Karolewicz
- Department of Drug Form Technology, Faculty of Pharmacy, Wroclaw Medical University, 211a Borowska Str, 50-556 Wroclaw, Poland
| | - Yaroslav Z Khimyak
- School of Pharmacy, University of East Anglia, Chancellors Drive, NR4 7TJ Norwich, UK.
| | - Jesús Angulo
- School of Pharmacy, University of East Anglia, Chancellors Drive, NR4 7TJ Norwich, UK; Instituto de Investigaciones Químicas (CSIC-US), Avda. Américo Vespucio, 49, Sevilla 41092, Spain.
| | - Karol P Nartowski
- Department of Drug Form Technology, Faculty of Pharmacy, Wroclaw Medical University, 211a Borowska Str, 50-556 Wroclaw, Poland; School of Pharmacy, University of East Anglia, Chancellors Drive, NR4 7TJ Norwich, UK.
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4
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Atomic-Resolution Structures and Mode of Action of Clinically Relevant Antimicrobial Peptides. Int J Mol Sci 2022; 23:ijms23094558. [PMID: 35562950 PMCID: PMC9100274 DOI: 10.3390/ijms23094558] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/18/2022] [Accepted: 04/18/2022] [Indexed: 02/01/2023] Open
Abstract
Global rise of infections and deaths caused by drug-resistant bacterial pathogens are among the unmet medical needs. In an age of drying pipeline of novel antibiotics to treat bacterial infections, antimicrobial peptides (AMPs) are proven to be valid therapeutics modalities. Direct in vivo applications of many AMPs could be challenging; however, works are demonstrating encouraging results for some of them. In this review article, we discussed 3-D structures of potent AMPs e.g., polymyxin, thanatin, MSI, protegrin, OMPTA in complex with bacterial targets and their mode of actions. Studies on human peptide LL37 and de novo-designed peptides are also discussed. We have focused on AMPs which are effective against drug-resistant Gram-negative bacteria. Since treatment options for the infections caused by super bugs of Gram-negative bacteria are now extremely limited. We also summarize some of the pertinent challenges in the field of clinical trials of AMPs.
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5
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Biswas K, Bhunia A. Probing the Functional Interaction Interface of Lipopolysaccharide and Antimicrobial Peptides: A Solution-State NMR Perspective. Methods Mol Biol 2022; 2548:211-231. [PMID: 36151500 DOI: 10.1007/978-1-0716-2581-1_13] [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: 06/16/2023]
Abstract
Antimicrobial peptides (AMPs) have been a topic of substantial research as the next-generation antibiotics. They have been extensively studied for the selectivity and action against microbial membrane lipids in imparting their targeted functioning. To determine the effectivity of the peptides against the Gram-negative pathogens, it is imperative to elucidate their role in interacting with the lipopolysaccharide moieties. Lipopolysaccharide is a major component of the outer membrane of the Gram-negative bacteria. It serves to protect the bacteria as well as govern the functionality of several antibacterial agents. It can prevent the access of the agents into the inner membrane of the bacteria, thus rendering them inactive. Several techniques have been employed to study the interaction for better designing of peptides; NMR spectroscopy is one of the most widely used techniques in determining the interactive properties of peptides with LPS as it can provide the details in atomistic level. NMR spectroscopy provides information about the structural and conformational changes as well as the dynamics of the interactions.
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Affiliation(s)
| | - Anirban Bhunia
- Department of Biophysics, Bose Institute, Kolkata, India.
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6
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Ajingi YS, Muhammad A, Khunrae P, Rattanarojpong T, Pattanapanyasat K, Sutthibutpong T, Jongruja N. Antibacterial Potential of a Novel Peptide from the Consensus Sequence of Dermaseptin Related Peptides Secreted by Agalychnis annae. Curr Pharm Biotechnol 2021; 22:1216-1227. [PMID: 33081682 DOI: 10.2174/1389201021666201020161428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/16/2020] [Accepted: 09/23/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND The consistently increasing reports of bacterial resistance and the reemergence of bacterial epidemics have inspired the health and scientific community to discover new molecules with antibacterial potential continuously. Frog-skin secretions constitute bioactive compounds essential for finding new biopharmaceuticals. The exact antibacterial characterization of dermaseptin related peptides derived from Agalychnis annae, is limited. The resemblance in their conserved and functionally linked genomes indicates an unprecedented opportunity to obtain novel bioactive compounds. OBJECTIVE In this study, we derived a novel peptide sequence and determined its antibacterial potentials. METHODS Consensus sequence strategy was used to design the novel and active antibacterial peptide named 'AGAAN' from skin secretions of Agalychnis annae. The in-vitro activities of the novel peptide against some bacterial strains were investigated. Time kill studies, DNA retardation, cytotoxicity, betagalactosidase, and molecular computational studies were conducted. RESULTS AGAAN inhibited P. aeruginosa, E. faecalis, and S. typhimurium at 20 μM concentration. E. coli and S. aureus were inhibited at 25 μM, and lastly, B. subtilis at 50 μM. Kinetics of inactivation against exponential and stationary growing bacteria was found to be rapid within 1-5 hours of peptide exposure, depending on time and concentration. The peptide displayed weak hemolytic activity between 0.01%-7.31% at the antibacterial concentrations. AGAAN efficiently induced bacterial membrane damage with subsequent cell lysis. The peptide's DNA binding shows that it also targets intracellular DNA by retarding its movement. Our in-silico molecular docking analysis displayed a strong affinity to the bacterial cytoplasmic membrane. CONCLUSION AGAAN exhibits potential antibacterial properties that could be used to combat bacterial resistance.
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Affiliation(s)
- Ya'u Sabo Ajingi
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, Thailand
| | - Auwal Muhammad
- Theoretical and Computational Physics Group, Department of Physics, King Mongkut's University of Technology, Thonburi, (KMUTT), Thailand
| | - Pongsak Khunrae
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, Thailand
| | - Triwit Rattanarojpong
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, Thailand
| | - Kovit Pattanapanyasat
- Office for Research and Development, Department of Immunology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Thana Sutthibutpong
- Theoretical and Computational Physics Group, Department of Physics, King Mongkut's University of Technology, Thonburi, (KMUTT), Thailand
| | - Nujarin Jongruja
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok, Thailand
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7
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Vincenzi M, Mercurio FA, Leone M. NMR Spectroscopy in the Conformational Analysis of Peptides: An Overview. Curr Med Chem 2021; 28:2729-2782. [PMID: 32614739 DOI: 10.2174/0929867327666200702131032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/21/2020] [Accepted: 05/28/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND NMR spectroscopy is one of the most powerful tools to study the structure and interaction properties of peptides and proteins from a dynamic perspective. Knowing the bioactive conformations of peptides is crucial in the drug discovery field to design more efficient analogue ligands and inhibitors of protein-protein interactions targeting therapeutically relevant systems. OBJECTIVE This review provides a toolkit to investigate peptide conformational properties by NMR. METHODS Articles cited herein, related to NMR studies of peptides and proteins were mainly searched through PubMed and the web. More recent and old books on NMR spectroscopy written by eminent scientists in the field were consulted as well. RESULTS The review is mainly focused on NMR tools to gain the 3D structure of small unlabeled peptides. It is more application-oriented as it is beyond its goal to deliver a profound theoretical background. However, the basic principles of 2D homonuclear and heteronuclear experiments are briefly described. Protocols to obtain isotopically labeled peptides and principal triple resonance experiments needed to study them, are discussed as well. CONCLUSION NMR is a leading technique in the study of conformational preferences of small flexible peptides whose structure can be often only described by an ensemble of conformations. Although NMR studies of peptides can be easily and fast performed by canonical protocols established a few decades ago, more recently we have assisted to tremendous improvements of NMR spectroscopy to investigate instead large systems and overcome its molecular weight limit.
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Affiliation(s)
- Marian Vincenzi
- Institute of Biostructures and Bioimaging, National Research Council of Italy, Via Mezzocannone 16, 80134, Naples, Italy
| | - Flavia Anna Mercurio
- Institute of Biostructures and Bioimaging, National Research Council of Italy, Via Mezzocannone 16, 80134, Naples, Italy
| | - Marilisa Leone
- Institute of Biostructures and Bioimaging, National Research Council of Italy, Via Mezzocannone 16, 80134, Naples, Italy
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8
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Dash R, Bhattacharjya S. Thanatin: An Emerging Host Defense Antimicrobial Peptide with Multiple Modes of Action. Int J Mol Sci 2021; 22:ijms22041522. [PMID: 33546369 PMCID: PMC7913509 DOI: 10.3390/ijms22041522] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/28/2021] [Accepted: 02/01/2021] [Indexed: 12/11/2022] Open
Abstract
Antimicrobial peptides (AMPs) possess great potential for combating drug-resistant bacteria. Thanatin is a pathogen-inducible single-disulfide-bond-containing β-hairpin AMP which was first isolated from the insect Podisus maculiventris. The 21-residue-long thanatin displays broad-spectrum activity against both Gram-negative and Gram-positive bacteria as well as against various species of fungi. Remarkably, thanatin was found to be highly potent in inhibiting the growth of bacteria and fungi at considerably low concentrations. Although thanatin was isolated around 25 years ago, only recently has there been a pronounced interest in understanding its mode of action and activity against drug-resistant bacteria. In this review, multiple modes of action of thanatin in killing bacteria and in vivo activity, therapeutic potential are discussed. This promising AMP requires further research for the development of novel molecules for the treatment of infections caused by drug resistant pathogens.
