Spider silk production

Y. Hsia, E. Gnesa, R. Pacheco, K. Kohler, F. Jeffery, C. Vieira, Synthetic spider silk production on a laboratory scale, J. Visualized Exp. 65 (2012). 

Spider Silk. Spider silks function ki prey capture, reproduction, and as vibration receptors, safety lines, and dispersion tools. Spider silks are synthesized ki glands located ki the abdomen and spun through a series of orifices (spinnerets). The types and nature of the various silks are diverse and depend on the type of spider (2). Some general categories of silks and the glands responsible for thek production are Hsted in Table 1. 

Production of Spider Silk Proteins in Transgenic Tobacco and Potato... 

Strategies for the Production of Recombinant Spider Silk Proteins... 

Knight, D. P., and Vollrath, F. (1999b). Liquid crystals and flow elongation in a spider s silk production line. Proc. It. Soc. Lond. B Biol. Sci. 266, 519-523. 

Richter, C. J. J., Stolting, H. C. J. and Vlijm, L. (1971). Silk production in adult females of the wolf spider Pardosa amentata. Journal of Zoology, London 165 285-290. 

Yeast and bacterial systems often give low levels of expression of silks, and this has led to the development of production systems in tobacco and potato. Scheller et al. (2001) have shown that spider silk proteins can be produced in transgenic plants. They inserted synthetic spider silk protein (spidroin) genes into transgenic plants under the control of the CaMV35S promoter. Using this system they were able to demonstrate the accumulation of recombinant silk proteins to a level of at least 2% of total soluble protein in the endoplasmic reticulum of tobacco leaves, and potato tubers. 

There are several reports of the use of silk in biomaterials. Kluge et al. (2008) provide a good overview of application of spider silks including recombinant versions. In addition to spider silks there are other types of silks that provide distinct and useful properties, such as those derived from mussels which will presumably become targets for recombinant protein production (Carrington, 2008). 

Recently, Foo et al. (2006) produced some novel nanocomposites from spider silk-silica fusion (chimeric) proteins. The composite morphology and structure could be regulated by controlling processing conditions to produce films and fibers. Silk and biomineralization being natural inspiration sources will allow production of numerous new materials in various fields of application. 

Vollrath, F., and Knight, D.P. "Structure and function of the silk production pathway in the Spider Nephila edulis". Int. ]. Biol. Macromol. 24(2-3), 243-249 (1999). 

Nexia is already working with the US army to develop bulletproof vests and surgical suture material from spider silk. The team produced soluble recombinant spider silk proteins with molecular masses of 60-140 kDa (Lazaris ef al., 2002). They were able to wet spin the silk monofilaments derived from a concentrated aqueous solution of soluble recombinant spider silk protein under conditions of low shear and coagulation. The spun fibers were water-insoluble with diameters ranging from 10 to 40 pm and exhibited toughness and modulus values comparable to those of native dragline silks but had lower tenacity. They anticipate that the manufacturing processes for these products would be more environmental friendly than the production of conventional plastics. 

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