scholarly journals Conformation and dynamics of soluble repetitive domain elucidates the initial β-sheet formation of spider silk

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Nur Alia Oktaviani ◽  
Akimasa Matsugami ◽  
Ali D. Malay ◽  
Fumiaki Hayashi ◽  
David L. Kaplan ◽  
...  
Keyword(s):  
Spider Silk ◽  
Repetitive Domain ◽  
Β Sheet

scholarly journals Interfacial Crystallization and Supramolecular Self-Assembly of Spider Silk Inspired Protein at the Water-Air Interface

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4239
Author(s):  
Pezhman Mohammadi ◽  
Fabian Zemke ◽  
Wolfgang Wagermaier ◽  
Markus B. Linder
Keyword(s):  
Self Assembly ◽  
Spider Silk ◽  
Assembly Process ◽  
Protein Solution ◽  
Time Resolved ◽  
Macromolecular Assembly ◽  
X Ray Scattering ◽  
Air Interface ◽  
Fundamental Research ◽  
Β Sheet

Macromolecular assembly into complex morphologies and architectural shapes is an area of fundamental research and technological innovation. In this work, we investigate the self-assembly process of recombinantly produced protein inspired by spider silk (spidroin). To elucidate the first steps of the assembly process, we examined highly concentrated and viscous pendant droplets of this protein in air. We show how the protein self-assembles and crystallizes at the water–air interface into a relatively thick and highly elastic skin. Using time-resolved in situ synchrotron X-ray scattering measurements during the drying process, we showed that the skin evolved to contain a high β-sheet amount over time. We also found that β-sheet formation strongly depended on protein concentration and relative humidity. These had a strong influence not only on the amount, but also on the ordering of these structures during the β-sheet formation process. We also showed how the skin around pendant droplets can serve as a reservoir for attaining liquid–liquid phase separation and coacervation from the dilute protein solution. Essentially, this study shows a new assembly route which could be optimized for the synthesis of new materials from a dilute protein solution and determine the properties of the final products.

scholarly journals Properties of Biomimetic Artificial Spider Silk Fibers Tuned by PostSpin Bath Incubation

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3248
Author(s):  
Gabriele Greco ◽  
Juanita Francis ◽  
Tina Arndt ◽  
Benjamin Schmuck ◽  
Fredrik G. Bäcklund ◽  
...  
Keyword(s):  
Spider Silk ◽  
Molecular Mechanisms ◽  
Efficient Production ◽  
Fiber Morphology ◽  
Silk Proteins ◽  
Silk Fibers ◽  
Aqueous Environments ◽  
Natural Counterpart ◽  
Phosphate Buffered Saline ◽  
Β Sheet

Efficient production of artificial spider silk fibers with properties that match its natural counterpart has still not been achieved. Recently, a biomimetic process for spinning recombinant spider silk proteins (spidroins) was presented, in which important molecular mechanisms involved in native spider silk spinning were recapitulated. However, drawbacks of these fibers included inferior mechanical properties and problems with low resistance to aqueous environments. In this work, we show that ≥5 h incubation of the fibers, in a collection bath of 500 mM NaAc and 200 mM NaCl, at pH 5 results in fibers that do not dissolve in water or phosphate buffered saline, which implies that the fibers can be used for applications that involve wet/humid conditions. Furthermore, incubation in the collection bath improved the strain at break and was associated with increased β-sheet content, but did not affect the fiber morphology. In summary, we present a simple way to improve artificial spider silk fiber strain at break and resistance to aqueous solvents.

Structural integrity of β-sheet assembly

2009 ◽  
Vol 37 (4) ◽  
pp. 671-676 ◽  
Author(s):  
Karen E. Marshall ◽  
Louise C. Serpell
Keyword(s):  
Spider Silk ◽  
Structural Integrity ◽  
Tertiary Structure ◽  
Structural Characteristics ◽  
Sequence Similarity ◽  
Underlying Structure ◽  
Β Sheet ◽  
Proteins And Peptides

The folding of a protein from a sequence of amino acids to a well-defined tertiary structure is one of the most studied and enigmatic events to take place in biological systems. Relatively recently, it has been established that some proteins and peptides are able to take on conformations other than their native fold to form long fibres known as amyloid. In vivo, these are associated with misfolding diseases, such as Alzheimer's disease, Type 2 diabetes and the amyloidoses. In vitro, peptide assembly leads to amyloid-like fibres that have high stability, resistance to degradation and high tensile strength. Remarkably, despite the lack of any obvious sequence similarity between these fibrillogenic proteins and peptides, all amyloid fibrils share common structural characteristics and their underlying structure is known as ‘cross-β’. Nature is rich in β-sheet protein assemblies such as spider silk and other ‘useful’ amyloids such as curli from Escherichia coli, where the strength of fibrils is fundamental to their function.