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Affiliation(s)
- Rachita Dash
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore;
- Department of Systems and Computational Biology, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana 500046, India
| | - Surajit Bhattacharjya
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore;
- Correspondence:
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9
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Cantini F, Luzi C, Bouchemal N, Savarin P, Bozzi A, Sette M. Effect of positive charges in the structural interaction of crabrolin isoforms with lipopolysaccharide. J Pept Sci 2020; 26:e3271. [DOI: 10.1002/psc.3271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 05/19/2020] [Accepted: 06/02/2020] [Indexed: 01/04/2023]
Affiliation(s)
- Francesca Cantini
- Magnetic Resonance Center (CERM)University of Florence Sesto Fiorentino Italy
- Department of ChemistryUniversity of Florence Sesto Fiorentino Italy
| | - Carla Luzi
- Department of Biotechnological and Clinical SciencesUniversity of L'Aquila L'Aquila Italy
| | - Nadia Bouchemal
- Sorbonne Paris Cité, CSPBAT LaboratoryUniversity of Paris 13 Bobigny France
| | - Philippe Savarin
- Sorbonne Paris Cité, CSPBAT LaboratoryUniversity of Paris 13 Bobigny France
| | - Argante Bozzi
- Department of Biotechnological and Clinical SciencesUniversity of L'Aquila L'Aquila Italy
| | - Marco Sette
- Sorbonne Paris Cité, CSPBAT LaboratoryUniversity of Paris 13 Bobigny France
- Department of Chemical Sciences and TechnologyUniversity of Rome Tor Vergata Rome Italy
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10
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Swarbrick JD, Karas JA, Li J, Velkov T. Structure of micelle bound cationic peptides by NMR spectroscopy using a lanthanide shift reagent. Chem Commun (Camb) 2020; 56:2897-2900. [PMID: 32037418 DOI: 10.1039/c9cc09207b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
[Tm(DPA)3]3- was used to generate multiple, paramagnetic nuclear Overhauser effect NMR spectra of cationic peptides when weakly bound to a lipopolysaccharide micelle. Increased spectral resolution combined with a marked increase in the number of distance restraints yielded high resolution structures of polymyxin and MSI-594 in the liposaccharide bound state.
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Affiliation(s)
- James D Swarbrick
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria 3010, Australia.
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11
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Munusamy S, Conde R, Bertrand B, Munoz-Garay C. Biophysical approaches for exploring lipopeptide-lipid interactions. Biochimie 2020; 170:173-202. [PMID: 31978418 PMCID: PMC7116911 DOI: 10.1016/j.biochi.2020.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 01/19/2020] [Indexed: 02/07/2023]
Abstract
In recent years, lipopeptides (LPs) have attracted a lot of attention in the pharmaceutical industry due to their broad-spectrum of antimicrobial activity against a variety of pathogens and their unique mode of action. This class of compounds has enormous potential for application as an alternative to conventional antibiotics and for pest control. Understanding how LPs work from a structural and biophysical standpoint through investigating their interaction with cell membranes is crucial for the rational design of these biomolecules. Various analytical techniques have been developed for studying intramolecular interactions with high resolution. However, these tools have been barely exploited in lipopeptide-lipid interactions studies. These biophysical approaches would give precise insight on these interactions. Here, we reviewed these state-of-the-art analytical techniques. Knowledge at this level is indispensable for understanding LPs activity and particularly their potential specificity, which is relevant information for safe application. Additionally, the principle of each analytical technique is presented and the information acquired is discussed. The key challenges, such as the selection of the membrane model are also been briefly reviewed. A brief overview of topics to understand the generalities of lipopeptide (LP) science. Main analytical techniques used to reveal the interaction and the distorting effect of LP on artificial membranes. Guidelines for selecting of the most adequate membrane models for the given analytical technique.
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Affiliation(s)
- Sathishkumar Munusamy
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, 62210, Cuernavaca, Mexico
| | - Renaud Conde
- Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, Mexico
| | - Brandt Bertrand
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, 62210, Cuernavaca, Mexico
| | - Carlos Munoz-Garay
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, 62210, Cuernavaca, Mexico.
