Electrochemical Shaping of Fibrous Protein Fibrils

1971 ◽  
Vol 10 (2) ◽  
pp. 160-163 ◽  
Author(s):  
Isao Karube ◽  
Shuichi Suzuki ◽  
Sakushige Kinoshita ◽  
Jun Mizuguchi
Keyword(s):  
Fibrous Protein ◽  
Protein Fibrils ◽  
Electrochemical Shaping

Relationships between hierarchical structure and properties in macromolecular systems

1987 ◽  
Vol 45 ◽  
pp. 440-443
Author(s):  
E. Baer
Keyword(s):  
Uniaxial Tension ◽  
Hierarchical Structure ◽  
Inorganic Material ◽  
Hierarchical Structures ◽  
Bone Collagen ◽  
Structure And Properties ◽  
Connective Tissues ◽  
Scale Level ◽  
Fibrous Protein ◽  
Macromolecular Systems

The most advanced macromolecular materials are found in plants and animals, and certainly the connective tissues in mammals are amongst the most advanced macromolecular composites known to mankind. The efficient use of collagen, a fibrous protein, in the design of both soft and hard connective tissues is worthy of comment. Very crudely, in bone collagen serves as a highly efficient binder for the inorganic hydroxyappatite which stiffens the structure. The interactions between the organic fiber of collagen and the inorganic material seem to occur at the nano (scale) level of organization. Epitatic crystallization of the inorganic phase on the fibers has been reported to give a highly anisotropic, stress responsive, structure. Soft connective tissues also have sophisticated oriented hierarchical structures. The collagen fibers are “glued” together by a highly hydrated gel-like proteoglycan matrix. One of the simplest structures of this type is tendon which functions primarily in uniaxial tension as a reinforced elastomeric cable between muscle and bone.

The microtubule associated protein (MAP) tau forms a new class of triple-stranded left-hand helical fibrous protein polymer

1992 ◽  
Vol 50 (1) ◽  
pp. 540-541
Author(s):  
G. C. Ruben ◽  
K. Iqbal ◽  
I. Grundke-Iqbal ◽  
H. Wisniewski ◽  
T. L. Ciardelli ◽  
...  
Keyword(s):  
Axial Ratio ◽  
Normal Structure ◽  
Paired Helical Filaments ◽  
Left Hand ◽  
New Class ◽  
Protein Polymer ◽  
Fibrous Protein ◽  
Protein Map ◽  
Neurotransmitter Transport ◽  
Alzheimer Neurofibrillary Tangles

In neurons, the microtubule associated protein, tau, is found in the axons. Tau stabilizes the microtubules required for neurotransmitter transport to the axonal terminal. Since tau has been found in both Alzheimer neurofibrillary tangles (NFT) and in paired helical filaments (PHF), the study of tau's normal structure had to preceed TEM studies of NFT and PHF. The structure of tau was first studied by ultracentrifugation. This work suggested that it was a rod shaped molecule with an axial ratio of 20:1. More recently, paraciystals of phosphorylated and nonphosphoiylated tau have been reported. Phosphorylated tau was 90-95 nm in length and 3-6 nm in diameter where as nonphosphorylated tau was 69-75 nm in length. A shorter length of 30 nm was reported for undamaged tau indicating that it is an extremely flexible molecule. Tau was also studied in relation to microtubules, and its length was found to be 56.1±14.1 nm.

scholarly journals Temperature-Dependent Structural Variability of Prion Protein Amyloid Fibrils

2021 ◽  
Vol 22 (10) ◽  
pp. 5075
Author(s):  
Mantas Ziaunys ◽  
Andrius Sakalauskas ◽  
Kamile Mikalauskaite ◽  
Ruta Snieckute ◽  
Vytautas Smirnovas
Keyword(s):  
Protein Aggregation ◽  
Prion Protein ◽  
Amyloid Fibrils ◽  
Prion Diseases ◽  
Morphological Properties ◽  
Large Sample Size ◽  
Structural Variations ◽  
Temperature Dependent ◽  
Protein Fibrils ◽  
Propagation Properties

Prion protein aggregation into amyloid fibrils is associated with the onset and progression of prion diseases—a group of neurodegenerative amyloidoses. The process of such aggregate formation is still not fully understood, especially regarding their polymorphism, an event where the same type of protein forms multiple, conformationally and morphologically distinct structures. Considering that such structural variations can greatly complicate the search for potential antiamyloid compounds, either by having specific propagation properties or stability, it is important to better understand this aggregation event. We have recently reported the ability of prion protein fibrils to obtain at least two distinct conformations under identical conditions, which raised the question if this occurrence is tied to only certain environmental conditions. In this work, we examined a large sample size of prion protein aggregation reactions under a range of temperatures and analyzed the resulting fibril dye-binding, secondary structure and morphological properties. We show that all temperature conditions lead to the formation of more than one fibril type and that this variability may depend on the state of the initial prion protein molecules.

scholarly journals Oxygen Permeability of Silk Fibroin Hydrogels and Their Use as Materials for Contact Lenses: A Purposeful Analysis