scholarly journals Post-secretion processing influences spider silk performance

2012 ◽  
Vol 9 (75) ◽  
pp. 2479-2487 ◽  
Author(s):  
Sean J. Blamires ◽  
Chung-Lin Wu ◽  
Todd A. Blackledge ◽  
I-Min Tso
Keyword(s):  
Mechanical Properties ◽  
Amino Acid ◽  
Ground State ◽  
Spider Silk ◽  
Mechanical Performance ◽  
Protein Composition ◽  
Compositional Changes ◽  
Spinning Speed ◽  
Spider Silks ◽  
Β Sheet

Phenotypic variation facilitates adaptations to novel environments. Silk is an example of a highly variable biomaterial. The two-spidroin (MaSp) model suggests that spider major ampullate (MA) silk is composed of two proteins—MaSp1 predominately contains alanine and glycine and forms strength enhancing β-sheet crystals, while MaSp2 contains proline and forms elastic spirals. Nonetheless, mechanical properties can vary in spider silks without congruent amino acid compositional changes. We predicted that post-secretion processing causes variation in the mechanical performance of wild MA silk independent of protein composition or spinning speed across 10 species of spider. We used supercontraction to remove post-secretion effects and compared the mechanics of silk in this ‘ground state’ with wild native silks. Native silk mechanics varied less among species compared with ‘ground state’ silks. Variability in the mechanics of ‘ground state’ silks was associated with proline composition. However, variability in native silks did not. We attribute interspecific similarities in the mechanical properties of native silks, regardless of amino acid compositions, to glandular processes altering molecular alignment of the proteins prior to extrusion. Such post-secretion processing may enable MA silk to maintain functionality across environments, facilitating its function as a component of an insect-catching web.

scholarly journals Hydrothermal Effect on Mechanical Properties of Nephila pilipes Spidroin

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1013 ◽  
Author(s):  
Hsuan-Chen Wu ◽  
Aditi Pandey ◽  
Liang-Yu Chang ◽  
Chieh-Yun Hsu ◽  
Thomas Chung-Kuang Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Spider Silk ◽  
Post Treatment ◽  
Molecular Structures ◽  
Random Coil ◽  
Silk Fibers ◽  
Physical Strength ◽  
Β Sheet ◽  
Post Treatment Process

The superlative mechanical properties of spider silk and its conspicuous variations have instigated significant interest over the past few years. However, current attempts to synthetically spin spider silk fibers often yield an inferior physical performance, owing to the improper molecular interactions of silk proteins. Considering this, herein, a post-treatment process to reorganize molecular structures and improve the physical strength of spider silk is reported. The major ampullate dragline silk from Nephila pilipes with a high β-sheet content and an adequate tensile strength was utilized as the study material, while that from Cyrtophora moluccensis was regarded as a reference. Our results indicated that the hydrothermal post-treatment (50–70 °C) of natural spider silk could effectively induce the alternation of secondary structures (random coil to β-sheet) and increase the overall tensile strength of the silk. Such advantageous post-treatment strategy when applied to regenerated spider silk also leads to an increment in the strength by ~2.5–3.0 folds, recapitulating ~90% of the strength of native spider silk. Overall, this study provides a facile and effective post-spinning means for enhancing the molecular structures and mechanical properties of as-spun silk threads, both natural and regenerated.

scholarly journals Blood, Sweat and Tears: Extraterrestrial Regolith Biocomposites with in Vivo Binders

2021 ◽  
Author(s):  
Aled Roberts ◽  
Dominic Whittall ◽  
Rainer Breitling ◽  
Eriko Takano ◽  
Jonny J. Blaker ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Serum Albumin ◽  
Spider Silk ◽  
Protein Secondary Structure ◽  
3D Printed ◽  
Martian Regolith ◽  
Β Sheet ◽  
Opening Up ◽  
Average Compressive Strength

In this work, we explore the use of human serum albumin (HSA) – a common protein obtained from blood plasma – as a binder for simulated Lunar and Martian regolith to produce so-called extraterrestrial regolith biocomposites (ERBs). In essence, HSA produced by astronauts in vivo could be extracted on a semi-continuous basis and combined with Lunar or Martian regolith to produce a concrete-like material. Employing a simple fabrication strategy, HSA-based ERBs were produced and displayed compressive strengths as high as 25.0 MPa. For comparison, standard concrete typically has a compressive strength ranging between 20 and 32 MPa. The incorporation of urea – which could be extracted from the urine, sweat or tears of astronauts – could further increase the compressive strength by over 300% in some instances, with the best-performing formulation having an average compressive strength of 39.7 MPa. Furthermore, we demonstrate that HSA-ERBs can be 3D-printed, opening up an interesting potential avenue for extraterrestrial construction using human-derived feedstocks. The mechanism of adhesion was investigated and attributed to the dehydration-induced reorganisation of the protein secondary structure into a densely hydrogen-bonded, supramolecular β-sheet network – analogous to the cohesion mechanism of spider silk. For comparison, synthetic spider silk and bovine serum albumin (BSA) were also investigated as regolith binders – which could also feasibly be produced on a Martian colony with future advancements in biomanufacturing technology.<br>