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12
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Roy D, Bhattacharyya D, Bhunia A. Do Catechins (ECG and EGCG) Bind to the Same Site as Thioflavin T (ThT) in Amyloid Fibril? Answer From Saturation Transfer Difference NMR. Nat Prod Commun 2019. [DOI: 10.1177/1934578x19849791] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Affiliation(s)
- Dipanwita Roy
- Department of Biophysics, Bose Institute, Kolkata, WB, India
| | | | - Anirban Bhunia
- Department of Biophysics, Bose Institute, Kolkata, WB, India
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13
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Singh S, Datta A, Borro BC, Davoudi M, Schmidtchen A, Bhunia A, Malmsten M. Conformational Aspects of High Content Packing of Antimicrobial Peptides in Polymer Microgels. ACS APPLIED MATERIALS & INTERFACES 2017; 9:40094-40106. [PMID: 29087182 DOI: 10.1021/acsami.7b13714] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Successful use of microgels as delivery systems of antimicrobial peptides (AMPs) requires control of factors determining peptide loading and release to/from the microgels as well as of membrane interactions of both microgel particles and released peptides. Addressing these, we here investigate effects of microgel charge density and conformationally induced peptide amphiphilicity on AMP loading and release using detailed nuclear magnetic resonance (NMR) structural studies combined with ellipsometry, isothermal titration calorimetry, circular dichroism, and light scattering. In parallel, consequences of peptide loading and release for membrane interactions and antimicrobial effects were investigated. In doing so, poly(ethyl acrylate-co-methacrylic acid) microgels were found to incorporate the cationic AMPs EFK17a (EFKRIVQRIKDFLRNLV) and its partially d-amino acid-substituted variant EFK17da (E(dF)KR(dI)VQR(dI)KD(dF)LRNLV). Peptide incorporation was found to increase with increasing with microgel charge density and peptide amphiphilicity. After microgel incorporation, which appeared to occur preferentially in the microgel core, NMR showed EFK17a to form a helix with pronounced amphiphilicity, while EFK17da displayed a folded conformation, stabilized by a hydrophobic hub consisting of aromatic/aromatic and aliphatic/aromatic interactions, resulting in much lower amphiphilicity. Under wide ranges of peptide loading, the microgels displayed net negative z-potential. Such negatively charged microgels do not bind to, nor lyse, bacteria-mimicking membranes. Instead, membrane disruption in these systems is mediated largely by peptide release, which in turn is promoted at higher ionic strength and lower peptide amphiphilicity. Analogously, antimicrobial effects against Escherichia coli were found to be dictated by peptide release. Taken together, the findings show that peptide loading, packing, and release strongly affect the performance of microgels as AMP delivery systems, effects that can be tuned by (conformationally induced) peptide amphiphilicity and by microgel charge density.
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Affiliation(s)
- Shalini Singh
- Department of Pharmacy, Uppsala University , SE-75232 Uppsala, Sweden
| | - Aritreyee Datta
- Department of Biophysics, Bose Institute , P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Bruno C Borro
- Department of Pharmacy, University of Copenhagen , DK-2100 Copenhagen, Denmark
| | - Mina Davoudi
- Division of Dermatology and Venereology, Department of Clinical Sciences, Lund University , SE-221 84 Lund, Sweden
| | - Artur Schmidtchen
- Division of Dermatology and Venereology, Department of Clinical Sciences, Lund University , SE-221 84 Lund, Sweden
- Lee Kong Chian School of Medicine, Nanyang Technological University , 11 Mandalay Road, Singapore 308232, Singapore
- Wound Healing Centre, Bispebjerg University Hospital , DK-2100 Copenhagen, Denmark
| | - Anirban Bhunia
- Department of Biophysics, Bose Institute , P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Martin Malmsten
- Department of Pharmacy, Uppsala University , SE-75232 Uppsala, Sweden
- Department of Pharmacy, University of Copenhagen , DK-2100 Copenhagen, Denmark
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14
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Chowdhury R, Ilyas H, Ghosh A, Ali H, Ghorai A, Midya A, Jana NR, Das S, Bhunia A. Multivalent gold nanoparticle-peptide conjugates for targeting intracellular bacterial infections. NANOSCALE 2017; 9:14074-14093. [PMID: 28901372 DOI: 10.1039/c7nr04062h] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Although nanoparticle-tagged antimicrobal peptides have gained considerable importance in recent years, their structure-function correlation has not yet been explored. Here, we have studied the mechanism of action of a designed antimicrobial peptide, VG16KRKP (VARGWKRKCPLFGKGG), delivered via gold nanoparticle tagging against Salmonella infection by combining biological experiments with high- and low-resolution spectroscopic techniques. In comparison with the free VG16KRKP peptide or gold nanoparticle alone, the conjugated variant, Au-VG16KRKP, is non-cytotoxic to eukaryotic cells, but exhibits strong bacteriolytic activity in culture. Au-VG16KRKP can penetrate host epithelial and macrophage cells as well as interact with intracellular S. Typhi LPS under both in vitro and in vivo conditions. Treatment of mice with Au-VG16KRKP post-infection with S. Typhi resulted in reduced intracellular bacterial recovery and highly enhanced protection against S. Typhi challenge. The three-dimensional high resolution structure of nanoparticle conjugated VG16KRKP depicted the generation of a well-separated amphipathic structure with slight aggregation, responsible for the increase of the local concentration of the peptide, thus leading to potent activity. This is the first report on the structural and functional characterization of a nanoparticle conjugated synthetic antimicrobial peptide that can kill intracellular pathogens and eventually protect against S. Typhi challenge in vivo.
