scholarly journals The Nephila clavipes genome highlights the diversity of spider silk genes and their complex expression

2017 ◽  
Vol 49 (6) ◽  
pp. 895-903 ◽  
Author(s):  
Paul L Babb ◽  
Nicholas F Lahens ◽  
Sandra M Correa-Garhwal ◽  
David N Nicholson ◽  
Eun Ji Kim ◽  
...  
Keyword(s):  
Spider Silk ◽  
Nephila Clavipes ◽  
Complex Expression

scholarly journals Nephila clavipes Flagelliform Silk-Like GGX Motifs Contribute to Extensibility and Spacer Motifs Contribute to Strength in Synthetic Spider Silk Fibers

2013 ◽  
Vol 14 (6) ◽  
pp. 1751-1760 ◽  
Author(s):  
Sherry L. Adrianos ◽  
Florence Teulé ◽  
Michael B. Hinman ◽  
Justin A. Jones ◽  
Warner S. Weber ◽  
...  
Keyword(s):  
Spider Silk ◽  
Nephila Clavipes ◽  
Silk Fibers

scholarly journals High-yield Production of Amyloid-β Peptide Enabled by a Customized Spider Silk Domain

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Axel Abelein ◽  
Gefei Chen ◽  
Kristīne Kitoka ◽  
Rihards Aleksis ◽  
Filips Oleskovs ◽  
...  
Keyword(s):  
Spider Silk ◽  
Amyloid Β ◽  
Silk Gland ◽  
High Yield ◽  
Efficient Production ◽  
Amyloid Β Peptide ◽  
Nephila Clavipes ◽  
Recombinant Production ◽  
Yield Production ◽  
High Yields

AbstractDuring storage in the silk gland, the N-terminal domain (NT) of spider silk proteins (spidroins) keeps the aggregation-prone repetitive region in solution at extreme concentrations. We observe that NTs from different spidroins have co-evolved with their respective repeat region, and now use an NT that is distantly related to previously used NTs, for efficient recombinant production of the amyloid-β peptide (Aβ) implicated in Alzheimer’s disease. A designed variant of NT from Nephila clavipes flagelliform spidroin, which in nature allows production and storage of β-hairpin repeat segments, gives exceptionally high yields of different human Aβ variants as a solubility tag. This tool enables efficient production of target peptides also in minimal medium and gives up to 10 times more isotope-labeled monomeric Aβ peptides per liter bacterial culture than previously reported.

Structure of the N-terminal domain of Euprosthenops australis dragline silk suggests that conversion of spidroin dope to spider silk involves a conserved asymmetric dimer intermediate

2019 ◽  
Vol 75 (7) ◽  
pp. 618-627 ◽  
Author(s):  
Wangshu Jiang ◽  
Glareh Askarieh ◽  
Alexander Shkumatov ◽  
My Hedhammar ◽  
Stefan D. Knight
Keyword(s):  
Electrostatic Interactions ◽  
Spider Silk ◽  
Quaternary Structure ◽  
Nephila Clavipes ◽  
Trigger Mechanism ◽  
Dragline Silk ◽  
Terminal Domain ◽  
Structure Changes ◽  
Molecular Events ◽  
Asymmetric Dimer

Spider silk is a biomaterial with exceptional mechanical toughness, and there is great interest in developing biomimetic methods to produce engineered spider silk-based materials. However, the mechanisms that regulate the conversion of spider silk proteins (spidroins) from highly soluble dope into silk are not completely understood. The N-terminal domain (NT) of Euprosthenops australis dragline silk protein undergoes conformational and quaternary-structure changes from a monomer at a pH above 7 to a homodimer at lower pH values. Conversion from the monomer to the dimer requires the protonation of three conserved glutamic acid residues, resulting in a low-pH `locked' dimer stabilized by symmetric electrostatic interactions at the poles of the dimer. The detailed molecular events during this transition are still unresolved. Here, a 2.1 Å resolution crystal structure of an NT T61A mutant in an alternative, asymmetric, dimer form in which the electrostatic interactions at one of the poles are dramatically different from those in symmetrical dimers is presented. A similar asymmetric dimer structure from dragline silk of Nephila clavipes has previously been described. It is suggested that asymmetric dimers represent a conserved intermediate state in spider silk formation, and a revised `lock-and-trigger' mechanism for spider silk formation is presented.

