Hagfish Slime Thread and Mussel Byssus Proteins as Sources for Regenerated Fibers

Abstract

Regenerated protein fibers were produced from the protein fibers (threads) found in hagfish slime [12Neg]. Proteins were solubilized in 98 % formic acid to obtain solutions (5, 7.5 %) that were spun into fibers and coagulated into an ethanol, methanol, or electrolyte buffer. However, fibers obtained were too weak and brittle. As an alternative approach, the protein solution was cast into films, and fibers were drawn from the films as shown in Fig. 49.1. Average fiber diameters obtained were between 46 and 137 μm, and the length of the fibers was about 3 mm. Table 49.1 shows the tensile properties of the fibers obtained under various conditions. Tensile properties of the regenerated fibers were considerably lower compared to the properties of the natural slime threads but similar to that of the regenerated fibers produced from spider silks as seen in Table 49.2. Structural analysis using X-ray diffraction and Raman spectroscopy showed that the fibers were composed of about 67 % α-helix and 26 % β-sheet content. Drawing of the fibers was found to increase orientation but not the crystallinity of the fibers.