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Affiliation(s)
- Rimi Chowdhury
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, P-33 CIT Road Scheme XM, Beliaghata, Kolkata-700010, India.
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15
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Synthesis of novel muramic acid derivatives and their interaction with lysozyme: Action of lysozyme revisited. J Colloid Interface Sci 2017; 498:395-404. [DOI: 10.1016/j.jcis.2017.03.060] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 03/13/2017] [Accepted: 03/13/2017] [Indexed: 12/16/2022]
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16
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Datta A, Yadav V, Ghosh A, Choi J, Bhattacharyya D, Kar RK, Ilyas H, Dutta A, An E, Mukhopadhyay J, Lee D, Sanyal K, Ramamoorthy A, Bhunia A. Mode of Action of a Designed Antimicrobial Peptide: High Potency against Cryptococcus neoformans. Biophys J 2017; 111:1724-1737. [PMID: 27760359 DOI: 10.1016/j.bpj.2016.08.032] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/11/2016] [Accepted: 08/29/2016] [Indexed: 12/11/2022] Open
Abstract
There is a significant need for developing compounds that kill Cryptococcus neoformans, the fungal pathogen that causes meningoencephalitis in immunocompromised individuals. Here, we report the mode of action of a designed antifungal peptide, VG16KRKP (VARGWKRKCPLFGKGG) against C. neoformans. It is shown that VG16KRKP kills fungal cells mainly through membrane compromise leading to efflux of ions and cell metabolites. Intracellular localization, inhibition of in vitro transcription, and DNA binding suggest a secondary mode of action for the peptide, hinting at possible intracellular targets. Atomistic structure of the peptide determined by NMR experiments on live C. neoformans cells reveals an amphipathic arrangement stabilized by hydrophobic interactions among A2, W5, and F12, a conventional folding pattern also known to play a major role in peptide-mediated Gram-negative bacterial killing, revealing the importance of this motif. These structural details in the context of live cell provide valuable insights into the design of potent peptides for effective treatment of human and plant fungal infections.
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Affiliation(s)
- Aritreyee Datta
- Department of Biophysics, P-1/12 CIT Scheme VII (M), Kolkata, India
| | - Vikas Yadav
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Anirban Ghosh
- Department of Biophysics, P-1/12 CIT Scheme VII (M), Kolkata, India
| | - Jaesun Choi
- Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul, Korea
| | | | - Rajiv K Kar
- Department of Biophysics, P-1/12 CIT Scheme VII (M), Kolkata, India
| | - Humaira Ilyas
- Department of Biophysics, P-1/12 CIT Scheme VII (M), Kolkata, India
| | | | - Eunseol An
- Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul, Korea
| | | | - Dongkuk Lee
- Department of Fine Chemistry, Seoul National University of Science and Technology, Seoul, Korea
| | - Kaustuv Sanyal
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | | | - Anirban Bhunia
- Department of Biophysics, P-1/12 CIT Scheme VII (M), Kolkata, India.
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17
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Yu HY, Chen YA, Yip BS, Wang SY, Wei HJ, Chih YH, Chen KH, Cheng JW. Role of β-naphthylalanine end-tags in the enhancement of antiendotoxin activities: Solution structure of the antimicrobial peptide S1-Nal-Nal in complex with lipopolysaccharide. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1114-1123. [PMID: 28288781 DOI: 10.1016/j.bbamem.2017.03.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 02/08/2017] [Accepted: 03/09/2017] [Indexed: 12/18/2022]
Abstract
Lipopolysaccharide (LPS, endotoxin) is the major component of Gram-negative bacterial outer surface membrane. LPS released from bacteria into bloodstream during infection may cause serious unwanted stimulation of host's immune system and lead to septic shock of the patient. Recently, we have developed a strategy to increase salt resistance and LPS neutralization of short antimicrobial peptides by adding β-naphthylalanine end-tags to their termini. Herein, correlations between membrane immersion depth, orientation, and antiendotoxin activities of the antimicrobial peptides S1 and S1-Nal-Nal have been investigated via solution structure, paramagnetic resonance enhancement, and saturation transfer difference NMR studies. Unlike the parent peptide S1, S1-Nal-Nal rotated its two terminal β-naphthylalanine residues into the hydrophobic lipid A motif of LPS micelles. The LPS-induced inflammation may then be prohibited by the blocked lipid A motif.
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Affiliation(s)
- Hui-Yuan Yu
- Institute of Biotechnology and Department of Medical Science, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Yi-An Chen
- Institute of Biotechnology and Department of Medical Science, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Bak-Sau Yip
- Institute of Biotechnology and Department of Medical Science, National Tsing Hua University, Hsinchu 300, Taiwan; Department of Neurology, National Taiwan University Hospital Hsinchu Branch, Hsinchu 300, Taiwan
| | - Siou-Ying Wang
- Institute of Biotechnology and Department of Medical Science, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Hsiu-Ju Wei
- Institute of Biotechnology and Department of Medical Science, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Ya-Han Chih
- Institute of Biotechnology and Department of Medical Science, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Kuan-Hao Chen
- Institute of Biotechnology and Department of Medical Science, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Jya-Wei Cheng
- Institute of Biotechnology and Department of Medical Science, National Tsing Hua University, Hsinchu 300, Taiwan.