Critical role of minor eggcase silk component in promoting spidroin chain alignment and strong fiber formation

2021 ◽  
Vol 118 (38) ◽  
pp. e2100496118
Author(s):  
Tiantian Fan ◽  
Ruiqi Qin ◽  
Yan Zhang ◽  
Jingxia Wang ◽  
Jing-Song Fan ◽  
...  
Keyword(s):  
Self Assembly ◽  
Spider Silk ◽  
Critical Role ◽  
Minor Component ◽  
Fiber Formation ◽  
Repetitive Domain ◽  
Chain Alignment ◽  
Main Components ◽  
Spider Silks

Natural spider silk with extraordinary mechanical properties is typically spun from more than one type of spidroin. Although the main components of various spider silks have been widely studied, little is known about the molecular role of the minor silk components in spidroin self-assembly and fiber formation. Here, we show that the minor component of spider eggcase silk, TuSp2, not only accelerates self-assembly but remarkably promotes molecular chain alignment of spidroins upon physical shearing. NMR structure of the repetitive domain of TuSp2 reveals that its dimeric structure with unique charged surface serves as a platform to recruit different domains of the main eggcase component TuSp1. Artificial fiber spun from the complex between TuSp1 and TuSp2 minispidroins exhibits considerably higher strength and Young’s modulus than its native counterpart. These results create a framework for rationally designing silk biomaterials based on distinct roles of silk components.

Scalable Spider Silk Inspired Materials with High Extensibility and Super Toughness

2021 ◽  
Vol 893 ◽  
pp. 31-35
Author(s):  
Jin Lian Hu ◽  
Yuan Zhang Jiang ◽  
Lin Gu
Keyword(s):  
Chemical Synthesis ◽  
Spider Silk ◽  
Helical Structure ◽  
Silk Proteins ◽  
Dragline Silk ◽  
Spider Dragline Silk ◽  
Argiope Trifasciata ◽  
Chemical Synthesis Route ◽  
Β Sheet ◽  
Huge Challenge

Spiders silks have extraordinary strength and toughness simultaneously, thus has become dreamed materials by scientists and industries. Although there have been tremendous attempts to prepare fibers from genetically manufacture spider silk proteins, however, it has been still a huge challenge because of tedious procedure and high cost. Here, a facile spider-silk-mimicking strategy is reported for preparing highly scratchable polymers and supertough fibers from chemical synthesis route. Polymer films with high extensibility (>1200%) and supertough fibers (~387 MJ m-3) are achieved by introducing polypeptides with β-sheet and α-helical structure in polyureathane/urea polymers. Notabley,the toughness of the fiber is more than twice the reported value of a normal spider dragline silk, and comparable with the toughest spider silk, aciniform silk of Argiope trifasciata.

Cloning and Characterization of Three Genes Encoding LMW-GSs from Triticum aestivum, Cultival Cheyenne

2012 ◽  
Vol 554-556 ◽  
pp. 1116-1120 ◽  
Author(s):  
Mei Rong Chen ◽  
Xing Shen ◽  
Lin Li ◽  
Song Qing Hu
Keyword(s):  
Amino Acid ◽  
Structure Prediction ◽  
Secondary Structure Prediction ◽  
Amino Acid Residues ◽  
Repetitive Domain ◽  
Genebank Accession ◽  
Genes Encoding ◽  
Α Helix ◽  
Β Sheet

Three low molecular weight subunit genes, named LMW-CND1 (GeneBank accession JQ780048), LMW-CND2 (GeneBank accession JQ779840), LMW-CND3 (GeneBank accession JQ779841), with a ORF of 1053 bp, 903 bp, 969 bp, respectively, were isolated from cv. Cheyenne and characterized detailed in molecular level. The proteins encoded by the genes, with 350, 300, 322 amino acid residues respectively, differ only in repetitive domain of sequences due to insertion or deletion of repeats in this domain. Highly similarity in amino-acid sequence between these three subunits and other published LMW-GSs was also observed, showing that all three genes published here are typical LMW-GS genes and closely related to the genes on chromosome 1D. Besides, secondary structure prediction of proteins indicated that, in the three LMW-GSs, random loop accounts for no less than 70 %, α-helix amounts to 26 %, average, and only 1.4 %~1.7 % is β-sheet.

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