title: Macroscopic fibers self-assembled from recombinant miniature spider silk proteins.
abstract: Strength, elasticity, and biocompatibility make spider silk an attractive resource for the production of artificial biomaterials. Spider silk proteins, spidroins, contain hundreds of repeated poly alanine/glycine-rich blocks and are difficult to produce recombinantly in soluble form. Most previous attempts to produce artificial spider silk fibers have included solubilization steps in nonphysiological solvents. It is here demonstrated that a miniature spidroin from a protein in dragline silk of Euprosthenops australis can be produced in a soluble form in Escherichia coli when fused to a highly soluble protein partner. Although this miniature spidroin contains only four poly alanine/glycine-rich blocks followed by a C-terminal non-repetitive domain, meter-long fibers are spontaneously formed after proteolytic release of the fusion partner. The structure of the fibers is similar to that of dragline silks, and although self-assembled from recombinant proteins they are as strong as fibers spun from redissolved silk. Moreover, the fibers appear to be biocompatible because human tissue culture cells can grow on and attach to the fibers. These findings enable controlled production of high-performance biofibers at large scale under physiological conditions.
authors.affiliation: Department of Anatomy, Physiology, and Biochemistry, The Biomedical Centre, Swedish University of Agricultural Sciences, SE-751 23 Uppsala, Sweden.
authors.forename: Margareta
authors.initials: M
authors.lastname: Stark
authors.forename: Stefan
authors.initials: S
authors.lastname: Grip
authors.forename: Anna
authors.initials: A
authors.lastname: Rising
authors.forename: My
authors.initials: M
authors.lastname: Hedhammar
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Engström
authors.forename: Göran
authors.initials: G
authors.lastname: Hjälm
authors.forename: Jan
authors.initials: J
authors.lastname: Johansson
mesh_terms: D000818:Animals; D001097:Arachnida / Q000235:genetics / Q000378:metabolism; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D005349:Fibroins / Q000096:biosynthesis* / Q000235:genetics / Q000648:ultrastructure*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000648:ultrastructure*; D012995:Solubility; D013718:Tensile Strength
chemical_list: D001672:Biocompatible Materials; D011994:Recombinant Proteins; C086087:spidroin 1; D005349:Fibroins