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 The Action of Antimicrobial Peptides on Supported Lipid Bilayers Investigated by Biophysical Methods written by Stefania Piantavigna and published by . This book was released on 2014 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt: The emergence of bacteria that have developed resistance towards "traditional" antibiotics is becoming a serious global health threat. Consequently, alternative approaches are needed to find new drugs that can act directly as antibiotics or to assist traditional drugs to improve efficacy. The emergence of antimicrobial peptides (AMPs) as a possible new class offers promise. AMPs represent a large and varied group of "natural antibiotics" present in virtually every organism. However, in order to develop new drugs derived from AMPs knowledge of the bioactivity of these is needed, such as concentration ranges and specific bacterial targets. Of great practical importance is to have a comprehensive understanding of the mechanism of action of AMPs, so that the risk of cross-reactivity and development of new bacterial resistance is minimised. All AMPs interact with the cell membrane, which is a complex and dynamic system, mostly containing phospholipids and proteins. Phospholipids are not simple "bricks" of the membrane, but they themselves are involved in various cellular processes. Therefore, biomimetic membranes, e.g. supported lipid bilayers (SLBs), represent a valid approach for investigating the interactions between lipids and AMPs. Creation of a supported membrane reduces the complexity of those studies to just one variable. Many variables influence the formation of SLBs and a protocol regarding the formation of SLBs assembled on gold-coated sensors is described in Paper 1. The membrane deposition and the peptide-membrane interactions were investigated using a Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) (Paper 2). Thus, the action of various peptides were investigated with zwitterionic membranes, which contained negatively charged lipid (bacterial membranes), or cholesterol (mammalian membranes).The action of the two most widely studied AMPs, melittin and magainin 2, on SLBs, has been examined using QCM-D in Chapter 3. These peptides formed "toroidal pores", which lead to membrane disruption. However, the action of these peptides has been found to be both concentration and composition dependent.Many AMPs are enriched in a particular amino acid residue. The influence of several of these peptide residues has been investigated using QCM-D in Chapters 4, 5 and 6. The action of proline-rich peptides apidaecins HbI and HbII, the variant Api88 and oncocin peptides on SLBs, are illustrated in Papers 3, 4 and 5, respectively. These peptides were found to insert into the membrane without any evidence of disruption. The influence of lipid composition on the activity of the arginine-rich peptide Tat has also been investigated with QCM together with scanning electrochemical microscopy (SECM) (Chapter 5). The cell-penetrating Tat peptide was shown to act as a lytic AMP in the presence of negatively charged membranes (Papers 6 and 7).The addition of tryptophan residues in the sequence of a short arginine-rich peptide, (RW)3, caused a dramatic switch from cell penetrating to lytic activity, while the inclusion of ruthenocene in the peptide RcCO-W(RW)2 did not affect the peptide activity (Chapter 6).Finally, in Chapter 7, Uperin 3.5, an amyloid-like AMP, demonstrated that the amyloid fibrils are not necessary for the membrane-disruption. However, the action of Uperin 3.5 towards zwitterionic membranes is switched to insertion if cholesterol is present in the membrane. Thus, QCM has been demonstrated to be an invaluable technique for characterising, in real time, the action of various peptides on SLBs of bacterial mimetic composition and mammalian. However, the combination of QCM with other techniques e.g. SECM, is always encouraged to reinforce this data and to gain a wide perspective of activity.

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 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 Vibrational Spectroscopic Study of the Interactions of Antimicrobial Peptides with Single Planar Supported Lipid Bilayers and the Effect of Mesoporous written by Ruth Helen Smith and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 Advances in Planar Lipid Bilayers and Liposomes written by A. Leitmannova Liu and published by Academic Press. This book was released on 2011-08-09 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Planar Lipid Bilayers and Liposomes, Volume 6, continues to include invited chapters on a broad range of topics, covering both main arrangements of the reconstituted system, namely planar lipid bilayers and spherical liposomes. The invited authors present the latest results in this exciting multidisciplinary field of their own research group. Many of the contributors working in both fields over many decades were in close collaboration with the late Prof. H. Ti Tien, the founding editor of this book series. There are also chapters written by some of the younger generation of scientists included in this series. This volume keeps in mind the broader goal with both systems, planar lipid bilayers and spherical liposomes, which is the further development of this interdisciplinary field worldwide. Contributions from newcomers and established and experienced researchers Exploring theoretically and experimentally the planar lipid bilayer systems and spherical liposomes This volume is dedicated to mark the Bilayer Lipid Membranes 45th anniversary

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 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 Lifting up of Supported Lipid Bilayers on Layer by layer Polyion alkylthiol Cushions written by Chen Ma and published by . This book was released on 2002 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bridging Membrane Biophysics to Microbiology Innovating Towards New Peptide and Peptide based Antimicrobials written by Miguel A. R. B. Castanho and published by Frontiers Media SA. This book was released on 2022-02-01 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances in Computational Biology written by Luis F. Castillo and published by Springer Science & Business Media. This book was released on 2013-08-04 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume compiles accepted contributions for the 2nd Edition of the Colombian Computational Biology and Bioinformatics Congress CCBCOL, after a rigorous review process in which 54 papers were accepted for publication from 119 submitted contributions. Bioinformatics and Computational Biology are areas of knowledge that have emerged due to advances that have taken place in the Biological Sciences and its integration with Information Sciences. The expansion of projects involving the study of genomes has led the way in the production of vast amounts of sequence data which needs to be organized, analyzed and stored to understand phenomena associated with living organisms related to their evolution, behavior in different ecosystems, and the development of applications that can be derived from this analysis.

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 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 Computer Simulations of Antimicrobial Peptides written by Himanshu Khandelia and published by . This book was released on 2006 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: