Fibrils
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The Nature And Origin Of Amyloid Fibrils
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Author : Gregory R. Bock
language : en
Publisher: John Wiley & Sons
Release Date : 2008-04-30
The Nature And Origin Of Amyloid Fibrils written by Gregory R. Bock and has been published by John Wiley & Sons this book supported file pdf, txt, epub, kindle and other format this book has been release on 2008-04-30 with Medical categories.
Amyloid fibrils are associated with a range of pathological disorders including Alzheimer's Disease, Down's syndrome, diabetes, cardiomyopathies, and transmissible spongiform encephalopathies. This volume is a comprehensive account of recent developments in the understanding of the process of amyloid fibrils. Contains up-to-date data on all of the clinical problems which, despite their pathological significance, are still largely unsolved.
Amyloid Fibrils And Prefibrillar Aggregates
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Author : Daniel Erik Otzen
language : en
Publisher: John Wiley & Sons
Release Date : 2013-06-04
Amyloid Fibrils And Prefibrillar Aggregates written by Daniel Erik Otzen and has been published by John Wiley & Sons this book supported file pdf, txt, epub, kindle and other format this book has been release on 2013-06-04 with Science categories.
Summing up almost a decade of biomedical research, this topical and eagerly awaited handbook is the first reference on the topic to incorporate recent breakthroughs in amyloid research. The first part covers the structural biology of amyloid fibrils and pre-fibrillar assemblies, including a description of current models for amyloid formation. The second part looks at the diagnosis and biomedical study of amyloid in humans and in animal models, while the final section discusses pharmacological approaches to manipulating amyloid and also looks at its physiological roles in lower and higher organisms. For Biochemists, Molecular Biologists, Neurobiologists, Neurophysiologists and those working in the Pharmaceutical Industry.
The Functional Studies Of Amyloid Fibrils And Their Toxicity
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Author : Abigail Kegomoditswe Elias
language : en
Publisher:
Release Date : 2015
The Functional Studies Of Amyloid Fibrils And Their Toxicity written by Abigail Kegomoditswe Elias and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with Amyloid categories.
Amyloid fibrils are a form of highly ordered, [beta]-sheet protein structure found in many sites in the body. Fibril formation occurs when intermediates along the protein-folding pathway irreversibly enter the off-folding pathway to form highly ordered amyloid fibrils. Amyloid fibril formation is of considerable research interest because of its intimate association with a wide range of debilitating diseases, including Alzheimer's, Huntington's and Parkinson's diseases and type II diabetes. Recently, it has been found that amyloid fibrils enhance human immunodeficiency virus (HIV-1) infection. Semen contains a fibril forming component that significantly increases the ability of HIV-1 to infect cells. This component is associated with peptide fragments of prostatic acid phosphatase and has been termed semen-derived enhancer of viral infection (SEVI). SEVI acts at the virus entry stage and only boots infectivity when the peptide has folded into highly structured arrays of amyloid fibrils. The work presented in this thesis describes the broader roles of SEVI in HIV-1 infection including its toxicity to neuronal and epithelial cells as well as the toxicity of [alpha]s2-casein [s2 subscript] (milk fibril forming protein). Firstly, the amyloidogenic regions of SEVI are identified by the use of computer algorithms. Accordingly, these regions were synthesised to examine their individual fibril-forming propensity. Fragments from the central regions formed fibrils of similar morphology to SEVI at physiological pH and temperature. Fibril formation was assessed via thioflavin T assay, circular dichroism spectrometry and transmission electron microscopy (TEM). In this study the toxicity of SEVI and its amyloidogenic fragments to neuronal and epithelial cells was investigated. SEVI and its fragments were toxic to neuronal cells but not to confluent epithelial cells. Secondly, the coreceptors used by SEVI and its amyloidogenic fragments are identified. HIV enters the cell by the interaction of glycoprotein (gp) 120 envelope with the cellular differentiation (CD) 4 protein and secondary coreceptors. Affinofile assays showed that SEVI and its fragments use CCR5 and CXCR4 secondary coreceptors to enhance HIV-1 entry to the host cells. Additionally the ability of clusterin to inhibit fibril formation by SEVI was investigated. Clusterin inhibited fibril formation by SEVI in a concentration dependent manner thereby inhibiting the cytotoxicity associated with the fibrils. Lastly, work detailing the toxicity of fibrils formed by milk protein [alpha]s2-casein [s2 subscript] is presented. [alpha]s2-casein [s2 subscript] forms fibrils spontaneously under physiological conditions. These fibrils have been found in corpora amylacea, an amyloid condition that infrequently develops within the mammary tissue of cows. The use of cell toxicity assays show that fibrils formed by [alpha]s2-casein [s2 subscript] were toxic to pheochromocytoma (PC) 12 cells. Furthermore, the use of Thioflavin T assay and TEM showed that a polyphenol epigallocatechin-3-gallate (EGCG), a component found in green tea extracts, inhibits fibril formation by [alpha]s2-casein [s2 subscript]. Previous research has found that, EGCG can reduce fibril formation and cellular toxicity of various fibril-forming proteins. EGCG has also been shown to inhibit SEVI enhancement of HIV infection in a manner dependent on the ability of EGCG to disrupt SEVI fibril formation, providing proof of principle for the potential of anti-fibril agents as inhibitors of HIV infection.