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18
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Datta A, Bhattacharyya D, Singh S, Ghosh A, Schmidtchen A, Malmsten M, Bhunia A. Role of Aromatic Amino Acids in Lipopolysaccharide and Membrane Interactions of Antimicrobial Peptides for Use in Plant Disease Control. J Biol Chem 2016; 291:13301-17. [PMID: 27137928 DOI: 10.1074/jbc.m116.719575] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Indexed: 01/11/2023] Open
Abstract
KYE28 (KYEITTIHNLFRKLTHRLFRRNFGYT-LR), the representative sequence of helix D of heparin co-factor II, was demonstrated to be potent against agronomically important Gram-negative plant pathogens Xanthomonas vesicatoria and Xanthomonas oryzae, capable of inhibiting disease symptoms in detached tomato leaves. NMR studies in the presence of lipopolysaccharide provided structural insights into the mechanisms underlying this, notably in relationship to outer membrane permeabilization. The three-dimensional solution structure of KYE28 in LPS is characterized by an N-terminal helical segment, an intermediate loop followed by another short helical stretch, and an extended C terminus. The two termini are in close proximity to each other via aromatic packing interactions, whereas the positively charged residues form an exterior polar shell. To further demonstrate the importance of the aromatic residues for this, a mutant peptide KYE28A, with Ala substitutions at Phe(11), Phe(19), Phe(23), and Tyr(25) was designed, which showed attenuated antimicrobial activity at high salt concentrations, as well as lower membrane disruption and LPS binding abilities compared with KYE28. In contrast to KYE28, KYE28A adopted an extended helical structure in LPS with extended N and C termini. Aromatic packing interactions were completely lost, although hydrophobic interaction between the side chains of hydrophobic residues were still partly retained, imparting an amphipathic character and explaining its residual antimicrobial activity and LPS binding as observed from ellipsometry and isothermal titration calorimetry. We thus present key structural aspects of KYE28, constituting an aromatic zipper, of potential importance for the development of novel plant protection agents and therapeutic agents.
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Affiliation(s)
- Aritreyee Datta
- From the Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Dipita Bhattacharyya
- From the Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Shalini Singh
- the Department of Pharmacy, Uppsala University, SE-75232 Uppsala, Sweden
| | - Anirban Ghosh
- From the Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Artur Schmidtchen
- the Department of Clinical Sciences, Division of Dermatology and Venereology, Lund University, SE-221 84 Lund, Sweden, and the Lee Kong Chian School of Medicine, Nanyang Technological University, 11 Mandalay Road, Singapore 308232
| | - Martin Malmsten
- the Department of Pharmacy, Uppsala University, SE-75232 Uppsala, Sweden,
| | - Anirban Bhunia
- From the Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India,
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19
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Ghosh A, Bera S, Shai Y, Mangoni ML, Bhunia A. NMR structure and binding of esculentin-1a (1–21)NH 2 and its diastereomer to lipopolysaccharide: Correlation with biological functions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:800-12. [DOI: 10.1016/j.bbamem.2015.12.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/26/2015] [Accepted: 12/21/2015] [Indexed: 12/13/2022]
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20
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NMR analysis of carbohydrate-binding interactions in solution: an approach using analysis of saturation transfer difference NMR spectroscopy. Methods Mol Biol 2015; 1200:501-9. [PMID: 25117260 DOI: 10.1007/978-1-4939-1292-6_41] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
One of the most commonly used ligand-based NMR methods for detecting ligand binding is saturation transfer difference (STD) nuclear magnetic resonance (NMR) spectroscopy. The STD NMR method is an invaluable technique for assessing carbohydrate-lectin interactions in solution, because STD NMR can be used to detect weak ligand binding (Kd ca. 10(-3)-10(-8) M). STD NMR spectra identify the binding epitope of a carbohydrate ligand when bound to lectin. Further, the STD NMR method uses 1H-detected NMR spectra of only the carbohydrate, and so only small quantities of non-labeled lectin are required. In this chapter, I describe a protocol for the STD NMR method, including the experimental procedures used to acquire, process, and analyze STD NMR data, using STD NMR studies for methyl-β-D-galactopyranoside (β-Me-Gal) binding to the C-terminal domain of an R-type lectin from earthworm (EW29Ch) as an example.
