Navigation Links
Native-like spider silk produced in metabolically engineered bacterium
Date:7/27/2010

Researchers have long envied spiders' ability to manufacture silk that is light-weighted while as strong and tough as steel or Kevlar. Indeed, finer than human hair, five times stronger by weight than steel, and three times tougher than the top quality man-made fiber Kevlar, spider dragline silk is an ideal material for numerous applications. Suggested industrial applications have ranged from parachute cords and protective clothing to composite materials in aircrafts. Also, many biomedical applications are envisioned due to its biocompatibility and biodegradability.

Unfortunately, natural dragline silk cannot be conveniently obtained by farming spiders because they are highly territorial and aggressive. To develop a more sustainable process, can scientists mass-produce artificial silk while maintaining the amazing properties of native silk? That is something Sang Yup Lee at the Korea Advanced Institute of Science and Technology (KAIST) in Daejeon, the Republic of Korea, and his collaborators, Professor Young Hwan Park at Seoul National University and Professor David Kaplan at Tufts University, wanted to figure out. Their method is very similar to what spiders essentially do: first, expression of recombinant silk proteins; second, making the soluble silk proteins into water-insoluble fibers through spinning.

For the successful expression of high molecular weight spider silk protein, Professor Lee and his colleagues pieced together the silk gene from chemically synthesized oligonucleotides, and then inserted it into the expression host (in this case, an industrially safe bacterium Escherichia coli which is normally found in our gut). Initially, the bacterium refused to the challenging task of producing high molecular weight spider silk protein due to the unique characteristics of the protein, such as extremely large size, repetitive nature of the protein structure, and biased abundance of a particular amino acid glycine. "To make E. coli synthesize this ultra high molecular weight (as big as 285 kilodalton) spider silk protein having highly repetitive amino acid sequence, we helped E. coli overcome the difficulties by systems metabolic engineering," says Sang Yup Lee, Distinguished Professor of KAIST, who led this project. His team boosted the pool of glycyl-tRNA, the major building block of spider silk protein synthesis. "We could obtain appreciable expression of the 285 kilodalton spider silk protein, which is the largest recombinant silk protein ever produced in E. coli. That was really incredible." says Dr. Xia.

But this was only step one. The KAIST team performed high-cell-density cultures for mass production of the recombinant spider silk protein. Then, the team developed a simple, easy to scale-up purification process for the recombinant spider silk protein. The purified spider silk protein could be spun into beautiful silk fiber. To study the mechanical properties of the artificial spider silk, the researchers determined tenacity, elongation, and Young's modulus, the three critical mechanical parameters that represent a fiber's strength, extensibility, and stiffness. Importantly, the artificial fiber displayed the tenacity, elongation, and Young's modulus of 508 MPa, 15%, and 21 GPa, respectively, which are comparable to those of the native spider silk.

"We have offered an overall platform for mass production of native-like spider dragline silk. This platform would enable us to have broader industrial and biomedical applications for spider silk. Moreover, many other silk-like biomaterials such as elastin, collagen, byssus, resilin, and other repetitive proteins have similar features to spider silk protein. Thus, our platform should also be useful for their efficient bio-based production and applications," concludes Professor Lee.


'/>"/>

Contact: Lan Yoon
hlyoon@kaist.ac.kr
82-423-502-295
The Korea Advanced Institute of Science and Technology (KAIST)
Source:Eurekalert

Related biology news :

1. Study: Crickets forewarn unborn babies about spiders
2. New spider species discovered by University of Haifa scientists
3. Spider web glue spins society toward new biobased adhesives
4. Male Australian redback spiders employ courtship strategies to preserve their life
5. Scary ancient spiders revealed in 3-D models, thanks to new imaging technique
6. New species of spiders discovered by UBC scientist in Papua New Guinea
7. Moving in for the winter toxic brown recluse spiders pose danger
8. Spider love: Little guys get lots more
9. Hops helps reduce ammonia produced by cattle
10. New boreal forest biomass maps produced from radar satellite data
11. Volcanic hazard map produced for island of Gran Canaria
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/4/2017)... , Oct. 4, 2017  GCE Solutions, a global clinical ... data and document anonymization solution on October 4, 2017. Shadow is ... field to comply with policy 0070 of the European Medicines Agency ... data. ... GCE Solutions ...
(Date:6/30/2017)... , June 30, 2017 Today, ... developer and supplier of face and eye tracking ... Featured Product provider program. "Artificial ... innovative way to monitor a driver,s attentiveness levels ... from being able to detect fatigue and prevent ...
(Date:5/16/2017)... TEANECK, N.J. , May 16, 2017  Veratad ... leading provider of online age and identity verification solutions, ... the K(NO)W Identity Conference 2017, May 15 thru May ... Ronald Regan Building and International Trade Center. ... across the globe and in today,s quickly evolving digital ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... Parks Associates announced today that Tom Kerber , Director ... , October 11 in Scottsdale, Arizona . Kerber will ... safety and security products impact the competitive landscape. ... Parks Associates: Smart Home Devices: Main Purchase Driver ... "The residential security market has experienced continued growth, and the introduction of ...
(Date:10/10/2017)... PITTSBURGH, PA (PRWEB) , ... October 10, 2017 ... ... this year’s recipients of 13 prestigious awards honoring scientists who ... be presented in a scheduled symposium during Pittcon 2018, the world’s leading conference ...
(Date:10/9/2017)... , ... October 09, 2017 , ... At its national ... Christopher Stubbs, a professor in Harvard University’s Departments of Physics and Astronomy, has been ... a member of the winning team for the 2015 Breakthrough Prize in Fundamental physics ...
(Date:10/7/2017)... ... October 06, 2017 , ... With ... microscopy and surface analysis, Nanoscience Instruments is now expanding into Analytical Services. ... range of contract analysis services for advanced applications. Services will leverage techniques ...
Breaking Biology Technology: