Spiber® - recombinant spider silk protein: The genetic construct of mini-spidroins, the possibility to modify and functionalize these proteins, as well as recombinant production and fiber formation are all part of this technology.
Recombinant production of Spiber® silk proteins
Proteins can be produced by the use of recombinant expression systems i.e. in a defined host. This strategy offers benefits such as control of defined components, reproducibility and scalability, and is therefore favorably used for production of proteins to be used in medical applications, e.g. insulin and antibodies. To produce a recombinant protein, one needs the description (the encoding gene) and a factory (the host cell). General steps:
- Find the genetic code for the protein to be produced, cut or copy from origin
- Insert the gene into a cell (safe bacteria, insect cell, plant cell, animal cell or human cell)
- With the new gene inside, the cell will produce the protein described by this gene (along with other proteins described by the other original genes)
- Cells are usually grown in stirred tanks, bioreactors, which provides suitable environment with enough nutrients. This allows one cell to divide into two identical copies, which in turn divides further.
- The protein is harvested from the cell soup and purified so that all other proteins and cell products are removed
Spiders produce special types of long and repetitive proteins, called spidroins. We have selected a portion of the gene sequence encoding a spidroin, cloned it into E. coli bacteria.
With several years of designing Spiber® constructs plus good control of its production, we know how to adjust the Spiber® format and bioactivity for different applications.
Formulation of Spiber® silk materials
After expression and purification under native conditions, the partial-spidroins can be allowed to self-assemble into several formats.
Bioactivation of Spiber® silk
The recombinant production process offers the possibility of facile inclusion of various bioactivities in fusion with the partial spidroins. The constructs can be modified in a lab using standard tools of recombinant DNA technology.
In theory, any other gene sequence can be added to give the silk materials new functionality. Because the formulations into silk materials is done by self-assembly under physiological conditions, the fold of the added protein domains is preserved, yielding bioactive Spiber® silk materials for various applications, e.g.;