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 58
Author(s):  
Traian V. Chirila
Keyword(s):  
Tissue Engineering ◽  
Bombyx Mori ◽  
Silk Fibroin ◽  
Biomedical Applications ◽  
Oxygen Permeability ◽  
Contact Lenses ◽  
The Past ◽  
Fibrous Protein ◽  
Silk Moth ◽  
Bombyx Mori Silk

Fibroin is a fibrous protein that can be conveniently isolated from the silk cocoons produced by the larvae of Bombyx mori silk moth. In its form as a hydrogel, Bombyx mori silk fibroin (BMSF) has been employed in a variety of biomedical applications. When used as substrates for biomaterial-cells constructs in tissue engineering, the oxygen transport characteristics of the BMSF membranes have proved so far to be adequate. However, over the past three decades the BMSF hydrogels have been proposed episodically as materials for the manufacture of contact lenses, an application that depends on substantially elevated oxygen permeability. This review will show that the literature published on the oxygen permeability of BMSF is both limited and controversial. Additionally, there is no evidence that contact lenses made from BMSF have ever reached commercialization. The existing literature is discussed critically, leading to the conclusion that BMSF hydrogels are unsuitable as materials for contact lenses, while also attempting to explain the scarcity of data regarding the oxygen permeability of BMSF. To the author’s knowledge, this review covers all publications related to the topic.

MnO2-capped silk fibroin (SF) nanoparticles with chlorin e6 (Ce6) encapsulation for augmented photo-driven therapy by modulating tumor microenvironment

2021 ◽  
Author(s):  
Lei Zhang ◽  
Ruihao Yang ◽  
Honglian Yu ◽  
Zhigang Xu ◽  
Yuejun Kang ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Bombyx Mori ◽  
Silk Fibroin ◽  
Chlorin E6 ◽  
Fibrous Protein

Silk fibroin (SF), derived from Bombyx mori, is a category of fibrous protein with outstanding potential for being applied in biomedical and biotechnological fields. In spite of many advantageous properties,...

Dynamics and Fluidity of Amyloid Fibrils:  A Model of Fibrous Protein Aggregates

2002 ◽  
Vol 124 (51) ◽  
pp. 15150-15151 ◽  
Author(s):  
Ami S. Lakdawala ◽  
David M. Morgan ◽  
Dennis C. Liotta ◽  
David G. Lynn ◽  
James P. Snyder
Keyword(s):  
Amyloid Fibrils ◽  
Protein Aggregates ◽  
Fibrous Protein

Protein nanowires with conductive properties

2015 ◽  
Vol 3 (25) ◽  
pp. 6499-6504 ◽  
Author(s):  
Anders Elfwing ◽  
Fredrik G. Bäcklund ◽  
Chiara Musumeci ◽  
Olle Inganäs ◽  
Niclas Solin
Keyword(s):  
Conductive Afm ◽  
Protein Fibrils ◽  
Conductive Properties

We have investigated protein fibrils decorated with metallic polymers using conductive AFM.

scholarly journals Flexible Biocomposites with Enhanced Interfacial Compatibility Based on Keratin Fibers and Sulfur-Containing Poly(urea-urethane)s

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1056 ◽  
Author(s):  
Ibon Aranberri ◽  
Sarah Montes ◽  
Itxaso Azcune ◽  
Alaitz Rekondo ◽  
Hans-Jürgen Grande
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bonds ◽  
Aromatic Diamine ◽  
Polymer Backbone ◽  
Neat Polymer ◽  
Fibrous Protein ◽  
The Matrix ◽  
Interfacial Compatibility ◽  
Superior Mechanical Properties ◽  
Keratin Fibers

Feathers are made of keratin, a fibrous protein with high content of disulfide-crosslinks and hydrogen-bonds. Feathers have been mainly used as reinforcing fiber in the preparation of biocomposites with a wide variety of polymers, also poly(urea-urethane)s. Surface compatibility between the keratin fiber and the matrix is crucial for having homogenous, high quality composites with superior mechanical properties. Poly(urea-urethane) type polymers are convenient for this purpose due to the presence of polar functionalities capable of forming hydrogen-bonds with keratin. Here, we demonstrate that the interfacial compatibility can be further enhanced by incorporating sulfur moieties in the polymer backbone that lead to new fiber-matrix interactions. We comparatively studied two analogous thermoplastic poly(urea-urethane) elastomers prepared starting from the same isocyanate-functionalized polyurethane prepolymer and two aromatic diamine chain extenders, bis(4-aminophenyl) disulfide (TPUU-SS) and the sulfur-free counterpart bis(4-aminophenyl) methane (TPUU). Then, biocomposites with high feather loadings (40, 50, 60 and 75 wt %) were prepared in a torque rheometer and hot-compressed into flexible sheets. Mechanical characterization showed that TPUU-SS based materials underwent higher improvement in mechanical properties than biocomposites made of the reference TPUU (up to 7.5-fold higher tensile strength compared to neat polymer versus 2.3-fold). Field Emission Scanning Electron Microscope (FESEM) images also provided evidence that fibers were completely embedded in the TPUU-SS matrix. Additionally, density, thermal stability, and water absorption of the biocomposites were thoroughly characterized.

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