Stress Strain Behavior Of Single Vimentin Intermediate Filament

Author : Johanna Lena Block
Publisher : Göttingen University Press
ISBN 13 : 3863953738
Total Pages : 177 pages
Book Rating : 4.37/5 ( download)

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Download or read book Stress-Strain Behavior of Single Vimentin Intermediate Filament written by Johanna Lena Block and published by Göttingen University Press. This book was released on 2018 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cells are the basic unit of living organisms and consist of a cytoplasm, which is enclosed by a membrane. As building blocks of life with a plethora of functions, cells have to be equipped with a high degree of mechanical resistance, durability, and variability. In eukaryotic cells three filamentous protein types – actin filaments, microtubules, and intermediate filaments (IFs) – form the so-called cytoskeleton, a network that is known to play a key role for the mechanical properties of cells. Among the three filament systems, IFs are special in terms of, for example, their hierarchical architecture, and their cell-type specific expression. In this thesis, vimentin, an IF mostly found in mesenchymal cells, is studied as a model system to learn more about the mechanical properties of IFs, and the underlying mechanisms that determine their robustness, stiffness, and flexibility. Using a combination of optical trapping and atomic force microcopy experiments and stochastic and numerical modelling, vimentin is found to possess impressive physical properties, such as an extendibility of about 3.6 times its initial length and a tensile memory that can be directly linked to the molecular architecture of the protein and the hierarchical construction of the filament. The experimental results show a clear loading-rate- and strain-dependent behavior of single vimentin IFs supporting the hypothesis that vimentin acts as a “safety belt” for cells, protecting them especially at large and fast deformations. The potential to dissipate a large amount of energy that is attributed to distinct non-equilibrium unfolding and refolding of the α-helices, which are the main structural feature of the vimentin monomer, enables vimentin to act as a shock absorber when exposed to large deformations. In case of cyclic deformations, such as in the cardiovascular system, the observed tensile memory could potentially help cells to be compliant with the repeated strain. In conclusion, vimentin is found to display highly interesting and diverse mechanical properties depending on the applied stress that could be linked to the molecular architecture of the filaments and enable vimentin to determine the mechanical properties of cells to a large extend.

Author : Johanna Lena Block
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.70/5 ( download)

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Download or read book Stress-Strain Behavior of Single Vimentin Intermediate Filament written by Johanna Lena Block and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : Johanna Lena Block
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.29/5 ( download)

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Download or read book Stress-strain Behavior of Single Vimentin Intermediate Filaments written by Johanna Lena Block and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Cells are the basic unit of living organisms and consist of a cytoplasm, which is enclosed by a membrane. As building blocks of life with a plethora of functions, cells have to be equipped with a high degree of mechanical resistance, durability, and variability. In eukaryotic cells three filamentous protein types - actin filaments, microtubules, and intermediate filaments (IFs) - form the so-called cytoskeleton, a network that is known to play a key role for the mechanical properties of cells. Among the three filament systems, IFs are special in terms of, for example, their hierarchical arc...

Author : Anna Veronika Schepers
Publisher : Universitätsverlag Göttingen
ISBN 13 : 3863955676
Total Pages : 247 pages
Book Rating : 4.70/5 ( download)

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Download or read book Intermediate Filament Mechanics Across Scales – From Single Filaments to Single Interactions and Networks in Cells written by Anna Veronika Schepers and published by Universitätsverlag Göttingen. This book was released on 2022 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanical properties of cells are largely determined by the cytoskeleton. The cytoskeleton is an intricate and complex structure formed by protein filaments, motor proteins, and crosslinkers. The three main types of protein filaments are microtubules, actin filaments, and intermediate filaments ( IFs ). Whereas the proteins that form microtubules and actin filaments are exceptionally conserved throughout cell types and organisms, the family of IFs is diverse. For example, the IF protein vimentin is expressed in relatively motile fibroblasts, and keratin IFs are found in epithelial cells. This variety of IF proteins might therefore be linked to the various mechanical properties of different cell types. In the scope of this thesis, I combine studies of IF mechanics on different time scales and in systems of increasing complexity, from single filaments to networks in cells. This multiscale approach allows for the simplification necessary to interpret observations while adding increasing physiological context in subsequent experiments. We especially focus on the tunability of the IF mechanics by environmental cues in these increasingly complex systems. In a series of experiments, including single filament elongation studies, single filament stretching measurements with optical tweezers, filament-filament interaction measurements with four optical tweezers, microrheology, and isotropic cell stretching, we characterize how electrostatic (pH and ion concentration) and hydrophobic interactions (detergent) provide various mechanisms by which the mechanics of the IF cytoskeleton can be tuned. These studies reveal how small changes, such as charge shifts, influence IF mechanics on multiple scales. In combination with simulations, we determine the mechanisms by which charge shifts alter single vimentin filament mechanics and we extract energy landscapes for interactions between single filaments. Such insights will provide a deeper understanding of the mechanisms by which cells can maintain their integrity and adapt to the mechanical requirements set by their environment.

Author :
Publisher : Academic Press
ISBN 13 : 9780128034705
Total Pages : 0 pages
Book Rating : 4.0X/5 ( download)

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Download or read book Intermediate Filament Proteins written by and published by Academic Press. This book was released on 2016-01-19 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intermediate Filament Proteins, the latest volume in the Methods in Enzymology series covers all the intermediate filaments in vertebrates and invertebrates, providing a unique understanding of the multiple different tissue-specific intermediate filaments. This volume also covers the latest methods that are currently being used to study intermediate filament protein function and dynamics. It will be an important companion for any experimentalist interesting in studying this protein family in their cell or organism model system.

