Download or read book Interaction of Antimicrobial Peptides with Model Lipid Membranes written by Ahmad Arouri and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The antimicrobial resistance is a growing problem that threatens our ability to treat infections and urges the need to develop novel alternatives for "conventional" antibiotics which are less susceptible for the development of bacterial resistance. Antimicrobial peptides (AMPs) are among the most promising candidates. This is due to their ability to disturb biological membranes via non-specific interactions with the membrane lipid components. In spite of the significant amount of experimental data, many of the issues concerning AMPs are still not well understood. This includes their molecular-based mechanism of action, the role of the membrane architecture, the importance of the structure and properties of the antimicrobial peptides, the extent and significance of the pore formation and membrane micellization processes, and others. We utilized several biophysical techniques, mainly DSC, ITC, DLS, IRRAS, FT-IR, and epifluorescence microscopy, to study the interaction of synthetic AMPs with various model lipid membranes of different composition. In this work two groups of AMPs were used: 1) KLA peptides with different helical propensities, and 2) a linear and a cyclic arginine- and tryptophan-rich antimicrobial hexapeptide with identical amino acid sequences (Ac-RW and C-RW, respectively). Phosphatidylglycerol (PG), phosphatidylethanolamine (PE) and PG/PE mixtures were used to model the cytoplasmic bacterial membrane, whereas phosphatidylcholine (PC) was used to model the outer leaflet of mammalian membranes. Our aim was to investigate the interplay between the peptide conformation, the membrane composition and properties, and the experimental conditions, as well as the role of membrane composition in modulating the activity of the peptides. In addition, an attempt was made to explain the bioactivity of these peptides in the light of the experimental results using model membranes. This study enriches our knowledge and understanding of the complicated interaction between AMP and model membranes. The coupling of various biophysical techniques is very beneficial to get insight into the studied systems from different perspectives as well as to check any variation in experimental results due to different techniques. Our findings emphasize the importance of the peptide conformation and local concentration in determining the mode of action of the peptides. Also, the findings show that a phenomenon observed with certain lipid membranes, preparation procedures, and experimental conditions cannot necessarily be generalized.
Download or read book Peptide Lipid Interactions written by Sidney A. Simon and published by Academic Press. This book was released on 2002-11-13 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains a comprehensive overview of peptide-lipid interactions by leading researchers. The first part covers theoretical concepts, experimental considerations, and thermodynamics. The second part presents new results obtained through site-directed EPR, electron microscopy, NMR, isothermal calorimetry, and fluorescence quenching. The final part covers problems of biological interest, including signal transduction, membrane transport, fusion, and adhesion. Key Features * world-renowned experts * state-of-the-art experimental methods * monolayers, bilayers, biological membranes * theoretical aspects and computer simulations * rafts * synaptic transmission * membrane fusion * signal transduction
Download or read book The Mechanism of Lipid Bilayer Disruption by the Human Antimicrobial Peptide LL 37 written by Katherine Anne Henzler Wildman and published by . This book was released on 2003 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Interactions of Antimicrobial Peptides with Model Lipid Bilayer and Biological Membranes written by Ronald N. MacElhaney and published by . This book was released on 1999 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lipid Bilayers written by J. Katsaras and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides the reader with an up to date insight of the current state of the art in the field of lipid bilayer research and the important insights derived for the understanding of the complex and varied behaviour of biological membranes and its function.
Download or read book Interaction of Antimicrobial Peptides with Lipid Membranes written by Mária Hanulová and published by . This book was released on 2008 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interactions of Antimicrobial Peptides AMPs with Model Membranes at Different PH Values written by Gagandeep K. Sandhu and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Antimicrobial peptides (AMPs) are important components of the innate immune systems of many different organisms. Their amphipathic and cationic characteristics promote interactions with the cell membrane. Gad peptides are rich in histidine, and thus have the potential to exhibit pH-dependent activity. The major focus of this study was to understand how Gad peptides interact with model lipid membranes and how these interactions depend on the peptides' overall charge and the composition of the model membranes. 2H NMR spectroscopy was used to study the effect of Gad peptides on lipid acyl chain order of model lipid bilayers at different pH values. 2H NMR results revealed that membrane disruption by Gad peptides was not pH-dependent. Zeta potential measurements were used to study the binding of Gad peptides to model lipid membranes. The binding studies showed that for both Gad-1 and Gad-2 at low pH, less peptide binds to the membrane and the peptide interacts with a larger number of lipid molecules. Experiments performed with model membranes containing cardiolipin (CL) in the presence of Gad-1 showed that the presence of CL allows the membrane to accommodate more Gad-1. In the presence of CL the peptide binds more strongly with the membrane and interacts with a larger number of lipids. Taken together, these results suggest that Gad peptides might disrupt membrane integrity by clustering anionic lipids. Clustering of anionic lipids away from zwitterionic lipids by cationic AMPs might be a contributing mechanism, which does not exclude other mechanisms, including the carpet mechanism and pore formation. The chemical shift values of 15N NMR spectroscopy can give an insight about the positioning of peptides in lipid bilayer surfaces. 15N NMR observations showed that Gad-1 aligned parallel to the membrane surface. The study of AMP-membrane interactions will help to identify criteria to recognize the important features of natural AMP sequences involved in the antimicrobial action and thus assist in the design of AMP-based antibiotics to help overcome the problem of antimicrobial resistance.