The Ultrastructure Of Protoplasmic Fibrils
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Author :
language : en
Publisher: Ardent Media
Release Date :
The Ultrastructure Of Protoplasmic Fibrils written by and has been published by Ardent Media this book supported file pdf, txt, epub, kindle and other format this book has been release on with categories.
Structural Biology Of Amyloid Fibrils
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Author : Vijay Kumar
language : en
Publisher: Academic Press
Release Date : 2023-09-01
Structural Biology Of Amyloid Fibrils written by Vijay Kumar and has been published by Academic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023-09-01 with Medical categories.
Structural Biology of Amyloid Fibrils is a comprehensive reference on the structure of protein aggregates in different neurodegenerative diseases and their molecular bases. Chapters describe these structures in detail, highlighting their similarities and differences across different disease states, alongside an unprecedented overview of current developments and new hypotheses emerging in amyloid fibril structure, stability, and mechanisms of formation. This volume also discusses how amyloid structure may affect the ability of fibrils to spread to different sites in a prion-like manner, as well as their role in disease. Featuring chapters on NMR, X-ray crystallography, and Cryo-EM methods, and discussing the structure of amyloid fibrils obtained directly from patients, the book allows readers to understand how polymorphism is associated with disease phenotype and how fibril structure affects and influences the cellular environment. Understanding the molecular architecture of amyloid fibrils and oligomers will be an important step towards developing therapeutic interventions based on targeting the fibrils and oligomers themselves, or the processes that generate them.
Structural Studies On Transthyretin Amyloid Fibrils
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Author : Ahmed A. Serag
language : en
Publisher:
Release Date : 2002
Structural Studies On Transthyretin Amyloid Fibrils written by Ahmed A. Serag and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2002 with categories.
Structural Studies Of Amyloid Fibrils Using Solid State Nmr
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Author : Marc Anthony Caporini
language : en
Publisher:
Release Date : 2008
Structural Studies Of Amyloid Fibrils Using Solid State Nmr written by Marc Anthony Caporini and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2008 with categories.
he development of solid-state NMR techniques and application to amyloid fibrils are presented. In addition, a new method of selective inversion based on chemical shift anisotropy is presented. An improved method for highly accurate distance measurement across parallel [beta]-sheets in amyloid fibrils has been developed. This method combines the a double quantum filtered version of the dipolar recoupling sequence DRAWS with the simulation and data fitting program SPINEVOLUTION to provide a simple and effective way to measure interstrand distances. This method was applied to TTR105.115 fibrils. Several other methods were applied to the TTR fibrils to measure interstrand and intersheet distances including REDOR, TEDOR, R2TRW, and DARR. The intermolecular distances were combined with the previously solved monomer structure to generate a high resolution (RMSD of 1.0 Å) of the TTR protofiliment. A disease associated mutant (L 11 M) of these fibrils was also studied by solid-state NMR to determine the monomer structure. Distance measurements on this system were done via 3D TEDOR and R2W, and torsion angle were also measured. A high resolution structure of the monomer is presented. Some non-fibril related research concerning the exploration of chemical shift anisotropy and cross polarization is presented in the later chapters. Both experimental evidence and a theoretical framework are presented to demonstrate the phenomenon of selective inversion based on the size of the chemical shift anisotropy. Further work concerning the use of cross polarization selectively was developed and is presented.
Atomic Resolution Structures Of Amyloid Fibrils By Solid State Nmr
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Author : Christian Wasmer
language : en
Publisher: Sudwestdeutscher Verlag Fur Hochschulschriften AG
Release Date : 2011-12
Atomic Resolution Structures Of Amyloid Fibrils By Solid State Nmr written by Christian Wasmer and has been published by Sudwestdeutscher Verlag Fur Hochschulschriften AG this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011-12 with categories.