scholarly journals Nanostructure and molecular mechanics of spider dragline silk protein assemblies

2010 ◽  
Vol 7 (53) ◽  
pp. 1709-1721 ◽  
Author(s):  
Sinan Keten ◽  
Markus J. Buehler
Keyword(s):  
Secondary Structure ◽  
Spider Silk ◽  
Mechanical Performance ◽  
Experimental Studies ◽  
Silk Protein ◽  
Nephila Clavipes ◽  
Protein Assemblies ◽  
Dragline Silk ◽  
Spider Dragline Silk ◽  
Secondary Structure Content

Spider silk is a self-assembling biopolymer that outperforms most known materials in terms of its mechanical performance, despite its underlying weak chemical bonding based on H-bonds. While experimental studies have shown that the molecular structure of silk proteins has a direct influence on the stiffness, toughness and failure strength of silk, no molecular-level analysis of the nanostructure and associated mechanical properties of silk assemblies have been reported. Here, we report atomic-level structures of MaSp1 and MaSp2 proteins from the Nephila clavipes spider dragline silk sequence, obtained using replica exchange molecular dynamics, and subject these structures to mechanical loading for a detailed nanomechanical analysis. The structural analysis reveals that poly-alanine regions in silk predominantly form distinct and orderly beta-sheet crystal domains, while disorderly regions are formed by glycine-rich repeats that consist of 3 1 -helix type structures and beta-turns. Our structural predictions are validated against experimental data based on dihedral angle pair calculations presented in Ramachandran plots, alpha-carbon atomic distances, as well as secondary structure content. Mechanical shearing simulations on selected structures illustrate that the nanoscale behaviour of silk protein assemblies is controlled by the distinctly different secondary structure content and hydrogen bonding in the crystalline and semi-amorphous regions. Both structural and mechanical characterization results show excellent agreement with available experimental evidence. Our findings set the stage for extensive atomistic investigations of silk, which may contribute towards an improved understanding of the source of the strength and toughness of this biological superfibre.

scholarly journals Spider silk proteome provides insight into the structural characterization of Nephila clavipes flagelliform spidroin

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
José Roberto Aparecido dos Santos-Pinto ◽  
Helen Andrade Arcuri ◽  
Franciele Grego Esteves ◽  
Mario Sergio Palma ◽  
Gert Lubec
Keyword(s):  
Structural Characterization ◽  
Spider Silk ◽  
Nephila Clavipes ◽  
Insight Into

Description of Test Setup and Approach to Measure Thermal Properties of Natural and Synthetic Spider Silks at Cryogenic Temperatures

2013 ◽  
Author(s):  
Troy Munro ◽  
Changhu Xing ◽  
Andrew Marquette ◽  
Heng Ban ◽  
Cameron Copeland ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Conformational Changes ◽  
Spider Silk ◽  
Protein Structures ◽  
Cryogenic Temperatures ◽  
Nephila Clavipes ◽  
Silk Fibers ◽  
Spider Silks ◽  
Better Than ◽  
Natural And Synthetic

Spider silk is well-known for its exceptional mechanical properties, such as strength, elasticity and flexibility. Recently, it has been reported that dragline silk from a Nephila clavipes also has an exceptionally high thermal conductivity, comparable to copper when the fiber is stretched. Synthetic spider silks have been spun from spider silk proteins produced in transgenic sources, and their production process has the optimization potential to have properties similar to or better than the natural spider silk. There is interest to measure the thermal properties of natural and synthetic silk at cryogenic temperatures for use of spider silk fibers as heat conduits in systems where component weight is an issue, such as in spacecraft. This low temperature measurement is also of particular interest because of the conformational changes in protein structures, which affect material properties, that occurs at lower temperatures for some proteins. A measurement system has been designed and is being tested to characterize the thermal properties of natural and synthetic spider silks by means of a transient electrothermal method.