Download or read book An Investigation of Protein and Antimicrobial Peptide Interactions with Model Lipid Membranes written by Mitaben D. Lad and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interaction of Cyclic Antimicrobial Hexapeptides with Model Lipid Membranes written by Sebastian Finger and published by . This book was released on 2021* with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antimicrobial peptides. Lipid-peptide interactions, Lipid clustering, Phosphatidylglycerol (PG), Phosphatidylethanolamine (PE), Cardiolipin, Ternary phase diagram, Differential scanning calorimetry (DSC), Isothermal titration calorimetry (ITC), Attenuated total reflection infrared spectroscopy (ATR-IR).
Download or read book Advances in Planar Lipid Bilayers and Liposomes written by Ales Iglic and published by Academic Press. This book was released on 2012-09-04 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Planar Lipid Bilayers and Liposomes volumes cover a broad range of topics, including main arrangements of the reconstituted system, namely planar lipid bilayers as well as spherical liposomes. The invited authors present the latest results of their own research groups in this exciting multidisciplinary field. Incorporates contributions from newcomers and established and experienced researchers Explores the planar lipid bilayer systems and spherical liposomes from both theoretical and experimental perspectives Serves as an indispensable source of information for new scientists
Download or read book Antimicrobial Peptides written by Katsumi Matsuzaki and published by Springer. This book was released on 2019-04-12 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an overview of antimicrobial peptides (AMPs), their mechanisms of antimicrobial action, other activities, and various problems that must still be overcome regarding their clinical application. Divided into four major parts, the book begins with a general overview of AMPs (Part I), and subsequently discusses the various mechanisms of antimicrobial action and methods for researching them (Part 2). It then addresses a range of activities other than antimicrobial action, such as cell penetration, antisepsis, anticancer, and immunomodulatory activities (Part 3), and explores the prospects of clinical application from various standpoints such as the selective toxicity, design, and discovery of AMPs (Part 4). A huge number of AMPs have been discovered in plants, insects, and vertebrates including humans, and constitute host defense systems against invading pathogenic microorganisms. Consequently, many attempts have been made to utilize AMPs as antibiotics. AMPs could help to solve the urgent problem of drug-resistant bacteria, and are also promising with regard to sepsis and cancer therapy. Gathering a wealth of information, this book will be a bible for all those seeking to develop antibiotics, anti-sepsis, or anticancer agents based on AMPs.
Download or read book Kinetics of the Interaction of the Antimicrobial Peptide Cecropin A with Model Lipid Bilayer Membranes written by Allison Christine Cavenaugh and published by . This book was released on 2005 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Supported Lipid Bilayers and Antimicrobial Peptides written by Radek Macháň and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supported lipid bilayers have been used as an artificial model of biological membranes and their interaction with 5 selected antimicrobial peptides was studied by several experimental techniques, mainly ellipsometry, laser scanning microscopy and fluorescence correlation spectroscopy. The work explains basic principles of the applied techniques focusing on their aspects relevant to characterization of lipid bilayers. The biological significance of antimicrobial peptides, their modes of interaction with membranes and the basic characteristics of the selected peptides are briefly discussed. The following text describes the main types of experimental studies performed and the interpretation of their results. Peptide-induced changes in lipid bilayer morphology were characterized by ellipsometry and laser scanning microscopy. Most interesting effects were observed in the case of melittin, which induced formation of long lipid tubules protruding from the bilayer. Lipid lateral diffusion measured by fluorescence correlation spectroscopy can provide information on bilayer organization on length-scales below resolution of optical microscopy.
Download or read book Peptide and Protein Interaction with Membrane Systems written by Sara Bobone and published by Springer. This book was released on 2014-05-31 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: In her thesis, Sara Bobone outlines spectroscopic studies of antimicrobial peptides (AMPs) which are promising lead compounds for drugs used to fight multidrug resistant bacteria. Bobone shows that AMPs interact with liposomes and she clarifies the structure of pores formed by one of these molecules. These results help us to understand how AMPs are selective for bacterial membranes and how their activity can be finely tuned by modifying their sequence. Findings which solve several conundrums debated in the literature for years. In addition, Bobone uses liposomes as nanotemplates for the photopolymerization of hydrogels - exploiting the self- assembly properties of phospholipids. Bobone was able to trap an enzyme using nanometeric particles, while still allowing its activity by the diffusion of substrates and products through the network of the polymer. The innovative nano devices described in this thesis could solve many of the hurdles still hampering the therapeutic application of protein-based drugs.
Download or read book Drug biomembrane interaction studies written by T. Musumeci and published by Elsevier Inc. Chapters. This book was released on 2013-10-31 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antimicrobial agents are from different classes of molecules that suppress multiplication and growth of or kill microorganisms such as bacteria, fungi, or viruses. The precise mechanism of action of some antimicrobial agents is unknown but they must interact with or cross the cell membrane to have an effect. Identification of the damage induced by these compounds is difficult due to the complexity of cell membranes. Studying interactions using membrane models is a first step in obtaining elementary information about the effects of such drugs. We discuss interaction studies in the recent literature that use calorimetric techniques, regarding the mechanism of action or side effects of antimicrobial agents. For interaction studies with mimetic membrane models using DSC analysis, we will try to answer some key questions: (a) Does lipid composition affect the interaction? (b) Does the composition of bilayers influence the secondary structure of a peptide antimicrobial? (c) Does lipid polymorphism influence the activity and toxicity of the molecules? We underline the importance of phospholipids (neutral or anionic) chosen to produce biomembrane vesicles as models for the different studies.
Download or read book Interaction Between Antimicrobial Peptides and Lipid Bilayers written by Jin Hua and published by . This book was released on 1994 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Membrane active Peptides written by Miguel A. R. B. Castanho and published by Internat'l University Line. This book was released on 2010 with total page 675 pages. Available in PDF, EPUB and Kindle. Book excerpt:
