Department: Integrative Biology

Advisor: Dr. Douglas Fudge, Dr. Todd Gillis

Education: M. Sc. candidate, Integrative Biology, University of Guelph (Sept 2010 - Present)
B. Sc. Hons Human Kinetics, University of Guelph (Sept 2006 - April 2010)

Research:

 Expression and purification of the intermediate filament vimentin from Escherichia coli for the production of renewable protein-based biofibres.

An increased awareness of petroleum consumption has led to attempts of developing protein-based materials that are renewable with similar physical characteristics as existing petroleum-based polymers. Previous attempts at the creation of protein-based materials involved the production of spider dragline silk proteins (spidroins) for the purpose of artificial spinning, but this was not successful. The large size of the spider silk gene made it difficult to express in Escherichia coli (E. coli) as well as the secondary structure of the protein, which renders the material insoluble.

Intermediate filaments (IFs) make up a major structural element in animal cells and can be grouped into five classes: types 1 and 2 consist of the acidic and basic keratins, respectively; desmin, vimentin and GFAP make up type 3, neurofilament proteins are type 4, and nuclear lamins are type 5. Recent work by our research group has found that IFs possess mechanical properties that compete with those of spider dragline silk. Their native α-helical coiled coils decrease the probability of their aggregation and allow them to self-assemble, unlike spidroins. In addition, IFs purified from hagfish slime have been found to undergo an α to β transition whereby the α-helices open up when exposed to a mechanical stress and through a series of lateral bonds form a strong β-sheet crystallite structure. The β-sheet crystallites are able to simultaneously cross-link protein molecules and arrange into a structure where these bonds increase the energy required to break the material.

The objective of my research is to determine the optimal conditions required to express and purify the recombinant IF vimentin using E.coli. Once successfully expressed and purified, we will look at the ability of this protein to self-assemble and form fibres. The results of these experiments are hoped to produce protein-based materials that can be used as an economically viable alternative and a sustainable recombinant source.

Contact Information:
pinton@uoguelph.ca