[PDF] Structure Dynamics And Inhibition Of Alzheimers Amyloid Peptides eBook

Author : Xiang Yu
Publisher :
Page : 258 pages
File Size : 32,39 MB
Release : 2012
Category : Alzheimer's disease
ISBN :

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Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder, pathologically linked to the abnormal self-aggregation of amyloid peptides ([Amyloid-beta] and tau) into amyloid fibrils. Accumulating evidence supports the "toxic oligomer hypothesis" that small soluble amyloid oligomers (intermediate species), rather than monomers (initial species) and insoluble fibrils (final species), are major toxic species responsible for neuron dysfunction and death. However, due to the polymorphic and transit nature of amyloid oligomers, atomic structures of amyloid oligomers are not available to date, causing the difficulty in the fundamental understanding of the mechanisms of amyloid formation and toxicity and in the rational design of structural-based inhibitors to treat AD. In this dissertation, we develop a multiscale computational framework to (1) determine atomic structures of amyloid oligomers; (2) investigate the conformation, orientation, and aggregation of amyloid oligomers upon adsorption on biological and artificial surfaces; (3) probe binding and inhibitory ability of organic ligands to amyloid oligomers. Throughout this work, we for the first time determine a series of atomic structures of [Amyloid-beta] micelles (Chapter II), [Amyloid-beta] globulomers (Chapter III), and tau fibrillar-like oligomers (Chapter IV). These oligomers vary considerably in overall structural morphologies, reflecting a highly polymorphic nature of amyloid oligomers in a rugged energy landscape. We also study the effects of cholesterol level on the mutual structure, dynamics, and interaction of [Amyloid-beta] and lipid bilayer (Chapter V). Increased cholesterol level greatly enhances [Amyloid-beta] binding to the bilayer, which provides atomic-level explanation as to why high-level cholesterol may have a higher risk for AD development. In parallel to lipid bilayer, molecular dynamics simulations of [Amyloid-beta] peptides on graphite reveal the important role of hydrophobic interactions in facilitating [Amyloid-beta] adsorption, reorientation, structural transition, and aggregation (Chapter VI). With the assistance of atomic structures of [Amyloid-beta] oligomers, we computationally examine binding events between tanshinones and [Amyloid-beta] oligomer (Chapter VII). Strong binding affinity of tanshinone-I, rather tanshinone-IIA, to [Amyloid-beta] is well correlated with inhibitory activity to [Amyloid-beta] aggregation. Combination of our computational and experimental results represent an important step towards a better understanding of the aggregation, toxicity, and inhibition mechanisms of amyloid peptides at atomic level.

Author : J. Robin Harris
Publisher : Springer Science & Business Media
Page : 416 pages
File Size : 10,48 MB
Release : 2006-11-22
Category : Science
ISBN : 0387232265

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To understand Alzheimer's disease (AD) is one of the major thrusts of present-day clinical research, strongly supported by more fimdamental cellular, biochemical, immunological and structural studies. It is these latter that receive attention within this book. This compilation of 20 chapters indicates the diversity of work currently in progress and summarizes the current state of knowledge. Experienced authors who are scientifically active in their fields of study have been selected as contributors to this book, in an attempt to present a reasonably complete survey of the field. Inevitably, some exciting topics for one reason or another have not been included, for which we can only apologize. Standardization of terminology is often a problem in science, not least in the Alzheimer field; editorial effort has been made to achieve standardization between the Chapters, but some minor yet acceptable personal / author variation is still present, i. e. P-amyloid/amyloid-P; Ap42/Apl-42/APi. 42! The book commences with a broad survey of the contribution that the range of available microscopical techniques has made to the study of Alzheimer's amyloid plaques and amyloid fibrillogenesis. This chapter also serves as an Introduction to the book, since several of the topics introduced here are expanded upon in later chapters. Also, it is significant to the presence of this chapter that the initial discovery of brain plaques, by Alois Alzheimer, utilized light microscopy, a technique that continues to be extremely valuable in present-day AD research.

Author : Kunal Roy
Publisher : Springer Nature
Page : 492 pages
File Size : 20,21 MB
Release : 2023-06-30
Category : Medical
ISBN : 1071633112

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This second edition volume expands on the previous edition with updated descriptions on different computational methods encompassing ligand-based, structure-based, and combined approaches with their recent applications in anti-Alzheimer drug design. Different background topics like recent advancements in research on the development of novel therapies and their implications in the treatment of Alzheimer’s Disease (AD) have also been covered for completeness. Special topics like basic information science methods for insight into neurodegenerative pathogenesis, drug repositioning and network pharmacology, and online tools to predict ADMET behavior with reference to anti-Alzheimer drug development have also been included. In the Neuromethods series style, chapter include the kind of detail and key advice from the specialists needed to get successful results in your laboratory. Cutting-edge and thorough, Computational Modeling of Drugs Against Alzheimer’s Disease, Second Edition is a valuable resource for all researchers and scientists interested in learning more about this important and developing field.

