Download or read book Nanoscale Sensing Methodology Via Functional Control of an Ion Channel forming Peptide Gramicidin A written by Michael X. Macrae and published by . This book was released on 2011 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gramicidin ion channels are formed by the association of two [Beta]-helix pentadecapeptides, each spanning half the lipid bilayer. A single dimerization event enables the flux of millions of cations across the bilayer per second. This signal amplification allows for the detection and monitoring of events on the single molecule level - a feat seldomly accomplished. Gramicidin is also remarkably simple to use as it both spontaneously self-incorporates into the membrane and forms channels under a broad range of conditions. Lastly, work primarily done by our lab has developed facile synthetic techniques for functional modifications of the native channel structure. This thesis represents a two-fold effort, both in the improved fundamental understanding of gramicidin A, as well as the exploration of this platform's utility as a tool for more applied problems. Through a comprehensive understanding of the influences which a permanent charge affixed to the channel entrance exert on both channel conductance and open channel lifetime, the ability to utilize the functional response to a wide variety of external stimuli has been realized.
Download or read book Designing Nanosensors Based on Ion Channel forming Derivatives of Gramicidin A written by Steven Blake and published by . This book was released on 2008 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation will focus on detecting analytes in aqueous solution that chemically react with or bind to functional groups near the opening of synthetic ion channels derived from gramicidin A (gA). Detection is achieved when a measurable change in the conductance of ions across the ion channel is produced after the analyte interacts with the channel. Ion channel sensors have great potential for achieving ultrasensitive detection since a single chemical modification near the lumen of the channel can lead to detectable changes in channel conductance. The dissertation will specifically focus on: (1) the development of design parameters to improve sensing with gA-based nanosensors; (2) the demonstration of sensing analytes in aqueous solution by manipulating the charge of a chemical group near the pore of gA (charge-based sensing); (3) the chemistry for producing reactive building blocks of gA for developing robust and diverse gA-based nanosensors; (4) the detection of enzyme activity using our charge-based sensing approach to achieve picomolar limits of detection; and (5) the small structural changes that can be introduced to the peptide near the lumen of the channel to control conductance.
Download or read book Cumulated Index Medicus written by and published by . This book was released on 1999 with total page 1856 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biomimetic Membranes for Sensor and Separation Applications written by Claus Hélix-Nielsen and published by Springer Science & Business Media. This book was released on 2012-01-02 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the possibilities and challenges in mimicking biological membranes and creating membrane-based sensor and separation devices. Recent advances in developing biomimetic membranes for technological applications will be presented with focus on the use of integral membrane protein mediated transport for sensing and separation. It describes the fundamentals of biosensing as well as separation and shows how the two processes are working in a cooperative manner in biological systems. Biomimetics is a truly cross-disciplinary approach and this is exemplified using the process of forward osmosis will be presented as an illustration of how advances in membrane technology may be directly stimulated by an increased understanding of biological membrane transport. In the development of a biomimetic sensor/separation technology, both channels (ion and water channels) and carriers (transporters) are important. An ideal sensor/separation device requires the supporting biomimetic matrix to be virtually impermeable to anything but the solute in question. In practice, however, a biomimetic support matrix will generally have finite permeabilities to water, electrolytes, and non-electrolytes. These non-protein mediated membrane transport contributions will be presented and the implications for biomimetic device construction will be discussed. New developments in our understanding of the reciprocal coupling between the material properties of the biomimetic matrix and the embedded proteins will be presented and strategies for inducing biomimetic matrix stability will be discussed. Once reconstituted in its final host biomimetic matrix the protein stability also needs to be maintained and controlled. Beta-barrel proteins exemplified by the E. Coli outer membrane channels or small peptides are inherently more stable than alpha-helical bundle proteins which may require additional stabilizing modifications. The challenges associated with insertion and stabilization of alpha-helical bundle proteins including many carriers and ligand and voltage gated ion (and water) channels will be discussed and exemplified using the aquaporin protein. Many biomimetic membrane applications require that the final device can be used in the macroscopic realm. Thus a biomimetic separation device must have the ability to process hundred of liters of permeate in hours – effectively demanding square-meter size membranes. Scalability is a general issue for all nano-inspired technology developments and will be addressed here in the context biomimetic membrane array fabrication. Finally a robust working biomimetic device based on membrane transport must be encapsulated and protected yet allowing massive transport though the encapsulation material. This challenge will be discussed using microfluidic design strategies as examples of how to use microfluidic systems to create and encapsulate biomimetic membranes. The book provides an overview of what is known in the field, where additional research is needed, and where the field is heading.
Download or read book Bacterial Exotoxins How Bacteria Fight the Immune System written by Inka Sastalla and published by Frontiers Media SA. This book was released on 2016-10-07 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bacterial pathogenicity factors are functionally diverse. They may facilitate the adhesion and colonization of bacteria, influence the host immune response, assist spreading of the bacterium by e.g. evading recognition by immune cells, or allow bacteria to dwell within protected niches inside the eukaryotic cell. Exotoxins can be single polypeptides or heteromeric protein complexes that act on different parts of the cells. At the cell surface, they may insert into the membrane to cause damage; bind to receptors to initiate their uptake; or facilitate the interaction with other cell types. For example, bacterial superantigens specifically bind to major histocompatibility complex (MHC) II molecules on the surface of antigen presenting cells and the T cell receptor, while cytolysins cause pore formation. For intracellular activity, exotoxins need to be translocated across the eukaryotic membrane. Gram-negative bacteria can directly inject effector proteins in a receptor-independent manner by use of specialized needle apparatus such as bacterial type II, III, or type IV secretion systems. Other methods of translocation include the phagocytic uptake of bacteria followed by toxin secretion, or receptor-mediated endocytosis which allows the targeting of distinct cell types. Receptor-based uptake is initiated by the binding of heteromeric toxin complexes to the cell surface and completed by the translocation of the effector protein(s) across the endosomal membrane. In the cytosol, toxins interact with specific eukaryotic target proteins to cause post-translational modifications that often result in the manipulation of cellular signalling cascades and inflammatory responses. It has become evident that the actions of some bacterial toxins may exceed their originally assumed cytotoxic function. For example, pore-forming toxins do not only cause cytolysis, but may also induce autophagy, pyroptosis, or activation of the MAPK pathways, resulting in adjustment of the host immune response to infection and modification of inflammatory responses both locally and systemically. Other recently elucidated examples of the immunomodulatory function of cell death-inducing exotoxins include TcdB of Clostridium difficile which activates the inflammasome through modification of cellular Rho GTPases, or the Staphyloccocus d-toxin which activates mast cells. The goal of this research topic was to gather current knowledge on the interaction of bacterial exotoxins and effector proteins with the host immune system. The following 16 research and review articles in this special issue describe mechanisms of immune modification and evasion and provide an overview over the complexity of bacterial toxin interaction with different cells of the immune system.
Download or read book Electrochemical Biosensors written by Serge Cosnier and published by CRC Press. This book was released on 2015-01-26 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since four decades, rapid detection and monitoring in clinical and food diagnostics and in environmental and biodefense have paved the way for the elaboration of electrochemical biosensors. Thanks to their adaptability, ease of use in relatively complex samples, and their portability, electrochemical biosensors now are one of the mainstays of analy
Download or read book Fighting Multidrug Resistance with Herbal Extracts Essential Oils and Their Components written by Mahendra Rai and published by Academic Press. This book was released on 2013-05-24 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fighting Multidrug Resistance with Herbal Extracts, Essential Oils and their Components offers scientists a single source aimed at fighting specific multidrug-resistant (MDR) microorganisms such as bacteria, protozoans, viruses and fungi using natural products. This essential reference discusses herbal extracts and essential oils used or under investigation to treat MDR infections, as well as those containing antimicrobial activity that could be of potential interest in future studies against MDR microorganisms. The need to combat multidrug-resistant microorganisms is an urgent one and this book provides important coverage of mechanism of action, the advantages and disadvantages of using herbal extracts, essential oils and their components and more to aid researchers in effective antimicrobial drug discovery - Addresses the need to develop safe and effective approaches to coping with resistance to all classes of antimicrobial drugs - Provides readers with current evidence-based content aimed at using herbal extracts and essential oils in antimicrobial drug development - Includes chapters devoted to the activity of herbal products against herpes, AIDS, tuberculosis, drug-resistant cancer cells and more
Download or read book Polymer Translocation written by M. Muthukumar and published by CRC Press. This book was released on 2016-04-19 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymer translocation occurs in many biological and biotechnological phenomena where electrically charged polymer molecules move through narrow spaces in crowded environments. Unraveling the rich phenomenology of polymer translocation requires a grasp of modern concepts of polymer physics and polyelectrolyte behavior. Polymer Translocation discusse
Download or read book Anion Receptor Chemistry written by Jonathan L Sessler and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anion recognition plays a critical role in a range of biological processes, and a variety of receptors and carriers can be found throughout the natural world. Chemists working in the area of supramolecular chemistry have created a range of anion receptors, drawing inspiration from nature as well as their own inventive processes. This book traces the origins of anion recognition chemistry as a unique sub-field in supramolecular chemistry while illustrating the basic approaches currently being used to effect receptor design. The combination of biological overview and summary of current synthetic approaches provides a coverage that is both comprehensive and comprehensible. First, the authors detail the key design motifs that have been used to generate synthetic receptors and which are likely to provide the basis for further developments. They also highlight briefly some of the features that are present in naturally occurring anion recognition and transport systems and summarise the applications of anion recognition chemistry. Providing as it does a detailed review for practitioners in the field and a concise introduction to the topic for newcomers, Anion Receptor Chemistry reflects the current state of the art. Fully referenced and illustrated in colour, it is a welcome addition to the literature.
Download or read book Molecular and Nano Tubes written by Oliver Hayden and published by Springer. This book was released on 2014-10-01 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular- and Nano-Tubes summarizes recent advancements in the synthesis, fabrication and applications of tubular structures. An interdisciplinary overview of innovative science focused on tubular structures is provided. The reader is offered an overview of the different fields that molecular and nano tubes appear in, in order to learn the fundamental basics as well as the applications of these materials. This book also: Shows how nanotechnology creates novel materials by crossing the barriers between biology and material science, electronics and optics, medicine and more Demonstrates that tubes are a fundamental element in nature and used in disparate applications such as ion channels and carbon nanotubes Molecular- and Nano-Tubes is an ideal volume for researchers and engineers working in materials science and nanotechnology.
Download or read book Piezo Channels written by and published by Academic Press. This book was released on 2017-07-17 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: Piezo Channels, Volume 79, the latest volume in the Current Topics in Membranes series provides the necessary membrane research to assist readers in discovering the current state of a particular field and future directions. New chapters in the updated volume include A Tour de Force: The Discovery, Properties, and Function of Piezo Channels, Piezo1 Channels in Vascular Development and the Sensing of Shear Stress, the Origin of the Force: The Force-From-Lipids Principle Applied to Piezo Channels, Genetic Diseases of PIEZO1 and PIEZO2 Dysfunction, and The Structural Basis for Sensing by the Piezo1 Protein. Users of this series will find an up-to-date presentation of the current knowledge in the field of Piezo Channels. - Written by leading experts in the field - Contains original material, both textual and illustrative, that make it a very relevant reference - Presented in a very comprehensive manner - Ideal reference for both researchers in the field and general readers who will find this book to be relevant and up-to-date
Download or read book Nanoscale Biophysics of the Cell written by Mohammad Ashrafuzzaman and published by Springer. This book was released on 2018-04-12 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Macroscopic cellular structures and functions are generally investigated using biological and biochemical approaches. But these methods are no longer adequate when one needs to penetrate deep into the small-scale structures and understand their functions. The cell is found to hold various physical structures, molecular machines, and processes that require physical and mathematical approaches to understand and indeed manipulate them. Disorders in general cellular compartments, perturbations in single molecular structures, drug distribution therein, and target specific drug-binding, etc. are mostly physical phenomena. This book will show how biophysics has revolutionized our way of addressing the science and technology of nanoscale structures of cells, and also describes the potential for manipulating the events that occur in them.
Download or read book Handbook of Cell Biosensors written by Gérald Thouand and published by Springer. This book was released on 2021-10-01 with total page 992 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook is an interdisciplinary and comprehensive reference covering all aspects of cell biosensors. It is divided into four main sections which are led and organized by numerous international experts. The scope of coverage includes: Fundamentals and genetics for biosensor applications Transducers, Materials and Systems Markets, innovation and education Application of biosensors in business Biosensor research is an exciting hybrid world where biologists, chemists, physicists, engineers and computer engineers come together. This handbook will serve as an invaluable living resource for all researchers in academia and industry working with cell biosensors.
Download or read book Channels Carriers and Pumps written by Wilfred D. Stein and published by Elsevier. This book was released on 2014-12-09 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introduction to the principles of membrane transport: How molecules and ions move across the cell membrane by simple diffusion and by making use of specialized membrane components (channels, carriers, and pumps). The text emphasizes the quantitative aspects of such movement and its interpretation in terms of transport kinetics. Molecular studies of channels, carriers, and pumps are described in detail as well as structural principles and the fundamental similarities between the various transporters and their evolutionary interrelationships. The regulation of transporters and their role in health and disease are also considered. - Provides an introduction to the properties of transport proteins: channels, carriers, and pumps - Presents up-to-date information on the structure of transport proteins and on their function and regulation - Includes introductions to transport kinetics and to the cloning of genes that code transport proteins - Furnishes a link between the experimental basis of the subject and theoretical model building
Download or read book Structure and Dynamics of Confined Polymers written by John J. Kasianowicz and published by Springer Science & Business Media. This book was released on 2002-07-31 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers are essential to biology because they can have enough stable degrees of freedom to store the molecular code of heredity and to express the sequences needed to manufacture new molecules. Through these they perform or control virtually every function in life. Although some biopolymers are created and spend their entire career in the relatively large free space inside cells or organelles, many biopolymers must migrate through a narrow passageway to get to their targeted destination. This suggests the questions: How does confining a polymer affect its behavior and function? What does that tell us about the interactions between the monomers that comprise the polymer and the molecules that confine it? Can we design and build devices that mimic the functions of these nanoscale systems? The NATO Advanced Research Workshop brought together for four days in Bikal, Hungary over forty experts in experimental and theoretical biophysics, molecular biology, biophysical chemistry, and biochemistry interested in these questions. Their papers collected in this book provide insight on biological processes involving confinement and form a basis for new biotechnological applications using polymers. In his paper Edmund DiMarzio asks: What is so special about polymers? Why are polymers so prevalent in living things? The chemist says the reason is that a protein made of N amino acids can have any of 20 different kinds at each position along the chain, resulting in 20 N different polymers, and that the complexity of life lies in this variety.
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 Emerging Nanotechnologies in Immunology written by Ranjita Shegokar and published by William Andrew. This book was released on 2018-05-17 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emerging Nanotechnologies in Immunology aims to deliver a systematic and comprehensive review of data concerning the nature of interaction and nano-related risks between the nanophamaceuticals currently in the pipeline of S&T development for skin, ocular, and nasal drug delivery, including absorption, toxicity, and the ability to distribute after systemic exposure.The scientific development of manufactured nanomaterials for drug delivery is increasing rapidly. One of the most prominent applications is topical drug delivery, where cutaneous, ocular, and nasal exposure becomes even more relevant. These targets are the first barrier that nanoparticles encounter when in contact with the human body.The contributors addresses a representative set of the broad spectrum of nanopharmaceuticals currently being used, including cationic lipid nanoparticles, polymeric PLGA, PLA nanoparticles, biomacromolecules-based nanoparticles, and other scaffolds tissue engineered skin substitutes. Regulation and risk is also covered, since the safety of these nanophamaceuticals still represents a barrier to their wide innovative use. - Provides the reader with a thorough knowledge of the safety aspects of nanopharmaceuticals which are currently under research - Focuses on the characterization and quantification of the nanopharmaceuticals - Allows readers to understand the correlation between the nature of the materials and their potential nanotoxicological effects - Includes an overview of regulatory aspects related to the R&D of nanopharmaceuticals
