High-yield production of a super-soluble miniature spidroin for biomimetic high-performance materials

The mechanical properties of artificial spider silks are approaching a stage where commercial applications become realistic. However, the yields recombinant silk proteins that can be used to produce fibers with good typically very low and many purification spinning protocols still require use urea, hexafluoroisopropanol, and/or methanol. Thus, improved production methods minimal environmental impact needed. We have previously developed miniature protein is characterized by high solubility in aqueous buffers spinnability biomimetic set-ups. In this study, we protocol resulted an expression level >20 g target per liter Escherichia coli fed-batch culture, subsequent under native conditions yielded 14.5 g/l. This corresponds nearly six-fold increase levels, 10-fold yield after compared reports for proteins. Biomimetic using only toughness modulus 74 MJ/m3, which highest reported biomimetically as-spun fibers. process described herein represents milestone economic industrial applications.