Author : Qiuming Wang
Publisher :
Page : 193 pages
File Size : 13,32 MB
Release : 2013
Category : Alzheimer's disease
ISBN :

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Alzheimer's disease (AD) is the most common age related neurodegenerative disorder pathologically linked with the accumulation of the extracellular senile plaques of [Beta]-Amyloid peptide (A[Beta]) and the intracellular neurofibrillary tangles of tau protein in AD's brains. The deposition of A[Beta] is regarded as the primary causative factor in AD, which involves both neuron cytotoxicity and tau protein hydrophosphorylation. Amyloid formation on the cell membrane involves multiple self-assembly processes in which A[Beta] peptides undergo complex conformational change, aggregation, and reorganization to form characteristic [Beta]-sheet rich fibrils. The kinetics of this self-assembly process and the inhibition of A[Beta] aggregation and toxicity remains an important but open question because of 1) the small size, fast transition, and heterogeneous intermediates of A[Beta] oligomers, 2) complicated surface environment of cell membrane, and 3) no effective pharmaceutical agent was produced to date to treat AD. In this dissertation, both computational and experimental approaches were conducted to (1) investigate the conformation, orientation, and aggregation of amyloid oligomers upon adsorption on artificial surfaces; (2) determine seeding effect of A[Beta] adsorption and kinetic on different artificial surfaces; (3) examine inhibition effect of tanshiones on A[Beta] aggregation and toxicity; (4) explore novel process for A[Beta] inhibitor design. Throughout this week, we for the first time determine the effect of surface chemistry on A[Beta] aggregation and adsorption (Chapter II); and reveal the role of size, conformation, and orientation of A[Beta] oligomer on A[Beta]-surface interaction (Chapter III and Chapter IV). As compared to A[Beta] aggregation in solution, all of the Self-Assembled Monolayers (SAMs) can greatly accelerate A[Beta] aggregation and promote the structural conversion from an unstructured conformation to a [Beta]-sheet-containing structure. Our results suggest that A[Beta] undergoes different aggregation pathways on different SAMs. All these experimental and simulation results represent the first important step towards a better fundamental understanding of amyloid aggregation and toxicity mechanisms at the molecular level. We also discover a type of novel inhibitors of tanshionones from herb extracts which possess multifunction of inhibiting A[Beta] aggregation, disaggregating A[Beta] fibers, and reducing A[Beta]-induced cell toxicity in vitro (Chapter V). Tanshinone-derived compounds constitute a new class of amyloid inhibitors with multiple advantages in amyloid inhibition, fibril disruption, and cell protection, as well as their well-known anti-inflammatory activity, which may hold great promise in treating amyloid diseases. In addition of investigating the naturally existed compounds, a novel technique for the design and identification of amyloidogenic hexapeptide-based A[Beta] inhibitor was developed (Chapter VI). We have suggested a novel hypothesis for the development of hexapeptide-based A[Beta] inhibitors and developed a high-throughput protocol for the design and screen of amyloidogenic hexapeptide sequences as A[Beta] aggregation and cytotoxicity inhibitors. The successful identification of A[Beta] inhibitors through this work highly confirmed that analyzing the self-recognition short peptide fragments is a promising strategy for developing peptide-based inhibitors of Alzheimer's disease. And the common concept of cross-amylid interaction could also potentially be used to the identification of inhibitors for other amyloid diseases. The self-recognition hexapeptide fragments designed in QSAR model, in together with the high throughput MD simulation model, can be widely used for amyloidosis mechanism study and amyloid inhibitor screen.

Author : Jesus Avila
Publisher : Frontiers E-books
Page : 114 pages
File Size : 35,66 MB
Release : 2014-08-18
Category : Medicine (General)
ISBN : 288919261X

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Neurofibrillary tangles (NFTs) composed of intracellular aggregates of tau protein are a key neuropathological feature of Alzheimer’s Disease (AD) and other neurodegenerative diseases, collectively termed tauopathies. The abundance of NFTs has been reported to correlate positively with the severity of cognitive impairment in AD. However, accumulating evidences derived from studies of experimental models have identified that NFTs themselves may not be neurotoxic. Now, many of tau researchers are seeking a “toxic” form of tau protein. Moreover, it was suggested that a “toxic” tau was capable to seed aggregation of native tau protein and to propagate in a prion-like manner. However, the exact neurotoxic tau species remain unclear. Because mature tangles seem to be non-toxic component, “tau oligomers” as the candidate of “toxic” tau have been investigated for more than one decade. In this topic, we will discuss our consensus of “tau oligomers” because the term of “tau oligomers” [e.g. dimer (disulfide bond-dependent or independent), multimer (more than dimer), granular (definition by EM or AFM) and maybe small filamentous aggregates] has been used by each researchers definition. From a biochemical point of view, tau protein has several unique characteristics such as natively unfolded conformation, thermo-stability, acid-stability, and capability of post-translational modifications. Although tau protein research has been continued for a long time, we are still missing the mechanisms of NFT formation. It is unclear how the conversion is occurred from natively unfolded protein to abnormally mis-folded protein. It remains unknown how tau protein can be formed filaments [e.g. paired helical filament (PHF), straight filament and twisted filament] in cells albeit in vitro studies confirmed tau self-assembly by several inducing factors. Researchers are still debating whether tau oligomerization is primary event rather than tau phosphorylation in the tau pathogenesis. Inhibition of either tau phosphorylation or aggregation has been investigated for the prevention of tauopathies, however, it will make an irrelevant result if we don’t know an exact target of neurotoxicity. It is a time to have a consensus of definition, terminology and methodology for the identification of “tau oligomers”.

