Hagfish slime reengineered into films, fibres
Solubilized hagfish proteins dropped onto a buffer solution of magnesium chloride form thin films that can be pulled into fibers.
By Tyler Irving
Posted January 2013
A team from the University of Guelph has become the first to make polymer-like films and fibres from solubilised proteins extracted from hagfish slime.
The Atlantic hagfish (Myxine glutinosa) is actually an eel-shaped invertebrate that scavenges animal corpses in the deep ocean. When perturbed, it produces copious amounts of thick slime made of mucus reinforced with long threads of proteins called intermediate filaments (IF); these proteins are also found in the cytoskeleton of all cells.
Douglas Fudge, associate professor in the Department of Integrative Biology at the University of Guelph, isolated IF protein threads from hagfish slime and tested their mechanical properties. He found they were almost as strong as spider silk, although the proteins are completely different in form. Previous researchers attempted to dissolve spider silk proteins and re-condense them into films or threads to be used to replace artificial fibres like Kevlar, without much success. “Since the proteins in slime are so different, we saw an opportunity to overcome the problems with artificial spider silk,” says Fudge.
Atsuko Negishi, a research associate in Fudge’s lab, describes methods to extract slime from hagfish and solubilise the IF proteins in formic acid in a paper published in Biomacromolecules. By dropping solutions containing between five to 10 per cent protein onto the surface of a buffer containing magnesium chloride, Negishi was able to make thin, transparent films. These films could also be drawn into fibres. Unfortunately, the tensile strength of these materials was not much greater than that of artificial spider silk which has a breaking strength of about150 megapascals. Both materials still fall short of their natural counterparts which boast a breaking strength of more than 750 megapascals. “What we learned is that we’re not nearly as good as the hagfish and spiders at this point,” says Fudge. The team is now investigating other proteins, including some from humans, in the hopes of generating new structural materials.
Photo credit: Julia Herr
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