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21
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Potent γ-secretase inhibitors/modulators interact with amyloid-β fibrils but do not inhibit fibrillation: A high-resolution NMR study. Biochem Biophys Res Commun 2014; 447:590-5. [DOI: 10.1016/j.bbrc.2014.04.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 04/08/2014] [Indexed: 01/12/2023]
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22
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Saravanan R, Joshi M, Mohanram H, Bhunia A, Mangoni ML, Bhattacharjya S. NMR structure of temporin-1 ta in lipopolysaccharide micelles: mechanistic insight into inactivation by outer membrane. PLoS One 2013; 8:e72718. [PMID: 24039798 PMCID: PMC3767682 DOI: 10.1371/journal.pone.0072718] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 07/12/2013] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Antimicrobial peptides (AMPs) play important roles in the innate defense mechanism. The broad spectrum of activity of AMPs requires an efficient permeabilization of the bacterial outer and inner membranes. The outer leaflet of the outer membrane of Gram negative bacteria is made of a specialized lipid called lipopolysaccharide (LPS). The LPS layer is an efficient permeability barrier against anti-bacterial agents including AMPs. As a mode of protection, LPS can induce self associations of AMPs rendering them inactive. Temporins are a group of short-sized AMPs isolated from frog skin, and many of them are inactive against Gram negative bacteria as a result of their self-association in the LPS-outer membrane. PRINCIPAL FINDINGS Using NMR spectroscopy, we have determined atomic resolution structure and characterized localization of temporin-1Ta or TA (FLPLIGRVLSGIL-amide) in LPS micelles. In LPS micelles, TA adopts helical conformation for residues L4-I12, while residues F1-L3 are found to be in extended conformations. The aromatic sidechain of residue F1 is involved in extensive packing interactions with the sidechains of residues P3, L4 and I5. Interestingly, a number of long-range NOE contacts have been detected between the N-terminal residues F1, P3 with the C-terminal residues S10, I12, L13 of TA in LPS micelles. Saturation transfer difference (STD) NMR studies demonstrate close proximity of residues including F1, L2, P3, R7, S10 and L13 with the LPS micelles. Notably, the LPS bound structure of TA shows differences with the structures of TA determined in DPC and SDS detergent micelles. SIGNIFICANCE We propose that TA, in LPS lipids, forms helical oligomeric structures employing N- and C-termini residues. Such oligomeric structures may not be translocated across the outer membrane; resulting in the inactivation of the AMP. Importantly, the results of our studies will be useful for the development of antimicrobial agents with a broader spectrum of activity.
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Affiliation(s)
- Rathi Saravanan
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Mangesh Joshi
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Harini Mohanram
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Anirban Bhunia
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Maria Luisa Mangoni
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche Università La Sapienza, Roma, Italy
| | - Surajit Bhattacharjya
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail:
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23
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Zídek Z, Kmoníčková E, Kostecká P, Jansa P. Microfiltration method of removal of bacterial contaminants and their monitoring by nitric oxide and Limulus assays. Nitric Oxide 2012; 28:1-7. [PMID: 22981390 DOI: 10.1016/j.niox.2012.08.078] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 08/09/2012] [Accepted: 08/28/2012] [Indexed: 12/19/2022]
Abstract
Similar to lipopolysaccharide (LPS), a product of Gram-negative bacteria, the signal macromolecules of Gram-positive bacteria lipoteichoic acid (LTA) and peptidoglycan (PGN) possess multiple biological activities. They may be a source of misinterpretation of experimental findings. We have found that not only LPS but also LTA and PGN can be detected by the Limulus amebocyte lysate (LAL) assay. All of them stimulate the high output in vitro nitric oxide (NO) production of in rat peritoneal cells. The onset of the NO enhancement was observed with 25-100pg/ml of LPS and 25-100ng/ml of PGN and LTA. Polymyxin B (PMX), if applied at concentration 10,000-fold higher than that of LPS, can completely inhibit the NO and LAL binding responses of LPS. The NO-stimulatory and LAL-binding properties of LTA and PGN are not eliminated by PMX. Handling of LPS contamination with PMX may be associated with serious problems because it possesses intrinsic biological activity and becomes cytotoxic at concentration >25μg/ml. The present findings suggest a convenient alternative avoiding these issues. As monitored by the NO and LAL assays, even high amounts of LPS as well as PGN and LTA can be removed by molecular mass cutoff microfiltration. All types of the filters (3kDa to 100kDa) are equally effective. It is suggested that the microfiltration procedure may be considered as a preferable, general and easy method of sample decontamination.
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Affiliation(s)
- Zdeněk Zídek
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Vídeňská 1083, 14220 Prague 4, Czech Republic.