Author : Jeffrey Cummings
Publisher : Cambridge University Press
Page : 575 pages
File Size : 40,96 MB
Release : 2022-03-31
Category : Business & Economics
ISBN : 1108838669

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Provides a definitive overview of the complex ecosystem facilitating Alzheimer's Disease drug research and development. Demonstrates a drug's journey from in the lab, clinical trial testing, regulatory review, and marketing by pharmaceutical companies. Details the use of artificial intelligence, clinical trial management, and financing models.

Author : Corinne Nardin
Publisher : John Wiley & Sons
Page : 288 pages
File Size : 20,7 MB
Release : 2021-04-06
Category : Technology & Engineering
ISBN : 3527810994

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Biological Soft Matter Explore a comprehensive, one-stop reference on biological soft matter written and edited by leading voices in the field Biological Soft Matter: Fundamentals, Properties and Applications delivers a unique and indispensable compilation of up-to-date knowledge and material on biological soft matter. The book presents a thorough overview about biological soft matter, beginning with different substance classes, including proteins, nucleic acids, lipids, and polysaccharides. It goes on to describe a variety of superstructures and aggregated and how they are formed by self-assembly processes like protein folding or crystallization. The distinguished editors have included materials with a special emphasis on macromolecular assembly, including how it applies to lipid membranes, and proteins fibrillization. Biological Soft Matter is a crucial resource for anyone working in the field, compiling information about all important substance classes and their respective roles in forming superstructures. The book is ideal for beginners and experts alike and makes the perfect guide for chemists, physicists, and life scientists with an interest in the area. Readers will also benefit from the inclusion of: An introduction to DNA nano-engineering and DNA-driven nanoparticle assembly Explorations of polysaccharides and glycoproteins, engineered biopolymers, and engineered hydrogels Discussions of macromolecular assemblies, including liquid membranes and small molecule inhibitors for amyloid aggregation A treatment of inorganic nanomaterials as promoters and inhibitors of amyloid fibril formation An examination of a wide variety of natural and artificial polymers Perfect for materials scientists, biochemists, polymer chemists, and protein chemists, Biological Soft Matter: Fundamentals, Properties and Applications will also earn a place in the libraries of biophysicists and physical chemists seeking a one-stop reference summarizing the rapidly evolving topic of biological soft matter.

Author : Robert Vink
Publisher : University of Adelaide Press
Page : 354 pages
File Size : 14,13 MB
Release : 2011
Category : Medical
ISBN : 0987073052

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The brain is the most complex organ in our body. Indeed, it is perhaps the most complex structure we have ever encountered in nature. Both structurally and functionally, there are many peculiarities that differentiate the brain from all other organs. The brain is our connection to the world around us and by governing nervous system and higher function, any disturbance induces severe neurological and psychiatric disorders that can have a devastating effect on quality of life. Our understanding of the physiology and biochemistry of the brain has improved dramatically in the last two decades. In particular, the critical role of cations, including magnesium, has become evident, even if incompletely understood at a mechanistic level. The exact role and regulation of magnesium, in particular, remains elusive, largely because intracellular levels are so difficult to routinely quantify. Nonetheless, the importance of magnesium to normal central nervous system activity is self-evident given the complicated homeostatic mechanisms that maintain the concentration of this cation within strict limits essential for normal physiology and metabolism. There is also considerable accumulating evidence to suggest alterations to some brain functions in both normal and pathological conditions may be linked to alterations in local magnesium concentration. This book, containing chapters written by some of the foremost experts in the field of magnesium research, brings together the latest in experimental and clinical magnesium research as it relates to the central nervous system. It offers a complete and updated view of magnesiums involvement in central nervous system function and in so doing, brings together two main pillars of contemporary neuroscience research, namely providing an explanation for the molecular mechanisms involved in brain function, and emphasizing the connections between the molecular changes and behavior. It is the untiring efforts of those magnesium researchers who have dedicated their lives to unraveling the mysteries of magnesiums role in biological systems that has inspired the collation of this volume of work.