Spider silk proteins

Hayashi C. and Lewis R., Molecular architecture and evolution of a modular spider silk protein gene. Science, 287, 1477, 2000. 

Hayash C.I., Shipley N., and Lewis R., Hypotheses that correlate the sequence, structure, and mechanical properties of spider silk proteins, Int. J. Biol. Macromol., 24, 271, 1999. 

Parkhe AD, Seeley SK, Gardner K (1997) Structural studies of spider silk proteins in the fiber. J Mol Recognit 10 1-6... 

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

Tab.11.1 Spider silk proteins MaSpI, MaSpll and Flag from Nephila davipes.

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

I I Synthetic spider silk protein SOI I I ER retention signal (KDEL)... 

The spinning of silk monofilaments from a concentrated aqueous solution (>20% protein) of recombinant spider silk protein might be the best way to generate stress-... 

Synthetic Spider Silk Proteins for the In Vitro Proliferation of Anchorage-dependent Cells... 

Spider silk proteins from plants remain soluble at high temperatures, allowing them to be enriched by boiling [26]. In order to enrich the spider silk-ELP fusion protein, we therefore exposed tobacco leaf extracts to heat treatment at 95°C for 60 min and then cleared the supernatant by centrifugation. In further steps, the reversible precipitation behavior of ELP fusion proteins was exploited to develop a suitable purification strategy. For the selective precipitation of SOl-lOOxELP, NaCl was added at a final concentration of 2 M and the temperature was increased to 60 °C. In this man-... 

Fig. 4. Time-induced conformational change of spider silk protein (spidroin) in solution. Solutions of silk proteins at 1% w/v in distilled water were monitored using circular dichroism. The graph shows a change in secondary structure with time. The silk proteins underwent a kinetically driven transition from a partially unfolded structure to a -sheet-rich structure (from Dicko et al., 2004c). ( ) after 0 days, (O) after 1 day, and (A) after 2 days. The conformational change appeared faster at 20°C compared to 5°C, suggesting a hydrophobically driven mechanism. (Copyright 2004 American Chemical Society.)...

Dicko, C., Vollrath, F., and Kenney, J. M. (2004d). Spider silk protein refolding is controlled by changing pH. Biomacromolecules 5, 704-710. 

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. 

C- and N-terminal regions of spidroin are highly conserved among the spider silk proteins and play an important role in the assembly of spidroin (Huemmerich et al., 2004 Motriuk-Smith et al., 2005). 

Motriuk-Smith, D., Smith, A., Hayashi, C.Y., and Lewis, R.V. Analysis of the conserved N-terminal domains in major ampullate spider silk proteins. Biomacromolecules 6(6), 3152-3159 (2005). 

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. 

Scheller J, Guhrs KH, Grosse E, et al. Production of spider silk proteins in tobacco and potato. Nature BiotechnoL, 2001 19(6) 573-577. 

Spider silk proteins 2% TSP tuber (potato), leaves (tobacco) 10... 

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