Spiders silk is built up of long proteins, called spidroins that have non-repetitive N- and C-terminal domains flanking an extensive repetitive region. The repetitive region consists of hundreds of tandem units of a glycine rich part followed by a poly-alanine block. Organisms as spiders are able to synthesize such repetitive proteins, but it is close to impossible to implement in low cost prokaryotic systems.
At Spiber Technologies we have overcome the problem by shortening the repetitive region for production in Escherichia coli. The so called mini-spidroins (Spiber® silk) are separated from the E. coli host proteins and debris by conventional purification methods, performed under physiological-like conditions.
The pure Spiber® silk protein solution can then easily be transformed into fibers, foam, films and coatings, depending on application, without addition of any chemical.
Our technology also enables us to produce silk proteins with selected functionalities, e.g. affinity or activity, by cloning the gene of interest to the N- or C-terminal end of the mini-spidroin.