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.

Triggered Morphology Generation in a Biosynthetic Model Spider Dragline Silk Protein

1999 ◽  
Vol 5 (S2) ◽  
pp. 1214-1215
Author(s):  
R. Valluzzi ◽  
S. Szela ◽  
D. Kirschner ◽  
D. Kaplan
Keyword(s):  
Recombinant Dna ◽  
Consensus Sequence ◽  
Water Soluble ◽  
Nephila Clavipes ◽  
Dragline Silk ◽  
Spider Dragline Silk ◽  
Structure Changes ◽  
Methionine Residues ◽  
Recombinant Dna Techniques ◽  
Β Sheet

Recombinant DNA techniques were used to prepare a protein modeled after the consensus sequence of Nephila clavipesspider dragline silk, incorporating methionine residues to serve as redox “triggers”. In addition a water-soluble 27 residue peptide model of the dragline silk consensus amorphous sequence, representing a single amorphous block in the protein sequence, was prepared and characterized to gain additional insight into the behavior of the amorphous phase. X-ray diffraction, electron diffraction, transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the ability of the recombinant protein to form (β-sheet crystals and the effect of the oxidation state of the redox trigger on crystallinity and noncrystalline order in the sample. The formation of intractable β-sheet crystallites is a major cause of insolubility in proteins that can form this type of secondary structure. Changes in crystallinity were observed when triggered/reduced (insoluble) and untriggered/oxidized (soluble) protein samples were compared.

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.

scholarly journals Photoreflectance/scattering measurements of spider silks informed by standard optics

2020 ◽  
Vol 7 (4) ◽  
pp. 192174
Author(s):  
Sean J. Blamires ◽  
Douglas J. Little ◽  
Thomas E. White ◽  
Deb M. Kane
Keyword(s):  
Optical Properties ◽  
Optical Materials ◽  
Spider Silk ◽  
Nephila Clavipes ◽  
Optical Elements ◽  
Scattering Spectrum ◽  
Modern Species ◽  
Uv Reflectance ◽  
Argiope Keyserlingi ◽  
Spider Silks

The silks of certain orb weaving spiders are emerging as high-quality optical materials. This motivates study of the optical properties of such silk and particularly the comparative optical properties of the silks of different species. Any differences in optical properties may impart biological advantage for a spider species and make the silks interesting for biomimetic prospecting as optical materials. A prior study of the reflectance of spider silks from 18 species reported results for three species of modern orb weaving spiders ( Nephila clavipes, Argiope argentata and Micrathena Schreibersi ) as having reduced reflectance in the UV range. (Modern in the context used here means more recently derived.) The reduced UV reflectance was interpreted as an adaptive advantage in making the silks less visible to insects. Herein, a standard, experimental technique for measuring the reflectance spectrum of diffuse surfaces, using commercially available equipment, has been applied to samples of the silks of four modern species of orb weaving spiders: Phonognatha graeffei , Eriophora transmarina , Nephila plumipes and Argiope keyserlingi . This is a different technique than used in the previous study. Three of the four silks measured have a reduced signal in the UV. By taking the form of the silks as optical elements into account, it is shown that this is attributable to a combination of wavelength-dependent absorption and scattering by the silks rather than differences in reflectance for the different silks. Phonognatha graeffei dragline silk emerges as a very interesting spider silk with a flat ‘reflectance'/scattering spectrum which may indicate it is a low UV absorbing dielectric micro-fibre. Overall the measurement emerges as having the potential to compare the large numbers of silks from different species to prospect for those which have desirable optical properties.

Conformational Transition of Regenerated Spider Silk in Water

2013 ◽  
Vol 796 ◽  
pp. 107-111
Author(s):  
Ye Mei Zhang ◽  
Zhi Juan Pan
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Spider Silk ◽  
Conformational Transition ◽  
Ph Value ◽  
Random Coil ◽  
Spider Dragline Silk ◽  
Turn Structure ◽  
Α Helix ◽  
Spider Silks

Spider silks have excellent mechanical properties, which can even compare with some high-performance synthetic materials. Although as reported, the impressive mechanical properties are closely related to the primary amino acid sequence, the conformation that molecular chains form is also an important determinant. In this paper, effects of solvent, pH value, temperature, centrifugation and concentrating on the secondary structure of regenerated Ornithoctonus huwenna spider dragline silk protein aqueous solution were investigated by circular dichroism. Spidroin solutions prepared from different LiBr solutions had a distinct combination of secondary structures. The increasing temperature and concentrating can promote the formation of β-sheet structure. While centrifugation was opposite, which elevate the content of β-turn structure. Circular dichroic spectra quantitatively verified an increased α-helix structure content but a decrease of random coil and β-turn structure content with the increasing of pH value.

Influence of technological factors on the properties of ultra-high-performance fiber reinforced concrete

2020 ◽  
pp. 135-147
Author(s):  
Igor Chilin ◽  
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Technological Factors ◽  
High Performance Fiber

Приведены результаты исследований и выполнена оценка влияния технологических факторов на реологические свойства самоуплотняющихся сталефибробетонных смесей, определены кратковременные и длительные физико-механические и деформативные характеристики сверхвысокопрочного сталефибробетона, включая определение его фактической морозостойкости.

scholarly journals Effects of Steel Fiber Percentage and Aspect Ratios on Fresh and Harden Properties of Ultra-High Performance Fiber

2021 ◽  
Vol 2 (3) ◽  
pp. 501-515
Author(s):  
Rajib Kumar Biswas ◽  
Farabi Bin Ahmed ◽  
Md. Ehsanul Haque ◽  
Afra Anam Provasha ◽  
Zahid Hasan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
High Performance ◽  
Steel Fiber ◽  
Setting Time ◽  
Fiber Reinforced Concrete ◽  
Future Research ◽  
Manufacturing Cost ◽  
Aspect Ratios ◽  
High Performance Fiber

Steel fibers and their aspect ratios are important parameters that have significant influence on the mechanical properties of ultrahigh-performance fiber-reinforced concrete (UHPFRC). Steel fiber dosage also significantly contributes to the initial manufacturing cost of UHPFRC. This study presents a comprehensive literature review of the effects of steel fiber percentages and aspect ratios on the setting time, workability, and mechanical properties of UHPFRC. It was evident that (1) an increase in steel fiber dosage and aspect ratio negatively impacted workability, owing to the interlocking between fibers; (2) compressive strength was positively influenced by the steel fiber dosage and aspect ratio; and (3) a faster loading rate significantly improved the mechanical properties. There were also some shortcomings in the measurement method for setting time. Lastly, this research highlights current issues for future research. The findings of the study are useful for practicing engineers to understand the distinctive characteristics of UHPFRC.

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