Anisotropic nanomechanical properties of Nephila clavipes dragline silk

2006 ◽  
Vol 21 (8) ◽  
pp. 2035-2044 ◽  
Author(s):  
Donna M. Ebenstein ◽  
Kathryn J. Wahl
Keyword(s):  
Mechanical Properties ◽  
Spider Silk ◽  
Imaging Techniques ◽  
Dynamic Stiffness ◽  
Longitudinal Section ◽  
Mechanical Anisotropy ◽  
Nephila Clavipes ◽  
Silk Fibers ◽  
Reduced Modulus ◽  
Anisotropic Mechanical Properties

Spider silk is a material with unique mechanical properties under tension. In this study, we explore the anisotropic mechanical properties of spider silk using instrumented indentation. Both quasistatic indentation and dynamic stiffness imaging techniques were used to measure the mechanical properties in transverse and longitudinal sections of silk fibers. Quasistatic indentation yielded moduli of 10 ± 2 GPa in transverse sections and moduli of 6.4 ± 0.5 GPa in longitudinal sections, demonstrating mechanical anisotropy in the fiber. This result was supported by dynamic stiffness imaging, which also showed the average reduced modulus measured in the transverse section to be slightly higher than that of the longitudinal section. Stiffness imaging further revealed an oriented microstructure in the fiber, showing microfibrils aligned with the drawing axis of the fiber. No spatial distribution of modulus across the silk sections was observed by either quasistatic or stiffness imaging mechanics.

Nephila Clavipes Dragline Silk: Approaches to a Recombinantly Produced Silk Protein

1993 ◽  
Vol 330 ◽  
Author(s):  
Charlene M. Mello ◽  
Steven Arcidiacono ◽  
Richard Beckwitt ◽  
John Prince ◽  
Kris Senecal ◽  
...  
Keyword(s):  
High Performance ◽  
Spider Silk ◽  
Recombinant Dna ◽  
Electromagnetic Spectrum ◽  
Nephila Clavipes ◽  
Natural Function ◽  
High Performance Fiber ◽  
Recombinant Dna Techniques ◽  
Clone And Express ◽  
Spider Silks

Spider silks exhibit an unusual combination of strength and toughness that distinguishes them from other natural and synthetic fibers. Silk proteins perform a key natural function as structural fibers, to absorb impact energy from flying insects without breaking. They dissipate energy over a broad area and balance stiffness, strength and extensibility (1,2). In addition to their unusual mechanical properties and visual lustre, silks also exhibit interesting interference patterns within the electromagnetic spectrum (3), unusual viscometric patterns related to processing (4), and piezoelectric properties (3,5,6). These properties suggest they would be good candidates for high performance fiber and composite applications. However, the spider is not capable of producing sufficient quantities of proteins to enable thorough evaluation of their potential. Consequently, we are pursuing recombinant DNA techniques to clone and express adequate quantities of recombinant spider silk for these studies.

Engineering Properties of Spider Silk

2001 ◽  
Vol 702 ◽  
Author(s):  
Frank K. Ko ◽  
Sueo Kawabata ◽  
Mari Inoue ◽  
Masako Niwa ◽  
Stephen Fossey ◽  
...  
Keyword(s):  
Spider Silk ◽  
Strain Curve ◽  
Engineering Properties ◽  
Transverse Compression ◽  
Nephila Clavipes ◽  
Stress Strain Curve ◽  
Torsional Deformation ◽  
Torsional Stability ◽  
High Level ◽  
Strength And Toughness

ABSTRACTMotivated by the high level of strength and toughness of spider silk and its multifunctional nature, this paper reports on the engineering properties of individual fibers from Nephila Clavipes spider drag line under uniaxial tension, transverse compression and torsional deformation. The tensile properties were compared to the Argiope Aurentia spider silk and show different ultimate strength but similar traits of the unusual combination of strength and toughness characterized by a sigmoidal stress-strain curve. A high level of torsional stability is demonstrated. comparing favorably to other aramid fibers (including Kevlar fibers).

scholarly journals Thermal, structural and mechanical characterization of Nephila clavipes spider silk in southwest Colombia

Heliyon ◽  
2020 ◽  
Vol 6 (11) ◽  
pp. e05262
Author(s):  
Gladis Miriam Aparicio-Rojas ◽  
Giovanni Medina-Vargas ◽  
Edgar Díaz-Puentes
Keyword(s):  
Spider Silk ◽  
Mechanical Characterization ◽  
Nephila Clavipes
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