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24
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Saravanan R, Mohanram H, Joshi M, Domadia PN, Torres J, Ruedl C, Bhattacharjya S. Structure, activity and interactions of the cysteine deleted analog of tachyplesin-1 with lipopolysaccharide micelle: Mechanistic insights into outer-membrane permeabilization and endotoxin neutralization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:1613-24. [DOI: 10.1016/j.bbamem.2012.03.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 03/14/2012] [Accepted: 03/16/2012] [Indexed: 12/17/2022]
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25
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Bhunia A, Bhattacharjya S, Chatterjee S. Applications of saturation transfer difference NMR in biological systems. Drug Discov Today 2012; 17:505-13. [DOI: 10.1016/j.drudis.2011.12.016] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 11/10/2011] [Accepted: 12/14/2011] [Indexed: 01/08/2023]
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26
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Pulido D, Nogués MV, Boix E, Torrent M. Lipopolysaccharide neutralization by antimicrobial peptides: a gambit in the innate host defense strategy. J Innate Immun 2012; 4:327-36. [PMID: 22441679 DOI: 10.1159/000336713] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 01/20/2012] [Indexed: 01/08/2023] Open
Abstract
Antimicrobial peptides (AMPs) are nowadays understood as broad multifunctional tools of the innate immune system to fight microbial infections. In addition to its direct antimicrobial action, AMPs can modulate the host immune response by promoting or restraining the recruitment of cells and chemicals to the infection focus. Binding of AMPs to lipopolysaccharide is a critical step for both their antimicrobial action and their immunomodulatory properties. On the one hand, removal of Gram-negative bacteria by AMPs can be an effective strategy to prevent a worsened inflammatory response that may lead to septic shock. On the other hand, by neutralizing circulating endotoxins, AMPs can successfully reduce nitric oxide and tumor necrosis factor-α production, hence preventing severe tissue damage. Furthermore, AMPs can also interfere with the Toll-like receptor 4 recognition system, suppressing cytokine production and contributing to modulate the inflammatory response. Here, we review the immune system strategies devised by AMPs to avoid an exacerbated inflammatory response and thus prevent a fatal end to the host.
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Affiliation(s)
- David Pulido
- Department of Biochemistry and Molecular Biology, Faculty of Biosciences, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
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27
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Bhunia A, Saravanan R, Mohanram H, Mangoni ML, Bhattacharjya S. NMR structures and interactions of temporin-1Tl and temporin-1Tb with lipopolysaccharide micelles: mechanistic insights into outer membrane permeabilization and synergistic activity. J Biol Chem 2011; 286:24394-406. [PMID: 21586570 PMCID: PMC3129218 DOI: 10.1074/jbc.m110.189662] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 04/27/2011] [Indexed: 11/06/2022] Open
Abstract
Temporins are a group of closely related short antimicrobial peptides from frog skin. Lipopolysaccharide (LPS), the major constituent of the outer membrane of gram-negative bacteria, plays important roles in the activity of temporins. Earlier studies have found that LPS induces oligomerization of temporin-1Tb (TB) thus preventing its translocation across the outer membrane and, as a result, reduces its activity on gram-negative bacteria. On the other hand, temporin-1Tl (TL) exhibits higher activity, presumably because of lack of such oligomerization. A synergistic mechanism was proposed, involving TL and TB in overcoming the LPS-mediated barrier. Here, to gain insights into interactions of TL and TB within LPS, we investigated the structures and interactions of TL, TB, and TL+TB in LPS micelles, using NMR and fluorescence spectroscopy. In the context of LPS, TL assumes a novel antiparallel dimeric helical structure sustained by intimate packing between aromatic-aromatic and aromatic-aliphatic residues. By contrast, independent TB has populations of helical and aggregated conformations in LPS. The LPS-induced aggregated states of TB are largely destabilized in the presence of TL. Saturation transfer difference NMR studies have delineated residues of TL and TB in close contact with LPS and enhanced interactions of these two peptides with LPS, when combined together. Fluorescence resonance energy transfer and (31)P NMR have pointed out the proximity of TL and TB in LPS and conformational changes of LPS, respectively. Importantly, these results provide the first structural insights into the mode of action and synergism of antimicrobial peptides at the level of the LPS-outer membrane.
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Affiliation(s)
- Anirban Bhunia
- From the School of Biological Sciences, Division of Structural and Computational Biology, Nanyang Technological University, Singapore 637551 and
| | - Rathi Saravanan
- From the School of Biological Sciences, Division of Structural and Computational Biology, Nanyang Technological University, Singapore 637551 and
| | - Harini Mohanram
- From the School of Biological Sciences, Division of Structural and Computational Biology, Nanyang Technological University, Singapore 637551 and
| | - Maria L. Mangoni
- the Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche Universita‘ La Sapienza, Piazzale Aldo Moro, 5-00185 Roma, Italy
| | - Surajit Bhattacharjya
- From the School of Biological Sciences, Division of Structural and Computational Biology, Nanyang Technological University, Singapore 637551 and
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Calle LP, Cañada FJ, Jiménez-Barbero J. Application of NMR methods to the study of the interaction of natural products with biomolecular receptors. Nat Prod Rep 2011; 28:1118-25. [DOI: 10.1039/c0np00071j] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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