Prions are infectious proteins best known as the agent of BSE and new variant Creutzfeldt-Jakob disease. Their infectious form has been identified as a beta-sheet-rich molecular aggregate termed amyloid fibril. Additionally, amyloid formation is eponymous for a group of diseases (Amyloidoses) that includes Alzheimer and Parkinson's. Yet amyloid fibrils remain structurally poorly characterized as they are neither accessible by X-ray crystallography nor solution NMR. My PhD work comprises structural studies of amyloid fibrils of prions and the development of new tools for structure determination by solid-state NMR (ssNMR), currently the sole source for atomic-level structural information about amyloids. The central piece of this work was the calculation of the structure of HET-s(218-289). This is the first known structure of an amyloid core of a prion in general. It enabled the following diverse studies on a range of subjects such as non-infectious fibrils of HET-s, a study on a homologue of HET-s and a structural study of bacterial inclusion bodies.
Synthesis And Characterization Of Fluorescent Stilbene Based Probes Targeting Amyloid Fibrils
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Author : Jun Zhang
language : en
Publisher: Linköping University Electronic Press
Release Date : 2018-11-27
Synthesis And Characterization Of Fluorescent Stilbene Based Probes Targeting Amyloid Fibrils written by Jun Zhang and has been published by Linköping University Electronic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018-11-27 with categories.
Alzheimer’s disease (AD) is characterized by two main protein aggregate hallmarks in the brain: extracellular deposition of the amyloid-? (A?) in senile plaques and intracellular neurofibrillary tangles (NFTs) consisting of hyperphosphorylated tau protein. The past decade has seen great progress in the development of imaging probes for the non-invasive detection of A? and tau aggregates. Here positron emission tomography (PET), single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI), are highly promising technologies for clinical diagnostics. However, as a research tool, optical imaging is superior because it is real-time, sensitive, inexpensive, not radioactive and that it in particular affords high-resolution studies both in vitro and in vivo. Fluorescent probes are especially useful for designing novel binding scaffolds for structure investigations of protein aggregates. This thesis describes design, synthesis and evaluation of a series of fluorescent probes for detection of amyloid fibrils, especially A? or tau aggregates in vitro. Firstly, trans-stilbenoid vinylbenzene-1,2-diol with benzene, naphthalene, anthracene, and pyrene are investigated with respect to their photophysical properties free in solution and when bound to amyloid fibrils, including time-resolved fluorescence measurements. It is noted that the extended conjugated systems retained the amyloid targeting properties of the probes and both the anthracene and pyrene moieties extensively enhanced the fluorescence intensity and prolonged lifetimes. Secondly, the synthesis of two molecules, Py1SA and Py2SA, based on pyrene linked to salicylic acid via a trans-stilbene C = C bond is presented. The compounds show strikingly different emission spectra when bound to preformed A?1-42 fibrils as well as to fibrils from four other distinct proteins. Additionally, excited state intramolecular proton transfer (ESIPT) coupled-charge transfer (ICT) is observed for the anionic form of the probes in polar solvents. This is likely the reason for the spectral differences of the probes when bound to amyloid fibrils. Moreover, the synthesis of a further development of the Congo red analogue X-34 [2,5-bis(4’-hydroxy-3’-carboxy-styryl) benzene] by rational design and synthesis is described. Full photophysical characterization was performed, including recording absorbance and fluorescence spectra, Stokes shift, quantum yield and fluorescence lifetimes. All ligands displayed high affinity towards recombinant amyloid fibrils of A?1-42 and tau as well as selectivity towards the corresponding disease-associated protein aggregates in human post mortem AD tissue. Lastly, the synthesis of a set of 2,1,3-benzothiadiazole (BTD)-based ligands with different conjugated spacers and variable patterns of OH substitutions of bis-styryl-BTD prototypes were developed. A? binding affinities (A?1-42 and A?1-40 fibrils) and the specificity towards A? plaques of all ligands were determined. These findings extend the structure to activity relationships of BTD-based ligands for A? fibril binding. Throughout the studies in this dissertation, new interesting properties of small molecule fluorescence probes have been discovered and analyzed. This knowledge should facilitate the development of noninvasive probes for early detection of Alzheimer's disease and to distinguish different A? fibril polymorphs.
A Study Of Coevolved Cofolding And Functionally Linked Proteins And The Characterization Of Amyloid Like Fibrils And Oligomers Towards The Understanding Of Protein Aggregation In Disease
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Author : Poh Kheng Teng
language : en
Publisher:
Release Date : 2010
A Study Of Coevolved Cofolding And Functionally Linked Proteins And The Characterization Of Amyloid Like Fibrils And Oligomers Towards The Understanding Of Protein Aggregation In Disease written by Poh Kheng Teng and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2010 with categories.