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MSBT

University of Michigan iGEM Team

Antibodies allow us to bind targets in a highly selective manner, giving them a paramount role in biotechnology and medicine. Antibody production remains difficult in E. coli because antibodies require an oxidizing environment to properly fold. We have constructed an expression system capable of secreting functional scFv (single chain fragment variable) antibodies by tagging them to OsmY, a naturally secreted protein. Fusions with OsmY are carried through the periplasm into the media; allowing disulfide bonds to form during translocation. We've demonstrated the utility of this system in the context of sensing Salmonella, the pathogen responsible for 23,000 hospitalizations in the US each year. To demonstrate efficacy of our purified scFv antibodies to bind antigen, we compared them to scFv antibodies purified from an industrial system using ELISA. Our construct has the potential of becoming a cost-effective industry applicable method for purifying scFv antibodies, as well as other proteins, in large quantities.

Abstract