Team:Toronto/Project

Tell us more about your project. Give us background. Use this is the abstract of your project. Be descriptive but concise (1-2 paragraphs)

Magnetotactic bacteria, commonly found in marine and freshwater sediment, have the remarkable ability to biomineralize perfectly shaped crystals of magnetite with more precision than any current manufacturing process. The bacteria align themselves with the Earth's magnetic field to seek out microaerobic environments in a process known as magnetotaxis. The mineral magnetite (Fe3O4) has been found inside the brains of many migrating animals, and is believed to play an important role in sense of direction.

Research has shown that magnetite nanoparticles, especially those of the cuboidal-octahedral shape produced solely by magnetotactic bacteria, have extensive nanotechnological and medical applications. Such applications include the incorporation of magnetite into immuno-lisosomes for cancer treatment. The magnetite can be heated by an external magnetic field to perform magnetic fluid hyperthermia to inactivate cancer cells. Magnetite is non-toxic and may travel through vasculature to localize target organs. Magnetic nanoparticles have also been shown to be able to attach to single strands of DNA nondestructively, exposing new venues for medical diagnostic applications.

Biogenic synthesis of magnetite is perferred over traditional chemical and physical procedures that incorporate the use of toxic solvents, generate hazardous waste by-products and involve high energy consumption. In addition, culturing Magnetotactic bacteria is very difficult due to its microaerophilic tendencies. The creation of a genetic machine that synthesizes magnetite in an economic, chemically and energy conservative, and environmentally friendly manner would be highly preferable. Therefore, we propose the creation of a gene pathway that will allow the biomineralization of magnetite in E.Coli.

In addition to the applications of creating perfectly shaped magnetite we also intend to create a novel method of gene expression in which a gene will be activated by the presence of a magnetic field. The induction of a gene by a magnetic field offers a number of unique opportunities. Given that electrical currents create magnetic fields, and expression system utilizing magnetic fields could play a role in interfacing the digital world with the biological.

We have researched the genes we believe to be vital to in-vivo magnetite formation in the magnetosome vesicles of the magnetotactic bacteria, Magnetospirillum magnetotacticum strain AMB-1. The principle gene that facilitates this biomineralization pathway appears to be mms-6. Prior to inducing in vivo gene expression of the desired genes, we intend to purify the proteins of importance for in-vitro experimentation to elucidate their specific functions in the pathway. The proteins will be localized to the periplasm of the E. coli to facilitate the synthetic biomineralization pathway which mimics the natural pathway organized and performed in magnetosomes. Magnetosomes are exceedingly complex to re-create, thus the localization of the pathway to the periplasm, whose controlled conditions match that of the external environment, is preferred.

To create an new expression system we intend to synthesize a fusion protein which contains a magnetite binding domain in the periplasm and a cytoplasmic domain which is able to transduce a signal once the fusion protein dimerized. In our research we have determined that ToxR fusion protein would be the ideal protein to fulfill this role.

Lastly, in order to make the isolation and purification of proteins simpler and more accessible to iGEM, we have designed a His-Tag biobrick vector, which will allow any biobricks to be his-tagged with ease. We will most likely not have time to construct / synthesize this construct however the design will be submitted to the registry for future teams to use.