ChBE Seminar Series: Amy Karlsson
Thursday, April 16, 2015
11:00 a.m.-12:00 p.m.
Room 2108, Chemical and Nuclear Engineering Bldg.
Professor Ganesh Sriram
Engineering Peptides and Proteins to Combat Human Disease
Amy J. Karlsson
Department of Chemical and Biomolecular Engineering
University of Maryland
Our lab uses both rational design and directed evolution approaches to engineer proteins and peptides for studying and combatting human disease. In this talk, I will describe results from our lab that illustrate the potential of protein engineering in developing diagnostic and therapeutic tools for fungal disease and cancer. To work towards improved diagnostic tools for fungal disease, we have developed a simple and robust method for immobilizing a wide range of antibody fragments that utilizes the high-affinity interaction of streptavidin and biotin. Our method allows us to efficiently immobilize antibody fragments without purification, and the immobilized antibodies show strong binding to their target antigens. The immobilized antibody fragments retain their ability to detect target antigen from purified solutions and cell lysate after over a month of storage. Our applications of protein engineering to fungal disease also include rational design of antifungal peptides with improved therapeutic potential and engineering peptides as molecular vehicles for delivering therapeutic cargo to the pathogen Candida albicans. In addition to our rational design approaches, we are also employing directed evolution to engineer antibody fragments that fold and function inside cells, which has broad applications in human diseases. Our screening approach harnesses the cytoplasmic folding quality control mechanisms of the Escherichia coli twin-arginine translocation pathway to engineer proteins able to fold in the cytosol, where the reducing environment typically prevents antibodies from properly folding and functioning. We have isolated an antibody fragment that binds to the apoptosis inhibitor survivin and exhibits a high level of intracellular solubility, and we are evolving this antibody to knockdown the function of survivin in cancer cells.