Orientation, structure, wet-spinning, and molecular basis for supercontraction of spider dragline silk

Jelinski, Lynn W.; Blye, Amy; Liivak, Oskar; Michal, Carl A.; LaVerde, George; Seidel, Andreas; Shah, Neeral; Yang, Zhijun

doi:10.1016/s0141-8130(98)00085-3

Cited by 105 publications

(99 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…At first wet-spinning processes were employed with promising results. 67,68 Using silicon micro-spinnerets several meters of insect or spider silk fibers could be produced. Although the wet-spun silks visually resembled natural ones, their diameter was up to ten times bigger than naturally occurring silks (and not for the other spider silks), it is time consuming and highly expensive, especially since most spiders are cannibals, rendering farming costly.…”

Section: Gpggx/gpgqq [Iii] Ggx (X = a S Or Y) And [Iv]mentioning

confidence: 99%

The elaborate structure of spider silk

Römer

Scheibel

2008

Prion

302

179

View full text Add to dashboard Cite

Section: Gpggx/gpgqq [Iii] Ggx (X = a S Or Y) And [Iv]mentioning

confidence: 99%

The elaborate structure of spider silk

Römer

Scheibel

2008

Prion

302

179

View full text Add to dashboard Cite

“…An additional oriented phase for silk fibers is proposed by a number of groups, 1,6,30,31 with local structure unlike either crystalline or ''normal'' amorphous domains. Evidence from Rotational Echo Double Resonance NMR experiments 17 suggests that this third phase forms compact turn-like structures. Two-dimensional (2D) spin diffusion NMR has demonstrated that the Gly-rich regions are ordered and form 3 1 -helices, 14 but these experiments, however, do not distinguish between ordered Gly-rich regions from Gly-rich amorphous regions.…”

Section: Introductionmentioning

confidence: 99%

“…Once thought to be entirely amorphous, the structure of the Gly-rich region may be semiordered in a 3 1 helix [14][15][16] or Type 1 turn. 11,17 Silk from the silkworm Bombyx mori has been extensively studied and is a fibrous protein consisting of a repeating sequence of (GAGAGS) somewhat similar in composition to spider silk and contains Gly (43.7%), Ala (28.8%), and Ser (11.9%). 18 NMR and other biophysical studies of B. mori and other silkworm silks have provided secondary structure information.…”

Section: Introductionmentioning

confidence: 99%

Orientational order of Australian spider silks as determined by solid‐state NMR

et al. 2006

View full text Add to dashboard Cite

A simple solid-state NMR method was used to study the structure of 13 C-and 15 Nenriched silk from two Australian orb-web spider species, Nephila edulis and Argiope keyserlingi. Carbon-13 and 15 N spectra from alanine-or glycine-labeled oriented dragline silks were acquired with the fiber axis aligned parallel or perpendicular to the magnetic field. The fraction of oriented component was determined from each amino acid, alanine and glycine, using each nucleus independently, and attributed to the ordered crystalline domains in the silk. The relative fraction of ordered alanine was found to be higher than the fraction of ordered glycine, akin to the observation of alanine-rich domains in silk-worm (Bombyx mori) silk. A higher degree of crystallinity was observed in the dragline silk of N. edulis compared with A. keyserlingi, which correlates with the superior mechanical properties of the former #

show abstract

“…a post-tensioning mechanism controlled by wetting. Supercontraction is thought to be controlled by specific motifs in the silk proteins [71,77] and induced by the entropy-driven recoiling of molecular chains [78,79], and has a scaling effect on mechanical properties [12,70,73,74]. To trigger the proposed molecular response, solvent must penetrate the protein structure, enhanced by the presence of fibril globules due to an increase in free volume (and thus exposed surface area).…”

Section: Voids and Free Volumementioning

confidence: 99%

Increasing silk fibre strength through heterogeneity of bundled fibrils

Cranford

2013

J. R. Soc. Interface.

View full text Add to dashboard Cite

Can naturally arising disorder in biological materials be beneficial? Materials scientists are continuously attempting to replicate the exemplary performance of materials such as spider silk, with detailed techniques and assembly procedures. At the same time, a spider does not precisely machine silk-imaging indicates that its fibrils are heterogeneous and irregular in cross section. While past investigations either focused on the building material (e.g. the molecular scale protein sequence and behaviour) or on the ultimate structural component (e.g. silk threads and spider webs), the bundled structure of fibrils that compose spider threads has been frequently overlooked. Herein, I exploit a molecular dynamics-based coarse-grain model to construct a fully three-dimensional fibril bundle, with a length on the order of micrometres. I probe the mechanical behaviour of bundled silk fibrils with variable density of heterogenic protrusions or globules, ranging from ideally homogeneous to a saturated distribution. Subject to stretching, the model indicates that cooperativity is enhanced by contact through low-force deformation and shear 'locking' between globules, increasing shear stress transfer by up to 200 per cent. In effect, introduction of a random and disordered structure can serve to improve mechanical performance. Moreover, addition of globules allows a tuning of free volume, and thus the wettability of silk (with implications for supercontraction). These findings support the ability of silk to maintain near-molecular-level strength at the scale of silk threads, and the mechanism could be easily adopted as a strategy for synthetic fibres.

show abstract

Orientation, structure, wet-spinning, and molecular basis for supercontraction of spider dragline silk

Cited by 105 publications

References 17 publications

The elaborate structure of spider silk

The elaborate structure of spider silk

Orientational order of Australian spider silks as determined by solid‐state NMR

Increasing silk fibre strength through heterogeneity of bundled fibrils

Contact Info

Product

Resources

About