Author : Normand Marceau
Publisher : Biota Publishing
ISBN 13 : 1615045414
Total Pages : 128 pages
Book Rating : 4.19/5 ( download)

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Download or read book Intermediate Filaments written by Normand Marceau and published by Biota Publishing. This book was released on 2014-06-01 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intermediate filaments (IFs), in concert with microfilaments (MFs) and microtubules (MTs), form the cytoskeleton, and each of these fibrillar networks exhibits rather unique structural and functional characteristics. Intermediate filaments were discovered in eukaryotic cells in the late 1960s, and their name comes from the fact that their diameter is intermediate between MFs and MTs. In contrast to the latter, IFs constitute a network that extends from the nuclear envelope throughout the cytoplasm, and in many cases, interact with cell surface domains involved in cell-cell and cell- matrix interactions. Several key features of their expression, assembly, structure and dynamics are highlighted in this eBook. For instance, IF proteins are encoded by several genes, which are classified into six types reflecting the tissues (cells) of origin. Moreover, IF proteins contain a conserved central α-helical (rod) domain flanked by N-terminal (head) and C-terminal (tail) globular domains that enables assembly of fibrous IFs exhibiting a tripartite structure. Although the rod domain is responsible for the formation of the coiled-coil framework and yields the main driving force during the IF protein assembly, the head and tail domains contribute to most of the structural heterogeneity of IF organization and undergo several types of post-translational modifications. Furthermore, the development of gene targeting methods to genetically knockout the expression of the IF genes in mice has uncovered the mechanical versus non-mechanical features of the IF networks, namely, their involvement in cell response to diverse forms of stress, growth stimulation, migration, or death insults. Finally, there is accumulating evidence revealing that the tissue and cell-type expression of IF genes reflects itself in the presence of causal or predisposition mutations responsible for numerous human tissue-specific diseases, known as IF-pathies. Table of Contents: List of Abbreviations / Introduction / IFs as a Multigene Family of Filamentous Proteins / Nuclear Lamina / IF Functional Interplay with Cell Surface Domains and Organelles / IFs and Cell Specialization / IF Relevance to Human Diseases / Conclusion / References / Author Biographies

Author : A.A. Collyer
Publisher : Springer Science & Business Media
ISBN 13 : 9401728984
Total Pages : 653 pages
Book Rating : 4.80/5 ( download)

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Download or read book Rheological Measurement written by A.A. Collyer and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 653 pages. Available in PDF, EPUB and Kindle. Book excerpt: In many cases rheological measurements are carried out in the simplest of geometries, but the interpretation involved in obtaining the rheological parameters of the test fluids from these measurements is surprisingly complex. The purpose of this book is to emphasise the points on which most workers in the field agree, and to let the authors deal with the contentious points according to their own beliefs and experience. This work represents a summary of the current thought on rheological meas urement by experts in the various techniques. When making measurements and obtaining from them parameters that describe the flow behaviour of the test fluids, it is essential that the experimentalist understands the underlying theory and shortcomings of the measurement technique, that he is aware of the likely microstructure of the fluid, and that from this he can appreciate how the fluid and the measuring system will interact with each other. It is this interaction that gives both the required rheological parameters of the fluids and the artefacts that confuse the issue. This book covers the main rheological measurement techniques from capillary, slit and stretching flows to rotational and oscillatory rheometry in various geometries including sliding plate measurements. These topics are backed up by chapters on more practical aspects, such as commercial instruments, and on computer control and data acquisition. The chapters deal with the basic methods, how the measurements are taken, and what assumptions and interpretations are made to obtain valid data on the test fluids.

Author : David A. D. Parry
Publisher : R G Landes Company
ISBN 13 : 9781570591204
Total Pages : 183 pages
Book Rating : 4.02/5 ( download)

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Download or read book Intermediate Filament Structure written by David A. D. Parry and published by R G Landes Company. This book was released on 1995 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covers the structure and role of intermediate filament (IF) proteins in a variety of cell types. The text examines the expression of IF proteins, the hierarchical assembly of those proteins into molecules, oligomers, protofilaments, protofilbrils and intact IF.

Author : Mohammad R. K. Mofrad
Publisher : Cambridge University Press
ISBN 13 : 1139458108
Total Pages : 231 pages
Book Rating : 4.08/5 ( download)

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Download or read book Cytoskeletal Mechanics written by Mohammad R. K. Mofrad and published by Cambridge University Press. This book was released on 2006-09-04 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a full spectrum of views on current approaches to modeling cell mechanics. The authors come from the biophysics, bioengineering and physical chemistry communities and each joins the discussion with a unique perspective on biological systems. Consequently, the approaches range from finite element methods commonly used in continuum mechanics to models of the cytoskeleton as a cross-linked polymer network to models of glassy materials and gels. Studies reflect both the static, instantaneous nature of the structure, as well as its dynamic nature due to polymerization and the full array of biological processes. While it is unlikely that a single unifying approach will evolve from this diversity, it is the hope that a better appreciation of the various perspectives will lead to a highly coordinated approach to exploring the essential problems and better discussions among investigators with differing views.

Author : Kunio Takeyasu
Publisher : CRC Press
ISBN 13 : 9814411590
Total Pages : 444 pages
Book Rating : 4.92/5 ( download)

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Download or read book Atomic Force Microscopy in Nanobiology written by Kunio Takeyasu and published by CRC Press. This book was released on 2016-04-19 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent developments in atomic force microscopy (AFM) have been accomplished through various technical and instrumental innovations, including high-resolution and recognition imaging technology under physiological conditions, fast-scanning AFM, and general methods for cantilever modification and force measurement. All these techniques are now highly