Multicomponent nature underlies the extraordinary mechanical properties of spider dragline silk

Dragline silk of golden orb-weaver spiders (Nephilinae) is noted for its unsurpassed toughness, combining extraordinary extensibility and tensile strength, suggesting industrial application as a sustainable biopolymer material. To pinpoint the molecular composition of dragline silk and the roles of its constituents in achieving its mechanical properties, we report a multiomics approach, combining high-quality genome sequencing and assembly, silk gland transcriptomics, and dragline silk proteomics of four Nephilinae spiders. We observed the consistent presence of the MaSp3B spidroin unique to this subfamily as well as several nonspidroin SpiCE proteins. Artificial synthesis and the combination of these components in vitro showed that the multicomponent nature of dragline silk, including MaSp3B and SpiCE, along with MaSp1 and MaSp2, is essential to realize the mechanical properties of spider dragline silk.

Scalable Spider Silk Inspired Materials with High Extensibility and Super Toughness

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.

Multicomponent nature underlies the extraordinary mechanical properties of spider dragline silk

Dragline silk of golden orb-weaver spiders (Nephilinae) is noted for its unsurpassed toughness, combining extraordinary extensibility and tensile strength, suggesting industrial application as a sustainable biopolymer material. To pinpoint the molecular composition of dragline silk and the roles of its constituents in achieving its mechanical properties, we report a multiomics approach combining high-quality genome sequencing and assembly, silk gland transcriptomics, and dragline silk proteomics of four Nephilinae spiders. We observed the consistent presence of the MaSp3B spidroin unique to this subfamily, as well as several non-spidroin SpiCE proteins. Artificial synthesis and combination of these components in vitro showed that the multicomponent nature of dragline silk, including MaSp3B and SpiCE, along with MaSp1 and MaSp2, is essential to realize the mechanical properties of spider dragline silk.

Microbial repellence properties of engineered spider silk coatings prevent biofilm formation of opportunistic bacterial strains

Bacterial infections are well recognised to be one of the most important current public health problems. Inhibiting adhesion of microbes on biomaterials is one approach for preventing inflammation. Coatings made of recombinant spider silk proteins based on the consensus sequence of Araneus diadematus dragline silk fibroin 4 have previously shown microbe-repellent properties. Concerning silicone implants, it has been further shown that spider silk coatings are effective in lowering the risk of capsular fibrosis. Here, microbial repellence tests using four opportunistic infection-related strains revealed additional insights into the microbe-repellent properties of spider silk-coated implants, exemplarily shown for silicone surfaces. Graphic Abstract

Xanthurenic Acid Is the Main Pigment of Trichonephila clavata Gold Dragline Silk

Spider silk is a natural fiber with remarkable strength, toughness, and elasticity that is attracting attention as a biomaterial of the future. Golden orb-weaving spiders (Trichonephila clavata) construct large, strong webs using golden threads. To characterize the pigment of golden T. clavata dragline silk, we used liquid chromatography and mass spectrometric analysis. We found that the major pigment in the golden dragline silk of T. clavata was xanthurenic acid. To investigate the possible function of the pigment, we tested the effect of xanthurenic acid on bacterial growth using gram-negative Escherichia coli and gram-positive Bacillus subtilis. We found that xanthurenic acid had a slight antibacterial effect. Furthermore, to investigate the UV tolerance of the T. clavata threads bleached of their golden color, we conducted tensile deformation tests and scanning electron microscope observations. However, in these experiments, no significant effect was observed. We therefore speculate that golden orb-weaving spiders use the pigment for other purposes, such as to attract their prey in the sunlight.

Super Bacteria: A New Hope of Manufacturing Spider Silk in an Efficient Way

The important properties of spider dragline silk and other protein polymers will find many applications. We have demonstrated the production of spider silk, which has many important properties, are produced from the bacteria including Escherichia coli. The productions of high molecular weight spider drag line encoded by synthetic genes. Silk protein can be efficiently produced by the microbial system has become an advantageous method like quick secretion and simple product recovery has become an efficient method .From the observation of various experiments done by several scientists has shown silk made in laboratory. The study of RIKEN centre for sustainable resource science has shown that spider silk can be produce huge amount. Observation shown that joining of the fragments by split intein sequence which then cut itself to yield full name protein .Spun into fibers make the microbial spider silk tough , stretchable and stronger. Better modification of bioengineering can increase the amount of production.